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A PRACTICAL TREATISE
ON THE
MANUFACTURE OF VINEGAR AND ACETATES, CIDER AND
FRUIT WINES, AND THE PRESERVATION OF FRUITS
AND VEGETABLES, MEAT, FISH AND EGGS.
A PRACTICAL TREATISE
ON
THE MANUFACTURE OF VINEGAR,
WITH
SPECIAL CONSIDERATION OF WOOD VINEGAR AND OTHER BY-
PRODUCTS OBTAINED IN THE DESTRUCTIVE DISTILLATION
OF WOOD ; THE PREPARATION OF ACETATES.
MANUFACTURE OF CIDER AND FRUIT-WINES ;
PRESERVATION OF FRUITS AND VEGETABLES BY
CANNING AND EVAPORATION;
PREPARATION OF FRUIT-BUTTERS, JELLIES, MARMALADES,
PICKLES, MUSTARDS, ETC.
PRESERVATION OF MEAT, FISH AND EGGS.
EDITED FROM VARIOUS SOURCES
BY
WILLIAM T. BRANNT,
EDITOR OF "THE TECHNO-CHEMIGAL RECEIPT BOOK."
THIRD EDITION.
THOROUGHLY REVISED AND LARGELY RE-WRITTEN.
ILLUSTRATED BY ONE HUNDRED AND ONE ENGRAVINGS.
PHILADELPHIA :
HENRY CAREY BAIRD & CO.,
INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS,
810 WALNUT STREET.
1914.
COPYRIGHT BY
HENRY CAREY BAIRD & CO.
1914.
PRINTED BY THE
WICKERSHAM PRINTING CO.,
111-117 E. Chestnut Street,
LANCASTER, PA., U. S. A.
PREFACE TO THE THIRD EDITION.
THE second edition of A PRACTICAL TREATISE ON THE
MANUFACTURE OF VINEGAR has been out of print for sometime,
and there being no recent work to take its place notwithstand-
ing the constant demand for a book on the various important
branches of industry treated of, the publication of a new edition
was deemed advisable.
Like the previous editions the volume is divided into three
parts.
Part I. is devoted to the Manufacture of Vinegar, and in-
cludes the production of wood vinegar and other by-products
obtained in the destructive distillation of wood, as well as the
preparation of acetates.
Part II. contains the Manufacture of Cider, Fruit Wines,
etc., and Part III. the Preservation by various methods of
Fruit and Vegetables, and of Meat, Fish and Eggs.
In this, the third edition, no essential changes have been
made in the arrangement of the book, bait it has been thor-
oughly revised and largely re-written, old and obsolete matter
having been eliminated and new material introduced. The
best authorities have been diligently consulted and freely
drawn on, for which due credit has, whenever possible, been
given in the text.
It is hoped that this new edition will meet with the same
favorable reception as the previous ones, and that it will be of
practical utility.
A copious table of contents as well as a very full index will
render reference to any subject in the book prompt and easy.
PHILADELPHIA, November 16, 1914.
W. T. B.
(v)
322567
CONTENTS.
PART I.
VINEGAR.
CHAPTER I.
INTRODUCTORY AND HISTORICAL.
PAGE
Nature of vinegar; Early knowledge of vinegar; Use of vinegar as a medicine
by Hippocrates; Anecdote of Cleopatra; Use of vinegar by Hannibal for
dissolving rocks. ........... 1
The process of increasing the strength of vinegar by distillation described by
Gerber in the eighth century; Other early historical data about vinegar;
Stael's method of strengthening vinegar; Count de Laragnais and Marquis
de Courtenvaux' experiments. . ....... 2
Loewitz's method of strengthening vinegar; Glacial acetic acid; Historical
data regarding the formation of an acetic body in the destructive distilla-
tion of wood; Determination of the exact chemical constitution of acetic
acid by Berzelius, and that of alcohol by Saussure; Historical data relating
to the generation of acetic acid; Introduction of the quick process of manu-
facturing vinegar, in 1823, by Schiitzenbach; Method of making vinegar
from wine made known by Boerhave, in 1732 ...... 3
Schiitzenbach' s original plan of working still in use in some localities; Neces-
sity of progress in making vinegar by the' quick process; Great purity of
acetic acid as at present prepared from wood; " Vinegar essence" and its
uses ..... .......... 4
Difference between the pure acetic acid produced from wood and vinegar pre-
pared from various materials; Principal defects in the process of making
vinegar by the quick process in general use 5
Probability of the discovery of a process for the production of acetic acid
from its elements ......... 6
CHAPTER II.
THEORY OF THE FORMATION OF VINEGAR.
Chemical processes by which acetic acid in large quantities is formed . . 7
Liebig's theory of the formation of vinegar; Present view of the formation of
vinegar; Pasteur's theory; Difference between Pasteur's and Nageli's views;
Nomenclature of organisms producing fermentation; The vinegar or acetic
ferment ............. 8
(vii)
Viii CONTENTS.
PAGE
Occurrence of acetic acid in nature; Formation of acetic acid by chemical
processes; Formation of acetic acid by the action of very finely divided
platinum upon alcohol .... . . . . . 9
Development of mother of vinegar; Pasteups investigations regarding the
relation of mother of vinegar to the formation of vinegar; Botanical na-
ture of the organisms causing the formation of vinegar ... .11
Disease causing bacteria; Hansen's investigations of the species of bacteria . 12
CHAPTER III.
THE VINEGAR FERMENT AND ITS CONDITIONS OF LIFE.
The vinegar ferment, its origin and its distribution; Fluid especially adapted
for nutriment; Experiment showing the conversion of wine into vinegar
by the vinegar ferment .13
Difference between the living and dead ferment as seen under the micro-
scope; Requirements of the ferment for its propagation . . . .15
Results of the withdrawal of oxygen from the ferment; Experiment showing
the great rapidity of propagation of the vinegar ferment; Conditions for
the nutriment of the ferment; Factors required for the settlement of the
vinegar bacteria upon a fluid and for their vigorous propagation . . 1&
Composition of the nutrient fluid; A large content of alcohol in the nutrient
fluid detrimental to the vegetation of the vinegar ferment; Experiment
showing that the ferment cannot live in dilute alcohol alone . . .17
Preparation of a fluid containing all the substances essential to the nutriment
of the ferment; Sensitiveness of the ferment to sudden changes in the com-
position of the fluid upon which it lives; The process of nutriment of the
vinegar ferment. . . . . . . . . . . .18
Supply of air required for the ferment; Limits of temperature at which the
propagation of the ferment and its vinegar-forming activities are greatest;
Effect of low temperature upon the ferment. . . • . . .19
Reason why acetic degeneration is not known in cold wine cellars; Reasons
for the frequent occurrence of disturbances in the formation of vinegar at
a high temperature. . ......... 20
Mother of vinegar; Origin of the term; Different opinions regarding the na-
ture of mother of vinegar; Formation of mother of vinegar. . . . 21
Summary of the theoretical conditions of frhe formation of vinegar. . . 22
CHAPTER IV.
PRODUCTS OF ACETIC FERMENTATION.
The regular propagation of the ferment the main point of the entire manu-
facture; Loss of alcohol in the production. ...... 23
Substances, besides alcohol and carbonic acid, formed in vinous fermentation.
Characteristic properties imparted to alcohol by fusel oils; Aromatic sub-
stances which reach the vinegar through the conversion of fusel oils;
Acetic aldehyde or acetaldehyde, commonly called aldehyde. . .24
Preparation of pure aldehyde; Acetal and its preparation. . . • 25
CONTENTS. IX
PAGE
Composition and nature of pure acetal 26
Acetic acid and its properties. ......... 27
Peculiar behavior of mixtures of acetic acid and water in regard to their spe-
cific gravity; Vinegar essence and its use for the preparation of table vin-
egar; Composition of acetic acid. ........
Theoretical yield of acetic acid. . . . . . . . 29
Manner of calculating the theoretical yield of acetic acid from alcohol. . 30
Quantity of oxygen required to form acetic acid and water from alcohol;
Quantity of alcohol which can daily be converted into vinegar by a gene-
rator ( 31
Calculation of the quantity of heat liberated by the conversion of alcohol in-
to acetic acid; What the manufacturer can learn from theoretical expla-
nations . 32
The acme of temperature and what is meant by it; Loss of alcohol and acetic
acid by evaporation and its reduction. ....... 33-
Conditions on which the most advantageous working depends; Yields of acetic
acid obtained in practice . . . . . . . . . . 34
Comparison of a vinegar generator to a furnace . . . . . .35
CHAPTER V.
METHODS OF MANUFACTURE OF VINEGAR.
Designation of the various methods employed; Substances which may be used
for the preparation of vinegar ......... 36
Alcohol the ultimate material for the manufacture of vinegar; The old or
slow process and modifications of it 37
Difference in the properties of vinegar derived from various sources . . 38
CHAPTER VI.
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
Invention of Schiitzenbach and analogous processes; On what the principle
involved depends; Comparison of the generator or graduator to a furnace . 39
Generators; Best form of the generator. ....... 40
Kinds of wood suitable for the.construction of generators . . . .41
Variations in the dimensions of the generators ...... 42
Dimensions of the most suitable generator; Cover of the generator . . 43
Disadvantage of a number of obliquely bored holes below the false bottom;
Scheme of incorrect conduction of air in generators ..... 44
Contrivances for the discharge of vinegar collected in the lower portion of
the generator ............ 45
Arrangement of the perforated false head of the generator . . . . 46
Arrangement for regulating the inflow of air from below . . . .47
Modification of the false head . . . . . • . .48
The tilting trough 49
The sparger ............. 50
Principal requisite for the correct working of the sparger . . . .51
X CONTENTS.
PAGE
A thermometer an indispensable adjunct to a generator; Filling the gener-
ators, and materials used for this purpose. ...... 52
•General use of beech shavings, their advantages and preparation; Volume
represented by a shaving in a rolled state; Space required for such shaving. 53
Freeing the shavings from extractive substances by water and by steaming;
Drying the steamed shavings 54
Swelling the shavings and placing them in the generator; Advantage of hav-
ing all the generators of the same size. ....... 55
CHAPTER VII.
ARRANGEMENT OF A VINEGAR FACTORY.
Principal requisites to be observed in a suitable arrangement; Provisions for
the maintenance of a uniform temperature .58
Materials for the floor; Heating of the workroom, and apparatus for this pur-
pose .............. 57
Advantage of the use of maximum and minimum thermometers . . .59
Location of the reservoirs in factories arranged according to the automatic
system 60
CHAPTER VIII.
ARTIFICIAL VENTILATION OF THE VINEGAR GENERATORS.
English process of sucking a current of air from above to below through
every generator; Incorrectness of this method 61
Principal reason advanced for the use of a current of air from above to
below - 62
Schulze's ventilating apparatus and generator ...... 63
Generators with constant ventilation and condensation; An apparatus well
adapted for the purpose .......... 65
Proposed method of regaining the vapors; Objection to this method . . 68
4Singer* s general >r 69
Michaelis' revolving generator ......... 72
CHAPTER IX.
AUTOMATIC VINEGAR APPARATUS.
Principal work which has to be performed in a vinegar factory; Disadvan-
tages of pouring at stated intervals the alcoholic fluid into the generators. 73
Debilitation of the vinegar ferment in consequence of repeated reduction of
the temperature in the generators; Explanation of many apparently inex-
plicable disturbances ......... 74
Advantages to be derived from the use of simple automatic contrivances;
Continuously-acting apparatus; The terrace system . . . . .75
Arrangement of a factory according to the terrace system; Drawback of this
system ........... 77
CONTENTS. XI
PAGE
Mode of working according to the terrace system 78
Lenze's chamber generator, and the principles upon which its construction is
based 80
Mode of operating Lenze's chamber generator; Plate generator, patented by
Dr. Bersch 82
Periodically working apparatus; The three-group system; Mechanical appli-
ances for admitting at certain intervals a fixed quantity of alcoholic fluid
into the generators; Modification of the tilting trough . . . .86
The siphon barrel 88
The bell-siphon ; Example for calculating the space required beneath the
false bottom for the reception of the vinegar 89
Arrangement of a vinegar factory working according to the automatic prin-
ciple; Arrangement of the generators in groups. . . . . .90
Description of a periodically-working establishment with 24 generators. . 91
Manner of working in such an establishment. ...... 93
Apparatus for heating the alcoholic liquid ....... 95
i
CHAPTER X.
OPERATIONS IN A VINEGAR FACTORY.
Acetification of the generators; Quantities of vinegar required for complete
acetitication . . . . . . . . . . . .96
Example illustrating the gradual commencement of regular production; Ac-
celerated acetification .......... 97
How the removal of water from the shavings and its substitution by vinegar
are effected ............ 98
Use of artificially dried shavings; Induction of the operation with an artifi-
cial culture of vinegar ferment. ....... .99
Pure culture of vinegar ferment and best fluid for the purpose. . . . 100
Preparation of nourishing fluid; Manner of cultivating vinegar ferment. . 101
Abortive culture of vinegar ferment 102
Disturbances by suddenly changing the nutrient fluid of the ferment, and
their prevention. ........... 103
CHAPTER XI.
PREPARATION OF THE ALCOHOLIC LIQUID.
Definition of the term 'alcoholic liquid;" Reason why a content of vinegar
in the alcoholic liquid exerts a favorable effect upon the formation of vin-
egar. 104
Proof that the alcoholic liquid does not require any considerable quantity of
acetic acid for its conversion into vinegar. . ..... 105
Reason why it is preferable to gradually increase the content of alcohol in
the alcoholic liquid; Experiment showing the destruction of acetic acid by
the vinegar ferment in the absence of alcohol 106
Xil CONTENTS.
PACK
Limit of acetic acid vinegar should have ; Conditions on which the advanta-
geous manufacture of high-graded or weak vinegar depends ; Quantity of
beer to be added to the alcoholic liquid .107
Quantity of finished vinegar to be added to the alcoholic liquid; Table of
the theoretical yield of acetic acid from alcohol . . . .308
lleason why practically less vinegar with a smaller percentage of acetic an-
hydride is obtained ; Table showing the content of alcohol required in an
alcoholic liquid for the production of vinegar with a certain content of
acetic acid ; Calculation for finding the number of gallons of water which
have to be added to alcohol of known strength to obtain an alcoholic liquid
with the desired- percentage of alcohol 109
Examples of the composition of alcoholic liquid . . . . . .110
Use of low wine for the preparation of alcoholic liquid . . . . .111
Determination of the content of alcohol in spirits of wine ; Compilation show-
ing the manner of preparing alcoholic liquid according to rational princi-
ples , 112
Determination of acetic acid in vinegar; Constitution of the fundamental
materials used in the preparation of alcoholic liquid . .... 113
Water suitable and unsuitable for the preparation of vinegar; Behavior of
mixtures of water and alcohol . . . . . . . . .114
River water and the possible introduction of vinegar eels by it; Importance
of the constitution of the spirits of wine used 115
Advisability of using a mixture of rectified and crude potato alcohol . . 116
CHAPTER XII.
EXECUTION or THE WOBK IN A VINEGAR FACTORY.
Simplicity of the work; Reduction of alcohol with water . . . .117
Quantity of fluid to be worked in a generator in the course of a day; Gradual
strengthening of the alcoholic liquid with alcohol ..... 118
Temperature to be maintained in the interior of the generators; Determina-
tion of acetic acid and of alcohol in the fluid running off from the gener-
ators 119
Plan of operation as resolved from the results of tests ..... 120
The actual prodoction according to the old method; Production of so-called
triple vinegar ............ 121
Group system; Principle of the operation; Operation with three groups of
generators. . . . . . . . . . . . .122
Taking samples for determining the content of acetic acid and alcohol; Cross-
ing the generators . . . . . . . . . . .124
Group system with automatic contrivances; Preparation of the alcoholic
liquid for 12 per cent, vinegar . . . . . . . . .125
Regulation of the automatic contrivances; Operation with the automatic
system . 126
Recognition of a disturbance in any one of the generators, and its preven-
tion . .127
CONTENTS. Xlll
PAGE
CHAPTER XIII.
DISTURBING INFLUENCES IN THE MANUFACTURE OF VINEGAR.
How serious disturbances can be avoided; Irregularities due to the nourish-
ing substances of the ferment, and how to remedy them .... 128
Sweet beer wort or malt extract for strengthening weak-working generators;
Favorable effect of phosphates; Disturbances ascribable to the quantity of
newly-formed acetic acid . . . . . . . . . .129
Controlling the working of the generators by frequent determinations of the
acetic acid; Phenomena indicative of the generator not being able to mas-
ter the alcoholic liquid introduced; Restoration of the generator to a proper
state of working ........... 130
Cause of the heating of generators; Sliming of the shavings in generators . 131
Causes of sliming; Alteration which takes place in the shavings . . . 132
Constitution of the slimy coat; How sliming can be remedied at the com-
mencement of the evil . . . . . . . . . . 133
Disturbances due to vinegar eels ......... 135
Remedies for the suppression of vinegar eels. ...... 137
Sulphuring the generator and apparatus for that purpose .... 138
Disturbances due to vinegar lice (vinegar mites) . . . ... . 140
Vinegar flies 142
CHAPTER XIV.
SLOW PROCESS OF MAKING VINEGAR.
Utensils required, Induction of the formation of vinegar; The wash and its
preparation ............ 143
Indications of the commencement of acetification; Excitation of " lazy "
barrels 144
Time required for acetification; Barreling and storing the vinegar; Modifi-
cations of the slow process. ......... 145
Household manufacture of vinegar . . . . . . . .147
Preparation of vinegar with the assistance of platinum black . . .. 148
CHAPTER XV.
FURTHER TREATMENT OF THE FRESHLY-PREPARED VINEGAR.
Odor of freshly-prepared vinegar, and on what it depends; Filling the
barrels 149
Means of improving the odor of vinegar ..'..... 150
Drawing oft' the vinegar from the sediment in the barrel; Constituents of the
vinegar brought into storage barrels ........ 151
Storing of vinegar; Processes which take place during storing. . . . 152
Filtering vinegar before bringing it into the storage barrels; Heating the
vinegar, and apparatus used. ......... 153
Filtration of vinegar and filters for this purpose 155
CONTENTS.
PAGE
Sulphuring of vinegar. . 158
Fining vinegar; Coloring vinegar. ........ 159
CHAPTER XVI.
PREPARATION OF VlNEGAR FROM VARIOUS MATERIALS.
Formation of diastase; How vinegar may be made from starch. . . . 160
Beer-wort not a suitable material for vinegar. . . . . . .161
Fermented whiskey mashes for the manufacture of vinegar; Manufacture of
malt or grain vinegar. 162
Most suitable variety of malt for making vinegar 163
Theoretical part in mashing; After-effect of the diastase 164
"Doughingin" 165
On what the strength of the vinegar to be made depends; Setting the mash
with yeast; Preparation of compressed yeast; Treatment of the completely
fermented "ripe" mash; Heating the mash. ...... 166
Conversion of the fermented malt-wort into vinegar. . . . . .167
Filtration of malt vinegar in rffininy or rape vessels; Manufacture of malt
vinegar by "fielding" ; Utilization of sour ale and beer for vinegar. . . 168
Vinegar from sugar beets, and from sugar, fruits and berries. . . . 169
Making vinegar on a small scale for domestic use. . . . . .170
Table showing the average content of sugar and free acid in the most com-
mon varieties of fruits; Treatment of currant juice for making vinegar. . 171
Preparation of vinegar from other berries. ....... 172
Peaches as vinegar stock; Cider vinegar. ....... 173
Use of a generator for the conversion of cider into vinegar; Directions for
home-made cider vinegar, by Mr. Walter G. Sackett 174
CHAPTER XVII.
VINEGAR SPECIALTIES.
Groups of specialties; Perfumed vinegar; Aromatized vinegar . . . 178
Manner of dissolving volatile oils in vinegar ...... 179
Preparation of aromatized vinegar; Toilet vinegars; Mohr's volatile spirits of
vinegar; Aromatic vinegar ......... 180
Henry's vinegar; Vinaigre des quatre voleurs; Hygienic or preventive vine-
gar; Cosmetic vinegar; Table vinegars; Anise vinegar . . . .181
Anchovy vinegar; Tarragon vinegar; Compound tarragon vinegar; Effervesc-
ing vinegar 182
Herb vinegar; Pineapple vinegar; Celery vinegar; Clove vinegar; Lovage
vinegar; Raspberry vinegar 183
Preparation of acetic ether. 184
CHAPTER XVIII.
MANUFACTURE OF WINE VINEGAR.
Materials for wine-vinegar; Theoretical and actual yield .... 186
Reasons why wine-vinegar is superior to the ordinary products . , ; . 187
CONTENTS. XV
PAGE
Table showing the composition of wine and of the vinegar formed from it;
"Sick" wines 188
Lactic acid and acetic degenerations of wine ...... 189
Young wine attacked by acid degeneration for making vinegar; Preparation
of after-wine, according to Petiot . . . . . . . .190
Use of this wine for making vinegar ........ 192
Older method of making wine vinegar; Orleans or old French process of
making wine-vinegar .193
Pasteur's or modern French method of preparing wine-vinegar . . . 196
Pasteurization and apparatus used; Undesirable phenomena which may ap-
pear in the conversion of wine into vinegar ...... 198
Claudon's method of making wine-vinegar described by Frederic T. Bioletti. 200
Bersch's method of making wine-vinegar; Culture of pure vinegar ferment . 201
Variety of wine most suitable for making vinegar . . . . . 203
Apparatus for making wine vinegar ........ 204
Operation in a wine-vinegar factory ........ 205
Disturbances in the production of wine-vinegar; Filtering wine-vinegar . 208
Storing and bottling wine-vinegar; Pasteurizing bottled vinegar and appa-
ratus for that purpose ..'.... ..... 209
Wine-vinegar by the quick process . . . . . . . .210
Wine-vinegar from marc . . . . . . . . . .211
CHAPTER XIX.
CHEMICAL EXAMINATION OF THE RAW MATERIALS, AND CONTROL OF THE
OPERATIONS IN A VINEGAR FACTORY.
Determination of sugar .......... 213
Determination of alcohol; The alcoholometer 214
Determination of the alcohol by the distilling test, and apparatus used. . 215
Determination of the alcohol by the ebullioscope 217
Vidal-Malligaud's ebullioscope ......... 218
Determination of the content of acetic anhydride in vinegar, or acetometry:
Titration or volumetric analysis, and apparatus for that purpose . . 220
Calculation of the quantity of acetic acid in the vinegar examined; Determi-
nation of the strength of vinegar by the vinegar tester, described by Fred-
.eric T. Bioletti . 224
CHAPTER XX.
EXAMINATION OF VINEGAR AS TO THE PRESENCE OF FOREIGN ACIDS AND OF
METALS, AS WELL AS TO ITS DERIVATION.
Detection of acids; Sulphuric acid 227
Hydrochloric acid; Nitric acid; Lactic acid; Sulphurous acid . . . 228
Detection of metals; Iron; Copper; Tin 229
Determination of the derivation of a vinegar ...... 230-
XVI . CONTENTS.
PAGE
CHAPTER XXI.
WOOD- VINEGAR AND OTHER BY-PRODUCTS OBTAINED IN THE DESTRUCTIVE
DISTILLATION OF WOOD.
Constitution of wood; Specific gravity of different woods .... 233
Average composition of air-dry wood; Decomposition of wood . . . 234
Effect of heating on wood; Effect of acids on wood ..... 235
Effect of dilute aqueous solutions of alkalies on cellulose 236
Products of destructive distillation; Gaseous products of distillation . . 237
Table showing the order in which the gaseous combinations are formed at
different temperatures; Composition of wood gases. .... 238
Origin of many bodies which appear among the products of the decomposi-
tion of wood. . . . . ....... 239
•Quantity of gas yielded by wood by destructive distillation. . . . 241
Liquid products of distillation; Wood vinegar; Fatty acids in wood vinegar 242
Production of methyl alcohol from marsh gas; Formation of acetone. . 243
Variation in the quantities of the bodies of which wood-vinegar is composed;
Tar . i>44
•Composition of the larger quantity of the tar products; Combinations which
are definitely known. . . . . . . . ... 245
"Yield of tar obtained in the destructive distillation of wood; Table of bodies
of technical importance appearing in the destructive distillation of wood. 246
'Character of wood tar ; Retort tar ; Boiled tar - . . 247
Properties of the combinations formed in wood tar; Acetic acid; Acetone. . 248
Methyl acetate; Aldehyde or acetaldehyde; Methyl alcohol or wood spirit 249
Tar products — hydrocarbons of the series CnH2n-6 • 250
Naphthalene and paraffin. . . . . . . . . . 251
Tar products containing oxygen (creosote); Properties of wood-tar creosote 252
Illuminating gases from wood; Complete series of compounds occurring in wood
tar mentioned by various chemists. ........ 253
CHAPTER XXII.
PREPARATION OF CHARCOAL, WOOD VINEGAR, AND TAR IN CLOSED VESSELS.
Selection of the apparatus for the installation of a plant for the utilization of
wood in a thermo-chemical way. ........ 254
Processes by which acetic acid on a large scale can be prepared. . . 255
Kilns or ovens and retorts; Charring of wood in heaps or pits. . . . 256
Schwartz's oven . . . ...... 257
Reichenbach's oven . . . . . . . . . . . 259
Swedish oven 260
Carbo-oven ; Retorts 262
Horizontal retorts; Wrought-iron retort of suitable construction . . . 263
Manner of bricking in six retorts 2(54
Utilization of the gases escaping from the condenser for heating . . . 266
-Oven-retort largely used in this country; Coolers; Vertical retorts . . 267
-Arrangement of the retort-ovens and the lifting apparatus .... 268
CONTENTS. XVU
PAGE
Distilling apparatus for wood waste; Halliday's apparatus .... 271
Apparatus suitable for the distillation of sawdust and waste of wood in gen-
eral 273
On what the selection of apparatus for the destructive distillation of wood
depends 274
Coolers; Counter-current pipe cooler ........ 275
Most suitable way of connecting two pipes ....... 276
Prevention of obstruction in the pipes. ....... 277
Box cooler; Collection of gas ......... 278
Reservoirs for the product of distillation 279
Collecting boxes 281
Utilization of the gases . . . . . . . . . 282
CHAPTER XXIII.
EXECUTION OF THE DESTKUCTIVE DISTILLATION OF WOOD.
Operation with a larger number of retorts; On what the time during which
distillation has to be continued depends ....... 284
Mode of placing a thermometer in one of the retorts ..... 2K5
Use of antimony in determining the commencement of the end of distillation. 286
Size of vats for the reception of the distillate; Collecting boxes sunk in the
ground 287
Yield of products; Manner in which accurate data regarding the quantities
of wood-vinegar and tar from a variety of wood may be obtained; Stolze's
experiments ............ 288
Results obtained by Assmus in manufacturing on a large scale; Yields ob-
tained with retorts, according to Klar 289
CHAPTER XX1Y.
TREATMENT OF THE WOOD- VINEGAR.
Uses of crude wood-vinegar; Separation of acetic acid. .... 290
Separation of the wood-vinegar fr m the tar; Methods by which concentrated
acetic acid can be obtained from crude wood-vinegar. . . . . 291
Distilled wood-vinegar .......... 292
F. H. Meyer's system of distilling the crude wood-vinegar in multiple evap-
orators in vacuum; Properties of freshly-distilled wood-vinegar. . . 293
Various methods proposed for the purification of wood-vinegar . . . 294
Production of pure acetic i cid from wood-vinegar; Preparation of calcium
acetate ............. 296
Evaporating pans ........... 297
Klar's continuously. working apparatus for evaporating and drying the cal-
cium acetate ............ 298
Preparation of sodium acetate ......... 299
Filter for obtaining pure sodium acetate ....... 301
Mode of obtaining sodium acetate for the preparation of perfectly pure acetic
acid . 302
XV111 CONTENTS.
PAGK
Preparation of sodium acetate from calcium acetate 304
Preparation of acetic acid from the acetates; Processes used; Hydrochloric
acid process ............ 305
Sulphuric acid process. .......... 307
Plant arranged for the sulphuric acid process 308
Preparation of glacial acetic acid. ........ 309
Vacuum process for obtaining highly concentrated acetic acid . . .310
Preparation of glacial acetic acid of the highest concentration . . .311
CHAPTER XXV.
ACETATES AND THEIR PREPARATION.
Properties of acetates . ........... 313
Potassium acetate ........... 314
Potassium acid acetate or potassium diacetate; Sodium acetate; Ammonium
acetate, neutral acetate of ammonia . . . . . . .316
Calcium acetate; Barium acetate. . . . . . . . . 317
Magnesium acetate ........... 319
Aluminium acetate; Normal or f aluminium acetate; Basic aluminium § ace-
tate; Basic aluminium g acetate ........ 320
Maganese acetate 323
Iron acetate; Ferrous acetate, black mordant 324
Neutral ferric acetate, sesquiacetate of iron. ...... 326
Chromium acetate; Chromous acetate; Nickel acetate; Cobalt acetate . . 328
Zinc acetate; Copper acetates; Cuprous acetate; Neutral cupric acetate, crys-
tallized verdigris 329
Basic cupric acetates; Sesquibasic cupric acetate ...... 332
Tribasic cupric acetate; French and English verdigris. .... 333
Lead acetates; Neutral acetate of lead (sugar of lead); Volkel's method . 335
Stein's method, and distilling apparatus used ...... 337
Crystallizing pans ........... 338
Preparation of sugar of lead from metallic lead, according to Berard . . 340
Brown acetate of lead . .......... 341
Properties of acetate of lead 342
Basic lead acetates; Manufacture of white lead according to the French
method; Lead vinegar or extract of lead.. ...... 344
Lead sesquibasic acetate, triplumbic tetracetate ...... 345
Sexbasic acetate of lead; Uranium acetate; Tin acetate; Bismuth acetate; Mer-
curous acetate. ........... 346
Mercuric acetate; Silver acetate 347
CHAPTER XXVI.
PREPARATION OF PURE WOOD SPIRIT OR METHYL ALCOHOL. AND OF
. ACETONE, AND WORKING THE WOOD TAR.
Preparation of wood spirit; Constitution of the crude wood spirit of com-
merce; Wood spirit for denaturing purposes ...... 348
CONTENTS. XIX
PAGE
Constitution of pure wood spirit; Rectification of crude wood spirit solutions,
and still for the purpose .......... 3-19
Preparation of wood spirit suitable for denaturing purposes .... 351
Preparation of acetone; Properties of acetone; Decomposition of the calcium
acetate, and apparatus for this purpose 352
Rectification of the crude distillate; Arrangement of a plant for the produc-
tion of acetone. ........... 353
Manufacture of pure acetone according to F. H. Meyer's system; Working
the wood tar; Preparation of creosote and tar oils; Distillation of wood tar 355
Yield from tar of hard woods by distillat on ...... 350
Rectification of the oils; Manner of obtaining creosote from the distillate . 357
Working the heavy oils; Results of experiments regarding birch-tar oil . 358
PART II.
MANUFACTURE OF CIDERS, FRUIT WINES, ETC.
CHAPTER XXVII.
INTRODUCTION.
Definition of the term wine; Ingred ents which are added to artificial wines;
Ripening of fruits ........... 360
Occurrence and behavior of pectose; Formation and properties of pectine . 3(51
Properties of metapectine; Constitution and action of pectose . . . 302
Pectous fermentation; Formation and properties of pectic acid . . . 363
Formation of metapectic acid; Definition of the term isomeric . . . 304
Development and ripening of a fruit viewed as a chemical process; Results
of chemical researches into the changes fruits undergo during their devel-
opment and perfection .......... 365
Stages a fruit passes through during development and ripening . . . 307
CHAPTER XXVIII.
FRUITS AND THEIR COMPOSITION.
Fruits used for the preparation of fruit wines; Table of the average percen-
tage of sugar in different varieties of fruit . . . ... 308
Tables of the average percentage of free acid expressed in malic acid, and
of the proportion between acid, sugar, pectine, gum etc., and of the pro-
portions between water, soluble and insoluble substances . . . . 309
Tables of the composition of the juice according to the content of sugar, pec-
tine, etc., and of the content of five acid ....... 370
Urape sugar or glucose; Acids 371
Albuminous substances; Pectous substances; Gum and vegetable mucilage . 372
Tannin; Pathological and physiological tannins ...... 373
Inorganic constituents; Fermentation ........ 374
XX CONTENTS.
Chief products of vinous fermentation . . . . . . . . 375
Succinic acid; Glycerin .......... 376
Carbonic acid; Alkaloid in wine ......... 377
CHAPTER XXIX.
MANUFACTURE OF CIDER.
Methods of obtaining the juice or must from the fruit; W. O. Hickock's
portable cider mill . . . . . . . . . . 378
Crushing mill; Davis's star apple grinder 379
Presses 880
Farmer's cider press ........... 381
Extra-power cider press .......... 382
Revolving platform of the extra-power cider press; Improved racks . . 383
Plain racks 384
Apple elevator ............ 385
Arrangement of a plant for making cider on a large scale .... 3£6
Testing the must as to the content of acid and sugar; Determination of acid. 387
Determination of sugar .......... 389
Glucose 390
Determination of the content of pure sugar in glucose ..... 391
Anthon's table for finding the content of anhydrous sugar in saturated solu-
tions of glucose; Cider from apples ........ 392
Type of composition for pure ciders; Analyses of ciders by the United States
Agricultural Department ......... 393
Choice of varieties of apples for making cider ...... 394
Composition of the apple 395
Juice constituents of the apple; Gathering and sweating apples for the pre-
paration of cider . . . . . . . . . . . 396
Reduction of the apples to an impalpable pulp; Diversity of opinion as re-
gards the crushing of the seeds ........ 397
Pressing; Primitive method of laying the cheese; Substitution of hair cloth
and cotton press-cloth for straw in laying the cheese. .... 398
Extraction of the juice by diffusion; Objections urged against pasteurizing
or sterilizing fresh apple juice; H. C. Gore's experiments to develop a
method for sterilizing apple juice ........ 399
Conclusions arrived at regarding the carbonating of fresh apple juice; Addi-
tion of benzoate of soda to apple juice sold in bulk; H. C. Gore's investiga-
tions of the cold storage of cider ........ 401
Testing apple juice to be fermented; Filling the fermentation casks . . 402
Fermentation of the apple juice, and pure cultures of yeast for this purpose. 403
Fermentation funnel or ventilating funnel ....... 404
First or tumultuous fermentation. ........ 405
Clarification of cider ........... 106
Additions to cider intended for export. ....... 407
Preparation of cider in the same manner as other fruit wines; Red apple wine
or red wine from cider ; Dr. Denis Dumont's directions for bottling cider . 408
CONTENTS. XXI
PAGE
Manufacture of cider in the island of Jersey. . . . . . . 409
Devonshire cider. . . . . . . . . . . .410
Cider as a basis for artificial wines ........ 411
Burgundy; Malaga wine; Sherry wine; Diseases of cider . . . .412
Acidity in cider; Viscosity or greasy appearance of cider . . . .413
Turbidity or lack of clarification of cider; Adulteration of cider; Minimum
for the composition of pure cider ... . . . . . . 414
Manufacture of brandy from cider ........ 415
Preparation of the juice for distillation; Brandy from plums, damsons, etc. 416
Distillation 417
Pear cider; Preparation of " port wine " from cider ..... 418
Quince wine ............ 419
CHAPTER XXX.
PREPARATION OF FRUIT WINES.
From small fruits; Means of preventing the wine from turning . . . 419
Advantage of using a mixture of various juices; Means of improving the flavor
and keeping qualities of the wine ........ 420
Selection of the fruit; Expression of the juice; Fermentation; Clarification
and drawing, off into bottles ......... 421
Currant wine ............ 422
Strawberry wine. ........... 424
Gooseberry wine. ........... 425
•Gooseberry champagne .......... 427
Raspberry wine . . . . . . . . . . . . 429
Blackberry wine 430
Mulberry wine; Elderberry wine; Juniperberry wine . . . . . 431
Rhubarb wine; Parsnip wine; Wine from various materials. . . . 432
From stone fruits; Cherry wine; Morello wine; Plum wine .... 433
Sloe or wild plum wine 434
PART III.
CANNING AND EVAPORATING OF FRUIT; MANUFACTURE
OF CATSUPS; FRUIT BUTTERS, MARMALADES,
JELLIES, PICKLES AND MUSTARDS; PRESER-
VATION OF MEAT, FISH AND EGGS.
CHAPTER XXXI.
PRESERVATION OF FRUIT.
Rules applying to all methods of preserving fruit 435
French method known as Baine-Marie; Preservation of the flesh of the fruit
without boiling. . . ...... ... 436
XX11 CONTENTS.
PAGE
Preparation of the fruit for preserving; Preservation of fine table pears; Pre-
servation in air-tight cans. ......... 438
Groups of canned articles embraced in the American trade lists; Fruits suit-
able and unsuitable for canning 439
Various styles of cans and jars ......... 440
Manner of coating and lining the inside of tin cans; Manufacture of tin cans
in the United States canneries 441
Division of labor in the canneries; Preparation of the syrup. . . . 442
Apparatus for the expulsion of the air by heating the cans; Cleansing and
testing the cans. ........... 443
Canning of tomatoes; Selection of a site for a canning establishment . . 445
How contracts for a supply of tomatoes are made; Arrangement of a canning
factory; Scalding the tomatoes ......... 446
Skinning the tomatoes; Machines for filling the cans; Cappers and their
work . . . . . . . 447
Labeling the cans. ......... . 448
Trials and vexations of a canner's life; Catchup ...... 449
Tomato catchup ............ 450
Walnut catchup ............ 451
Gooseberry catchup; Horseradish catchup ; Fruit butter, marmalades and
jellies; Fruit butter; Manufacture of apple butter ..... 453
Preparation of raisine ; Marmalade ........ 454
Derivation of the wood marmalade; Manufacture of marmalade on a large
scale. ............. 455
Quantity of sugar to be used; Secret of the great reputation the products of
the principal American factories enjoy; Selection of fruit for marmalade . 456
Apple pulp as a foundation for marmalade, and its preparation; Storage of
fruit pulp 457
Tutti-frutti; English marmalade; Jelly; Erroneous opinion regarding the
quantity of sugar required in making jelly; Apple jelly without sugar . 458
Use of the saccharometer in jelly boiling; Jellies from pears, mulberries and
other small fruit 459
Preparation of jelly from stone-fruit, quinces, rhubarb, etc ; French perfumed
jelly 460
Manufacture of apple jelly in one of the largest plants for that purpose; Ar-
rangement of the factory 461
Grating the apples and expressing the juice; The defecator and its object . 462
The evaporator ............ 463
Proper consistency for perfect jelly; Yield of jelly from a bushel of fruit . 464
Saving of the apple seeds .......... 465
CHAPTER XXXII.
EVAPORATION OF FRUIT.
The Alden Patent for evaporating fruit. ....... 465
Theory of evaporating fruit 466
CONTENTS. XX111
Absorption of moisture by the air. ........ 467
lieason why drying fruit in the oven must yield unsatisfactory results . . 468
Chemical analysis of a parcel of Baldwin apples, showing the changes in the
composition of the fruit by drying in the oven, and by evaporation . . 4('9
Tower evaporators; The improved Alden evaporator ..... 470
The Williams evaporator . . . . . . * . . . . 472
Manner of operating the Alden evaporator ....... 474
Table of intervals of time at which the trays must be placed in the evapora-
tor; Handling and packing the evaporated fruit 475
Kiln evaporators, described by H. T. Gould; Construction of a kiln . . 476
Heating the kiln and appliances for that purpose . . . . . 477
Arrangement of an evaporator having four or five kilns .... 479
Selection of the varieties of fruit to be evaporated; Paring and bleaching ap-
ples; Types of bleachers .......... 480
Temperature to be maintained in the kiln ....... 481
Manner of placing the fruit in the trays when drying in the tower evapora-
tor; Treatment of plums after evaporating; Conversion of grapes into rais-
ins; Mode of obtaining Malaga grapes; Evaporation of tomatoes . . 482
Evaporation of various vegetables, and of potatoes ..... 483
Sun-drying apparatus ........... 484
French method of drying fruit in the oven ... .... 485
CHAPTER XXXIII.
PREPARATION OF PICKLES AND MUSTARD.
Pickles; Manner of packing pickles; General rule for the preparation of pick-
les 487
Preparation of spiced vinegar ......... 488
"Greening" pickles; Fruits and vegetables chiefly used for the preparation
of pickles 489
Mixed pickles; Picalilli; Pickled gherkins . ... . . 490
Gherkins in mustard; Pickled mushrooms; Pickled onions, peaches, peas,
and tomatoes ............ 491
Pickled walnuts; Mustard; English method of preparing mustard; Substan-
ces used for seasoning mustard ......... 492
Gumpoldskircher must-mustard; Moutarde des Jesuites, French mustard;
Ordinary mustard ........... 493
Frankfort mustard; Wine mustard; Aromatic or hygienic mustard; Diissel-
dorf mustard; Sour Diisseldorf mustard ....... 494
Sweet and sour Kremser must-mustards; Moutarde de maille; Moutarde aux
Apices; Moutarde aromatisee; English mustard. ..... 495
CHAPTER XXXIV.
PRESERVATION OF MEAT. FISH, AND EGGS.
Appert's method of canning meats; Cans used; Placing the prepared meats in
the cans; Heating the cans and steam-chamber for the purpose . . . 496
XXIV CONTENTS.
PAGE
Object to be attained in operating according to Appert's method . . . 497
Preparation of corned beef according to Appert's method; Meat biscuit ac-
cording to Gallamond .......... 498-
Soup tablets 499
Beef extract; Quick salting of meat by liquid pressure; Quick process of
smoking meat ^ 500
Preparation of powdered meat; Preservation of fish 502
Preservation of eggs . .......... 503
APPENDIX.
Table I. Hehner's alcohol table. . 506
Table II., which indicates the specific gravity of mixtures of alcohol and
water * 509
Table III. Proportion between the per cent, by weight and by volume of
alcoholic fluids at 59° F 510
Table IV. The actual content of alcohol and water in mixtures of both fluids
and the contraction which takes place in mixing ..... 511
Table V. For'comparing the different aerometers with Tralles's alcoholo-
meter 512
Determination of the true strengths of spirit for the standard temperature of
59° F 5ia
Table VI. Determination of the true strengths of spirit for the standard
temperature of 59° F. (15° C.). 514
Explanation of Table VI 519
Table VII. Determination of the true volume of alcoholic fluids from the
apparent volume at different temperatures; Explanation of Table VII. , 520
Table VIII. Preparation of whiskey of various strengths from spirits of
wine. ... t ......... 522
Table IX. For the reduction of specific gravities to saccharometer per cent. 523
Table X. Comparative synopsis of the aerometers for must generally used . 526
Table XL Table to Oechsle's aerometer for must 527
Table XII. Table to Massonfour's aerometer for must 527
Table XIII. For comparing per cent, of sugar with per cent of extract and
specific gravity 527
Table XIV. For determining the content of per cent of acetic acid contained
in a vinegar of — specific gravity (according to A. C. Oudemans) . . 528
Table XIV. For determining the content of per cent, of acetic acid con-
tained in a vinegar of — specific gravity (according to Mohr) . . . 529
Table XVI. Comparison of the scales of Keaumur's, Celsius's and Fahren-
heit's thermometers 530
Index . . 531
PART I.
VINEGAR.
CHAPTER I.
INTRODUCTORY AND HISTORICAL.
Ordinary vinegar consists of a weak solution of acetic acid
in aqueous fluids prepared by the oxidation of alcoholic liquors
by means of acetic acid bacteria, Bacterium aceti, of which
there are many varieties, the best races being propagated by
pure culture methods, and used for impregnating the alcoholic
liquors to be fermented. The color of vinegar and, to a cer-
tain extent, also its odor and taste are influenced by the ma-
terials from which it is prepared. In this form it has been
known from the earliest times, and it must have been used
contemporaneously with wine, because it is evident that at the
temperature of the Eastern countries, where the first .experi-
ments with the juice of the grape were made, fermentation
must have set in rapidly and the wine been quickly trans-
formed into an acid compound. Vinegar is mentioned in the
Old Testament, and Hippocrates made use of it as a medicine.
That the solvent effects of vinegar were understood by the
ancients, is shown by the well-known anecdote of Cleopatra,
related by Pliny. To gain a wager that she could consume
at a single meal the value of a million sesterces, she dissolved
pearls in vinegar which she drank. This is also shown by
the equally well known, but exaggerated account by'Livy and
Plutarch, that Hannibal overcame the difficulties offered by
2 MANUFACTURE OF VINEGAR.
the rocks to the passage of his army over the Alps, by dissolv-
ing them with vinegar. Admitting the exaggeration, or the
explanation which some give, viz.: that Hannibal used the
vinegar by way of strategem, to incite his men to greater ex-
ertion by the belief that the difficulties of the path were
diminished, the case nevertheless shows that the solvent action
of vinegar upon certain substances was well known at that
period.
Vitruvius also states that rocks which cannot be attacked
by either fire or iron, will yield when heated and wet with
vinegar.
Although there can be no doubt that vinegar was in very
general use at an early period, there was no definite knowledge
as to the cause of its production and the mode of its formation,
and we are indebted to the much-abused alchemists for the
first knowledge of its purification and concentration by dis-
tillation.
Gerber, who flourished in the eighth century, gives us the
earliest description of the process of increasing the strength of
wine-vinegar by distillation, and Albucases, about 1100, stated
the fact that vinegar to be colorless has to be distilled over a
moderate fire. Basilius Valentinus, a monk and celebrated
alchemist of the fifteenth century, knew that by the slow dis-
tillation of vinegar, first a weak, and then a stronger product
is obtained, and he was probably also acquainted with the
process of obtaining strong acetic acid by distilling cupric ace-
tate (verdigris.) In fact, for a long time this was the only way
of preparing acetic acid, the result of the further rectification of
the product being termed radical vinegar, spiritus Veneris,
Venus' s vinegar, spiritus aeruginis, etc.
Stael, in 1697, strengthened vinegar by freezing out some of
its water. In 1702, he taught the method of obtaining strong
acetic acid by neutralizing vinegar by an alkali, and distilling
the acetate thus formed with oil of vitriol. The Count de
Laragnais (1759), and the Marquis de Courtenvaux (1768),
showed that the most concentrated acetic acid obtained from
INTRODUCTORY AND HISTORICAL. 3
verdigris was capable of crystallization. Loewitz (1789)
taught how pure, but weak acetic acid might be strengthened
by passing it repeatedly over charcoal powder. It may thus
be deprived of so much of its water that it crystallizes by cold.
This crystallizable acetic acid is the strongest which it is pos-
sible to obtain. Durande (1777), gave to it the name which
it still bears, of glacial acetic acid.
The formation of an acid body in the destructive distillation
of wood was known as early as the seventeenth century. How-
ever, it was for a long time not recognized as acetic acid, but
considered a special acid (pyroligneous acid). Fourcroy and
Vauquelin, in 1800, were the first to recognize this acid as
acetic acid, and Thenard, in 1802, demonstrated the presence
of acetic acid among the products formed in the destructive
distillation of animal substances.
Berzelius, in 1814, determined the exact chemical constitu-
tion of acetic acid, and Saussure, in the same year, that of alco-
hol. Dr. J. Davy observed that spongy platinum, in contact
with vapor of alcohol, became incandescent and generated
acetic acid. Dobereiner further studied the nature of the acid,
and proved that the alcohol was oxidized at the expense of the
atmospheric air, producing acetic acid and water, and that no
carbonic acid was formed, thus pointing out the fallacy of the
opinion held by the chemists of his time that carbonic acid
was one of the products of acetic fermentation.
Schiitzenbach, in 1823, one year after the establishment by
Dobereiner of the now generally accepted theory of the forma-
tion of acetic acid from alcohol, introduced the quick process
of manufacturing vinegar.
Without detracting from the credit due to Schiitzenbach for
the introduction of his method and the improvement in the
process of manufacturing vinegar, it may be mentioned that as
early as 1732, nearly a century before, the celebrated Dutch
chemist and physician, Boerhave, made known a method for
making vinegar from wine, which contained the principles of
the quick process.
4 MANUFACTURE OF VINEGAR.
Although it is now more than ninety years since the intro-
duction of Schiitzenbach's process into practice, the manufac-
ture of vinegar from alcohol remains nearly the same. While
no change can be made as regards the theoretical part of the
process, it being erected on a foundation clearly indicated by
a knowledge of natural laws, many important improvements
may surely be introduced in the manufacture of vinegar on a
large scale, this being especially the case where it is uninter-
ruptedly carried on with the use of suitable apparatus. Many
manufacturers still work according to Schiitzenbach's original
plan, i. e., they use an ^immense amount of labor for a per-
formance which can be attained in a much simpler manner.
Progress is essential in every business, but for several reasons
it is especially necessary for the manufacturer engaged in mak-
ing vinegar by the quick process. Alcohol in every form —
whiskey, beer, wine — is everywhere subjected to a high tax, and
the constantly increasing taxation of this fundamental material
for the manufacture of vinegar, of course increases the price
the manufacturer has to pay for it. Another reason why the
production of vinegar from alcohol becomes constantly more
difficult is found in the great competition arising from the
continued improvements in the manufacture of pure acetic
acid from wood. Not many years ago it was considered im-
possible to obtain entirely pure acetic acid from wood when
manufacturing on a large scale, but the article produced at
the present time may be almost designated as " chemically
pure " in the true sense of the word, it containing, besides
acetic acid, only water, and the most accurate analysis cannot
detect a trace of the products of tar, which render unpurified
wood vinegar unfit for use.
For consumption on a large scale, especially where only a
body of an acid taste is required, the use of so-called " vinegar
essence," i. e., pure 80 to 90 per cent, acetic acid, obtained from
wood, and which, when properly diluted, furnishes ordinary
vinegar, will undoubtedly gradually supersede vinegar pre-
pared from alcohol, it being considerably cheaper. And not-
INTRODUCTORY AND HISTORICAL. 5
withstanding that the price of wood vinegar is declining every
year, in regions where wood is plentiful and cheap its manu-
facture is a remunerative industry on account of the many
valuable by-products — tar, wood spirit, charcoal — obtained
besides acetic acid. At the present time, for all industrial pur-
poses where acetic acid is required, as for instance in the man-
ufacture of tar colors, that obtained from wood is used, and
the quantities consumed in the production of vinegar for do-
mestic purposes becomes larger every year.
But the manufacture of vinegar from alcohol and alcoholic
liquids will nevertheless continue to flourish, because the pro-
duct obtained from them possesses different properties from
the pure acetic acid prepared from wood. Vinegar obtained
from alcohol, and still more so that from fermented fruit juices,
such as wine, cider, skins of pressed grapes, or from malt, con-
tains, besides acetic acid and water, small quantities of bodies
which, on account of their being analogous to those occurring
in wine, may be designated as " bouquet bodies," and which
give to the vinegar an agreeable smell and taste entirely want-
ing in acetic acid prepared from wood. These properties are
so characteristic that any one gifted with a sensitive and prac-
ticed sense of smell can at once distinguish pure acetic acid
vinegar from that prepared from wine, cider, beer, etc.
By the addition of volatile oils or compound ethers an agree-
able odor may, of course, be imparted to vinegar obtained by
diluting pure wood acetic acid with water, but it is impossible
to produce the harmonious bouquet peculiar to vinegar pre-
pared from alcohol or fruit juices, a similar relation existing
here as between genuine and artificial wine. The latter may
be made so that, as regards taste and smell, it nearly ap-
proaches genuine wine, but a connoisseur will at once detect
the difference.
The principal defects of the manner of manufacturing vine-
gar by the quick process in general use are not in the method
itself, for that, as already indicated, corresponds entirely to the
theoretical conditions, and yields as good a product as can be
6 MANUFACTURE OF VINEGAR.
obtained from the raw material used. The weak point of the
process is found in practical execution of it, the losses of
material being much more considerable and greater than
absolutely necessary : the consumption of labor is large, and, as
every manufacturer knows from experience, interruptions in the
regular process of working are of too frequent occurrence.
All these disadvantages can be reduced to a minimum, if not
absolutely overcome, and it is hoped sufficient hints how this
can be done will be found in the following chapters.
As will be explained later on acetic acid contains the same
elements found in carbonic acid and water, and to judge from
the results already attained by chemistry in building up com-
pounds from their elements, a method will no doubt be found
by which acetic acid can on a large scale be produced from its
elements. It is difficult to predict the effect the discovery of
such a process would have upon the life of all other methods
of vinegar manufacture. In fact, acetic acid has already been
prepared in this manner, but the method employed is not
adapted for operations on a large scale.
CHAPTER II.
THEORY OF THE FORMATION OF VINEGAR.
INDEPENDENT of the formation of acetic acid by destructive
distillation, the chemical processes by which acetic acid in
larger quantities is formed are at present quite well understood,
and may be briefly explained as follows :
As previously mentioned, Dobereiner, in 1822, established
the theory of the formation of acetic acid from alcohol, and the
processes taking place thereby may be expressed by the fol-
lowing formula :
C2H60 + 02 = C2H402 + H20
Alcohol. Oxygen. Acetic acid. Water.
THEORY OF THE FORMATION OF VINEGAR. 7
According to the above formula, acetic acid and water are
formed by the action of oxygen upon alcohol, and hence the
formation of acetic acid takes place by a partial combustion or
oxidation of the latter. Alcohol and acetic acid are, however,
only two members of the process, and that besides them other
bodies are formed from the alcohol, can in a vinegar manufac-
tory be. readily detected by the sense of smell.
By treating alcohol with pyrolusite and sulphuric acid —
hence by the action of oxygen at the moment of its liberation
from a combination, i. e., in its nascent state — Dobereiner ob-
tained a body which he called " light oxygenated ether "
(leichter Sauerstoffather). Liebig later on studied this com-
bination more accurately, and found that, as regards its com-
position, it differed from that of alcohol only by containing two
atoms less of hydrogen. He applied to it the term ''alde-
hyde." Aldehyde is composed of C2H40, and its formation is
represented by the formula —
C2H60 + 02 = C2H402 + H20
Alcohol. Oxygen. Aldehyde. Water.
In the examination of the properties of aldehyde it was
shown that it is readily converted into acetic acid by the ab-
sorption of oxygen and, based upon these facts, Liebig estab-
lished a theory of the formation of vinegar which was for many
years considered correct.
Essentially Liebig's theory is as follows : By the exposure,
under suitable conditions, of alcohol to the action of the atmos-
pheric oxygen, one-third of the entire quantity of hydrogen
contained in it is withdrawn, and aldehyde is formed. The lat-
ter, however, immediately combines further with oxygen, and
is converted into acetic acid ; the formation of vinegar from
alcohol being, therefore, a partial process of combustion.
From the present standpoint of our knowledge regarding the
formation of acetic acid from alcohol, the correctness of this
theory is about parallel with that according to which alcohol
and carbonic acid are formed by the alcoholic fermentation of
8 MANUFACTURE OF VINEGAR.
sugar. The latter process can also be illustrated by an equa-
tion in 'as simple a manner as the conversion of alcohol into
acetic acid by aldehyde. At the present time, the processes
taking place in the formation of acetic acid from alcohol must,
however, be considered as far more complicated than supposed
by Liebig. According to the latter, a simple oxidation, i. e., a
simple chemical process, takes place. But, according to the
now universally accepted view, the formation of vinegar is due
to a chemico-physiological process with the co-operation of a
living organism. Alcohol and oxygen alone do not suffice for
this purpose, the presence of nitrogenous bodies and salts, be-
sides that of an organism, being absolutely necessary.
The French chemist,, Pasteur, was the first to establish the
formation of vinegar as a peculiar process of fermentation, and
he maintains that a certain organism, the " vinegar ferment"
or " vinegar yeast," consumes the alcohol, nitrogenous sub-
stances and salts, and separates acetic acid, aldehyde, etc.,
as products of the change of matter taking place in the living
organism. On the other hand, the German chemist Niigeli is
of the opinion that the role of the organism is to bring the
particles of the substance to be fermented — in this case alcohol
— lying next to it, into such vibrations as to decompose them
into more simple combinations — in this case, acetic acid,
aldehyde, etc.
The scientific dispute over these two different views is not
yet settled, though the majority of chemists are inclined to
accept Pasteur's theory. For the practical man it is of no
consequence which of these views will be finally accepted as
the correct one; the fact that the process of the formation of
vinegar is connected with the living process of an organism
being alone of importance to him.
As is well known, organisms producing fermentation are
named after certain products which they form in larger quan-
tities, the organisms forming alcohol from sugar being, for in-
stance, briefly termed "alcoholic ferment." In this sense we
may also speak of a vinegar or acetic ferment, since a definite
THEORY OF THE FORMATION OF VINEGAR.
organism causing the formation of larger quantities of acetic
acid from alcohol is known, and the cultivation of this ferment
is one of the principal tasks of the manufacturer of vinegar.
Numerous observations have established the fact that the
properties of forming large quantities of acetic acid are inher-
ent only in this ferment. Small quantities of acetic acid are,
however, also, constantly formed by other ferments, so that
in examining products due to the process of decomposition
induced by organisms, acetic acid will generally be found
among them. In the alcoholic fermentation, at least in that
of wine and bread dough, acetic acid is always found. It
originates in the germination of many seeds, and generally
appears in the putrefaction of substances rich in nitrogen, such
as albumen, glue, etc. It appears also in the so-called lactic
fermentation, the lactic acid formed by the specific ferment of
this species of fermentation being by farther processes of fer-
mentation decomposed into butyric and acetic acids.
Acetic acid is found in many animal juices, for instance, in
meat juices, milk, sweat and urine. It also occurs in the
fresh fruit of the tamarind. The processes which take place
in its formation in these cases are not known, though it is
very likely directly formed from certain varieties, of sugar.
There is quite a large series of X'hemical processes in which
certain quantities of acetic acid are formed. Sugar, starch,
woody fibre and, in general, all compounds known as carbo-
hydrates, when fused with caustic alkalies, yield certain quan-
tities of acetic acid, and also by themselves when subjected to
destructive distillation. Among the processes by which acetic
acid is produced in a purely chemical manner, i. e., without
the co-operation of organisms, the most interesting is that by
which its formation is effected by the action of very finely
divided platinum, the so-called platinum black, upon alcohol.
Platinum black is readily prepared by boiling a solution of
platinic chloride, to which an excess of sodium carbonate and
a quantity of sugar have been added, until the precipitate
formed after a little time becomes perfectly black, and the
10
MANUFACTURE OF VINEGAR.
FIG. 1.
supernatant liquid colorless. The black powder is collected
on a filter, washed and dried by gentle heat. On account of
the minute state of its division, this substance condenses within
it several hundred times its volume of oxygen, and conse-
quently when the vapor of alcohol comes in contact with it, a
supply of oxygen in a concentrated state is presented to it,
and the platinum, without losing any of its inherent proper-
ties, effects chemical combination, the alcohol undergoing slow
combustion and being converted into acetic acid. In order
that the reaction may continue it is, of course, necessary to
present fresh oxygen to the platinum to replace that which
has been withdrawn. The two actions then go on side by
side.
This can be illustrated by an apparatus similar to Fig. 1.
It consists of a glass bell through
the mouth of which a long funnel
passes. The lower end of this funnel
terminates in a fine point so that the
alcohol may percolate very slowly.
The vessel is placed upon supports
within a dish in which is a saucer
or small shallow basin containing
the platinum black. The interspace
between the bottom of the dish and
the glass bell serves for the circula-
tion of air in the latter. A short,
time after the alcohol has been
poured into the funnel an odor of
acetic acid, arising from the acetic
acid vapors which are generated, is
perceived at the mouth of the bell.
These vapors condense on the walls of the bell and trickle to
the bottom, where they collect in the vessel in the dish. It is
of advantage, for the success of the experiment, to have the
alcohol heated to about 90° F. before pouring it in. By
washing and igniting the platinum used for the oxidation of
the alcohol, it can be again employed for the same purpose.
THEORY OF THE FORMATION OF VINEGAR. 11
Independent of the purely chemical methods which, with
the exception of that by which acetic acid is produced by the
destructive distillation of wood, are of no practical importance,
the formation of vinegar, no matter what method may be
adopted, can only be effected in the presence of certain organ-
isms. It has long been known that organisms to which the
term mother of vinegar has been applied, develop upon liquids
containing, besides alcohol, certain other substances, for
Instance, upon weak wine or beer, and this mother of vinegar
has also been used for making vinegar on a large scale. To
Pasteur, however, belongs the incontestable merit of having
more accurately examined the relations of these organisms to
the formation of vinegar. These examinations gave rise to
his experiments on the diseased alteration of wine, which were
later on superseded by his researches on the formation of wine
vinegar.
Pasteur found that upon the surface of every fluid capable,
by reason of its composition, of being converted into vinegar,
organisms develop immediately after the commencement of the
formation of vinegar. He recognized these organisms as fun-
goid plants of a low order and called them Mycoderma aceti.
More recent researches on the botanical nature of these plants
show them to belong to the group of lowest fungoid organisms,
to which the term bacteria or schizomycetes has been applied.
The Bacterium aceti, the name applied to this organism,
consists of a single, generally globular or filiform cells, its
special characteristic being its mode of propagation, which is
effected by the division of the cell into two, and then a separa-
tion or splitting of both.
The exceedingly minute size of the schizomycetes and their
great resemblance to each other make their accurate determina-
tion very difficult, and hence it is customary to name the better
known species in accordance with the chemical products they
form or in accordance with the phenomena they produce.
Among the first kind may be classed those which effect the
formation of acetic, lactic, butyric acids, while other very little
12 MANUFACTURE OF VINEGAR.
known bacteria must be considered as the cause of the so-
called nitric acid fermentation, and again others appear in
putrid fermentation. A special group of bacteria reaches de-
velopment in animal organisms and gives rise to terrible dis-
eases, some causing rinderpest, others tuberculosis and various
other maladies. Cholera and other epidemics have been found
to be due to certain bacteria.
The bacteria causing disease are of course very interesting
to the physician, but to the manufacturer of vinegar a thorough
knowledge of the conditions of life governing the vinegar
bacteria is of the utmost importance in order to conduct the
manufacture in such a manner that disturbances shall rarely
occur, and should they happen, that he may be able to remove
them. It may therefore be said that the entire art of the man-
ufacture of vinegar consists in an accurate knowledge of the
conditions of life of the vinegar bacteria and in the induction
of these conditions of life. As long as the latter are main-
tained the process of the formation of vinegar will go on with-
out disturbance, and the origination of new generations of
vinegar ferment be connected with the conversion of certain
quantities of alcohol into vinegar.
Pasteur regarded the bacterial growth mentioned above as
consisting of a single species. Hansen, however, showed in
1878, that in the spontaneous souring of beer at least two dif-
ferent species of bacteria can come into action, one of which
he named Mycpderma aceti and the other Mycoderma Pasteur-
ianum. At the suggestion of W. Zopf, he afterwards changed
these names to Bacterium aceti and Bacterium Pasteurianum re-
spectively. The number of species has been further increased
by recent investigations, and among these acetic acid bacteria
there are several, the activity of which is distinctly different,
and the employment of a pure culture of systematical!^ selected
species would be desirable in the manufacture of vinegar.
Searching investigations into the chemical activity of the dif-
ferent species of acetic acid bacteria would be not only oppor-
tune in the interests of science, but also highly important in the
practice of the vinegar industry.
VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 13
CHAPTER III.
THE VINEGAR FERMENT AND ITS CONDITIONS OF LIFE.
A. The Vinegar Ferment — While but little is known about
the origin of the vinegar ferment, experiments have shown
these organisms to be everywhere distributed throughout the
air and to multiply at an enormous rate when fluids of a com-
position suitable for their nutriment are presented to them.
A fluid especially adapted for this purpose is, for instance,
throughly fermented ripe wine, its exposure in a shallow vessel
at the ordinary temperature of a room being sufficient to in-
duce the propagation of the vinegar bacteria reaching it from
the air.
The experiment is, however, certain of success only when
made with ripe wine, by which is meant wine which shows but
little turbidity when vigorously shaken in contact with air and
exposed in a half-filled bottle to the air. Young wine contains
a large quantity of albuminous substances in solution, and- is
especially adapted for the nutriment of an organism, the sac-
charomyces mesembryanthemum belonging to the saccharomy-
cetes. It develops upon the surface of such wine as a thick
white skin, which later on becomes wrinkled and prevents the
growth of the vinegar ferment. A fluid well adapted for the
nutriment of the vinegar ferment and which may be substituted
for wine for its culture is obtained by adding 5 to 6 per cent.
of alcohol and about J per cent, of malt extract to water.
By exposing this fluid, or ripe wine at the ordinary tempera-
ture of a room, best in a dish covered by a glass plate resting
upon small wooden blocks to prevent the access of dust, the
formation of a thin veil-like coating upon the surface will in a
few days be observed. The wine soon exhibits the character-
istic odor and taste of acetic acid, and in a few days assumes a
somewhat darker color, and deposits a slight brownish sedi-
ment consisting of decayed vinegar ferment. In 14 to 21 days
14 MANUFACTURE OF VINEGAR.
the fluid is entirely converted into vinegar, i. e., it contains no
more alcohol, but in place of it the corresponding quantity of
acetic acid.
By exposing the vinegar, thus obtained for a longer time to
the air, a thick white skin of mold may happen to form on the
surface, and on testing the fluid, it will be found that the con-
tent of acetic acid steadily decreases, the mold which is able to
convert the alcohol into water and carbonic acid possessing
also the power of forming the same products from acetic acid.
The process above described of the destruction of the wine
FIG. 2
and its conversion into vinegar by a veil-like coating of vinegar
ferment occurs most frequently, though a thick spume, the so-
called mother of vinegar, may also happen upon the surface.
This phenomenon will be referred to later on.
On examining under the microscope a drop taken from the
surface of the wine when the veil of vinegar ferment com-
mences to form, a picture like that shown in Fig. 2 presents
itself. In a somewhat more advanced stage, formations re-
sembling chains and strings of beads appear more frequently,
and when finally the development of the ferment is in full
VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 15
progress, it appears as an aggregation of numerous single cells
mixed with double cells and many other cells strung together
like beads. The field of vision of the microscope is then com-
pletely filled with a large number of colorless globules, which
are present either singly or in combinations of two, formations
resembling chains or strings of beads being of rare occurrence.
In many of the separately-occurring formations oval forms, gen-
erally slightly contracted in the centre, are observed, this con-
traction indicating the place where the splitting of one cell
into two new cells takes place. By vigorously shaking the
fluid before viewing it under the microscope, very few of the
above mentioned bead-like formations will be found, but more
frequently the contracted ones. By observing for hours a drop
of the fluid containing the ferment in an advanced state of de-
velopment, the globules strung together will be noticed to fall
apart when at rest. Hence it may be supposed that in the
propagation of cells by splitting, the newly formed cells ad-
here together up to a certain stage, and later on separate in the
fluid when in a quiescent state. Like every other organism
the vinegar ferment only lives for a certain time, and after
dying sinks below the fluid and forms upon the bottom of the
vessel the above-mentioned sediment. The latter appears
under the microscope in "the same form as the living ferment,
but differs from it in being less transparent, and of a brownish
color. The propagation of the vinegar ferment takes place
very rapidly, and it will be found in a few hours after the com-
mencement of its development in all stages of life upon the sur-
face of the fluid, it being possible to distinguish cells of from
1.5 to 3.5 micromillimeters.*
The vinegar ferment requiring free oxygen for its propa-
gation, grows exuberantly only upon the surface of the nutrient
fluids. By filling a bottle about four fifths full with wine, and
after allowing the vinegar ferment to develop, closing the mouth
of the bottle with the hand, and submerging the neck of the
* One micromillimeter =• j^ millimeter.
16 MANUFACTURE OF VINEGAR.
bottle in water, the fluid will be seen to rise for some time in
the bottle, and then remain stationary. A determination of the
content of acetic acid immediately before the commencement
of this experiment, and a few days after, shows but a slight in-
crease in acetic acid, because the ferment has consumed the
free oxygen present in the bottle, the essential condition for its
further development is wanting, and it must cease its. activity,
without, however, perishing. It may here be remarked that
the vinegar ferment, like the majority of bacteria, possesses an
extraordinary vitality. Under unfavorable conditions it passes
into a kind of quiescent state, during which no perceptible in-
crease of cells takes place, and it may remain in this state for
a long time without suffering destruction, but as soon as the
conditions for its nutriment are again presented, propagation
in a normal manner recommences.
The great rapidity of propagation of the vinegar bacteria
is shown by an experiment of some importance to the practice.
Pour into a shallow vat, about three feet in diameter, a fluid
suitable for the nutriment of the bacteria, and divide upon the
surface by means of a thin glass rod small drops of wine, upon
which the frequently mentioned veil has been formed. In a
few hours the entire surface of the fluid in the vat will be
covered with vinegar bacteria, spreading concentrically froni
the points where the drops of wine have been distributed.
From this it will be seen that the culture of the ferment for
the purpose of manufacturing vinegar offers no difficulties,
provided all conditions for its propagation be observed.
7?. Conditions for the Nutriment of the Vinegar Ferment. The
conditions most favorable for the development of the vinegar
ferment, and for converting in the shortest time the largest
quantity of alcohol into acetic acid, have been determined by
many observations and long experience in the practice. These
conditions will first be briefly enumerated, and then the sep-
arate points more fully discussed.
For the vinegar bacteria to settle upon a fluid, and for their
vigorous propagation, the following factors are required :
VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 17
1. A fluid which, besides alcohol and water, contains nitro-
genous bodies and alkaline salts. The quantities of
these bodies must, however, not exceed a certain limit.
2. The fluid must be in immediate contact with oxygen
(atmospheric air).
3. The temperature of the fluid and the air surrounding it
must be within certain limits.
As regards the composition of the nutrient fluid itself, it
must contain all the substances required for the nutriment of
a plant of a low order, such substances being carbohydrates,
albuminates and salts. Alcohol must be named as a specific
nutriment of the vinegar ferment, provided the supposition
that the latter consumes the alcohol and separates in its place
acetic acid, is correct. The quantity of alcohol in the fluid
intended for making vinegar must, however, not exceed a
certain limit, a content of 15 per cent, appearing to be the
maximum at which acetic fermentation can be induced.
But even a content of 12 to 13 per cent, of alcohol is not very
favorable for the vegetation of the vinegar ferment, and every
manufacturer knows the difficulty of preparing vinegar from
such a fluid. A small quantity of acetic acid in the nutrient
medium exerts also an injurious influence upon the vinegar
ferment. Upon a fluid containing 12 to 13 per cent, of acetic
acid and 1 to 2 per cent, of alcohol, the ferment vegetates only
in a sluggish manner, and considerable time is required to con-
vert this small quantity of alcohol into acetic acid.
That the vinegar ferment cannot live in dilute alcohol alone
may be shown by a simple experiment. By impregnating a
fluid consisting only of water and alcohol, a very small quan-
tity of acetic acid is formed to be sure, but the ferment perishes
in a short time — it starves to death. A fluid suitable for its
nourishment must, therefore, contain the above-mentioned
nutrient substances, sugar, dextrine, or similar combinations
occuring in wine, malt extract, and beer, being generally em-
ployed as carbohydrates. These fluids further contain nitro-
genous combinations which may serve as nutrient for the fer-
2
18 MANUFACTURE OF VINEGAR.
inent, also considerable quantities of phosphates. Hence, by
an addition of wine, malt extract, beer, or any fruit wine (apple
or pear cider) to a mixture of alcohol and water, a fluid can
be prepared that contains all the substances essential to the
nutriment of the ferment.
The necessary quantity of these nutrient substances, as com-
pared with that of alcohol, is very small, since the quantity by
weight of vinegar ferment required for the conversion of a very
large amount of alcohol into vinegar is only a few fractions of
one per cent, of the weight of alcohol used. Hence the manu-
facturer may be very sparing with the addition of nutrient
substances to the fluid to be converted into vinegar, without
having to fear that the ferment will be stinted.
The vinegar ferment is very sensitive to sudden changes
in the composition of the fluids upon which it lives, and suf-
fers injury by such changes which are recognized by dimin-
ished propagation and a decrease in the conversion of alcohol
into acetic acid.
By transferring, for instance, vinegar ferment which had nor-
mally vegetated upon a fluid containing only 4 to 5 per cent,
of alcohol, to one with a content of 10 to 11 per cent., its pro-
pagation, as well as its fermenting energy, decreases rapidly
and remains sluggish, until a few new generations of cells have
been formed which are better accustomed to the changed con-
ditions. By bringing, on the other hand, a ferment from a
fluid rich in alcohol upon one containing a smaller percentage,
the disturbances in the conditions of the ferment can also be
observed, but they exert a less injurious influence upon the
process of the formation of vinegar than in the former instance.
The process of nutriment of the vinegar ferment, however,
must not be understood to consist simply in the consumption
of sugar, albuminates and salts. It differs according to the
composition of the nutrient medium, and is so complicated as
to require very thorough study for its explanation. If, for in-
stance, wine is converted into vinegar, and the composition of
the latter compared with that of the original wine, it will be
VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 19
found that not only the alcohol has been converted into acetic
acid and the fluid has suffered a small diminution of extractive
substances and salts, which might be set down to the account
of the nutriment of the ferment, but that the quantity of tar-
taric, malic and succinic acids has also decreased, as well as
that of glycerine, and of the latter even nothing may be pres-
ent. Hence it must be supposed that the vinegar ferment
derives nutriment also from these substances, or that the fer-
menting activity acts upon them as well as upon the alcohol.
There is finally the fact of great importance for the practice,
but which has not yet been sufficiently explained, that the
vinegar ferment develops more rapidly upon a fluid which,
besides the req-uisite nutrient substances, contains a certain
quantity of acetic acid, than upon a fluid entirely destitute of
it. Regarding the supply of air, it may be said that, while
for mere existence the vinegar ferment requires comparatively
little air, large quantities of it are necessary for its vigorous
propagation and fermenting activity. In the practice it is
aimed to accomplish this by exposing the fluid in which the
ferment lives in thin layers to the action of the air, and, in
fact, upon this the entire process of the quick method of man-
ufacture is based.
Besides the above-mentioned factors, the temperature to
which the ferment is exposed is of great importance as regards
its development. The limits at which the propagation of the
ferment and its vinegar-forming activity are greatest, lie be-
tween 68° and 95° F. Above this limit the formation of
vinegar decreases rapidly, and ceases entirely at 104° F.
However, when the temperature is again reduced to 86° F.,
the ferment reassumes its activity. At a temperature exceed-
ing 104° F. the ferment suffers perceptible injury ; heated to
103° F. it becomes sensibly weaker, and at first propagates
very slowly, regaining its original vigorous development only
after several generations. When the temperature of the fluid
is raised to 122° F. the ferment perishes.
The ferment appears to be less affected by low temperatures.
20 MANUFACTURE OF VINEGAR.
If the temperature of a fluid which shows an exuberant vege-
tation of ferment is reduced to 50° F., the formation of vinegar
continues, though at a much reduced rate. Special experi-
ments have shown that when wine with a vegetation of fer-
ment is converted into ice by being exposed to a temperature
of 14° F., and then melted and heated to 59° F., the ferment
recommences to grow and to form acetic acid. It must, how-
ever, be remarked that while vinegar ferment in a state of
development keeps up a slow vegetation when the fluid is re-
duced to a low temperature, it is extremely difficult to culti-
vate it upon a cold fluid. This is very likely the reason why
acetic degeneration is not known in cold wine cellars, while
in cellars with a temperature of over 59° F., this dreaded pro-
cess can only be guarded against by the greatest care.
Since the propagation of the ferment and its fermenting
activity increase with a higher temperature, it would appear
most suitable to keep the temperature of the fluid to be con-
verted into vinegar as near the uppermost limit of 95° F. as
possible. Experience, however, has shown that at this temper-
ature disturbances are of frequent occurrence in -the genera-
tors, and for this reason one of 86° to 89° F. is generally
preferred. The process of the formation of vinegar itself ex-
plains why disturbances may easily occur at a high tempera-
ture. It is a chemical (oxidizing) process in which a certain
quantity of heat, depending on the quantity of alcohol to be
oxidized within a certain time, is always liberated. If now
by the use of a temperature close to 95° F., the activity of the
ferment is strained to the utmost, a large quantity of alcohol
is in a short time converted into acetic acid, and consequently
so much heat is liberated that the temperature in the gener-
ator rises above the permissible maximum and the ferment
immediately ceases its activity. Thus it may happen that in
a generator which has satisfactorily worked for some time,
tne formation of vinegar ceases all at once, and on examining
the thermometer placed on the apparatus the cause will be
generally found to be due to too high a temperature.
VINEGAR FE11MENT AND ITS CONDITIONS OF LIFE. 21
Mother of Vinegar — In connection with the description of
the conditions of life of the vinegar bacteria, a peculiar form-
ation, playing in many cases a role in the practice of making
vinegar, has to be mentioned. This is the so-called mother of
vinegar, the term having very likely been applied to it on ac-
count of its causing acetification when brought into a fluid
suitable for the formation of acetic acid. The first botanical
investigation of this substance was made in 1822 by Persoon,
who described the organized skin developing on various fluids,
and gave it the general name of Mycoderma, i. e., mucinous
skin or fungoid skin.
Kiitzing, in 1837, showed that the " mother of vinegar" is
constructed of a number of minute dot-like organisms — which
are now called bacteria — arranged together in the form of
chains. These he classified as algae, and named them Ulvina
aceti, and asserted quite positively that alcohol is converted
into acetic acid by the vital activity of these organisms.
Kiitzing's results, however, attracted but little attention because
two years after their publication, Liebig appeared on the scene
with his theory of acetic fermentation, which has already been
referred to, in which no mention was made of the potency of
living organisms, but the " mother of vinegar " was asserted to
be a formation devoid of life, a structureless precipitate of
albuminous matter. One of the reasons put forward in sup-
port of this view was a chemical analysis of the " mother of
vinegar" by the Dutch chemist, G. Mulder, who because he
failed to discover the presence of any ash constituents, thought
that it must be regarded as a compound of protein and cellu-
lose. Mulder's statement was refuted in 1852 by R. Thomson,
who showed that a. sample of " mother of vinegar" contained
94.33 per cent, water, 5.134 per cent, organic matter and 0.336
per cent. ash.
The formation of mother of vinegar can always be success-
fully attained by exposing young wine to the air until the
commencement of the formation of mold is indicated by the
appearance of white dots and then transferring the wine to a
22 MANUFACTURE OP VINEGAR.
room having a temperature of 86° F. At this temperature the
development of the vinegar ferment proceeds so vigorously
that it suppresses the mold ferment, and the peculiar mass con-
stituting the mother of vinegar soon forms upon the surface.
Mother of vinegar occurs so generally in young wine which
is largely used for the preparation of wine vinegar, that its
formation was considered as inseparably connected with that of
acetic acid from alcohol, while actually it is only due to the
peculiar constitution of the fluid to be converted into vinegar.
In many places this opinion is still entertained, and especially
where, as is generally the case, the manufacture of vinegar
from wine is yet carried on in the primitive way of centuries
ago. In speaking of the preparation of vinegar from wine, it
will be shown that the conversion can be effected by means of
the ordinary vinegar ferment without the appearance of mother
of vinegar.
Summary.
Briefly stated, the points of the theoretical conditions of the
formation of vinegar of importance to the manufacturer are : —
1. Acetic acid is formed during many chemical conversions.
However, for the manufacture of acetic acid, and con-
sequently of vinegar on a large scale, only two methods
are available, viz., the preparation of vinegar from al-
cohol by fermentation, or the production of acetic acid
by the destructive distillation of wood.
2. All alcoholic fluids formed by vinous fermentation of
sacchariferous plant juices or fermented malt extracts
are suitable for the preparation of vinegar by fermenta-
tion. Specially prepared mixtures of water, alcohol
and vinegar may also be used for the purpose, provided
they contain small quantites of certain organic sub-
stances and salts,. and not over 14 per cent of alcohol.
3. Acetic fermentation is induced by a microscopic organ-
ism belonging to the bacteria, and the conversion of the
alcohol into acetic acid is in a certain ratio to the pro-
pagation of this organism.
PRODUCTS OF ACETIC FERMENTATION. 23
4. Besides the substances mentioned in 2, the vinegar fer-
ment requires for its vigorous development free oxygen
and a temperature lying between 68° and 95° F.
5. In the acetic fermentation the greater portion of the al-
cohol is converted into acetic acid and water ; besides
these, small quantities of other products are formed
which are in a measure not yet thoroughly known. In
the conversion of wine, beer, etc., other combinations
contained in the fluids, besides alcohol, are also essen-
tially changed.
CHAPTER IV.
PRODUCTS OF ACETIC FERMENTATION.
THE formation of vinegar by fermentation being a chemico-
physiological process, many and complicated chemical pro-
cesses must take place in the fluid to be converted into vine-
gar in order to produce all the combinations required for the
propagation of the ferment. Attention cannot be too fre-
quently called to the fact that from the standpoint of the manu-
facturer, the regular propagation of the ferment is the main
point of the entire manufacture, the quick conversion of the
alcohol contained in the fluid being a necessary consequence
of it.
The body of the ferment, however, contains cellulose, albu-
minous substances, very likely fat and other combinations not
yet known, all of which must be formed from the nutrient
substances (sugar, dextrine, albuminous substances, etc.),
present. It being very probable that a portion of the alcohol
contained in the fluid is consumed for this purpose, a small
but nevertheless perceptible loss of alcohol will occur in the
production. It would be erroneous to suppose that the con-
version of alcohol into acetic acid and water is effected accord-
24 MANUFACTURE OF VINEGAR.
ing to the formula given on p. 6, since a certain portion of it
is always converted into other combinations, the nature and
formation of which can only be, to a certain extent, explained.
In the vinous fermentation, which of all fermenting pro-
cesses has been most thoroughly studied, it is found that from
the sugar, besides alcohol and carbonic acid, large quantities
of glycerine and succinic acid and probably other bodies ,are
formed, which must undoubtedly be classed among the pro-
ducts of vinous fermentation. Similar processes, no doubt,
take place in acetic fermentation, and besides acetic acid and
water other little-known products of fermentation are regularly
formed.
According to the nature of the sacchariferous fluids sub-
jected to vinous fermentation, small quantities of certain
bodies called fusel oils are formed which are decidedly pro-
ducts of fermentation. They impart to the fermented fluid,
as well as to the alcohol distilled from it, such characteristic
properties that from the odor of the alcohol a correct judg-
ment can be formed as to the material employed in its prepa-
ration.
In the conversion of such a fluid, or of alcohol prepared
from it, into vinegar, the fusel oils are also changed — very
likely oxydized — and with some experience the material (wine,
beer, malt, etc.), from which the vinegar has been made can
be determined by the sense of smell. The quantities of aro-
matic substances which reach the vinegar in this manner are,
of course, very small, but they must nevertheless be classed
among the most important products of acetic fermentation,
they being characteristic as regards the derivation of the vine-
gar. Of the products of acetic fermentation, besides acetic
acid, aldehyde and acetal are best known, these combinations
appearing always, even in small quantities, in making vinegar
according to the methods customary at the present time.
Acetic Aldehyde or Acetaldeliyde, commonly called simply
aldehyde (from alcohol dehydrogenatum), is obtained by oxidiz-
ing spirits of wine by means of manganese dioxide (pyrolu-
PRODUCTS OF ACETIC FERMENTATION. 25
site) and sulphuric acid, or platinum black, in the presence
of air, or if alcohol or ether be burning without a sufficient
supply of air. It is also formed by heating a mixture of cal-
cium acetate and calcium formate. It is contained in con-
siderable quantities in the first runnings obtained in the
manufacture of spirit of wine.
To prepare pure aldehyde, 3 parts of potassium dichromate
in small pieces are placed in a flask surrounded by a freezing
mixture and a well-cooled mixture of 2 parts of spirit of
wine, 4 of sulphuric acid, and 4 of water added. After con-
necting the flask with a condenser the freezing mixture is re-
moved ; a violent reaction soon sets in, and the liquid begins
to boil. The vapors have first to pass through an ascending
tube surrounded by warm water at about 122° F. Alcohol
and various other products are condensed and flow back, while
the vapor of the aldeh}Tde, after having passed through a de-
scending condenser, is absorbed in anhydrous ether.
Pure aldehyde thus obtained is a colorless liquid of the
composition C2H40. Its specific gravity is 0.800, and it boils
at about 71.5° F. It has a pungent and suffocating odor,
and is readily soluble in water, alcohol and acetic acid. Like
all the aldehydes it is very easily oxidized and acts, therefore,
as a powerful reducing agent. Thus, on heating it with a
little ammonia and nitrate of silver, metallic silver separates
outj coating the sides of the vessel with a bright mirror. It
combines with ammonia, and forms a crystalline compound
which has the peculiar odor of mice.
Though it is likely that in the manufacture of vinegar by the
quick process, besides aldehyde, acetic and formic ethers are
formed, they are of comparatively little importance for our
purposes. Of more importance, however, is acetal, the forma-
tion of this combination affording an interesting insight into
acetic acid.
Acetal is best prepared by distributing pieces of pumice,
previously moistened with 25 per cent, alcohol, over a large,
glass plate, placing watch crystals containing platinum black
126 MANUFACTURE OF VINEGAR.
upon the pieces of pumice, and covering the whole with a large
bell-glass. The alcohol absorbed by the pumice being con-
verted into acetic acid, 60 percent, alcohol is poured upon the
plate and the air in the bell-glass from time to time renewed.
In a few weeks quite a thick fluid of an agreeable odor has
collected upon the glass plate. This is collected and dis-
tilled, the portion passing over at 219° F. being collected by
itself.
Pure acetal is composed of C6H1402. It is a colorless
liquid, has a specific gravity of 0.821, and boils at 219.2° F.
It has a refreshing odor, calling to mind that of fruit ethers.
By oxidizing agents it is rapidly converted into acetic acid.
Nitrate of silver in the presence of ammonia, however, is not
reduced by it, and it remains unchanged on boiling with
potash lye. From its composition acetal may be considered
from several points of view. It may be regarded as an ethyl
alcohol (glycol) C2H602, in which two atoms of hydrogen
have been replaced by two molecules of the radical ethyl
C2H5, hence thus
__
" C6HUO2 acetal.
This view of the composition of acetal is supported by the
fact that methyl or amyl can be substituted for either one or
both molecules of ethyl in the combination.
According to other opinions, acetal may be considered as a
combination of aldehyde and aldehyde ether : —
C2H,O aldehyde
C4H100 aldehyde ether
C6H^62 acetal,
or as a combination of aldehyde with ethyl alcohol, one mole-
cule of water in the latter having been replaced by the alde-
hyde : —
PRODUCTS OF ACETIC FERMENTATION. 27
Ethyl alcohol: 2(C2H60— H20=C4H10O
aldehyde C2H4O
acetal C4HM02
By keeping in view the fact that the process of the formation
of vinegar is an oxidation of the alcohol which does not pro-
ceed with equal energy in all parts of the apparatus, it will be
understood that during this process aldehyde, acetal, and acetic
ether may be formed which, if the operation be correctly con-
ducted, will be finally converted into acetic acid, though small
quantities of them will be found in the vinegar when just fin-
ished and exert an influence upon its constitution.
Pure acetic acid, C2H402, cannot be directly obtained from
vinegar, but only from acetates by methods which will be de-
scribed later on. The strongest acetic acid which can be pre-
pared is known as glacial acetic acid, from its crystallizing in
icy leaflets at about 40° F. Above about 60° F. the crystals
fuse to a thin, colorless liquid of an exceedingly pungent and
well-known odor. Pure acetic acid is a powerful restorative
when applied to the nostrils in impending fainting. It is the
strongest of organic acids and nearly as corrosive as sulphuric
acid. Applied to the human skin it acts as an irritant, causing
redness and swelling, followed by paleness of the part, and, if
its application be prolonged, it is followed by vesication and
desquamation of the cuticle. It first whitens mucous mem-
branes, then turns them brown, causing meanwhile a severe
burning pain. Highly concentrated acetic acid is a solvent of
many volatile oils and resins, and in practice its high con-
centration is tested by its ability to dissolve lemon oil, since in
the presence of only 2 per cent, of water in the acid, lemon oil
is no longer dissolved by it.
The specific gravity of pure acetic acid is at 59° F.: —
According to Oudemans ....... 1.0553
Roscoe 1.0564
" Kopp 1.0590
Mendelejeff 1.0607
" Mohr . . 1.0600
28 MANUFACTURE OF VINEGAR.
According to Mohr's determinations, the specific gravity of
pure acetic acid varies much at different temperatures, it being
1.0630 at 54.5° F.
1.0600 " 59.0 "
1.0555 u 68.0 "
1.0198 77.0 "
1.0480 79.0 ki
Mixtures of acetic acid and water show a peculiar behavior
in regard to their specific gravity, the latter rising steadily
until the content of water amounts to from 20 to 23 per cent.
The density of the liquid then diminishes so that a mixture
containing 46 per cent, of water shows the same specific
gravity as the anhydrous acid. From this point on, the
specific gravities of the mixtures decrease with the increase in
the content of water.
This peculiar behavior of the mixtures renders the accurate
determination of the content of acid in a concentrated mix-
ture, by means of the aerometer, impossible. There are a
number of determinations of specific gravities of acetic acid
with varying contents of water (by Mohr, von der Toorn,
Oudemans, etc.), but they differ considerably from each other,
like the tables at the end of this volume, so that, while the
specific gravity test answers very well for the determination
of the amount of anhydrous acid in dilute solutions, it is very
fallacious when the acid increases in strength, and an accurate
determination can only be effected by chemical methods.
Highly concentrated acetic acid has found considerable ap-
plication in photography and surgery, and frequently occurs
in commerce in the form of so-called vinegar essence. The acetic
acid occurring under this name is generally prepared from
wood vinegar, and is only fit for the preparation of table
vinegar when a chemical examination shows no trace of tar
products, which, besides acetic acid, are formed in abundance
in the destructive distillation of wood.
In regard to the composition of acetic acid, it may be men-
tioned that one atom of hydrogen can be readily replaced by
PRODUCTS OF ACETIC FERMENTATION. 29
univalent metals or univalent compound radicals which may
be expressed by
H '\0
C2H30 JC
TT -|
whereby the acetic acid is considered as water ^r V 0 in which
one atom of hydrogen is replaced by the compound radical
C2H30 = acetyl.
If the one atom of hydrogen standing by itself be replaced
by a univalent metal, a neutral acetate is formed, for instance :
Na
C2H30
or sodium acetate.
If this atom of hydrogen is replaced by a univalent com-
pound radical, for instance, by methyl CH3, or ethyl C2H5,
the so-called compound ethers are formed.
CH3
C2H30
Acetic acid— methyl ether. Acetic acid— ethyl ether.
If a bivalent metal or compound radical yields a neutral
combination with acetic acid, the substituted hydrogen in two
molecules of acetic acid must evidently be replaced by this
bivalent metal, for instance : —
Ca \Q
2(C2H80) j u*
Neutral calcium acetate.
Theoretical Yields of Acetic Acid — In industries based upon
chemical processes a distinction is made between the theoreti-
cal and practical yields.
By theoretical yield is understood the quantity of the body
to be manufactured which would result if no losses of substance
were connected with the chemical process; the practical yield,
on the other hand, is that in which such losses are taken
into account^ the average being ascertained by long-continued
30 MANUFACTURE OF VINEGAR.
comparison of daily yields. The closer the practical yield ap-
proaches the theoretical one, the more suitable the method
pursued in the production evidently is, and thus the manu-
facturer, who has a clear idea of the theoretical yield, can
readily judge of the value of his method by comparing it
with the practical yield attained.
Now suppose no loss of substance (by evaporation or forma-
tion of other combinations) occurs in the conversion of alcohol
into acetic acid, it can be readily calculated from the composi-
tion of the two bodies how many parts by weight of acetic acid
can be formed from a determined number of parts by weight
of alcohol.
Alcohol has the composition C2H60, or an atomic weight
of 46, because : —
C2 = . . .24
H6= 6
0 = . . .16
Make . .46
The composition of acetic acid is C2H402 and its molecular
weight 60, because :
C2 = . ' . .24
H4= . . . 4
02 = . . .32
Make . . 60
Hence from 46 parts by weight of alcohol 60 parts by
weight of acetic acid may be formed, or by taking 100
parts of alcohol it follows that 100 parts by weight of alcohol
must yield 130.43478 parts by weight of acetic acid. This in-
crease in weight has to be attributed to the absorption of one
atom of oxygen, atomic weight 16, against the loss of two
atoms of hydrogen, atomic weight 2. Since these two atoms
of hydrogen are themselves oxidized to water by the absorp-
PRODUCTS OF ACETIC FERMENTATION. 31
tion of oxygen, the total yield from 100 parts by weight of
alcohol would be :
Acetic acid . . . 130.43478 parts by weight.
Water 39.13043 " "
Total. . 169.56521 parts by weight.
The quantity of oxygen required to form acetic acid and
water from 46 parts by weight of alcohol, amounts to 32 parts
by weight, hence for 100 parts to 69.562 parts by weight. The
oxygen is conducted to the alcohol in the form of air, and it
can be readily calculated how much of the latter is required to
convert a given quantity of alcohol, for instance ,100 grammes,
into acetic acid. In round numbers the air contains in 100
parts by weight 23 parts by weight of oxygen. Since 1 liter
of air of 68° F., i. e., of that temperature which should at the
least always prevail in the vinegar generators, weighs 1.283
grammes, the oxygen contained in it weighs 0.29509 grammes.
Since, as above stated, 69.562 parts by weight are necessary
for the conversion of 100 parts by weight of alcohol into acetic
acid, it follows that 235.70 liters of air are required for the
same purpose.
Examinations as to the content of oxygen in the air escap-
ing from well-conducted vinegar generators have shown that
on an average only one-quarter of the entire content of oxygen
is consumed in the formation of vinegar, hence four times the
theoretically calculated quantity of air must pass through the
apparatus to completely convert the alcohol into acetic acid.
Hence 100 grammes of alcohol require at least 942.92 liters of
air for their conversion into acetic acid, and, without being far
wrong, it may be assumed that in a vinegar factory, in round
numbers, 1000 liters, or one cubic metre of air, are required
for every 100 grammes of alcohol to be converted into acetic
acid.
A vinegar generator, on an average, converts daily 3 litres
of alcohol into acetic acid ; 3 litres of absolute alcohol (specific
32 MANUFACTURE OF VINEGAR.
gravity 0.794) weigh 2382 grammes. Now, if, as stated above,
1 cubic metre of air is required for every 100 grammes of
alcohol, it follows that 23.82 cubic metres, or 23,820 liters of
air must pass daily through each vinegar generator in opera-
tion. *
Calculated to 16 working hours a day, somewhat more than
0.4 liter (more accurately 0.413 liter) must pass every
second through the generator in order to supply the quantity
of oxygen required for the conversion of alcohol into acetic
acid.
Since the formation of vinegar has theoretically to be con-
sidered as a process of combustion, in which of 4G parts by
weight of alcohol, 2 parts by weight of hydrogen, or of 100
parts by weight of alcohol 4.34782 parts by weight of hydro-
gen, are consumed, the quantity of heat liberated by the con-
version of 100 parts by weight of alcohol into acetic acid can
also be calculated. By combustion, 1 gramme of hydrogen
yields 34.126 units of heat, and hence 4.34782 grammes of
hydrogen, 148.373 units of heat, i. e., in the conversion of 100
grammes of alcohol into acetic acid sufficient heat is liberated
to heat 148.373 kilogrammes of water from 0° C. to 1° C., or
1.48 kilogrammes from 0° C. to boiling, and thus a consider-
able development of heat is caused by the rise of temperature
in the apparatus, in which a vigorous formation of vinegar
takes place.
In answer to the question, what can the practical manufac-
turer of vinegar learn from these theoretical explanations, it
may be said there are many points of great importance for the
execution of the work. The calculation of air shows that the
alcohol requires a large supply ; but the generators in general
use in the quick process are by no means so arranged as to be
adequate to the theoretical demands. In fact it may be said
that most of them allow only a limited change of air and con-
* It is always supposed that the manufacture of vinegar is effected in generators
used in the quick process.
PRODUCTS OF ACETIC FERMENTATION. 33
sequently work slower than they actually should. That the
generators now in use are deficient is conclusively proved by
the numerous constructions which have been proposed, especi-
ally in modern times, whose chief aim is to afford a free pas-
sage to the air.
The fact that considerable heat is developed in the interior
of the generator deserves consideration in connection with the
heating of the manufactory. If the temperature in the latter
is so high as nearly to approach the acme, i. e., the temperature
most favorable for the formation of vinegar, it may easily
happen that, in consequence of the vigorous oxidation of the
alcohol, the temperature in the interior of the generators be
increased to such an extent as to exceed this acme, and the
activity of the vinegar ferment would immediately diminish
and even cease altogether.
If, on the other hand, the temperature of the workroom is
kept too low, the generators act sluggishly and do not produce
so much as when the correct conditions are observed. Bat
while by raising the temperature of the workroom the activity
of the generators is increased, too low a temperature is less
injurious to the regular course of the process than too high a
one.
The acme of the formation of vinegar is at about 86° F.,
and hence the aim should be to maintain this temperature as
nearly as possible in the interior of the generator. The tem-
perature of the workroom must, however, be kept sufficiently
low, so that the acme in the interior of the generator may not
be exceeded.
Another factor may here be mentioned. The closer the
temperature in the interior of the generator approaches the
acme and the quicker the supply of air, the more alcohol and
acetic acid are lost by evaporation, or in other words, the
smaller the yield of acetic acid. By the skillful utilization of
conditions the manufacturer must aim to reduce this loss to a
minimum, and this can be best effected by a suitable arrange-
ment of the workroom. By regulating the change of air so
3
34 MANUFACTURE OF VINEGAR.
that it is not greater than absolutely necessary, the air will
soon become so saturated with vapors of alcohol and acetic
acid that no further loss will take place until the renewing of
the air in the workroom appears necessary. In which manner
the manufacturer is to work in order to carry on the business
most advantageously depends on the conditions of trade. If
large orders have to be filled, he will endeavor to increase the
capacity of the generators to the utmost by maintaining the
acme of temperature and a vigorous change of air in them,
and in this case must submit to the increased losses insepar-
ably connected with this high performance. If, on the other
hand, he works for stock, he will not force the capacity of the
generators to the utmost, but in order to work as cheaply as
possible direct his attention to reduce the losses to a minimum.
Yields of Acetic Acid Obtained in the Practice — By keeping
for some time an accurate account of the actual yields and
comparing them with those theoretically obtainable, the
former will be found to fall more or less short of the latter,
and the difference will be the smaller, the better the method
of production in use.
In a vinegar factory occur many unavoidable losses, the
sources of which have been indicated in the preceding explana-
tions ; alcohol and acetic acid evaporate, and further a portion
of them is entirely destroyed by too much oxidation. Now a
loss by evaporation, etc., of ten per cent, of the quantity of
alcohol originally used must no doubt be considered a large
one ; but from numerous observations it may be asserted that
even 'with the greatest care in working, the loss in some vine-
gar factories is not less than from 15 to 20 percent., and may
even be as much as 30 per cent.
These enormous losses of material conclusively prove the
defectiveness of the processes in general use and the urgent
necessity for reformation. The experiments made for this
purpose, and which have been especially directed towards a
remodeling of the apparatus used, cannot be considered en-
tirely satisfactory, though they were partially instituted by
PRODUCTS OF ACETIC FERMENTATION. 35
practical manufacturers, who, however, lacked the necessary
theoretical knowledge.
The principal requirement is to provide the generator with
a suitable ventilator, which will allow of the passage of ex-
actly the quantity of air required for the conversion of the
alcohol into acetic acid, and is so constructed that the vapors
of alcohol and acetic acid (or at least the larger portion) car-
ried away by the current of air are condensed and thus re-
gained.
A vinegar generator has frequently been compared to a fur-
nace, and in continuation of this comparison it may be said,
that the construction generally used is a furnace lacking every
arrangement for the regulation of combustion. In such a fur-
nace as much fuel is burned as corresponds to the quantity of
oxygen entering, while in a furnace of suitable construction
the combustion of fuel can be accurately regulated by increas-
ing or decreasing at will the supply of air by means of a
simple contrivance.
A vinegar generator of suitable construction should be pro-
vided with a similar arrangement. If the thermometer on the
apparatus shows too low a temperature — hence too slow a pro-
cess of oxidation — the course of the operation can in a short
time be accelerated by the production of a stronger current of
air, and the temperature correspondingly increased. If, on the
other hand, oxidation proceeds too rapidly, which on account
of the high temperature then prevailing in the apparatus is
accompanied by considerable loss of substance, it can be
quickly reduced to within the correct limits by decreasing the
current of air. An apparatus unprovided with a ventilator is
left more or less to itself, while one provided with such an
arrangement is under the entire control of the manufacturer.
36 MANUFACTURE OF VINEGAK.
CHAPTER V.
METHODS OF MANUFACTURE OF VINEGAR.
FROM what has been previously said, two methods of man-
ufacturing vinegar can only be distinguished, namely, by
fermentation and by destructive distillation. It has, however,
been deemed advisable to describe separately the old or slow
process by fermentation and the new or quick process. The
The various methods employed for the manufacture of vine-
gar may therefore be designated as follows :
1. By fermentation according to the old or slow process.
2. By the quick process, or manufacture by fermentation
with the application of improved methods in keeping with
our present knowledge of chemistry.
3. Manufacture of wood vinegar, or the preparation of acetic
acid by destructive distillation.
4. The preparation of pure acetic acid from acetates.
It would seem proper to commence the description of the
manufacture of vinegar with the old or slow process, but for
reasons of an entirely practical nature, it has been concluded
not to do so, and the quick process will be first considered.
Since alcoholic fluids, directly formed by the vinous fer-
mentation of sacchariferous plant juices, possess the property
of changing, under circumstances favorable to acetic fermenta-
tion, into vinegar, it is evident that the latter can be prepared
from them and, in fact, it is possible to prepare it from all
sweet fruits and parts of plants, such as cherries, strawberries,
figs, bananas, etc., as well as from the juices of the sugar cane,
beet, chicory root, etc.
Honey, which represents a concentrated solution of ferment-
able sugar, as well as crystallized cane sugar, can likewise be
indirectly used for the preparation of vinegar, since solutions
of either can be brought into vinous fermentation, and the re-
sulting alcohol converted into acetic acid.
METHODS OF MANUFACTURE OF VINEGAR. 37
By malting grain, a peculiar body called diastase is formed,
which possesses the property of converting starch into ferment-
able sugar, and upon this fact is based the manufacture of beer
and alcohol. In an indirect manner — the starch having to be
converted first into sugar, and the latter into alcohol — -it is
therefore possible to prepare vinegar from every substance
containing starch, and for this reason, we can speak of grain
and malt vinegars. The beer prepared from the malt con-
tains a certain quantity of alcohol, and can thus be directly
converted into vinegar.
Alcohol forming ultimately the material for the manufacture
of vinegar, the direct use of dilute alcohol became obvious.
By the employment of a suitable process, i. e., one correspond-
ing to the laws of acetic fermentation, it was found that the
conversion of dilute alcohol into acetic acid could be effected
in a much shorter time than by the old method, and upon
this process is based the quick process now in general use.
Hence, as previously stated, two principal methods of manu-
facture may be distinguished, viz. : the old or slow process,
which requires more time, and the new, or quick process.
In the old process many modifications are found, which are
partially based upon old usage and partially upon the differ-
ence in the chemical composition of the raw material used.
Beer, for instance, which contains only about 4 per cent, of
alcohol and a large quantity of extractive substances (sugar,
dextrin, salts, etc.), requires a different treatment from wine,
which contains on an average 10 per cent, of alcohol, but
scarcely 2 per cent, of extractive substances. Fruit-wines,
(cider, etc.), with only 5 to 6 per cent, of alcohol but a large
quantity of extractive substances, again require different treat-
ment from grape wine, etc., so that, in a certain sense, it may
be said there are as many different methods of making vin-
egar as there are fundamental materials, and by taking into
consideration the difference in the chemical composition of the
latter, it is evident that there must be just as many varieties
of vinegar. Besides acetic acid and a certain amount of water,
38 MANUFACTURE OF VINEGAR.
every vinegar contains other substances, which, though fre-
quently only present in very minute quantities, nevertheless
exert considerable influence upon its properties.
Even vinegar obtained from dilute alcohol shows differ-
ences in odor, which depend on the material used in the pre-
paration of the specific alcohol. Potato alcohol always con-
tains traces of potato fusel oil (amyl alcohol), while other fusel
oils are found in alcohol prepared from grain or molasses.
In the oxidation of the alcohol by the vinegar ferment, these
fusel oils are also oxidized and converted into combinations
distinguished by their peculiar and very strong odor.
Though these bodies occur in vinegar in such minute quan-
tities that they can scarcely be determined by chemical analy-
sis, an expert can detect them by the sense of smell, and from
the specific odor of the vinegar form a conclusive judgment as
to the material used in its preparation.
The differences in vinegar from wine, fruit, beer and malt
are still more pronounced, and extend not only to the odor,
but also to the taste. Besides a specific odoriferous principle,
every kind of wine contains oenanthic ether, tartar, tartaric
and succinic acids, glycerin, and a series of extractive sub-
stances not thoroughly known. The odoriferous substances
and the oenanthic ether also undergo alteration in the oxida-
tion of alcohol, and are converted into other odoriferous com-
binations with suclx a characteristic odor that wine vinegar
can at once be recognized as such by it. On account of the
presence of so many substances each possessing a specific taste,
that of the wine vinegar must, of course, differ from that of
pure dilute acetic acid.
Similar conditions prevail in fruit-wine, beer, malt extract,
etc., and hence vinegar prepared from these fluids must pos-
sess definite properties.
QUICK PROCESS OF MANUFACTURE OF VINEGAR. 39
CHAPTER VI.
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
IN 1823 Schiitzenbach conceived the idea that by greatly
enlarging the relative surfaces of contact Of the alcoholic solu-
tion and air containing oxygen, the process of acetification
would be greatly facilitated. His experiments proved suc-
cessful, and soon after the quick vinegar process was generally
adopted. Analogous processes were nearly at the same time
invented, in Germany by Wagmann, and in England by Ham.
The principle involved of course depends on an extreme
division of the liquid being effected. This is very skilfully
contrived. By making the alcoholic solution percolate slowly
through, and diffuse over, a mass of shavings, wooden blocks,
pieces of coal or cork, etc., it forms a very thin layer, present-
ing a large surface, and is therefore better adapted for the
chemical appropriation of the oxygen in the current of air
which is transmitted over it. The mass of shavings, etc.,
serves not only for the division of the liquid into fine drops,
but also as a carrier of the vinegar ferment.
It will be readily understood that this arrangement presents
in a high degree all the conditions required for the formation
of vinegar, the vinegar ferment upon the shavings acquiring
from the liquid all the substances required for its nutriment
and propagation, and by the current of air passing through
between the shavings is enabled to oxidize the alcohol to acetic
acid. This process taking place simultaneously on thousands
of points in a normally working generator explains why a
large quantity of alcohol can in a comparatively short time be
converted into acetic acid. The term quick process is hence
very appropriate for this method, it differing from the older
slow process only in less time being required for its execution,
the chemical processes being the same in both cases.
It will be seen that the generator, technically called "grad-
uator," used in the quick process may be compared to a fur-
40 MANUFACTURE OF VINEGAR.
nace in which the fuel (in this case the alcoholic fluid) is in-
troduced from above and the air from below. The spaces
between the shavings, etc., may be compared to the interstices
of a grate, combustion taking place on the points of contact of
the alcoholic fluid, vinegar ferment and air. The product of
(partial) combustion — the vinegar — collects in a reservoir in
the lower part of the generator.
Each generator, as previously stated, requires about 0.4 liter
of air per second, which must ascend uniformly from below
through the mass of shavings, etc. At the first glance this
would seem very simple, but its practical execution is accom-
panied by many difficulties, and hence a large number of vari-
ous constructions of generators have been proposed by which
this object is claimed to be best attained.
Generators — A peculiarly constructed vessel, called the gen-
erator, is required for the production of vinegar by the quick
process. It is divided into three spaces above one another,
the uppermost serving for the division of the alcoholic liquid
into many small drops ; in the center one, which forms the
largest part of the apparatus, the alcoholic liquid is converted
into vinegar, while the lower one serves for the collection of
the vinegar.
The best form of the generator is that of a truncated cone.
This form offers to the alcoholic liquid in its passage from the
upper part of the generator the opportunity of spreading over
a constantly increasing surface, and by thus coming in con-
tact with the fresh air entering the lower part of the apparatus
its oxidation must evidently be promoted. The current of air
in passing from below to above yields a certain portion of its
oxygen in the lower part of the apparatus, and if it were
allowed to ascend in a vessel of a purely cylindrical shape, the
alcoholic fluid running down would come in contact with air
quite poor in oxygen. Hence this evil must be sought to be
overcome by the acceleration of the motion of the air upwards,
which is accomplished by giving the vessel the form of a
slightly truncated cone.
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
41
Fig. 3 shows a common form of generator. It consists of
the wooden vat K provided with a perforated false bottom L
a few inches from the bottom, and another S, similar in struc-
ture, at the same distance from the top. The aperture A
serves for the discharge of the fluid collecting underneath the
false bottom L. The cover D, the arrangement of which will
be described later on, serves for regulating the drought of air
in the generator. In the lower part of the generator, holes, Or
are bored. These holes are intended for the entrance of air,
and in number may be as many as desired, since the regula-
tion of the current of air is not to be effected on the lower
portion of the apparatus, but on the cover.
For the construction of the generator wood thoroughly
seasoned and as free as possible from knots should be used.
Formerly oak was largely employed for the purpose but, be-
sides its being too expensive, it has the disadvantage of be-
42 MANUFACTURE OF VINEGAR.
ing so rich in extractive substances that a generator con-
structed of it, has to be several times lixiviated with water
before use, as otherwise the vinegar prepared in it would for
a long time acquire a disagreeable tang and dark color.
Larch is an excellent wood for the construction of generators.
In this country pitch pine is largely used, and is well adapted
for the purpose, as it is cheap and readily obtainable every-
where. It is claimed by some manufacturers that the pitch
pine protects fermentation in generators constructed of it from
the influence of rapid variations in temperature which are of
frequent occurrence in portions of this country.
The hoops of the generators, as well as all other metallic
parts in the factory, should be coated with good linseed-oil
varnish or asphaltum lacquer, and care should be had imme-
diately to repair any injury to this coating, as otherwise heavy
rusting is caused by the vapors of acetic acid contained in the
air of the work room.
There is considerable variation in the dimensions of the
generators, some having only a height of 5 feet, with a lower
diameter of 3 feet 3 inches, and others again a height of 20 feet
or more, with a diameter of up to 6J feet. The small gen-
erators have the disadvantage of rapidly yielding heat to the
exterior, and hence a correspondingly high temperature must
be maintained in the workroom in order to keep up the proper
degree of heat in their interior. On the other hand, generators
of considerable height have the drawback of the shavings,
etc., with which the center space is filled, becoming strongly
compressed by their own weight, thus obstructing the proper
passage of the air. It has been sought to overcome this evil
by placing several false perforated bottoms in the generator, in
order to divide the weight of the filling into as many smaller
weights as there are false bottoms. But this arrangement is
also attended with inconveniences, it being difficult to main-
tain a sufficiently strong draught of air in generators of such
height.
Some manufacturers hold that the production of very
QUICK PROCESS OF MANUFACTURE OF VINEGAR. 43
strong vinegar containing 11 to 12 per cent, of acetic acid is
only possible in very tall generators. This opinion is, how-
ever, unfounded, the manufacture of very strong vinegar being
just as well or rather better effected in small generators than
in those twenty feet or more high, which besides are very
expensive.
The manufacture of vinegar should be carried on in a room
with a low ceiling, since even with the best heating arrange-
ment the temperature near the ceiling is always much higher
than on the floor. However, with the use of generators 20
feet high, the ceiling of the work room must be at least 26
feet high, which makes it impossible to maintain a uniform
temperature, as the difference between the upper and lower
parts would frequently amount to more than 25°.
The most suitable generators are very likely those with a
height not exceeding 10 feet, and a lower diameter of about 45
inches and an upper one of about 35 inches. A large diameter,
to be sure, contributes towards the maintenance of a uniform
temperature in the generator, but it has the disadvantage of
making it difficult for the air to ascend uniformly through all
parts of the filling. This drawback is sought to be evercome.
by placing in the center of the generator a tube open above and
below and provided on the sides with holes. Such tube, how-
ever, does not produce the intended favorable effect upon the
draught of air in the parts of the filling surrounding it, expe-
rience having shown that the greater portion of the warm cur-
rent of air ascending in the interior takes the nearest road to
the top, i. e., through the tube, without passing sideways into
the filling. Every generator of suitable construction should be
provided with a well-fitting cover. In this cover, Fig. 4, are
bored, in concentric circles, holes which are intended for
draught apertures. If the draught of air in the interior is too
great, it can be at once diminished by closing a number of
these holes, it being even possible to direct it towards a cer-
tain portion of the filling. This arrangement is, however, only
available when the false bottom to be described later on is
44
MANUFACTURE OF VINEGAR.
either not used or provided with a number of short vertical
tubes which permit the passage of the air.
Many generators are provided with a number of obliquely
bored apertures below the false bottom through which the air
can escape. This is, however, attended with the disadvantage
that a regular draught of air only takes place in the outer layers
of filling next to the walls, while it is not sufficiently strong
in the center of the apparatus. It is also incorrect to have but
one air aperture in the cover, which can be made larger or
smaller by means of a slide. In a generator thus arranged, the
FIG. 4.
current of air entering below will naturally pass chiefly through
the conical portion of the filling, the base of which is formed
by the lower false bottom and the apex by the draught aper-
ture in the cover. The lower portion of the filling, which
embraces this cone, remains without sufficient ventilation and
is ineffective as regards the oxidation of alcohol.
In Figs. 5 and 6 the hatched surfaces terminated by the
dotted lines illustrate the portions of the generator in which,
with the use of many apertures below the false bottom and a
single one in the center of the cover, the. regular current of air
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
45
from below to above passes. Although a current of air takes
place outside of these lines, it is in most cases too weak, and
consequently the entire available space of the generator is not
sufficiently utilized.
FIG. 5.
FIG. 6.
m
Each generator may also be entirely open below and stand
in a shallow tub, which serves for the collection of the vinegar.
Generally, however, the lower portion of the generator itself is
used for this purpose, and is provided with an arrangement for
FIG. 7.
the occasional discharge of the collected fluid. This can be
effected either by a spigot fixed immediately above the bottom
or, as in Fig. 7, by a glass tube, which bends upwards nearly
as high as the air-holes and then curves downward so as to dis-
46
MANUFACTURE OF VINEGAR.
charge the liquid, when it rises as high as the shelf in the
interior of the apparatus, into an appropriate vessel placed to
receive it. Simple as this arrangement is, it is scarcely suit-
able in the practice on account of its being too liable to break-
age, and hence it is better to provide the generator with an
ordinary spigot, and prevent the vinegar from rising too high,
by boring about J inch below the draught apertures a hole
in which is fitted a pipe leading to a tub. The vinegar rising
to the height of this pipe will commence to run off, and thus
give warning to empty the generator by opening the spigot.
In generators of older construction a strong hoop is fixed
about one foot from the top, on which is placed a perforated
disk which serves for distributing the alcoholic fluid as uni-
formly as possible over the entire filling. The disk, Fig. 8, is
perforated with numerous holes (about 400 with a disk diam-
eter of 3 feet) arranged in concentric circles. These holes are
loosely filled with cotton wick or packthread, a knot being
made at the top end to keep them from falling through. The
threads reach down to the shavings, and serve the double
purpose of conducting the liquid equally through the body of
QUICK PROCESS OF MANUFACTURE OF VINEGAR. 47
the generator and also of stopping it from passing too rapidly
through it (see Fig. 9). It is important to pack the disk so
tightly against the walls of the generator that none of the
liquid can percolate, which is best effected by a packing of tow,
and coating this with a mixture of equal parts of wax and
rosin. The dripping of the alcoholic fluid through the disk
taking place uniformly only when the latter lies perfectly hori-
zontal, great care must be exercised in placing the generator.
To prevent warping several strong cross-pieces are inserted in
the lower side of the disk.
As previously mentioned the current of air must pass through
FIG. 9.
all portions of the filling, and for this purpose seven short glass
tubes, r (Fig. 8), about f inch in diameter, are inserted in the
disk. These tubes are so arranged that one is in the center of
the disk and the others in a circle equidistant from the center
and the periphery. Upon the disk is placed the well-fitting
cover, provided with an aperture for the passage of the air.
This aperture, about 3 inches square, is provided with a well-
fitting slide, so that it can be made larger or smaller at will.
As previously stated, it is more suitable to provide the cover
with a large number of draught holes arranged in concentric
circles and to fit each hole with a wooden stopper. By with-
drawing or inserting the stoppers the draught of air can then
be properly regulated.
To effect the influx of air from below in such a manner that
it takes place not only through the draught holes in the circum-
ference, but also assures its conveyance to the center of the
apparatus, it is recommended to insert in the center of the
lower part in which the fluid collects a tube, R, Fig. 10, open
48
MANUFACTURE OF VINEGAR.
at both ends and protected above by the hood H against the
dropping in of alcoholic liquid.
A uniform distribution of the alcoholic liquid upon all por-
tions of the filling of the apparatus would be effected if about
FIG. 10.
the same quantity of liquid dripped from all the threads. This
being, however, difficult to attain, it has been sought to give
the disk a more suitable arrangement, which consists, for in-
stance, in the insertion of small wooden tubes with a small
FIG. 11.
I
aperture on the side (Fig. 11). This arrangement, though
very suitable in itself, becomes, however, useless in case of the
slightest warping of the disk, a number of the tubes being
then raised so high that no fluid runs through them, while it
passes in a full stream through the others.
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
49
These drawbacks connected with the use of a disk can be
somewhat diminished by the employment of a so-called " tilt-
ing trough " (Figs. 12 and 13), which is arranged as follows : —
Upon a perfectly horizontal axis is placed a rotatory, trough-
like vessel divided by a partition into two equal parts.
If the tilting trough is in the position shown in Fig. 12, the
alcoholic liquid runs through the cock, placed above, into the
partition marked 1.
As soon as this partition is filled to a certain height it turns
ovef in consequence of the disturbance of the equilibrium of
the trough and assumes the position shown in Fig. 13. In
this position partition 2 is gradually filled with alcoholic
liquid ; the trough then tilts back into position 1, and so on.
FIG. 12.
FIG. 13.
It will be seen that with the assistance of such a tilting
trough the same quantities of liquid can always be poured out
at certain intervals, and that this arrangement can be used for
distributing the alcoholic liquid upon the disk, the latter in
this case being best provided with holes having the form of an
inverted cone. The apex of this cone forms a very narrow
aperture through which the alcoholic liquid poured upon the
disk trickles in very thin jets upon the filling of the generator.
But even this arrangement is not free from objections, it
working entirely satisfactorily only as long as the disk remains
in a perfectly horizontal position. In the more modern con- >
structions of vinegar generators the disk is generally entirely I
4
50
MANUFACTURE OF VINEGAR.
omitted and the distribution of the alcoholic liquor effected by
a so-called " sparger," similar to the one used in beer brewing
for sprinkling malt residues. The sparger is arranged like a
simple turbine, and is moved by reaction in the direction
opposite to that in which the discharge of the fluid takes place.
Spargers used in vinegar factories can be constructed only of a
material indifferent to the action of acetic acid, such as wood,
glass, hard rubber, etc. Their construction will be understood
FIG. 14.
from Figs. 14 and 15, showing a view from above and a cross-
section.
Into a hollow cylinder of wood are screwed four thin wooden
tubes, closed at both ends and perforated ^lengthwise with
numerous small holes. The tubes are so arranged that all the
holes are directed toward one side. The basin in the center is
closed on top by a glass tube about 20 inches long and of
sufficient width to allow of the passage of as much fluid as can
at one time run off through all the lateral tubes.
QUICK PROCESS OF MANUFACTURE OF VINEGAR.
51
The principal requisite of the correct working of the sparger
is that it revolves with ease around its vertical axis. This is
effected by placing in the center of the vessel a glass pin drawn
out to a fine point and running in a small glass step. The
FIG. 15.
vertical glass tube is guided in a sharp-edged wooden ring
fastened to a stay placed upon the cover of the generator (Fig.
16). The sparger finds its center of motion upon a strip in-
serted in the direction of the diameter of the generator. This
strip is placed at such a height that the sparger can move
FIG.
freely between it and the cover of the generator. The sparger
being in position as shown in Fig. 16, a funnel-shaped vessel,
through which the alcoholic fluid is poured in, is placed upon
the glass tube.
52 MANUFACTURE OF VINEGAR.
By now pouring through this funnel-shaped vessel the alco-
holic liquid in a sufficiently strong stream, so that during its
influx the glass tube remains filled, it passes in fine jets
through the lateral openings, and, the sparger revolving in an
opposite direction, is distributed in the form of a fine spray
over the filling in the generator.
The use of the sparger overcomes the difficulties frequently
occurring with the disk, especially as regards the position of
the latter, and the circulation of air through the apparatus also
takes place in a perfectly uniform manner. A number of
apertures in the cover of the generator serve also here for the
regulation of the current of air.
A thermometer is an indispensable adjunct to a generator,
and should be so placed that the temperature prevailing in the
apparatus, and especially in the center, can be readily read
off. This is best effected by introducing at about half the
height of the apparatus, through an obliquely bored hole in
one of the staves, a glass tube closed at the lower end and
reaching to the center of the filling. This tube serves for the
reception of a thermometer fastened to the lower end of a stick
of wood. The latter projects from the glass tube, so that the
thermometer can be quickly drawn out and the temperature
read off.
Filling the generators. — The space between the upper disk
and lower false bottom is filled with a material offering a large
surface for the distribution of the alcoholic liquid. Pieces of
charcoal and of pumice washed in hydrochloric acid and well
rinsed in water to remove empyreurnatic substances, which
would render induction of acetic fermentation impossible,
have been used for the purpose. Small pieces of cork and
cork waste have also been recommended for filling. This
material absorbs liquids like a sponge, but when sucked full
does not press evenly together, dry places being thus formed
during the operation. Corn cobs thoroughly dried and finely
divided may be used to advantage, especially in the manufac-
ture of wine and cider vinegar. Grape stems are still occa-
QUJCK PROCESS OF MANUFACTURE OF VINEGAR. 53
sionally used. They actually present a very large surface
but, independent of the fact that they cannot be everywhere
obtained in sufficient quantities, they have the drawback of
becoming in a short time so firmly compressed as to prevent
the free passage of air.
Beechwood shavings, however, are now almost generally em-
ployed for filling the generators. Indeed, beechwood presents
many advantages: It can be had easily and is cheap; it curls
well and stands without breaking for a length of time. White
woods will curl as well, but they will not stand so well as
beech ; resinous woods are not porous enough, and besides
their rosin is objectionable, as it may partly dissolve in the
vinegar ; oak wood does not curl as well and contains too
much coloring matter and tannin.
The beech shavings are generally made in special factories.
They consist of wooden bands about 0.02 inch thick, 1 J inches
wide, and 16 to 20 inches long. They are rolled into close
spirals by a special machine, and each shaving, according to
the above dimensions, presents a surface of about 62 square
inches. Now, as a generator of moderate size contains many
thousands of such shavings, it will be readily seen that the
surface over which the alcoholic fluid is distributed is an
extraordinarly large one.
A shaving of the stated dimensions represents in a rolled
state a cylinder with a volume in round numbers of 1.7 cubic
inches. By allowing an interspace of .85 cubic inch between
the shavings, 1.7 -f- 0.85 = 1.92 cubic inches space is required
for each shaving. The space to be filled with shavings in a
generator 3.28 feet in diameter and 6.56 feet high is equal to
55.44 cubic feet, and hence 58,000 shavings, with a total sur-
face of 22,733.56 square feet, are required for the purpose.
Now suppose only 5 per cent, of this surface is continually
active in the formation of vinegar, we have still a surface of
over 1075 square feet at our disposal. But the active surface
would seem to be actually much smaller even with the most
favorable working of the generator, as otherwise the average
54 MANUFACTURE OF VINEGAR.
quantity of alcohol daily converted into acetic acid in a gen-
erator would be much larger than is actually the case.
Beechwood shavings contain a considerable quantity of ex-
tractive substances, which if not removed, would for a long
time impart a disagreeable tang (woody taste) to the vinegar.
Hence it is recommended to lixiviate the shavings in water
repeatedly renewed, in order to get rid of the substances
soluble in cold water, and remove the last traces of them by
treatment with steam.
This steaming is best effected in a large tub or vat, which is
later on to be used as a generator. The shavings are thrown
in loosely and covered with a loaded lid. A steam-pipe is
introduced through a hole near the lid, and the tap-hole near
the bottom is opened. The steam-pipe being connected with a
boiler, in which prevails a tension of 1J to 2 atmospheres, the
steam-cock is at first opened but slightly, to prevent the steam
entering with great force from throwing off the lid, or even
bursting the vessel. In the commencement of the operation
the steam condenses on the shavings, but after some time the
vessel becomes very hot, and a dark-colored fluid, consisting
of almost boiling water charged with extractive substances of
the wood, begins to run off. After continuous steaming for
about 20 to 60 minutes — according to the size of the vessel —
the fluid running off becomes clearer until finally clear water
is discharged, which is indicative of the removal of the
extractive substances soluble in water.
Although not absolutely necessary, it is advisable to dry the
steamed shavings. When air-dry they still contain about 20
per cent, of water, which in the subsequent " acetification " of
the generator must be replaced by vinegar. Hence it is
recommended to dry the shavings completely by exposing
them for some time to a current of air of 194° to 212° F.
In a factory provided with a central heating apparatus * in
the cellar, this drying of the shavings can be effected without
*The arrangement of a central heating apparatus will be described later on in
speaking of the arrangement of the factory.
QUICK PROCESS OF MANUFACTURE OF VINEGAR. 55
difficulty, it only being necessary to put them in a vessel with
a perforated bottom and open on top, and place the vessel
over an aperture of the register through which the hot air
from the heating apparatus ascends, closing all other apertures.
As perfectly dry wood absorbs with avidity moisture from
the atmosphere, the shavings thus dried should immediately
be brought into another vessel and, while still hot, moistened
with the vinegar intended for acetification.
Before using the shavings for filling the generators, it is
necessary to allow them to swell by placing them in water or
alcoholic liquid. If this were omitted and the shavings in-
troduced in a dry state, they would rise above the generators
as soon as moistened, on account of the increase in volume
by swelling.
In most factories it is customary simply to pour the shav-
ings into the generator, but for a uniform distribution of the
alcoholic fluid it is advisable to proceed with the filling in a
certain order. First place the shavings in three or four regu-
lar layers upon the false bottom, then pour them in loosely to
a height of 8 to 12 inches, and after leveling the surface as
much as possible pour in again, and continue in this manner
until the generator is filled. The uppermost portion should
again consist of three or four regular layers.
All the generators used in a vinegar factory should be of
the same size and charged with the same number of shavings,
which is best effected by filling them with the same quantity
by weight. The total surface of shavings being thus nearly the
same in all generators, the latter will work uniformly, i. e., with
an equal temperature and draught of air; and in the same time
convert equally large quantities of alcohol into acetic acid.
56 MANUFACTURE OF VINEGAR.
CHAPTER VII.
ARRANGEMENT OF A VINEGAR FACTORY.
THE arrangement of the manufacturing rooms formerly cus-
tomary even in large factories is by no means a suitable one.
The generators were generally simply placed in a room adapted
for the purpose by its size, while the high temperature re-
quired was sought to be maintained by heating. By con-
sidering, however, that every considerable variation in the
temperature causes also a disturbance in the formation of
vinegar, it will be seen that the object of keeping up an undis-
turbed working of the factory cannot be attained by such
primitive means. A suitable arrangement of the room in
which the vinegar is to be manufactured is, therefore, abso-
lutely necessary.
The principal requisites to be observed are : The mainten-
ance of a uniform temperature in the room and a suitable
arrangement for ventilation. Further, simple devices for the
conveyance of the raw materials and the finished product
must be provided for, and means devised for regaining the
acetic acid, with the vapors of which the air in the manufac-
turing room is constantly saturated.
For the maintenance of a uniform temperature in the work-
room, which should remain almost constant even in the cold-
est season of the year and during abrupt changes in the outer
temperature, the waljs should be of more than ordinary thick-
ness and the number of windows and doors sufficient only for
the necessary light and communication, and so arranged that
no unintentional ventilation can occur. The windows and
doors should, therefore, be double, and the latter so placed
that one can be closed without opening the other. The walls
and ceilings should be plastered and preferably papered with
heavy packing paper ; asbestus shingles are also highly recom-
mended for this purpose.
ARRANGEMENT OF A VINEGAR FACTORY. 57
Asphaltum being impermeable and also indifferent to the
action of acetic acid, is undoubtedly the best material for the
floor of the workroom, though it may also be constructed of
large slabs of sandstone with the joints filled in with asphal-
tum. Cement floors can only be recommended provided they
are immediately after their construction coated with silicate of
soda until they cease to absorb it. In constructing the floor
care must be had to give it such an inclination that the entire
surface can be cleansed by a simple jet of water. If the heat-
ing channel is conducted lengthwise through the workroom,
gutters for the rinsing water to run off must be arranged on
both sides.
The height of the room depends on that of the generators.
Heating of the Workroom — Heating by a stove placed in the
workroom itself can only be recommended for very small fac-
tories ; in larger ones a special heating apparatus should always
be provided. Where stoves are used it is recommended to
arrange them so that the fuel can be supplied and the ashes
removed from the outside, i. e., from a room adjoining the
actual workroom. In attending to the stoves fine particles of
ashes will unavoidably reach the air, and from the latter they
may get into the generators, and being soluble in acetic acid
may injure the vinegar ferment.
For large factories a heating apparatus similar to the one
shown in Figs. 17 and 18 can be recommended. The heater,
provided with the feeding-door H and the air-regulating door
A, stands in a vault beneath the center of the room to be
heated. It is surrounded on all sides by the sheet-iron jacket
Mt reaching from the floor of the cellar to the top of the vault.
In the vault is a circular aperture, 0, for the reception of the
flues C and Ci. The latter ascending slightly, run along the
center of the room to be heated. Above they are covered by
cast-iron plates, P, and by pushing these plates apart or sub-
stituting a lattice plate for one of them in any part of the flue,
warm air can be admitted to the room. If the room is to be
heated without renewing the air, the register in the flue L,
OO MANUFACTURE OF VINEGAR.
which communicates by a flat iron pipe with the lower part of
the jacket, is opened. The furnace being heated, the air in the
room is sucked in the direction of the arrow through 'the flue
L, and passing between the jacket and the furnace, ascends
strongly heated through 0 and penetrates through the open-
ings in the flue, air being again sucked through L, and so on.
FIGS. 17, 18.
If, however, the air in the workroom is to be entirely re-
newed, the air-flue L is closed and a register (not shown in
the illustration) in the lower part of the jacket opened. In
this case the air in the cellar is sucked in, heated and distrib-
uted through the flues C and Cj. By partially opening this
ARRANGEMENT OF A VINEGAR FACTORY.
59
FJG. 19.
register and that in L, a portion of the air can be renewed at
will.
In order to be able to form a correct idea of the state of the
temperature prevailing in the room, it is
advisable to have several ordinary thermom-
eters and also a maximum and minimum
thermometer. If the latter shows no greater
variation than from 4° to 5°, the process of
heating may be considered as satisfactory.
A very suitable apparatus for controlling
the temperature in a vinegar factory is an
electrical thermometer, which is so arranged
that a bell rings in case the temperature
rises above or falls below a certain degree.
By placing two such thermometers in the
room, the bell of the one indicates the rise
of the temperature above the limit, and that
of the other that it has fallen below it.
Fig. 19 illustrates the principle of a maxi-
mum electrical thermometer, i. e., one which
rings a bell when the temperature of the
room exceeds a certain limit. Into the bulb
of an ordinary mercury thermometer is
melted a platinum wire ; another platinum
wire. is inserted in the tube up to the mark
indicating the temperature not to be ex-
ceeded, for instance, 35° C. The ends of
the platinum wires projecting from the ther-
mometer are connected by insulated copper
wires with a galvanic battery consisting of several elements,
an ordinary door-bell being inserted in one part of the con-
ductor. If now, in consequence of a continued increase in the
temperature, the mercury rises to the point of the platinum
wire at the figure 35°, the circuit of the battery is closed at
the same time by the column of mercury, and the bell rings
and keeps ringing until the circuit is again opened by the
mercury falling below 35°.
45
-20
— 15
60 • MANUFACTURE OP VINEGAR.
The minimum electrical thermometer, used for indicating
the falling of the temperature below a certain degree, is so
arranged that one platinum wire is melted into the bulb of the
thermometer and the other in the tube at the point below
which the temperature is not to fall. As long as the mercury
remains above this point a battery, which changes a piece of
iron to an electro-magnet, whose armature opens a second bat-
tery which is connected with an electric bell, remains closed.
If the temperature falls below the minimum, the circuit of
the first battery is opened, and the armature of the electro-
magnet falling down effects the closing of the second battery
and sets the bell ringing.
By placing such thermometers not only in the working
room but also in every generator, the control of the entire
process would be immensely facilitated, but at the present
time these useful and at the same time inexpensive instru-
ments are but little used in vinegar factories.
In factories arranged according to the automatic system, the
alcoholic liquid is contained in vessels placed at such a level
that their contents can run directly into the generators. The
alcoholic liquid having to be correspondingly heated, adequate
provision must be made for heating the space in which the
reservoirs are placed. In order not to increase the height ot
the entire room, it is recommended to place these vessels in
the center and give only to this portion the required height.
This has the further advantage that the alcoholic liquid can
be pumped up by the use of a pump with a short rising-pipe,
and the liquid can be readily conducted from the reservoirs
to the separate generators by means of pipes.
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 61
CHAPTER VIII.
ARTIFICIAL VENTILATION OF THE VINEGAR GENERATORS.
THE first experiments in conveying direct air to every gen-
erator were made in England ; but though this step towards
improvement in making vinegar must be considered an
important advance, the English process failed of being ac-
cepted in practice on account of the inadequacy of the
apparatus used.
In the English factories by a special apparatus a current of
air was sucked from above to below through every generator.
As shown in Fig. 20, the tall generator is open on top and
divided into several partitions by false bottoms, upon which the
shavings, etc., rest. Above each false bottom holes are bored
in the circumference of the generator. In the bottom of the
generator is inserted a pipe which is connected with an
arrangement for sucking in the air, a blower or air-pump
being used for the purpose.
As will be seen from the illustration, the suction of air
through all parts of the generator cannot be uniformly effected
by the use of this apparatus, the current of air being much more
checked in the upper portions by the false bottoms and holes
in the circumference, than in the lower. Hence the effect of
the air-pump or blower will chiefly assert itself in the lowest
partition. This drawback might be remedied by leaving out
the false bottoms and placing no air-holes in the circumference
of the generator entirely open at the top. By this means the
air would be forced to pass in a uniform current through the
entire layer of the filling material.
That the passage of the current .of air from above to below
is entirely incorrect, because contrary to all theoretical require-
ments, can readily be explained: In a generator in full activity,
oxidation of alcohol must already take place in the uppermost
portion, and hence a certain quantity of oxygen is withdrawn
62
MANUFACTURE OF VINEGAR.
FIG. 20.
from the air. This process being also continued in the lower
parts of the generator, a current of air already deprived of a
portion of its oxygen, and hence less suitable for the further
formation of acetic acid, would be
sucked in the same direction which
the drops of alcohol take.
The principal reason advanced
for the use of a current of air from
above to below is that by these
means a uniform temperature is
maintained in all parts of the gen-
erators, while it rises considerably
in the upper part of those in which
the air passes from below to above.
This rise of temperature is, however,
agreeable to nature. The air enter-
ing from below oxidizes the alcohol
to acetic acid, becoming thereby
poorer in oxygen and again heated.
By the higher temperature it ac-
quires, it is, however, capable of a
more vigorous chemical activity, so
that it will induce the process of the
formation of vinegar, even in the
uppermost portions of the genera-
tor. Besides, the warmer current
of air moving upwards has the fur-
ther advantage of yielding heat to
the drops of alcoholic fluid trickling down. With the use of
generators of moderate height, and with a suitable regulation
of the draught of air, the maximum temperature will not be
exceeded, even in the uppermost portions of the generator.
If no rise of temperature is observed in the lower portions
of a generator in which the air passes from above to below, it
only proves that the air has lost too much oxygen to further
effect a vigorous oxidation of the alcohol. It will be readily
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 68
understood that under these conditions a diminution in the
loss of substance can, to a certain degree, be effected, but it i&
doubtful whether the generators are utilized in the manner
they should be ; besides, the diminution in loss of substance
cannot be very considerable. Since a high temperature also
prevails in ventilated generators, the current of air passing
downward will be loaded with as much vapor of alcohol or of
acetic acid as it can absorb at this temperature, and, hence, it
would seem, no diminution in loss by evaporation could be
effected. To render this possible, the current of air sucked
from the generator would have to be sufficiently cooled off by
a suitable arrangement to allow of the greater portion of the
vapors carried away by the current of air being condensed to
a fluid.
Schulze's Ventilating Apparatus. — The ventilation of the vine-
gar generators, according to the previously described method,
requires the presence of an uninterruptedly acting power for
working the air-pump, blower, etc. As is well known, a cur-
rent of air can, however, be also produced by heating the air
passing through an ascending pipe, by which it becomes
specifically lighter and ascends, while denser air enters from
below, etc. Schulze, as will be seen from Fig. 21, has applied
this method to the ventilation of vinegar generators.
Schulze's generator differs somewhat from the ordinary con-
struction, and is arranged as follows : The vat has a height of
about 8 feet, and a diameter of 2 feet 6 inches. In the upper
part it is terminated by a false head, fitting air-tight, and is
further provided with a cover, in the center of which is an
aperture about 2J inches in diameter, which serves for the
entrance of air, while another aperture on the side serves for
pouring in the alcoholic liquid. In the false head are in-
serted four glass tubes, open at both ends, and about f inch in
diameter, which afford a passage to the air. The generator is
filled with pieces of washed and assorted charcoal, so that
pieces of the size of a nut are placed upon the false bottom,
and upon this smaller pieces, gradually decreasing in size
64
MANUFACTURE OF VINEGAR.
until those on the top are only that of a pea. In the center
of the bottom is inserted a wooden tube, open at both ends
and provided on top with a hood to prevent the trickling in
of vinegar (see Fig. 10). By a suitable intermediate piece,
this tube is connected with the draught-pipe (see Fig. 21), in
which the ascension of the air by heating is effected.
The draught-pipes are of cast-iron, and are about J inch
thick and about 4 \ feet long, with a clear diameter of 2 inches.
FIG. 21.
They are placed, strongly inclined, over the flues of a heating-
apparatus and covered above by a double course of stone. The
air in the iron draught-pipes, being heated by the escaping
gases of combustion, ascends and effects the passage of a cur-
rent of air from above to below in the generators. For keep-
ing up a constant ventilation it is claimed to be sufficient to
heat the furnace only once a day. With this construction it
is necessary to have as many draught-pipes as there are gener-
ators. The same effect might, however, also be attained by
connecting the pipes leading from several generators with a
draught-pipe of a somewhat greater diameter and length.
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 65
It is not difficult to prove that a uniform ventilation of the
generators cannot be obtained by the use of this construction.
As long as the draught-pipes are strongly heated, a very rapid
current of air will pass through them and the generators con-
nected with them, which will, however, decrease in the same
degree as the pipes cool off. Hence, in the first case, a too
rapid current of air, accompanied by a correspondingly strong
evaporation of alcohol, would pass through the generators, and
in the latter, ventilation would be so sluggish that the process
of the formation of vinegar would not proceed in a normal
manner.
Generators with Constant Ventilation and Condensation. — The
object to be attained by the use of special ventilating contriv-
ances is a double one : To conduct a constant current of air
through the generators, and, further, not to allow the tem-
perature to rise above a certain limit, so as to decrease by
these means the loss by evaporation of alcohol and acetic acid.
This object can, however, be attained only by the use of an
apparatus which allows of the most accurate regulation of the
current of air passing through the generator, and is connected
with a contrivance by which the vapors of alcohol and acetic
acid carried along by the current of air can be condensed as
much as possible. The apparatus described below is well
adapted for the purpose. Its principal parts consist of the
generator, the apparatus for condensing the vapors, and the
ventilator.
The construction of the lower part of the generator, Fig. 22,
is the same as of those previously described. The cover fits
tightly upon the upper edge of the vat, the joint being made
air-tight by strips of paper pasted over it. In the center of
the cover is a square aperture, from which rises a quadrang-
ular pyramid, P, constructed of boards, upon which sits a low
prism, A. The sparger D has its center of motion upon the
strip L, placed in the uppermost portion of the generator, and
is guided above in the short strip Lv which carries the sharp-
edged ring described on page 51. E is the glass tube through
5
66
MANUFACTURE OF VINEGAR.
which the alcoholic liquid flows into the funnel of the sparger.
On the point where the pyramid passes into the prism A, is a
bottom provided with a circular aperture, 0, 2J to 3 inches in
diameter. Upon the top of the prism A is placed a nut, in
which runs a wooden screw, provided on the lower end with
a wooden disk, S, of a somewhat greater diameter than the
aperture 0. By raising or lowering this screw, the aperture
0 can be closed more or less or entirely, and thus the strength
of the current of air regulated at will in every generator. The
prisms A of all the generators are connected with each other
by the conduit R, constructed of boards.
FIG. 22.
FIG. 23.
This conduit R is connected — best in the center between
an equally large number of generators — with the condensing
apparatus, the chief feature of which is a worm similar to
that used in a still. Fig. 24 shows the apparatus in cross-
section.
In a sheet-iron vessel of the same height as the generator is
placed another vessel, so that there is a distance of about 5}
inches between the walls. From a reservoir situated at a
higher level cold water runs into the apparatus through the
pipe K, and off through the short pipe W. In the space be-
tween the walls of the two vessels lies a tin coil with very thin
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 67
walls and a diameter of at least 2J inches. On top this tin
coil is connected with the wooden tube R (Fig. 23) and below
with the iron pipe R±, which leads to the ventilating appa-
ratus. C is a glass tube about 16 inches long and J to f inch
FIG. 24.
in diameter, which reaches nearly to the bottom of the flask
half filled with water.
The ventilating apparatus consists of an ordinary self-feeding
stove, but its jacket is closed below so that air can only pass in
between the heating cylinder and the jacket through the pipe
Rl coming from the condensing apparatus.
The apparatus works as follows : According as combustion
in the stove proceeds slowly or quickly by the corresponding
position of the regulating register, the air between the heating
68 MANUFACTURE OF VINEGAR.
cylinder and the jacket becomes less or more heated and as-
cends with corresponding velocity. But as the further entrance
of air can take place only through the pipe Rly the tin coil, and
the wooden tube R, a uniform current of air from below to
above must pass through all the generators. To regulate the
strength of the current for each generator, it is only necessary
to close the aperture 0 (Fig. 22) more or less by raising or
lowering the screw.
The current of air passing from the wooden tube R into the
tin coil carries with it the total amount of evaporated alcohol
or acetic acid. By passing through the tin coil, which is cooled
by the water, the air itself becomes cooled off, and the greater
portion of the vapors held by it condense to liquid and run off
through the tube C into the bottle. The fluid thus obtained
consists chiefly of alcohol, water, and acetic acid, and is again
used for the preparation of alcoholic liquid. On account of the
peculiar form of the cooling vessel but little water is required
for feeding it. As the quantity of vapor separated from the air
will, however, be the greater the more energetically the tin coil
is cooled off, it is recommended to reduce the temperature of
the water to nearly 32° F. by throwing in pieces of ice.
It has been proposed to regain the vapors by conducting the
air containing them into a large vessel in which water in the
form of a fine spray trickles down or is injected. It is, of
course, possible in this manner to condense the greater portion
of vapors of a higher temperature and tension, but with vapors
of at the utmost 95° F. little success would be attained. The
greater portion of the vapors remaining uncondensed, a very
large quantity of fluid containing but little alcohol would be
obtained in the course of a day, and this fluid could at the best
be used only instead of water for the preparation of alcoholic
liquid. The value of the material thus regained would not
cover the working expenses of the apparatus. By working,
however, with the condensing apparatus described above, the
condensed alcohol does not even contain the total quantity of
water evaporated with it, and it need only be compounded
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 69
with the corresponding quantity of water and vinegar again
to yield alcoholic liquid.
The generator manufactured by Singer, of Berlin, shows an
essential difference in construction from those previously de-
scribed. It consists of several shallow wooden vessels arranged
one above the other and connected with each other by wooden
FIG. 25.
tubes so that the alcoholic fluid runs drop by drop from one
vessel into the other, passing thereby through the tubes. In
order to distribute the fluid as much as possible, the tubes are
inside provided with horizontal gutters, whereby the surface of
the fluid passing through is greatly increased. In addition,
70
MANUFACTURE OF VINEGAR.
FIG. 26.
each of the tubes is provided in the center with a slit running
length-wise, allowing of a free passage of the air. The latter
encounters in the tubes the finely-divided fluid and effects the
oxidation of the alcohol to vinegar. This is repeated four
times and oftener before the alcoholic fluid has passed through
the apparatus, whereby, it is claimed, a very complete forma-
tion of vinegar is attained. The entire apparatus stands in a
case which protects it from cooling off and from too great an
access of air, and which can be heated in winter.
Fig. 25 shows Singer's generator in cross section, and Fig.
26 the separate vessels and their connection by drip tubes.
Fig. 25 represents five shallow vats standing one above the
other, at uniform distances, the
latter being effected by elongated
staves.
In the bottoms of the vats A
and A1 are inserted 37 tubes, a, b,
by which they are connected with
the vats B and B1 below. The
bottoms of the latter are provided
only with 32 tubes, which above
connect the vat B with A1 and
below pass into the vat C.
As will be seen from Fig. 26,
the sections of the tubes through
which the alcoholic fluid is to run
slowly are provided above with
six annular gutters. Above these
gutters are four apertures for the
entrance of the alcoholic fluid. In the center the tubes are
slit lengthwise for the free admission of air. The lower end of
each tube is also provided with two gutters. On top each tube
is closed with a lid, but the end entering the vat below is open.
Of all the five vats only the upper one, A, is provided with
a cover, and upon the latter is fixed a holder, /, for securing
the tube g. Above, the latter is connected with the reservoir
ARTIFICIAL VENTILATION OF VINEGAR GENERATORS. 71
E, filled with alcoholic fluid and below ends in the short pipe
h, which permits the alcoholic fluid to run into the upper vat
A. In addition to the drip-tubes, every two vats standing one
above the other are connected with a knee. , The upper one
of these knees i issues from the bottom of the vat A and enters
the vat B close to the bottom. The second tube connects in
the same manner, B with J.1, the third, A1 with B1, and
lowest one, B1 with C. Each of these tubes is provided with
a cock to allow of the separate vats being connected or discon-
nected at will. The lowest vat, (7, is provided with two dis-
charge pipes, one, i, at the bottom, and the other, k, about 1J
inches higher up.
The five vats rest upon the reservoir, D, which serves for
the reception of the total quantity of alcoholic liquid which
has passed through the apparatus. It is provided with the
opening, #, which is connected by a rubber tube with the
cock, J, on C. In addition, D, is provided with a glass gauge,
PJ which by turning it downward, serves for discharging the
fluid from D.
The case enclosing the apparatus is constructed of wood and
glass, the rubber tube, g, passing through the roof of the reser-
voir E, holding the alcoholic fluid. On top the roof is pro-
vided with a trap, m, which can be opened and closed at will
by means of a rope. Below the case is provided with slides
n n. By opening the slides and the trap, the admission of air
can be regulated.
In the commencement of the operation the cock on E is
opened and the alcoholic fluid is allowed to run through the
tube g, and the short pipe h, until it stands 1 J to 2J inches
deep over the drip-tubes. The cock on the pipe i is then
closed. The alcoholic fluid now penetrates into the drip-tubes,
and runs through them into B, which is soon filled so far that
the openings of the drip-tubes are reached by the level of
the fluid. As the admission of alcoholic fluid continues un-
interruptedly, one vat after another is filled, and the alcoholic
fluid is in the separate drip tubes distributed over a compara-
72 MANUFACTURE OF VINEGAR.
tively very large surface, being at the same time brought in
intimate contact with fresh air.
The admission of alcoholic fluid can readily be regulated,
so that on reaching the lowest vat it is converted into vinegar.
When the apparatus is once in operation, the formation of
vinegar progresses without interruption, it being only neces-
sary regularly to fill the reservoir with fresh alcoholic fluid,
and to draw off the finished vinegar into barrels. If for some
reason the operation is to be interrupted, the alcoholic fluid
still contained in the vats is drawn off through the respective
knees, and the apparatus is filled with water to prevent dry-
ing out. When manufacture is to be recommenced, the water
is drawn off, and alcoholic fluid admitted.
It is doubtful whether this apparatus possesses advantages
over the ordinary generator, since the surface over which
the alcoholic fluid is distributed is much smaller than in gen-
erators filled with shavings.
Michaelis' revolving generator consists essentially of a strong
barrel, 3 feet 3 inches in diameter at the widest point, and a
space of 3 feet 3 inches between the two bottoms. The barrel
rests horizontally upon two supports, so that it can be rolled to
and fro upon them. The interior of the barrel is divided by a
horizontal lath-grating into two partitions, .the upper smaller
one being filled with shavings. Below the lath-grating in the
bottom of the barrel is a horizontal tube for the admission of
air, and above in the side of the barrel a cock for its escape.
The alcoholic fluid is poured in close to the lath-grating by
means of a funnel, the air-cock is closed and the barrel re-
volved to allow of the shavings to become thoroughly saturated
with the alcoholic liquid. In about 15 minutes the barrel is
brought back to its original position, and the air-cock opened.
The commencement of the formation of vinegar will soon be
recognized by the increase of temperature in the shavings,
and the operation is then in full progress.
For the constant continuation of the formation of vinegar, it
is only necessary to revolve the barrel for a few moments sev-
AUTOMATIC VINEGAR APPARATUS. 73
eral times a day to saturate the shavings with the alcoholic
fluid. The progress of the formation of vinegar is shown by
a thermometer placed in the bottom of the upper space, the
lowering of the temperature indicating the completion of the
process.
The apparatus is cleaned by rinsing the shavings, without
taking them from the barrel, with hot water, and filling the
barrel with strong vinegar, which is drawn off in 24 hours.
The advantages of this generator consist, according to the
inventor, in cheapness of first cost, simple operation, larger
yield, saving of alcohol, and better quality of the product.
CHAPTER IX.
AUTOMATIC VINEGAR APPARATUS.
THE principal work to be performed in a vinegar factory
consists in pouring at stated intervals the alcoholic fluid into
the generators. In a large factory several workmen are con-
stantly engaged in this work, and losses by spilling are un-
avoidable. Further, it is almost next to impossible always to
pour in the same quantity at exactly the same intervals, and
sometimes a generator may even be entirely overlooked, and
thus remain inactive until the next supply of alcoholic liquid
is poured in.
The greatest disadvantage is, however, the interruption for
several hours daily, of the formation of vinegar in all the gen-
erators, so that, for instance, in a factory working 16 hours a
day, one-third of the time is lost. Independently of the small
return on the capital invested, these interruptions are accom-
panied by many other conditions injurious to the regular run-
ning of the factory.
The greatest of these evils is that with the cessation of the
supply of alcoholic fluid the propagation of the vinegar fer-
74 MANUFACTURE OF VINEGAR.
ment diminishes and finally ceases altogether. Further, the
development of heat in the interior of the apparatus at the
same time ceases and the temperature is reduced several de-
grees, this phenomenon appearing even in factories provided
with the best heating apparatus and keeping up a constant
temperature in the workroom during the night.
In the morning when work is resumed, it is in most cases
necessary to vigorously air the apparatus by opening all the
•draught holes, in order to gradually restore the temperature
to the required degree, and it will be some time before the
apparatus again works in a normal manner.
The vinegar ferment, however, is very sensitive to changes
of temperature, as well as to the concentration of the nourish-
ing substances surrounding it, and there can be no doubt that
its propagation is prejudiced by the continuous variations of
temperature to which it is exposed during the interruptions of
several hours a day. That such is actually the case is shown
by the fact that the quantity of vinegar ferment formed in the
generators is small as compared with that which, under con-
ditions favorable to the ferment, forms in a short time upon
alcoholic liquids.
Besides the debilitation of the vinegar ferment and the con-
sequent disturbance in the regular working of the factory, the
repeated reduction of the temperature in the generators has the
further disadvantage that, besides the vinegar ferment, other fer-
ments for whose development a low temperature is more favor-
able may be formed, and these ferments may increase to such
an extent as to entirely suppress the vinegar ferment. There
can scarcely be a doubt that the many apparently inexplicable
disturbances in the working of the generators, such as their
remaining cool notwithstanding an increased current of air,
the vinegar becoming suddenly weaker, or the entire cessation
of its formation, find their easy explanation in the daily
interruptions lasting for hours in the regular working of the
factory.
Besides the increase in the capacity of the factory, disturb-
AUTOMATIC VINEGAR APPARATUS. 75
ances are, therefore, less likely to occur where the work is
carried on uninterruptedly, but in order to do this there must
also be a corresponding increase in the number of workmen
employed in pouring alcoholic liquid into the generators.
By the use of simple automatic contrivances for the regular
pouring out of the alcoholic liquid, the number of workmen
employed in a vinegar factory can, however, be reduced to the
attendance required for looking after the heating apparatus,
raising the alcoholic liquid to a certain height, and an occa-
sional control of the temperature in the interior of the genera-
tors. A factor}^ thus arranged requires but little attendance,
as when once in good working order it may be left to itself for
many hours without the occurrence of any disturbance.
According to the characteristics which distinguish the differ-
ent constructions of continuously working apparatus from each
other, they may be divided into two principal systems, viz.,
into those with an uninterrupted, and those with a periodical,
pouring out of the alcoholic liquid, but in either case the latter
has to be brought into a reservoir placed at a certain height
above the generators.
CONTINUOUSLY ACTING APPARATUS.
The Terrace System. — The alcoholic liquid, as is well known,
cannot be converted into finished vinegar by passing once
through the generator, a repeated pouring into several, gen-
erally three, different generators being required. To avoid
the necessity of raising the alcoholic liquid three times, three
rows of generators have been arranged one above another, so
that" the alcoholic liquid coming from a reservoir placed at a
higher level flows first into the uppermost generator, and pass-
ing through this, runs directly into the second, and from
there into the third, which it leaves as finished vinegar. Fig.
27 shows a vinegar factory arranged according to this system,
/. II, III, representing the three rows of generators placed one
above another, V1 the reservoir for the alcoholic liquid, P the
arrangement for pumping the alcoholic liquid into the reser-
76
MANUFACTURE OF VINEGAR.
voir, V the distributing vessel for the alcoholic liquid, 8 the
collecting vessel for the finished vinegar, .fiTthe heating appa-
ratus for the entire establishment.
For a uniform supply of alcoholic liquid to the generators
FIG. 27.
standing on the same level a conduit, L, from which the alco-
holic liquid flows into each generator, runs above the upper-
most row. Another conduit, Ll, common to all the genera-
tors, serves for the reception of fluid (finished vinegar) running
off from the lowest row, and conducts it to the collecting ves-
AUTOMATIC VINEGAR APPARATUS. 77
sel, S. The arrows indicate the course the alcoholic liquid
has to traverse.
From all appearances the arrangement of a factory according
to the above-described system would be most advisable, there
being actually nothing to do but to raise the alcoholic liquid
once and to remove the finished vinegar from the collecting
vessel. In practice, however, this so-called terrace system pre-
sents many difficulties not easily overcome, the greatest un-
doubtedly being the solution of the heating problem. Experi-
ence shows that the temperature in a generator must be the
higher the more acetic acid the alcoholic liquid contains.
According to this, the highest temperature should prevail in
the lowest series of generators (///, Fig. 27) and the lowest in
the uppermost (/).
But in practice just the reverse is the case even with the
use of the best heating apparatus, the highest temperature
prevailing in I and the lowest in III, as, according to natural
law, the warm air being specifically lighter than the cold
constantly strives to ascend.
To overcome this drawback nothing can be done but to place
the series J, // and III of the generators in as many different
stories entirely separated from each other, or, in case there is a
central heating apparatus in the cellar, to correctly distribute
the warm air in the separate stories by suitably arranged reg-
isters. The solution of this problem offers no insuperable
difficulties, but requires the arrangement of the entire factory
to be carefully planned in accordance with the laws of physics.
An unavoidable drawback of the terrace system is the cost-
liness of the factory building, and, finally, that a disturbance
occurring in one of the generators must simultaneously affect
two others of the vertical series, which must necessarily remain
idle until the disturbance is removed. Considering all the
disadvantages connected with the terrace system, though it is
seemingly so suitable, it is but little adapted to practice, it
being much preferable to place all the generators on the same
level and to divide them into three groups, each of which is
78 MANUFACTURE OF VINEGAR.
provided with a reservoir for the alcoholic liquid and a col-
lecting vessel.
The mode of working according to this system is as follows :
The alcoholic liquid is pumped into a reservoir, from which it
passes through group / of generators and collects in a vessel.
From the latter it is pumped into a second reservoir placed on
the same level with the first, and runs through group II of
generators into another collecting vessel ; from there it is again
pumped into a third reservoir, and after passing through group
/// of generators finally collects as finished vinegar in a third
collecting vessel.
Though the arrangement of all the generators on the same
level renders it necessary to raise the alcoholic liquid three
times, it would seem more suitable than the terrace system for
the following reasons: 1. By a suitable regulation of the heat-
ing apparatus the required temperature can be readily main-
tained in the separate groups of generators. 2. In case of a
disturbance in one of the groups, the generator in question can
be left out without causing an interruption in the work of the
other groups. 3. The power required to pump the alcoholic
liquid three times into the reservoirs Vl, V2, and F3, is not
much greater than that which has to be used to raise it to the
height of the reservoir in factories arranged according to the
terrace system. 4. Notwithstanding the greater area required,
the erection of a one-story factory is less expensive than that
of a three-story building with complicated heating apparatus
and very strong, solid floors, which are required on account of
the great weight of the generators.
The uniform distribution of the alcoholic liquid into each
generator is very simple in factories arranged according to the
terrace system, and can be effected in the following manner :
The false heads are fitted water-tight in the generators ;
they are provided either with narrow holes alone, or with aper-
tures loosely filled with cotton-wick, pack-thread, etc. The
pipes ascending from the vinegar-forming space, which is filled
with shavings, are inserted water-tight in the false bottoms.
AUTOMATIC VINEGAR APPARATUS.
On the reservoir containing the alcoholic liquid is a spigot
which can be accurately adjusted, and is securely connected
with the conduit leading to the separate generators. At the
place on the conduit where the alcoholic liquid is to be intro-
duced into the generator is a discharge-pipe also provided with
a spigot.
When the factory is to be put in operation the reservoir is
first filled with alcoholic liquid, the spigots on the several gen-
erators being entirely open, but the principal spigot closed.
Now, by suddenly opening the latter, the air in the conduit i&
expelled by the alcoholic liquid flowing in, and the latter
rushes in a full stream from the spigots connecting the conduit
with the generators. These spigots are then closed so far that
only the quantity of alcoholic liquid required for the regular
process of the formation of vinegar can enter the generators.
To prevent the force of pressure from varying too much in the
conduit by the lowering of the level of the fluid in tire reser-
voir, it is recommended to give the latter only a slight height
but a large bottom surface.
From the lower portion of the uppermost series of genera-
tors the alcoholic fluid then gradually reaches through a pipe
the false bottoms of the next series, and from this the lowest
series, from which it runs off as finished vinegar into the col-
lecting vessel.
It will readily be seen that some time for experimenting is
required before a factory arranged according to this system
can be brought into regular working order, it being necessary
to test the fluids running off from the different groups of gen-
erators as to their contents of acetic acid in order to find out
whether too much or too little or just enough alcoholic liquid
reaches the generator, so that the liquid running off from the
lowest series contains no alcohol and may be considered a&
finished vinegar. Any fault in the working of the generators
can in this case be overcome by a corresponding adjustment
of the spigots so as to regulate the influx of alcoholic liquid.
Theoretically no more simple or convenient process for
80' MANUFACTURE OF VINEGAR.
making vinegar than the terrace system could be devised.
Provided the spigots supplying the separate generators be once
correctly adjusted and the temperature of the different stories
suitably regulated, it is only necessary constantly to supply
the reservoir with alcoholic liquid, and the heating apparatus
with fuel, in order to carry on the work for any length of
time desired. The disadvantages connected with this system
having been already explained need not be further referred to.
Lcnze's chamber generator : * This apparatus is a Schuetzen-
bach generator of logically improved construction, and not, as
might be supposed at the first glance, an arbitrary modifica-
tion of the exterior shape. Its construction is based upon the
following principles :
1. Saving of space and volume. 2. Simplification of the
work and facility of control. 3. Utilization to the best ad-
vantage of the square fermentation-surface. 4. The process is
carried on without being separated by partitions in many iso-
lated narrow columns of shavings. 5. Surface-fermentation
with little height. 6. Large producing capacity.
The average height of the apparatus is about 7 feet. It is
rectangular in form, is built entirely of wood, no hoops what-
ever being used, and is of solid and massive construction. It
is made in three sizes. Fig. 28 shows a No. 3 apparatus with
a base of about 107 square feet, length 10 feet, width 6 feet,
and a capacity of producing 20 to 25 quarts of 13 per cent,
vinegar per 10J square feet of shavings-surface (base of gen-
erator).
The alcoholic liquid is periodically supplied at fixed inter-
vals, but the operation may also be carried on continuously
day and night.
The attendance of the apparatus is entirely mechanical, by
means of a pump operated by hand or power. Losses of
material by spilling or otherwise are impossible since the
alcoholic liquid moves in closed tin pipes and the finished
vinegar is conveyed in the same manner.
*.J. Lenze, Iserlohn, Westfalen, Germany.
AUTOMATIC VINEGAR APPARATUS,
81
The apparatus is furnished with a lath-bottom and a per-
forated head, the intermediate space being packed with beech
shavings. The air-holes are between the actual bottom and
the lath-bottom and the air-outlets below the perforated head.
The alcoholic liquid is very uniformly distributed over the
entire large surface of shavings by the perforated head. The
latter is tightly covered with cloth, divided into square fields,
FIG. 28.
and so secured that it cannot warp or get out of position.
Notwithstanding its large superficial area the perforated head
is the coolest place in the apparatus and this evidently con-
tributes towards reducing the loss by evaporation to a mini-
mum, and such loss can be still further limited by the use of
a cover fitting almost air-tight. The upper layer of shavings
is also not impaired by higher degrees of heat, because the as-
cending air which has been heated and exhausted, is con-
6
82 MANUFACTURE OF VINEGAR.
stantly cooled by the pourings of alcoholic liquid and partly
condenses on the lower surface of the perforated head, and
thus cooled, escapes through a pipe-system below the perforated
head.
The mode of operating such an apparatus and its attend-
ance is illustrated by Fig. 28.
The alcoholic liquid is contained in the vat C and a suffi-
cient quantity of it is by means of the pump P conveyed to
the vat A, where it is diluted to a weak wash. When the
operation is carried on with back pourings, the vat B contains
the vinegar; otherwise it is omitted. The intermediate vat
E effects automatically by suitable contrivances the measuring
off of the separate pourings, so that after pumping the entire
quantity of alcoholic liquid required for one day, the actual
labor is finished, which requires about one hour's consump-
tion of time and power, no matter whether one or several ap-
paratuses are operated, larger pumps being used in the latter
case.
For the accurate control of the operation a contrivance is
provided which indicates in the office whether and at what
time the separate pourings have been effected.
The product running off from the apparatus collects in the
course of the day in the vat D. When the latter is full, the
overflow passes through a pipe to the storage-vat. By this
arrangement the danger of any of the vats running over is
excluded.
Plate Generator. — This generator, patented by Dr. Bersch, of
Vienna, Austria, is so arranged as to render the formation of
aldehyde as well as the destruction of acetic acid already
formed impossible, and the loss by evaporation is reduced to
a minimum. As will be seen from the description, the
arrangement of the apparatus is such that on all portions of
the surface of the plates air and alcoholic liquid are in undis-
turbed contact. Hence the formation of vinegar takes place
constantly and the regulation of the current of air can be
effected with the utmost accuracv. Since the effective surface
AUTOMATIC VINEGAR APPARATUS. 83
of each apparatus, i. e., the surface upon which the formation
of vinegar actually takes place, is more than 10,764 square
feet, the performance of this generator is extremely large, sur-
passing by far that of a generator packed with shavings.
This generator is provided with a contrivance which auto-
matically attends to the pouring-in of alcoholic fluid with the
regularity of clock-work, and thus the work of a factory using
a large number of generators can be done by a single work-
man, he having nothing else to do than to fill once a day the
reservoir for alcoholic fluid.
In its most recent construction the plate-generator consists
of a vat filled inside with layers of extremely thin plates of
wood arranged in such a manner that the separate layers are
fixed crosswise at right angles one above the other. Since
every two plates in the layers lying alongside each other are
kept apart by prismatic wooden rods, fluid can run down on
both sides of the plates, and air ascend undisturbed between
them.
Since the total surface of 'the wooden plates in a generator
about 8J feet high is more than 10764 square feet, and for-
mation of vinegar takes place uninterruptedly upon this
entire surface, the efficacy of the plate generator as regards
producing capacity is the highest attainable.
Through a pipe, open at both ends, in the bottom of the
generator, air is admitted to the interior. The upper portion
of this pipe is furnished with a hood to prevent fluid from
dropping into it, and the lower opening is covered with fine
gauze to exclude the entrance of vinegar lice (vinegar mites).
The strength of the current of air in the generator is regu-
lated by a register-bar in the cover of the apparatus, in which
is also fixed a thermometer. In the commencement of the
operation the register-bar is so set that the thermometer indi-
cates the temperature — about 91° to 93° F. — suitable for the
formation of vinegar. So long as alcoholic liquid runs in
and the temperature of the workroom remains the same, the
same temperature will be indicated by the thermometer, be-
84
MANUFACTURE OF VINEGAR.
cause in equal periods of time the same quantity of vinegar
will always be formed and a quantity of heat corresponding
to it developed.
The uniform distribution of the alcoholic fluid in the form
of very fine drops over the plates in the interior of the gen-
erator is effected by a sparger fixed over the uppermost layer
of plates.
The apparatus, like every other generator, can be charged
by pouring in the alcoholic liquid by hand. However, to
make it entirely independent of the workman, and especially
to keep it working regularly day and night without interrup-
tion, it is provided with an automatic pouring contrivance.
This contrivance consists of a vat of such a size as to be capa-
ble of holding the fluid required for supplying for 24 hours
one generator or a group of two, three, four or more genera-
tors. In this supply-vat floats in a suitable guide a wooden
float-gauge,|which rises and sinks with the level of the fluid.
To this float-gauge is secured a siphon, the longer leg of which
is furnished with ^a [checking contrivance which has to be
AUTOMATIC VINEGAR APPARATUS.
85
accurately regulated. By shifting this checking contrivance,
the quantity of fluid discharged in a certain unit of time, for
instance, in one hour, can be determined. Since the siphon
sinks with the level of the fluid, and its length remains un-
changed, the fluid always runs off under the same pressure.
The liquid running from the siphon passes into a distribut-
ing vessel underneath. The latter should be of sufficient
capacity to hold the total quantity of liquid required for one
FIG. 30.
pouring upon all the generators in a battery. If, for instance,
every generator in a battery of twenty-four is to receive a
pouring of 3 quarts, the distributing vessel should have a
capacity of at least 3 X 24 = 72 quarts. The automatic pour-
ing contrivance is fixed in the distributing vessel. When the
latter contains the quantity of alcoholic liquid required for
one pouring for a determined number of generators, the time
fixed between every two pourings has elapsed. The auto-
matic pouring contrivance then opens the distributing vessel
and the alcoholic liquid passes through the conduits to the
86 MANUFACTURE OF VINEGAR.
generators. When the distributing vessel has been emptied,
the discharge-contrivance closes automatically, the distribut-
ing vessel is filled within the determined time, and is again
emptied when this time has elapsed. The automatic distribut-
ing contrivance thus continues working without interruption
so long as liquid is contained in the supply-vat. If the latter
is of sufficient capacity to hold enough alcoholic liquid for 24
hours, it is only necessary to fill it in the morning.
Figs. 29 and 30 show the arrangement of the separate parts
of a plant for automatically working plate generators. Fig.
29 is a view from above and Fig. 30 a side view. V is the
supply-vat for the alcoholic liquid, S the float-gauge to which
is secured the siphon H. A is the automatic. distributor, and
J the conduits conveying the alcoholic liquid to the separate
plate-generators P. The dotted line aa represents the level of
the fluid in the supply-vat.
PERIODICALLY WORKING APPARATUS.
The Three-group System. — In the second system of automatic
generators it has been sought to imitate the ordinary working
of a vinegar factory by providing the apparatus with certain
mechanical appliances which allow of the distribution at cer-
tain stated intervals of any desired quantity of alcoholic liquid
into the generators. The term " periodical " may be applied
to this system of automatic apparatus.
The mechanical appliances used for the purpose of admitting
at certain intervals a fixed quantity of alcoholic fluid into the
generator may be constructed in various ways, the tilting
trough, shown in Figs. 12 and 13, p. 49, being an example.
By a modification of the apparatus, as shown in Fig. 31, any
desired quantity of fluid can with its assistance be at certain
intervals admitted to the generator. The fluid may be either
poured out upon the false head, or, what is more suitable
for its better distribution, used for feeding a sparger.
As seen from the illustration a prismatic box with a bottom
formed of two slightly inclined planes, stands at a suitable
AUTOMATIC VINEGAR APPARATUS.
87
height over each generator. In this box a tilting trough is
placed so that its axis of revolution runs parallel with the line
formed by the two bottom surfaces of the box. On the point
of contact of the two, a pipe is inserted which extends to the
false head or to the funnel of the sparger. Above the box is
a spigot connected by a pipe with a reservoir for the alcoholic
FIG. 31.
fluid placed at a higher level. This reservoir serves for sup-
plying a large number of generators, and can be shut off by a
carefully adjusted spigot. From the latter a vertical pipe
leads to the conduit running in a horizontal direction over the
generators. The pipe is provided with small spigots which
discharge the fluid into the tilting troughs.
88
MANUFACTURE OF VINEGAR.
By giving each tilting trough such a capacity that, for in-
stance, each partition holds 5 quarts, and adjusting the spigot
so that 30 minutes are required for filling one partition, the
trough will, at the expiration of this time, tilt over and empty
the fluid upon the inclined planes. From here it runs into
the sparger, and setting the latter in motion is poured in the
form of a fine spray over the shavings. Since the other parti-
tion of the tilting trough has the same capacity, as the first,
and the quantity of the alcoholic fluid remains the same, the
FIG. 32.
trough will, after the expiration of 30 minutes, again tilt over,
and again empty 5 quarts of fluid, this being continued as
long as the reservoir contains any fluid.
In place of the tilting trough the so-called " siphon-barrel,"
Fig. 32, may be used for effecting the discharge of a certain
quantity of fluid at a stated interval. In a spherical vessel
placed at a higher level than the edge of the funnel of the
sparger is a siphon, the longer leg of which passes through the
bottom of the vessel into the funnel. On the edge of the vessel
AUTOMATIC VINEGAR APPARATUS.
89
Fro. 88.
is a spigot which is connected with the pipe conveying the
fluid, and so adjusted that within a previously determined space
of time the vessel is filled with fluid up to the height indicated
by the dotted line. As soon as the fluid reaches that height,
action of the siphon commences, and the content of the vessel
runs through the longer leg into the funnel of the sparger until
its level is sunk to the edge of the shorter leg. The action of
the siphon then ceases until the vessel is again filled up to the
line, when it recommences, and so on.
The siphon of bent glass tubes being very liable to breakage,
it is frequently replaced by the so-called bell-siphon, the ar-
rangement of which is shown in Fig. 33. It consists of a glass
tube which forms the longer leg of
the siphon, while a glass cylinder
secured to this tube by means of a
perforated cork, represents the other
leg. The action of this siphon is
the same as the other.
In working with automatic appa-
ratus, fixed quantities of fluid being
at stated intervals introduced, pro-
vision for the reception of the fluid
must be made in the apparatus itself,
or for its being conducted to a spe-
cial reservoir at the rate at which it
trickles from the shavings. In the
first case the space beneath the false
bottom must be of sufficient size to
receive the fluid passed through the apparatus in a certain
time. This time being suitably fixed for 12 hours, the appa-
ratus can during this time work without further attendance,
so that the required space beneath the false bottom can be
calculated by multiplying the number of pourings with the
quantity of fluid poured in at one time.
Example : — The generator receives at intervals of 30 min-
utes a pouring of 5 quarts, hence in 12 hours 24 pourings of
90 MANUFACTURE OF VINEGAR.
5 quarts each = 120 quarts. The space beneath the perfo-
rated false bottom must therefore be of sufficient capacity to
receive up to the height of the draught-holes at least 120
quarts of fluid.
As will be seen from the following general description of a
vinegar factory, arranged according to the automatic principle,
it is decidedly preferable to arrange the generators so that the
fluid trickling from . the shavings is at once conducted to a
collecting vessel.
Arrangement of a Vinegar Factory Working According to the
Automatic Principle. — As previously stated, it is not possible to
convert all the alcohol contained in the liquid into acetic acid
by one pouring ; only a portion of the alcohol being converted,
and this semi-product is brought into a second generator, and,
if the liquid used is very rich in alcohol, into a third. In the
second apparatus another portion of the alcohol is converted
into acetic acid, and the process finished in the third.
It being in all cases advisable to prepare vinegar with a
high percentage of acetic acid, most manufacturers now pass
the alcoholic liquid successively through three generators. In
practice it is recommended to place the generators which are
to receive alcoholic liquid of the same content of acetic acid
alongside each other, which leads naturally to the division of
the generators into three groups. If, for instance, a factory
contains 48 generators, each group contains 16 ; group I is
charged with freshly prepared alcoholic liquid ; the generators
of group II contain the alcoholic liquid which has already
passed through those of group I, and group III is charged
with the fluid yielded by group II.
Besides the easy control of the work, this arrangement into
groups has another advantage. The generators in which the
last remnants of the alcohol of a quite strong fluid are to be
converted into acetic acid are best kept at a somewhat higher
temperature ; and with a suitably arranged heating apparatus
and the eventual use of curtains by which the workroom can
be divided at will into two or three partitions, it can be readily
AUTOMATIC VINEGAR APPARATUS. 91
arranged to convey somewhat more heat to the second group
of generators and the greatest quantity of it to the third.
The height of the actual workroom of the factory should not
be greater than required by that of the generators. The reser-
voir is placed under the roof of the workroom, while the col-
lecting vessels are either sunk in the floor or placed in the
cellar.
Below is given a description of a periodically working estab-
lishment with 24 generators. The generators are arranged in
three groups, I, II, and III, the following articles belonging
to each group : —
8 generators ;
1 reservoir;
1 collecting vessel ;
8 apparatuses for the distribution of the alcoholic liquid into
the generators ;
Conduits for the alcoholic liquid to be poured in ;
Conduits for the alcoholic liquid running off.
For the three groups in common : —
A pump to convey the alcoholic liquid from the collecting
vessels to the reservoirs.
A flue for the conveyance of warm air from the heating
apparatus in the cellar and for its distribution in the work-
room.
An apparatus for heating the alcoholic liquid.
The three reservoirs rest upon the joists of the ceiling of the
workroom, each being enclosed by a small chamber con-
structed of boards which are papered. In the floor of each
chamber is a man-hole for access to the reservoir. The man-
holes should not be furnished with doors, it being of import-
ance that the reservoirs should constantly be surrounded by
warm air which ascends through the man-holes. To prevent
loss by evaporation the reservoirs should be provided with
well-fitting covers.
To retain solid bodies such as shavings, flakes of mother of
vinegar, etc., which might eventually obstruct the fine aper-
92 MANUFACTURE OF VINEGAR.
tures in the false head or sparger, a filter is placed on the
end of the pipe through which the alcoholic liquid passes into
the reservoirs. A suitable filter for the purpose is a horse-hair
sieve containing a linen bag, the latter being from time to
time replaced by a new one.
The conduits for the conveyance of the alcoholic liquid to
the distributing vessels and from there to the generators are
best constructed of thick glass tubes, the connection of two
pieces being effected by pieces of rubber hose pushed over the
ends and secured with twine.
Each generator may be furnished with a vessel containing the
automatic arrangement, it being, however, in this case neces-
sary to provide for each a special conduit from the reservoir,
which for a factory containing a large number of generators is
rather expensive. Hence it is recommended to use for each
group only one or at the utmost two distributing vessels, and
from them to extend smaller conduits to the separate -gene-
rators. Each of the principal conduits is provided, at the place
where it enters the distributing vessel, with a spigot, which is
adjusted for the discharge of a certain quantity of alcoholic
liquid. If, as above mentioned, every generator is to receive
a pouring of 5 quarts of alcoholic liquid every 30 minutes, the
distributing vessel serving for a group of 8 generators must
have a capacity of 40 quarts, and the spigot has to be so
adjusted that exactly this quantity passes through it in 30
minutes.
The discharge-pipe of the automatic arrangement must enter
a space in which are inserted eight pipes having the same
diameter, which conduct the alcoholic liquid to the separate
generators. By this arrangement all the generators receive
simultaneously a pouring of an equal quantity of fluid which
either sets the sparger in motion or gradually trickles through
the apertures in the false head. The alcoholic liquid which
has passed through the generators collects either in the space
under the false bottom or runs directly through conduits to
the collecting vessels.
AUTOMATIC VINEGAR APPARATUS. 93
The conduits placed before the discharge apertures of the
generators are intended to conduct the alcoholic liquid to the
reservoirs, and there being no pressure of fluid in them they
might be merely open gutters. For the sake of cleanliness and
to avoid losses by evaporation it is, however, advisable to use
glass tubes for the purpose. At the places where the dis-
charge-pipes of the generators are located, the connection of
two glass tubes is effected by a wooden joint with an aperture
on top in which is placed a glass funnel. For collecting ves-
sels for the alcoholic fluid running off from the generators of
one group, vats provided with lids are used. They have to be
placed so low that some fall can be given to the conduits, and
in each of them is a pipe provided with a spigot, which serves
as a suction-pipe for the pump intended to raise the alcoholic
fluid.
The manner of working in a factory thus arranged is as
follows : * The collecting vessel Ci serves for the preparation
of the alcoholic liquid, which is then pumped into the reser-
voir Ri, from whence it runs through the first group of gen-
erators, Gi, to the collecting vessel, Cn. From this it is
pumped into Rn, and runs through the second group of gen-
erators, Gn, into the collecting vessel Cm. On being pumped
up the third time it runs from the reservoir Rm through the
third group of generators Gm, and passes as finished vinegar
either into a fourth collecting vessel or is at once conducted
into storage barrels.
The distance the alcoholic liquid has to be raised from the
bottom of the collecting vessels to the reservoir amounting to
not more than from 23 to 25 feet, an ordinary suction-pump
may be used for the purpose, though a forcing pump is better,
it doing the work more rapidly. The pump must be con-
structed of material entirely indifferent to acetic acid (wood,
glass, hard rubber, tin,, or thickly silvered metal).
*To avoid repetition the collecting vessels are designated : Ci, n, in ; the res-
ervoirs Ri, iiTand.iii1.; the groups of generators Gi, n, in.
94
MANUFACTURE OF VINEGAR.
Any metallic vessels used in the factory should be of pure
tin, i. e., unalloyed with other metals, it being the only metal
entirely indifferent towards acetic acid, but unfortunately it is
too soft to be suitable for the construction of pumps.
The pump is generally located in the immediate neighbor-
hood of the collecting vessels, and the three branches of its
suction pipe pass into the latter. When one of the collecting
FIG. 34.
vessels is to be emptied, the spigot of the branch pipe entering
it is opened and the spigots of the other branch pipes are
closed.
Ordinary well or river water being used in the preparation
of the alcoholic liquid, the temperature of the latter does not
generally exceed 54° F., and if it were thus introduced into
the generators acetification would be very sluggish until the
temperature rises to above 68° F. Independently of the loss
AUTOMATIC VINEGAR APPARATUS. 95
of time, there would be the further danger of injuring the de-
velopment of the vinegar ferment ; hence it is necessary to heat
the alcoholic liquid to the temperature required. This is best
effected by passing it through a coil surrounded by hot water.
Fig. 34 shows an apparatus especially adapted for heating the
alcoholic liquid. In a copper or iron boiler filled with water,
which can be heated from below, is a coil, S, of pure tin ; it
enters the boiler above at a and leaves it at 6, so that the place
of inflow is at the same level with that of outflow. With
this form of construction the coil of course remains always
filled with liquid, which with the use of pure tin is, however,
of no consequence ; besides, this can be remedied by placing
on the lower coil a narrow pipe, R, which projects above the
edge of the boiler and is bent like a siphon. By opening the
spigot h the fluid contained in the coil runs off through R.
^The rising pipe of the forcing-pump is provided with an
arrangement by which the alcoholic liquid can be brought
either directly from the collecting vessel into the reservoirs, or
first forced through the heating apparatus. It consists of a
prismatic wooden body provided with three spigots. By clos-
ing spigots 2 and 3 and opening 1, the alcoholic liquid is
immediately conveyed from the collecting vessels to the reser-
voirs. By closing spigot 1 and opening 2 and 3, which are
connected by short pieces of rubber hose with the ends of the
coil, S, the alcoholic liquid forced upward from the collecting
vessels by the pump must pass through the heating coil, and
after being heated it returns to the rising pipe, which conveys
it to the reservoirs. The arrows in the illustration indicate
the course of the alcoholic liquid has to traverse when spigots
2 and 3 are open and 1 closed.
The diameter and length of the tin coil depends on the
quantity of fluid which is to pass through it, though one with
a clear diameter of 12 to 14 inches and a length of 23 to 26
feet will, as a rule, suffice. Besides by slower or quicker
pumping the fluid can be forced with less or greater velocity
through the coil and correspondingly more or less heated.
96 MANUFACTURE OF VINEGAR.
The walls of the coil should be as thin as possible so as to
yield heat rapidly.
The heating of the alcoholic liquid, of course, can also be
effected by heating one portion more strongly than necessary
and reducing it to the required temperature by mixing with
cold fluid. In working, however, with a fluid containing living
vinegar ferment — and such, as will be explained later on, is
claimed to be already contained in freshly prepared alcoholic
fluid — care must be had not to heat the liquid above 120° F.,
this temperature being destructive to the ferment.
CHAPTER X.
OPERATIONS IN A VINEGAR FACTORY.
Acetification of the Generators. — The object of acetification is
to thoroughly saturate the filling material — shavings, char-
coal, etc.— of the generators with vinegar and to cause the
development of the vinegar ferment upon it. The generators
are first filled with the filling material, the false heads or
the spargers are next placed in position, and the temperature
of the workroom is brought up close to 86° F. For acetifica-
tion, i. e., saturating the shavings, vinegar of the same
strength, i. e., with the same content of acetic acid as that
which is to be prepared in the generators, is used. For every
35J cubic feet of the space filled with shavings or charcoal are
required for complete acetification the following quantities of
vinegar :
For shavings loosely poured in 60| to 71£ gallons.
For shavings piled up one alongside the other ..90 to 105£ gallons.
For charcoal, the size of a walnut 142J to 211 \ gallons.
The value of the vinegar used for acetification has to be
considered as dead capital.
OPERATIONS IN A VINEGAR FACTORY. 97
The first vinegar running off from the generators is not only
considerably weaker than that used for acetification, but, not-
withstanding the previous lixiviation of the wood, has a dis-
agreeable taste so as to render it unfit for the preparation of
table vinegar, and can only be utilized, for instance, in the
preparation of acetate of lead, etc. When the vinegar running
off exhibits a pure taste, it is collected by itself and later on
converted into a product of greater strength by mixing it with
alcohol and passing again through the generators. By this
saturation of the shavings with vinegar, the vinegar ferment
locates in abundance upon the surface of the shavings, and
the generators are fit for the formation of vinegar.
Regular production, however, can be commenced only grad-
ually, which may be illustrated by an example as follows :
At first, for instance, alcoholic liquid is introduced only
once a day, either early in the morning or in the evening.
In about eight days, or under certain conditions even later,
the temperature in the generators has risen to from 86° to 95°
F., and alcoholic liquid may now be introduced twice daily,
for instance, early in the morning and in the afternoon. The
fact that the generator is working is recognized by the in-
creased temperature and by the flame of a candle held near a
draught-hole being drawn inwards. After eight to fourteen
days more the thermometer shows 96° to 98° F., and then
alcoholic liquid is introduced three times daily, for instance,
early in the morning, in the forenoon and in the afternoon,
whereby the temperature rises to 102° or 104° F. If now the
vinegar running off shows the desired strength, the generators
are in good working order, and are subjected to the regular
treatment.
Accelerated Acetification. — By closely considering the process
which must take place in acetification and the first stage of
the operation, it will be plainly seen that the above-described
method cannot be called a rational one, there being a waste of
time as well as of material, and the commencement of regular
working being largely dependent upon accident.
7
98 MANUFACTURE OF VINEGAR.
The object of Rectification is, as previously stated, first to
thoroughly saturate the shavings with vinegar and next to
develop the vinegar ferment upon them. This can, however,
be attained in a more suitable and a quicker manner than by
the above process.
Air-dry wood contains on an average 20 per cent, of water,
and during acetification this water must be gradually replaced
by vinegar ; hence the vinegar trickling from the generators
will remain poor in acetic acid and rich in water until the
shavings are entirely saturated with pure vinegar and the
water has been expelled.
The removal of the water from the shavings and its substitu-
tion by vinegar are effected by osmose, i. e., the cells of the
wood surrounded by vinegar yield a fluid consisting of water
and extractive substances of the wood and absorb sufficient of
the exterior fluid until both liquids have the same composition.
Now, by pouring only a small quantity of vinegar at one time
over the shavings in the generator, as is done in acetification
according to the old method, the course of the process is very
slow, 14 days or more, as already mentioned, being required
before the vinegar running off' shows no longer a change in its
concentration.
In a generator in a stage of acetification an uninterrupted,
though slight, current of air upwards takes place, since even
with the use of the best heating apparatus the air in the upper
layers is warmer than in the lower. This current of air be-
comes stronger with the development of larger quantities of
vinegar ferment and causes a large absolute loss of vinegar.
The greater portion of this loss must be set down as being due
to evaporation, which must be considerable on account of the
great surface over which the vinegar is distributed, and the
smaller portion, to consumption by the vinegar ferment.
By placing the shavings in vinegar the above-described pro-
cess of substitution of vinegar for the fluid contained in the
cells of the wood takes place very quickly, and, theoretically,
it would therefore seem to be advisable to follow the same
OPERATIONS IN A VINEGAR FACTORY. 99
course on a large scale, i. e., to saturate the shavings with
vinegar before placing them in the generators. By using
artificially dried shavings (see p. 54) the saturation is effected
in the course of a few hours, the dry" woody tissue absorbing
the fluid like a sponge.
The shavings, while still hot, are brought into a vat and
covered with the vinegar to be used for acetification. In about
12 hours they are thoroughly saturated. The excess of vine-
gar is drawn off through the tap-hole in the bottom of the vat,
and having absorbed neither water nor extractive substances
from the steamed and thoroughly dried shavings can be imme-
diately re-used for the saturation of another portion of shav-
ings. The saturated shavings are at once used for filling a
generator, and the latter, which may now be considered as
completely acetified, can at once be employed for the process
of the formation of vinegar according to the method described
below.
Instead of in a vat, the shavings can also be saturated
directly in the generator. For this purpose the shavings,
after having been artificially dried, are immediately brought
into the generator, and vinegar is poured over them either by
means of the false head or the sparger until a considerable
quantity has accumulated in the space below the false bottom.
This accumulation is then drawn off and again poured over
the shavings, this being continued until they are thoroughly
saturated, which is effected in a comparatively short time.
Induction of the Operation with an Artificial Culture of Vinegar
Ferment. — In the process of accelerated acetification of the
generators no development of vinegar ferment can of course
take place, since by heating the shavings to about 212° F.
any fermenting organisms accidentally adhering to them are
destroyed. The vinegar ferment increases with astonishing
rapidity provided it finds nutriment suitable for its develop-
ment. Vinegar is, however, a very poor material for this
purpose, and this is very likely the reason why weeks are re-
quired before production can be commenced in generators
100 MANUFACTURE OF VINEGAR.
acetified according to the old method. The ferment cany
however, be so rapidly propagated in the generator that pro-
duction can be commenced almost immediately after acetifi-
cation is complete.
For this purpose a method similar to that employed in the
manufacture of alcohol and yeast has to be pursued and vigor-
ous ferment obtained by cultivation. As previously mentioned,
the ferment causing acetic fermentation is widely distributed
throughout nature and is most abundantly found in the air of
thickly populated regions.
The "pure culture" of the vinegar ferment, i. e., in which
no other than the desired ferment is developed, is not diffi-
cult, it being only necessary to prepare a fluid especially
adapted for its nutriment and allow it to stand at a suitable
temperature in order to obtain in a few days a vigorous
growth produced by a few individual germs reaching the fluid
from the air. The best fluid for the purpose is one which con-
tains, besides a large quantity of water — about 85 to 90 per cent.
— a certain amount of alcohol and acetic acid, and very small
quantities of nitrogenous substances and mineral salts. Hence
its preparation is not difficult, it being only necessary to mix
ordinary vinegar and alcohol in suitable proportions and add a
small quantity of a fluid containing nitrogenous substances
and mineral salts, such as wine, cider, beer or malt extract.
Numerous experiments have shown that a fluid containing
from 4 to 6 per cent, of acetic acid and the same quantity of
'alcohol with the addition of a small quantity of one of the
above-mentioned fluids is best adapted for the vigorous nour-
ishment of the vinegar ferment. Ordinary table vinegar con-
tains as a rule from 4 to 6 per cent, of acetic acid ; the average
percentage of alcohol is in wine from 8 to 10 ; in cider from
4 to 6 ; and in beer from 3 to 5. Taking this statement as a
guide, the preparation of a fluid containing from 4 to 6 per
cent, of acetic acid, 4 to G per cent, of alcohol, and the required
nitrogenous combinations and salts will not be diflicult.
Fluids of this composition are obtained by mixing, for in-
OPERATIONS IN A VINEGAR FACTORY. 101
stance, equal parts of cider and vinegar, or one part of wine
with two of vinegar, or one part of beer with three of vinegar,
and adding 5 per cent, of 90 per cent, alcohol to the mixture.
Such mixtures, possessing the power of vigorously nourishing
the vinegar ferment, can at the same time be considered as
types for the preparation of alcoholic liquid of suitable com-
position.
To assure the exclusive development of vinegar ferment
upon any of the above-mentioned mixtures it is best to heat
it to the boiling-point of water. Young wine as well as cider
contains considerable quantities of albuminous substances in
solution, and fluids of this nature being well adapted for the
nutriment of the mold ferment, the development of the latter
might increase to such an extent as entirely to suppress the
vinegar ferment and thus render its cultivation a failure.
Beer is also very suitable for the nutriment of the mold fer-
ment, though in a less degree than young wine, and besides
living yeast, contains alcoholic ferment.
By heating wine or beer only for a moment to about 158°
P., a large portion of the albuminous substances in solution
becomes insoluble, and on cooling separates as a flaky precipi-
tate, all ferments present in the fluid being at the same time
destroyed. Hence for the preparation of a fluid especially
adapted for the cultivation of pure vinegar ferment, it is
recommended quickly to heat to the boiling point 1 quart of
ordinary white wine in a covered porcelain vessel, and after
cooling to the ordinary temperature, to mix it with 2 quarts
of vinegar. To remove the separated insoluble albuminous
substances, filter through blotting paper.
To prepare a nourishing fluid from beer, heat a quart of it
to the boiling point, mix it after cooling with 3 quarts of
vinegar, add J quart of 90 per cent, alcohol, and filter.
Distribute this fluid in a number of shallow porcelain vessels
and place the latter near a window in the heated workroom.
To prevent dust from falling into the fluid, cover each dish with
a glass plate resting upon two small wooden sticks placed
102 MANUFACTURE OF VJNKGAR.
across the dish. In two or three days, and sometimes in 24
hours, the commencement of the development of the vinegar
ferment will be recognized by the stronger odor of vinegar than
that possessed by the original fluid and by the appearance of
the surface of the liquid. By observing the latter at a very
acute angle, dull patches resembling grease-stains and consist-
ing of a large number of individuals of the vinegar ferment
will be seen. In a few hours these patches will have increased
considerably, until finally the entire surface appears covered
by a very delicate veil-like layer of vinegar ferment.
By touching the surface with the point of a glass rod a cer-
tain amount of the coating adheres to it, and by rinsing it off
in a fluid of similar composition not yet impregnated, the fer-
ment quickly develops upon it. By placing a drop of the fluid
under the microscope a picture similar to that shown in Fig.
2, p. 14, presents itself, the entire field of vision being covered
with germs of vinegar ferment.
By the development of mold ferment the cultivation of pure
vinegar ferment may sometimes result in failure even with the
use of the above-mentioned fluids. The development of this
ferment is recognized by the appearance of white dots upon
the fluid, which quickly increase to white opaque flakes, and if
left to themselves finally combine to a white skin of a peculiar
wrinkled appearance. Fig. 35 shows a microscopical picture
of such abortive culture of vinegar ferment. By observing
at the commencement of this phenomenon the fluid with the
microscope, very small individuals of vinegar ferment, 6, will
be observed alongside of the much larger oval cells a, of the
mold ferment. Such fluid being not adapted for our purposes
has to be thrown away and the dish rinsed off with boiling
water.
When the fluid in the dishes is entirely covered with pure
vinegar ferment, it is poured into a vessel containing the
greater portion of the alcoholic fluid intended for the first
charge of the generators, and in the course of 10 hours the
entire surface of this fluid is covered with vinegar ferment.
OPERATIONS IN A VINEGAR FACTORY.
103
This fluid being poured into the sufficiently acetified genera-
tors and trickling gradually through them, the greater portion
of the ferment adheres to the shavings, and increases with
such rapidity that the great rise of temperature in the interior
of the generators shortly indicates the regular beginning of
their activity, and the pouring in of alcoholic liquid can at
once be commenced.
Vinegar ferment developed upon one of the above-mentioned
fluids is evidently so constituted that it can be thoroughly
'^t i' l A.
n tvf <#> y _/:
/ Q V «
/ ^ / • ^v .
/ :/ ' ,-. ,. ,.'•'•?'
, &*&**
nourished by it, and hence the generators might be continued
to be charged with alcoholic liquid of a corresponding com-
position. It being, however, as a rule, desired to manufacture
as strong a product as possible, an alcoholic liquid much richer
in alcohol than the above-mentioned nourishing fluids has to
be used.
By, however, suddenly changing the nourishing fluid of the
vinegar ferment, for instance, from a fluid containing only 4
to 6 per cent, of alcohol to one with 12 to 13 per cent., the
action of the ferment would very likely be sluggish before it
104 MANUFACTURE OF VINEGAR.
became accustomed to the new conditions. Further, its
activity might suffer serious disturbance and its propagation
decrease very sensibly, so that notwithstanding strong heating
of the workroom and thorough ventilation of the generators,
the temperature in the latter would suddenly fall, and would
only be restored to the required degree after the ferment had
become accustomed to the new conditions and recommenced
its vigorous propagation.
To overcome such annoying disturbances, 'it is only neces-
sary to gradually change the composition of the nourishing
fluid to that which the alcoholic liquid to be worked in the
generators is to have. Commencing, for instance, with an alco-
holic liquid containing 5 per cent, of alcohol, the next day
one with 6 per cent, is used, the succeeding day one with 7
per cent., and so on until the maximum percentage of alcohol
the liquid is to have is reached.
CHAPTER XI.
PREPARATION OF THE ALCOHOLIC LIQUID.
BY the term " alcoholic liquid" is to be understood every
kind of fluid to be converted into vinegar which, besides water
and small quantities of nourishing salts and albuminous sub-
stance, does not contain over 14 per cent, of alcohol. The
term " wash " or " mixture " is frequently applied to the alco-
holic liquid. In the directions generally given for the prepa-
ration of such liquids, vinegar is mentioned as an indispensa-
ble constituent. While it cannot be denied that a content of
vinegar in the alcoholic liquid exerts a favorable effect-upon
the formation of vinegar, it must be explicitly stated that it is
not the acetic acid in the vinegar which in this case becomes
active, but the ferment contained in it.
In a vinegar factory, vinegar just finished and quite turbid
is as a rule used in the preparation of alcoholic liquid, and a
PREPARATION OF THE ALCOHOLIC LIQUID. 105
microscopical examination shows such vinegar to contain in-
numerable germs of vinegar ferment. This ferment on com-
ing in contact with much air in the generators will evidently
increase rapidly and contribute to the rapid acetification of the
alcohol. That it is actually the ferment in the vinegar used
which exerts a favorable effect can be shown by a simple ex-
periment. By adding vinegar previously heated to from 140°
to 158° F. to the alcoholic liquid, the formation of vinegar in
the generators proceeds more slowly, the ferment contained in
the vinegar having been killed.
The best proof, however, that the alcoholic liquid does not
require any considerable quantity of acetic acid for its conver-
sion into vinegar is furnished by the behavior of wine. Prop-
erly prepared wine of a normal composition contains only a
few ten-thousandths of its weight of acetic acid, and this must
very likely be considered as ar product of vinous fermentation.
If such wine be stored for years in a cool cellar, its content of
acetic acid does not change. By, however, exposing it in a
shallow vessel to the air at from 66° to 78° F., microscopical
examination will show the development of vinegar ferment upon
it, and a chemical analysis a constant increase, soon amounting
to several per cent, of acetic acid. A fluid composed of 5 to &
per cent, of alcohol, 94 to 95 per cent, of water, and a very
small quantity of malt extract, acts in a similar manner. In
many cases the vinegar ferment is developed without the fluid
containing acetic acid.
The alcoholic fluid to be used may from the start contain a
sufficiently large percentage of alcohol to correspond to the de-
sired strength of the vinegar to be made, and in this case the
fluid has to be poured several times into the generators, it
being impossible to convert a large quantity of alcohol into
acetic acid by passing it through but once. By another
method an alcoholic liquid is first prepared containing but
little alcohol, which is almost completely converted into acetic
acid by one passage through the generators. The fluid run-
ning off from the generators is then further mixed with a cer-
106 MANUFACTURE OF VINEGAR.
tain quantity of alcohol, and being poured into a generator in
which the vinegar ferment is already accustomed to larger
quantities of alcohol and vinegar, is also converted into acetic
acid. More alcohol can then be added, and so on. The last
method is evidently the best as regards the conditions of life
of the vinegar ferment, and actually the only one by which
the strongest vinegar (with from 12 to 13 per cent, of acetic
acid) can be obtained in generators.
That it is advisable only gradually to increase the content
of alcohol in the alcoholic liquid is shown by the behavior of
the ferment towards alcohol and acetic acid. Both bodies, if
present in large quantities, are decidedly inimical to the prop-
agation of the ferment, a fluid containing from 14 to 15 per
cent, of alcohol, or as much acetic acid, being capable of check-
ing it to such an extent as to disturb the process of production.
Another argument against the use of the total quantity of al-
cohol in the preparation of the alcoholic liquid to be employed
for the first pouring, is the fact that evidently more alcohol will
be lost by evaporation than by commencing with a fluid con-
taining less alcohol, and adding a corresponding quantity of
the latter after the fluid has once passed through the genera-
tors. The quantity .of alcohol for the first pouring should be so
chosen that the fluid running off still contains a small quantity
of unchanged alcohol, this being an assurance that only alcohol
and not unfinished acetic acid has undergone an alteration.
So long as alcohol is present in the alcoholic liquid the vinegar
ferment is almost entirely indifferent towards acetic acid, but
after the oxidation of all the alcohol, it attacks the acetic acid
and decomposes it to carbonic acid and water. This can be
shown by a very simple experiment. If finished vinegar, in-
stead of alcoholic liquid, be poured into a generator in full
operation, the vinegar running off shows a smaller percentage
of acetic acid than that poured in, the acetic acid missing
having been destroyed by the ferment.
To what an extent even smaller quantities than 14 to 15
per cent, of alcohol or acetic acid exert a restraining influence
PREPARATION OF THE ALCOHOLIC LIQUID. 107
upon the propagation and activity of the vinegar ferment can
be seen in generators charged with alcoholic liquid of different
strengths, those containing less concentrated liquid can in the
same time form a much larger quantity of acetic acid than
those in which a liquid is used which already contains certain
quantities of acetic acid. Hence, the greater the quantity of
acetic acid already contained in the alcoholic liquid, the slower
the conversion of the alcohol still present in the acetic acid.
It may, therefore, be laid down as a rule that the manufac-
turer should not strive to prepare vinegar with more than about
12 per cent, of acetic acid. Though in exceptional cases a
product with 13 per cent, can be obtained, it will also be ob-
served that the respective generators gradually yield a weaker
product, or that their activity suddenly ceases to such an
extent as to require them to be placed out of operation.
The preparation of high-graded vinegar being undoubtedly
subject to greater difficulties than that of a weaker product,
the question might be raised whether the manufacture of weak
vinegar only would not be the most suitable. This must be
largely decided by local conditions. For a manufacturer whose
custom lies in the immediate neighborhood, for instance, in a
large city, the production of weak vinegar only would be advis-
able; but if he has to send his product a considerable distance,
the fact that the more freight has to be paid on what is of no
value, the weaker the vinegar is, and that the expense of trans-
porting a strong article is relatively less, deserves considera-
tion. The consumer can readily prepare vinegar of any
described strength by diluting the strong product with water.
The quantity of beer required for the purpose of offering
suitable nutriment to the vinegar ferment is very small, an ad-
dition of 1 per cent, to the alcoholic liquid being ample. Sour
or stale beer can of course be used. The reason for the em-
ployment of larger quantities of beer in mixing the alcoholic
fluids is found in the fact that the vinegar prepared from such
mixtures sooner acquires a pure taste than that made from
fluids containing but little beer. The addition of beer should,
108
MANUFACTUKE OF VINECJAK.
however, not exceed 15 per cent, of the total quantity of alco-
holic liquid, as on account of the comparatively high percent-
age of albuminous substances and the maltose, dextrin, and
extractive matters of hops it contains, a larger quantity would
be injurious to the process of acetic fermentation, the genera-
tors being frequently rendered inactive by the so-called " slim-
ing of the shavings." The production of the latter is due to
the fact that by being partially excluded from contact with the
air by the comparatively thick fluid passing over it, the vine-
gar ferment deposited upon the shavings assumes the form of
mother of vinegar which adheres to the shavings as a slimy
mass.
The quantity of finished vinegar added to the alcoholic
liquid varies between 10 and 33 per cent. The use of large
quantities is however decidedly inexpedient, since the only
effect produced by the vinegar is, as previously stated, due to
the ferment contained in it. Of freshly prepared, turbid vine-
gar, 10 per cent, is ample for the preparation of alcoholic
liquid, and a greater quantity can only be considered as use-
less ballast.
Theoretically a certain quantity of alcohol yields exactly a
certain quantity of acetic acid. The following table shows the
proportions between the two bodies : —
I
— .'
A mixture con-
taining the follow-
Is composed by
weight of
And yields
Total
o> "f:
fj.
ing per cent, of
vinegar.
alcohol by volume
Alcohol.
Water.
Acetic
anhydride.
Water.
I"
1
0.8
99.2
10
99.5
100.5
1.0
2
1.6
98.4
2.1
99.0
101.1
2.1
3
2.4
97.6
3.1 98.5
101.6
3.1
4
3.2
96.8
4.2 98.0 102.2
4.1
5
4.0
96.0
5.2 97.6
102.8
5.1
6
4.8
95.2
6.3 97.1
103.3
6.0
7
5.6
94.4
7.3 . 96 6
103.9
7.0
8
6.4
93.6
8.3
96.1
104.4
80
9
7.2
92.8
9.4
95.6
105.0
' 8.9
10
8.1
91.9
10.4
950
105.4
9.9
11
8.9
91.1
11.6
94.6
106 2
10.9
12 9.7
90.3
12.6
94.1
106.7
11.8
PREPARATION OF THE ALCOHOLIC LIQUID.
109
Practically less vinegar with a smaller percentage of acetic
anhydride is, however, always obtained, this being due to losses
of material caused partially by evaporation and partially by
the oxidation of the alcohol extending beyond the formation
of acetic acid. In preparing the alcoholic liquid these un-
avoidable losses must be taken into consideration, and more
alcohol has to be used for the production of vinegar with a de-
termined percentage of acetic acid than is theoretically re-
quired. How much more has to be taken depends on the
kind of apparatus used and on the strength the vinegar to be
prepared is to show. The higher the percentage of acetic acid
which is to be obtained, the greater the losses will be, and con-
sequently the greater the content of alcohol in the alcoholic
liquid must be. Theoretically one per cent, of alcohol yields
one per cent, of acetic acid, but practically the proportions are
as follows :
For the production of
vinegar with a con-
tent of acetic acid of—
5 per cent .
6
7
8
10
11
12
Is required an alcoholic
liquid with a content
of alcohol of—
5.4 to 5.5 per cent.
6.5" 0.6
7.6 k' 7.7
8.7 k' 88
9.8 -k 99
10.9 ^ 11.0
11.9 " 12.1
13.0 " 13.2
The strength of commercial alcohol varying considerably,. it
is of importance to the manufacturer to be able to calculate in
a simple manner how many gallons of water have to be added
to alcohol of known strength in order to obtain an alcoholic
liquid with the desired percentage of alcohol. The calcula-
tion is executed as follows : —
Suppose :
p = per cent, of alcohol in the spirits to be used.
E = per cent, of alcohol in the alcoholic liquid to be pre-
pared, the quotient obtained by dividing P by E gives the
volume to which the spirits have to be reduced by the addi-
110 MANUFACTURE OF VINEGAR.
tion of water in order to obtain alcoholic liquid with the de-
sired percentage of alcohol.
Example : —
From spirits of 86 per cent. Tralles', alcoholic liquid with
11 per cent, of alcohol is to be prepared.
P = 86 ; E = 11 ? = 7.818.
xL
Hence one volume of the spirits to be used has to be brought
to 7.818 volumes, or to one gallon of spirits 6.818 gallons of
water have to be added.
Examples of the composition of alcoholic liquid : —
A. Alcoholic liquid from alcohol, water, and vinegar :
For vinegar with about 7 per cent, of acetic acid. — Alcohol of
90 per cent. Tr. 10 parts by volume, water 107, vinegar with
7 per cent, of acetic acid 12.
For vinegar with about 12 per cent, of acetic acid. — Alcohol of
90 per cent. Tr. 10 parts by volume, water 65, vinegar with
12 per cent, of acetic acid 7.
It is advisable to add about 1 per cent, of the entire volume
of beer to the above alcoholic liquids.
B. Alcoholic liquid from alcohol, water, vinegar, arid beer.
For vinegar with about 5 per cent, of acetic acid. — Alcohol of
90 per cent. Tr. 10 parts by volume, water 107, vinegar with
5 per cent, of acetic acid 13, beer 14.
C. For vinegar with about 8 per cent, of acetic acid — Alcohol
of 90 per cent. Tr. 10 parts by volume, water 92, vinegar with
8 per cent, of acetic acid 10, beer 9.
In many factories it is customary not to determine the com-
position of the alcoholic liquid by calculation, but simply to
work according to certain receipts. Vinegar of a certain per-
centage is obtained, but its strength cannot be predetermined
with the same nicety as by calculating the percentage of alco-
hol in the alcoholic liquid by the above formula. The follow-
ing may serve as examples of such receipts : —
PREPARATION OF THE ALCOHOLIC LIQUID. Ill
D. Alcohol of 50 per cent. Tr. 100 quarts, water 600,
vinegar 900.
.E. Alcohol of 90 per cent. Tr. 100 quarts, water 1200,
vinegar 300.
F. Alcohol of 90 per cent. Tr. 100 quarts, water 1350,
vinegar 175, beer 175.
G. Alcohol of 90 per cent. Tr. 100 quarts, water 1400,
vinegar 300, beer 100.
H. Alcohol of 80 per cent. Tr. 100 quarts, water, 850,
beer 750.
I. Alcohol of 50 per cent. Tr. 100 quarts, water 100, beer
100.
The mixtures A, B and C are only given as examples of how
alcoholic liquids which yield vinegar containing the desired
percentage of acetic acid are prepared according to receipts.
Though it may be very convenient for the manufacturer to
work according to such receipts as are given under D to I,
their use without a previous examination cannot be recom-
mended. It is far better for the manufacturer to prepare the
alcoholic liquid according to a receipt of his own, and not
shrink from the slight labor it involves. He has then at least
the assurance of obtaining vinegar with exactly the percent-
age of acetic acid desired, and is in the position to obtain an
accurate view of the entire process of the operation.
In the United States low wine containing 12 to 15 per cent,
by volume of alcohol is as a rule used for the preparation of
the alcoholic liquid. Some manufacturers prepare the sac-
chariferous mash themselves, allow it to ferment by the addi-
tion of yeast, and then distil off to between 12 and 15 per cent,
by volume. As the manufacture of yeast is frequently com-
bined with that of vinegar, the distillates obtained from the
fermented liquors are after skimming off the yeast utilized for
vinegar manufacturing purposes.
Alcohol being the initial material in the preparation of
alcoholic liquid, it is necessary to know exactly the per cent,
by weight of alcohol it contains. With the assistance of the
112 MANUFACTURE OF VINEGAR.
tables at the end of this volume, the content of alcohol in
spirits of wine can be readily determined by means of the
alcoholometer and thermometer.
With the temperature of the spirits of wine at exactly 59° F.,
it suffices to determine its specific gravity by testing with an
aerometer and to find the indicated figure in Table I (Hehner's
alcohol table). The figure in the next horizontal column gives
the per cent, by weight, and the next the per cent, by volume
of alcohol contained in the spirits of wine examined. Tables
II, III and IV give data relating to the proportion between
the specific gravity and per cent, by weight and volume of
spirits of wine of various concentration, as well as the decrease
in volume by mixing with water. Table V shows the relation
between the statements of Tralles' alcoholometer and a few
others used in different places.
The specific gravity as well as the volume of spirits of wine
varies with the temperature, and the statements of the aero-
meter for temperatures above the normal of 59° F. requires a
corresponding correction, the execution of which is simplified
by the use of Tables VI and VII. It being desirable, especially
during the cold season of the year, to raise the temperature of
the spirits of wine by mixing with water, Table VIII shows
how much water has to be added in order to obtain from
105.6 quarts of spirits of wine of known strength, whiskey of
any desired concentration.
In order to know exactly the yield of acetic acid which is
obtained from a given quantity of alcohol, the acetic acid con-
tained in the vinegar added must necessarily be taken into
account as well as the alcohol in the beer, which is, of course,
converted into acetic acid. It is best to make the content of
alcohol in the alcoholic liquid so that it produces vinegar
whose strength corresponds with that of the vinegar added.
If, for instance, vinegar with 7 per cent, of acetic acid is used,
alcohol of 7.G to 7.7 per cent, by weight would have to be
employed according to the table on page 109. The following
compilation shows the manner of preparing alcoholic liquid
.according to rational principles.
PREPARATION OF THE ALCOHOLIC LIQUID. 113
Suppose vinegar with 7 per cent, acetic acid is to be pre-
pared. There would be required —
Spirits of wine of 7.6 to 7.7 per cent, by weight 105.6 quarts.
Vinegar with 7 per cent, of acetic acid 10.56 "
Beer . 10.56 "
Suppose the beer contains, for instance, exactly 3 per cent,
by weight of alcohol, hence 10.58 ounces in 10.56 quarts.
According to this, a result of 126.78 quarts of vinegar with
exactly 7 per cent, of acetic acid could not be expected, since
10.56 quarts of the alcoholic liquid do not contain, as should
be the case, 26.82 to 27.18 ounces of alcohol, but only 10.58
ounces. Hence actually to obtain vinegar with 7 per cent, of
acetic aci$ a sufficient quantity of spirits of wine will have
to be added to the alcoholic liquid to increase the content of
alcohol by 16.22 to 16.57 ounces, or spirit of wine with more
than 7.6 to 7.7 per cent, by weight will have to be used from
the start.
It will, of course, be understood, that the data given above
hold good only for the quality of the vinegar in reference to
its content of acetic acid, the factor of the qualitative yield
being left out of consideration. The material lost in the
course of production amounts, as previously stated, to at least
15 per cent., and in determining the quality of the vinegar
to be produced this circumstance has to be taken into con-
sideration.
The content of acetic acid in vinegar can be determined with
great ease and accuracy (up to T5^ per cent.) by volumetric
analysis, and from the result of such determination it can be
readily seen how near the correct proportion of alcohol in the
alcoholic liquid has been attained, and should the latter con-
tain too little of it, it can be readily brought up to the deter-
mined percentage by the addition of some strong spirit of wine,
or, if too much, by the addition of some water.
Constitution of the Fundamental Materials used in the Prepara-
tion of Alcoholic Liquids. — Spirits of wine, water, vinegar, and
8
114 MANUFACTURE OF VINEGAR.
in most cases beer, constitute the fundamental materials for
the preparation oi alcoholic liquids.
. Any kind of wholesome drinking water is suitable for the
manufacture of vinegar. Water containing a large amount of
organic substance or living organisms, or which possesses a
specific taste from the admixture of salts, should not be used
under any circumstance.
Many well-waters are very hard, i. e., they contain a com-
paratively large quantity of calcium carbonate in solution. If
such water be used in the preparation of alcoholic liquid, the
calcium carbonate is decomposed by the acetic acid and the
vinegar contains a corresponding quantity of calcium acetate
in solution. Other well-waters contain a large quantity of
gypsum (calcium sulphate) in solution. This salt is not
changed by acetic acid, but remains partially dissolved in the
finished vinegar.
When water very rich in gypsum is mixed with alcohol the
fluid, at first entirely clear, becomes in a short time opalescent
and finally perceptibly turbid. After long standing a very
delicate white sediment separates on the bottom of the vessel,
the fluid becoming again clear. This phenomenon is ex-
plained by the fact that gypsum, while soluble in water with
comparative ease, is next to insoluble in a fluid containing
alcohol, and hence gradually separates in the form of minute
crystals.
Water containing no gypsum but much calcium carbonate
shows after mixing with spirits of wine a similar behavior ; it
at first becoming turbid and again clear after separating a deli-
cate white precipitate. Calcium carbonate is soluble only in
water containing a corresponding quantity of carbonic acid ;
on standing in the air the carbonic acid escapes and the cal-
cium carbonate separates.
This behavior of water when mixed with alcohol and stand-
ing in the air can be utilized for the almost complete separation
of the gypsum and calcium carbonate. Mixtures of water and
alcohol, in the proportion the alcoholic liquids are to have, are
PREPARATION OF THE ALCOHOLIC LIQUID. 115
first prepared and the fluid stored in barrels in a warm apart-
ment near the workroom. The mixtures at first turbid be-
come clear after some time, and are then drawn off from the
sediment by means of a rubber hose. A comparative exami-
nation of the water and the mixtures shows that the latter
contain only very small quantities of gypsum and calcium
carbonate in solution.
River water, though generally soft, i. e., poor in the above-
mentioned salts, is seldom sufficiently clear to be used without
previous filtration. It is further very likely that the small
worms, known as vinegar eels, which frequently become very
annoying in vinegar factories, reach the alcoholic liquid
through the use of river water, and, therefore, the use of well-
water wherever possible is recommended.
The constitution of the spirits of wine used in the prepara-
tion of the alcoholic liquids is of great importance, the bouquet
of the vinegar to be prepared depending on it. Commercial
spirits of wine always contains certain foreign bodies known as
" fusel oils," which have a very intense odor and can only be
removed by careful rectification. For the vinegar manufac-
turer it is of great importance to know the behavior of spirits
of wine containing fusel oil when converted into acetic acid,
and a number of experiments with different varieties (from
potatoes, grain, wine) have shown the respective vinegar also
possessed of a specific odor, differing, however, from that of
the original fusel oil and developing by storing into a bouquet
of a peculiar but agreeable odor. This phenomenon is ex-
plained by the fact that the energetic oxidizing process which
takes place in the generators extends not only to the alcohol
but also to the other bodies present, and the greater portion of
the fusel oils is thereby converted into odoriferous combina-
tions or compound ethers.
By treating potato fusel oil (amyl alcohol) with sulphuric
acid and an acetate, amyl acetate is formed which in a diluted
state smells like jargonelle pears and is used by confectioners
under the name of " pear essence " for flavoring so-called fruit
116 MANUFACTURE OF VINEGAR.
bonbons. The same process would seem to take place by
passing spirits of wine containing potato fusel oil through the
generators, the vinegar prepared from such spirits of wine
showing an agreeable odor immediately when running off
from the generators, while vinegar prepared from entirely pure
spirits of wine has at first a stupefying smell and acquires a
harmonious odor only by long storing.
It would, therefore, be advisable for the manufacturer who
works with potato alcohol not to use the highly rectified pro-
duct, but a mixture of it and of crude spirits containing fusel
oil, the vinegar prepared from such a mixture acquiring a
more agreeable odor than that obtained from the rectified pro-
duct. How much of the crude spirits has to be used can only
be determined by experience, but, as a rule, only enough
should be taken to assure the conversion of the entire quantity
of amyl alcohol present.
The fusel oil contained in spirits of wine from grain consists
largely of a mixture of fatty acids, and offers far greater resist-
ance to oxidation in the generators than amyl alcohol. The
same may be said of cenanthic ether, the fusel oil of brandy.
In working with alcoholic liquid prepared with a large quan-
tity of grain spirits containing fusel oil, the smell of un^
changed fusel oil is perceptible in the vinegar besides the odors
of the products of its decomposition. With the use of small
quantities of grain spirits containing fusel oil, vinegar possess-
ing a more agreeable odor than that from entirely pure spirits
is obtained.
CHAPTER XII.
EXECUTION OF THE WORK IN A VINEGAR FACTORY.
WHEN the factory is in proper working order the further
execution of the operation is very simple, it being only neces-
sary to admit at stated intervals to the generators a previously
EXECUTION OF THE WORK IN A VINEGAR FACTORY. 117
determined quantity of alcoholic liquid and to collect the
vinegar running off. With the operation running its proper
course, attention has only to be paid to the maintenance of the
correct temperature in the workroom and in the generators,
the chemical process proceeding regularly without further
assistance. In many cases, however, deviations from the reg-
ular order occur, and are due to external influences, such as
changes in the temperature in the generators, variations in
the composition of the alcoholic liquid, etc. They will later
on be discussed in a special chapter.
The capacity of a factory depends on the number of gen-
erators in operation. A regularly working generator is sup-
posed to be capable of daily converting 3 liters (3.16 quarts)
of absolute alcohol, and this quantity will be taken as the basis
for calculating the execution of the operation. If, for instance,
vinegar with 8 per cent, of acetic acid is to be manufactured,
alcohol of 8.8 per cent, by weight has to be used, and to pre-
pare this, 3 liters of 100 per cent, alcohol have to be reduced
with water, so that, according to Table I, the fluid shows a
specific gravity of 0.9858 at 59° F. According to Table III,
8.98 liters of water have to be added to every liter of 100 per
cent, alcohol to obtain spirits of wine of 8.8 per cent, by
weight ; hence 3 liters have to be compounded with 2G.94
liters of water (according to Table III, alcohol with 90 per
cent, by volume of alcohol contains 11.80 per cent, by volume
of water, 80 per cent, alcohol 22.83, etc., which has to be
taken into consideration in making the dilution).
According to Table III, the contraction in this case amounts
to 0.799 part by volume for every 100 parts by volume of the
fluid. Hence the 3 liters of 100 per cent, alcohol yield, when
diluted to spirits of wine of 8.8 per cent, by weight, 26.94 + 3
= 29.94 liters of fluid. Actually the quantity is somewhat
smaller, as in mixing alcohol with water a decrease in vol-
ume takes place. If the alcoholic liquid is to contain 10 per
cent, each of vinegar and beer, the quantity of fluid is as
follows : —
118 MANUFACTURE OF VINEGAR.
Dilute spirits of wine ........ 29.94 litres.
Vinegar with 8 per cent, acetic acid ..... 2.994 "
Beer 2.994 "
35.928
Hence the quantity to be worked in a generator in the course
of a day amounts to 35.928 liters, or taking into account the
quantity of alcohol (about 90 grammes or 3.17 ozs.) contained
in the beer, to about 36 liters. This quantity has to be divided
among the separate pourings so that in a working time of 15
hours, 2.4 liters would have to be poured every hour. How-
ever, by this method, too much alcohol would, on the one
hand, be lost by evaporation, and, on the other, the work of
the generators would be comparatively slow, since, as is well
known, the conversion into acetic acid is effected with greater
rapidity when the alcoholic liquid contains less alcohol.
Hence it is advisable to use in the commencement of the oper-
ation a fluid which contains only about one-half or two-thirds
of the total quantity of alcohol, and to add a corresponding
quantity of strong alcohol to every fresh pouring.
When all the alcohol has been converted into acetic acid,
the vinegar ferment, as previously mentioned, commences^with
great energy to oxidize the latter to carbonic acid and water,
and hence the quantity of spirits of wine added to the alcoholic
liquid must be sufficiently large for the vinegar running off to
contain always a minute quantity of it.
Much has been written about this gradual strengthening of
the alcoholic liquid with alcohol, and explicit directions are
given as to the original composition of the alcoholic liquid, as
well as to how much, how often, and when the alcohol is to be
added. These directions may have proved useful in many
cases, but local conditions exert too great an influence upon
the process of manufacture for them to be of general value.
Besides the content of alcohol in the alcoholic liquid, the size
of the generators, the strength of the draught in them, the
temperature prevailing in the workroom and in the interior of
the generators, are factors which must be taken into consider-
EXECUTION OF THE WORK IN A VINEGAR FACTORY. 119
ation in determining on a plan of operation actually adapted
to existing conditions.
The size of the generators is, of course, fixed once for all.
In a proper state of working the strength of the current of air
must be so regulated that the temperature in the interior of the
generators is only about 4.5° F. higher than that of the work-
room, which is readily accomplished with a suitable central
heating apparatus. There still remains the determination of
the most favorable proportion of the content of alcohol in the
alcoholic liquid to be first used and its gradual strengthening
by the addition of spirits of wine, which can only be effected
by a chemical examination of the fluid running off from the
generators.
This chemical examination is restricted to the accurate de-
termination of the quantity of acetic acid in the fluid and to
that of the alcohol to 0.1 per cent. The determination of the
acetic acid is effected by volumetric analysis, and with some
experience requires four to five minutes for its execution. For
the determination of the alcohol an examination with the
ebullioscope suffices, which can also be accomplished in four to
five minutes.* These two determinations, which every vine-
gar manufacturer should be able to make, are the only means
of obtaining an accurate control of the working of the factory,
and also serve, of course, for settling the exact plan of opera-
tion from the start.
If, with reference to the example given above, vinegar with
8 per cent, of acetic acid is to be prepared, the alcoholic liquid
must contain a total of 8.8 per cent, by weight 'of alcohol.
Now if the manufacture is commenced with an alcoholic liquid
containing the total quantity of water, vinegar, and beer, but,
for instance, only 5 per cent, by weight of alcohol, the follow-
ing method will have to be pursued in order to accurately
determine when and how much alcohol has to be added.
The first portion of the alcoholic liquid being poured into
* The manner of executing these determinations will be described later on.
120 MANUFACTURE OF VINEGAR.
the generator, the fluid running off is tested as to its content
of acetic acid and alcohol, the test being repeated after the
second and each successive pourings. Each test must show an
increase in the content of acetic acid and a decrease in that of
alcohol, and the latter must finally have disappeared so far
that a new addition of alcohol seems to be in order. If the
test after the third pouring shows the fluid to contain only 0.3
to 0.4 per cent, of alcohol, this quantity would be quickly and
completely oxidized in the fourth pouring, and a certain quan-
tity of acetic acid be at the same time destroyed. Hence it is
necessary to add, for instance, 2 per cent, by weight of alcohol
to the alcoholic liquid before the fourth pouring. When this
2 + 0.3 or 2 -f- 0.4 per cent, of alcohol, which the alcoholic
liquid now contains, is again reduced, after the sixth or
seventh pouring, to 0.3 or 0.4 per cent., the last addition of
1.8 per cent, of alcohol is made, the total quantity of alcohol,
5 + 2 + 1.8 = 8.8 per cent, having now been used.
When, after a certain number of pourings, a test of the fluid
running off shows a content of 8 per cent, of acetic acid and
only 0.1 or 0.2 per cent, of alcohol (a small remnant of alcohol
should always be present) the process is considered as finished,
and a further pouring into the generator would not only be
useless labor, but contrary to the end. in view, since, after the
complete oxidation of the last remnants of alcohol, that of
acetic acid would immediately commence, and weaker vinegar
would be obtained after each pouring.
If a generator works up the quantity of alcoholic liquid in-
tended for 12 or 15 hours in 10 or 12 hours, it is more proper,
on account of the diminished loss by evaporation, to induce
slower work by decreasing the draught of air in order to
maintain the rule that a generator has to work up 3 liters of
absolute alcohol in the working time of a day.
After controlling for several days the work of a generator,
by examining the products as to their contents of acetic acid
and alcohol, the plan of operation resolves itself from the
results of these tests, since then it is accurately known after
EXECUTION OF THE WORK IN A VINEGAR FACTORY. 121
how many pourings of an alcoholic liquid of known composi-
tion an addition of alcohol is required ; further, after how many
pourings a finished product is present, so that directions for
the progress of the operation can be given to the workmen ac-
cording to time and quantities. The normal working of the
generators can always be controlled by from time to time re-
peating the test of the products.
Now, suppose the work in a newly arranged factory having
reached the point at which acetification is complete, the actual
production, according to the old method, will be gradually
commenced by pouring in alcoholic liquid of corresponding
concentration.
The shavings of the generator having been saturated with
acetifying vinegar, the latter is partially replaced by the fluid
poured in, and as much as is expelled runs off. If the gener-
ator should at once commence to work regularly, the tempera-
ture in its interior would be observed to rise, though it would
at first be impossible to establish a change in the composition
of the fluid running off. Slight variations in the content of
acetic acid and a small percentage of alcohol could be deter-
mined in the fluid only after the acetifying vinegar originally
present has been entirely expelled by a series of pourings.
With the progress in the manufacture of vinegar, it became
customary to produce the strongest vinegar possible, the so-
called triple vinegar, with about 12 per cent, of acetic acid.
On account of its greater commercial value, this article could
be sent greater distances, the consumer reducing it to a weaker
product by the addition of water.
To prepare directly vinegar with such a high percentage of
acetic acid, it would, however, be necessary to acetify all the
generators with vinegar of the same strength, and to use alco-
holic liquid very rich in alcohol. By this method the losses of
alcohol by evaporation, and also of acetic'acid, would, however,
be so great as to make the product too expensive. Further-
more, the work would require most careful and constant atten-
tion on account of the difficulty with which oxidation takes
122 MANUFACTURE OF VINEGAR.
place in alcoholic liquid containing much acetic acid, and it
might only too readily happen that the generators suddenly
worked with less vigor, i. e., that the content of acetic acid in
the vinegar running off would decrease, and the quantity of
alcohol remaining unchanged correspondingly increase.
On account of these difficulties, it has become customary to
charge the greater number of generators with alcoholic liquid
yielding the so-called double vinegar with about 8 per cent, of
acetic acid, and to work this vinegar with the addition of the
required quantity of strong spirits of wine in a number of
generators, which, of course, must be acetified with 12 per
cent, vinegar.
It will be readily understood that the employment of this
method is not only advantageous for the production of vinegar
with the highest attainable content of acetic acid, but also for
general purposes. Passing the alcoholic liquid but once
through the generators does not suffice, even for vinegar with
only 5 to 6 per cent, of acetic acid, an examination always
showing a considerable quantity, J per cent, and more, of un-
converted alcohol in the vinegar running off. The conversion
of alcoholic liquid with a small content of alcohol into vinegar
by one pouring can, to be sure, be accomplished, but it neces-
sitates the use of very tall generators and a constant struggle
with difficulties on account of the irregular draught of air,
caused by the packing together of the shavings.
Group System. — Theoretically, as well as practically, the
group system may be considered as the perfection of the quick
process. The principle of the operation consists in the divi-
sion of the generators into two or three groups, each group
preparing vinegar of determined strength. In factories which
do not produce vinegar of the greatest attainable strength (12
per cent, vinegar), but only double vinegar with about 8 per
cent, of acetic acid, two groups might suffice. The manufac-
ture of a product of the greatest attainable strength being,
however, advisable in most cases, it is recommended to ar-
range the factory for continuous work with three groups of
generators.
EXECUTION OF THE WORK IN A VINEGAR FACTORY. 123
For this purpose the number of generators must be divisible
by three; Hence 3, 6, 9, 12, etc., generators have to be pro-
vided, of which 1, 2, 3, 4, etc., form one group, so that, for in-
stance, in a factory working with 24 generators belonging to
one group with the same number, we have groups I, II and
III, and in acetifying and operating, the generators belonging
to one group are treated in the same manner.
For the preparation of the strongest vinegar (12 per cent.)
the generators belonging to group I can, for instance, be acet-
ified with vinegar of 6 per cent, acetic acid, those of group II
with 9 per cent, vinegar, and those of group III with 12 per
•cent, vinegar. The process of operation is then as follows : —
Group I'. The generators belonging to this group are
charged with an alcoholic liquid which yields vinegar
with a content of 6 per cent, acetic acid, and the fluid
running off is poured back into the generators until a
test shows the alcohol, with the exception of a small
remnant, to have been converted into acetic acid. To
this vinegar is then added sufficient strong alcohol to
form an alcoholic liquid which will yield 9 per cent,
vinegar.
Group II. The alcoholic liquid for 9 per cent, vinegar- is
poured into the generators belonging to group II, the
pourings being repeated until all but a very small quan-
tity of the alcohol is oxidized. The vinegar running
off is again compounded with sufficient alcohol to form
alcoholic liquid for 12 per cent, vinegar, and is brought
into
Group III. The pourings are here repeated until the oxi-
dation of alcohol is nearly complete. The finished
product is then stored or clarified.
As will be seen from the above, in operating according to
the group system, the entire factory is, so to say, divided into
three factories, I, II, and III, of which I produces vinegar of
6 per cent., II vinegar of 9 per cent., and III vinegar of 12
124 MANUFACTURE OF VINEGAR.
per cent. The product of I, after having been converted by a
suitable addition of alcohol into alcoholic liquid adapted for
the preparation of 9 per cent, vinegar, is directly used for
charging the generators of group II, and that of II for charg-
ing III.
The generators belonging to one group having been aceti-
fied with vinegar of the same strength, the fluid running off
from one generator need not necessarily be returned to it.
The work can, therefore, be simplified by conducting the fluid,
running off from all the generators by means of a suitable
pipe-system into a common receiver instead of allowing the
fluid, which has passed through a generator, to collect under
a false bottom and then drawing it off and returning it to the
same generator. If, for instance, 8 generators belong to one
group and 3 litres have at the same time been poured into
each, the passage of the liquid through all the generators will
be shown by a measuring scale placed in the common receiver,
indicating that the latter contains 3x8=24 litres.
The samples for determining the content of acetic acid and
alcohol are taken from the common receiver, and the latter
also serves for the conversion of the vinegar, after it has ac-
quired the percentage of acid attainable in that group, into
stronger alcoholic liquid by the addition of alcohol. In order
to effect an intimate mixture, and at the same time prevent
the vinegar ferment floating in the fluid from suffering injury
by coming in contact with the highly concentrated spirits of
wine, the required quantity of the latter is introduced in a
thin jet and with constant stirring.
In many factories it is customary from time to time to alter-
nate with the pourings in the groups or " to cross the genera-
tors." By this " crossing " the alcoholic liquid, which, accord-
ing to the above method, would, for instance, pass from group
II to group III, is poured into group I, so that after some time
the generators of this group are converted into generators of
group III (with 12 per cent, acid), and group III becomes
group I, it now containing the weakest alcoholic liquid (with 6
EXECUTION OF THE WORK IN A VINEGAR FACTORY. 125
per cent. acid). Crossing, however, cannot be recommended,
because a sudden change in the constitution of the nourishing
fluid always exerts an injurious influence upon the propaga-
tion of the vinegar ferment.
Recourse to crossing is most frequently had for the purpose
of " strengthening " the vinegar ferment by working weaker
alcoholic liquid in the generators of one group— generally that
which yields the strongest vinegar — when their activity dimin-
ishes. This strengthening of the ferment can, however, be
effected in a more simple and suitable manner by diminishing
the quantity of alcoholic liquid poured in at one time and by
increasing the draught of air, and the consequent change of
temperature in the generators, so that the principal reasons for
" crossing the generators " (which many manufacturers consider
indispensable) have no force.
Group System with Automatic Contrivances. If the pourings
of the alcoholic liquid are to be effected at determined inter-
vals by an automatic contrivance, the group system as de-
scribed on p. 122 et seq. should be used. The operation of
such a factory is very simple. As seen from the description
of the arrangement, the generators are divided into three
groups, I, II, and III. Besides the generators each group must
be provided with a reservoir, which may be designated R, and
a collecting vessel C. (The other component parts, distribu-
ting arrangements and conduit, can here be left out of con-
sideration.)
For the production of 12 per cent, vinegar in such a factory
it is the best so to prepare the alcoholic liquid for the several
groups that
Group I contains alcoholic
liquid with . . . . 6 p. c. acetic acid and 6.5 to 6.6 p. c. alcohol.
Group II contains alcoholic
liquid with .... 9 " +3.2 to 3. 3
Group III contains alco-
holic liquid with . . . 12 " " +3.2 to 3.3
126 MANUFACTURE OF VINEGAR.
Group I having been acetified with 6 per cent, vinegar,
group II with 9 per cent, vinegar, and group III with 12 per
cent, vinegar, the fluid running off from group I, after being
compounded with 3.2 to 3.3 per cent, of alcohol, is used in
group II as alcoholic liquid for 9 per cent, vinegar, and yields
9 per cent, vinegar, which after being again compounded with
3.2 to 3.3 per cent, of alcohol, yields 12 per cent, vinegar after
having passed through group III.
The uninterrupted working of the generators constituting
one of the principal advantages of the automatic system, it is
advisable to regulate the automatic contrivance so that but a
small quantity of alcoholic liquid be at one time poured out,
and to fix the intervals between two pourings so that the sec-
ond pouring takes place after about one-half of the first has
run off. Under these conditions there will be in the lower
half of the generator an alcoholic liquid in which the alcohol
is nearly as much oxidized as it can be by one passage through
the generator, while in the upper half will be fresh alcoholic
liquid in which oxidation is continued without interruption.
A further advantage obtained by this is that a generator will
yield quantitatively more than one working only 15 to 16
hours ; further, the conditions of temperature in the interior
of the generator remain always the same, and the ferment con-
stantly finds nutriment.
The alcoholic liquid for group I is pumped into the reser-
voir B^ and passes through the generators of group I into the
collecting vessels Cr All the alcoholic liquid having run off
from RV the fluid collected in Cv after having been tested as
to its content of acetic acid, is for the second time pumped in-
to R! and passes again through the generators of group I. The
automatic contrivance is so regulated that the alcoholic liquid,
after being twice poured in, contains but a very small remnant
of alcohol.
To the vinegar of 6 per cent, collected in Gl is now added
3.2 to 3.3 per cent, by weight of alcohol, best in the form of
80 to 90 per cent, spirits of wine. The resulting stronger alco-
EXECUTION OP THE WORK IN A VINEGAR FACTORY. 127
holic liquid is at once pumped into J?2, and passing through
the generators of group II reaches the collection vessel C2. It
is then tested, pumped back into .7?2, and again collected in C2.
If it now shows the required strength, it is mixed with the
second portion of 3.2 to 3.3 per cent, by weight of alcohol and
is pumped into J?3, and after passing twice through the gene-
rators collects as finished vinegar in (73.
It will be seen from the above description of the process that
in making the tests, the product of all the generators of one
group is treated as a whole. A disturbance may, however,
occur in either one of the generators, and it would take consid-
erable time before its existence would be detected by a change
in the constitution of the entire product. The thermometer
with which each generator is provided is, however, a reliable
guide as to the activity of the latter, and if it shows in one of
them a temperature varying from 37° to 49° F. from that pre-
vailing in the others, it is a sure sign of the respective generator
not working in the same manner as the others, and the product
running off from it should be tested by itself as to its content
of acetic acid and alcohol.
Generally it will contain either no alcohol or very much of it.
In the first case the temperature of the respective generator is
higher than that prevailing in the others, and its activity has
to be moderated by decreasing the admission of air; in the
other case, the generator works too sluggishly, and the differ-
ence is sought to be equalized by increasing the current of air
or giving a few pourings of somewhat warmer alcoholic liquid.
With a good heating apparatus producing a uniform tempera-
ture in the workroom such disturbances will, however, but
seldom happen, and by the use of the above means the normal
working of the generators can be restored.
128 MANUFACTURE OF VINEGAR.
CHAPTER XIII.
DISTURBING INFLUENCES IN THE MANUFACTURE OF VINEGAR.
IN no other industry based upon the process of fermentation
are irregularities and disturbances of such frequent occurrence
as in the manufacture of vinegar. Besides the nourishing sub-
stances dissolved in the fluid and free oxygen, the vinegar fer-
ment requires a certain temperature for its abundant propaga-
tion, by which alone large quantities of alcohol can in a short
time be converted into acetic acid. By exercising the neces-
sary care for the fulfillment of these conditions serious dis-
turbances can be entirely avoided, and the slighter ones due
to insufficient acetic fermentation of the ferment readily re-
removed.
As regards- the nourishing substances of the ferment, irregu-
larities can actually occur only in working continuously with
an alcoholic liquid composed exclusively of water and alcohol.
In such alcoholic liquid the nitrogenous substances necessary
for the nutriment of the ferment are wanting, nor are the phos-
phates present in sufficient quantity. The consequences are
the same as in every insufficiently nourished ferment-organism •
The fermenting activity suddenly diminishes, propagation pro-
ceeds sluggishly and ceases entirely if abundant nutriment is
not introduced. Hence it may happen that from a generator
containing alcoholic liquid composed only of water, alcohol,
and vinegar, the greater portion of the alcohol suddenly runs
off unchanged, the temperature in the interior of the generator
at the same time falling, and the draught of air ceasing soon
afterwards. When these phenomena appear it should first be
ascertained whether the disturbance is not due to too slight a
current of air. For this purpose the draught-holes are entirely
opened, and if the temperature rises the generator gradually
resumes its normal working. If, however, no improvement is
observed, the disturbance is due to defective nutriment, and the
composition of the alcoholic liquid has to be changed, which is
DISTURBING INFLUENCES IN MANUFACTURE. 129
best effected by the addition of a few per cent, of beer or of
fermented alcoholic mash, either one of them containing a suffi-
cient quantity of phosphates and albuminous substances. The
use of sweet beer wort or malt extract has also been highly
recommended for ''strengthening weak-working generators."
These substances also furnish albuminous bodies and phos-
phates to the alcoholic liquid, but they also contain maltose and
dextrin, and as it has not yet been ascertained whether the
latter and the carbohydrates in general can be consumed and
digested by the ferment, they possibly may pass unchanged
into the vinegar. Honey and glucose are also sometimes used
for strengthening purposes, but while the former might be
useful on account of the abundance of salts and nitrogenous
substances it contains, no substances of any value to the fer-
ment are present in the latter. At any rate the addition of
beer, mash, or malt extract is to be preferred.
An addition of phosphate to the alcoholic liquid is also
claimed to produce a favorable effect upon the propagation of
the ferment. Commercial phosphoric acid is dissolved in
water and the solution neutralized with potassium, a solution
of potassium phosphate being in this manner obtained. The
vinegar ferment being very sensitive towards this salt, a very
small quantity of the solution, about 10ouo of the weight of the
alcoholic fluid may be added. The experiment must, how-
ever, be made very cautiously, and the effect upon the working
of the generator carefully noted.
Disturbances ascribable to the quantity of newly formed Acetic
Acid. Under proper working conditions the alcoholic liquid
brought into the generators should be completely converted
into vinegar, and theoretically, the product running off show
the same strength a? the vinegar used for acetification. Act-
ually there are, however, slight variations not exceeding a few
tenths of one per cent. Should greater differences appear, a
disturbance actually exists and may show itself in various ways.
The generator may work too feebly or too vigorously. In the
first case the content of acetic acid in the fluid running off de-
9
130 MANUFACTURE OF VINEGAR.
creases considerably, while that of alcohol increases. The
process of the formation of vinegar is, so to say, only half
carried through, a great portion of the alcohol being converted,
not into acetic acid, but into aldehyde. The greater portion
of this combination is lost to the manufacturer on account of
its low boiling point (71.6° F.), it escaping in the form of vapor,
the stupefying odor of which when noticed in the air of the
workroom is accepted by all manufacturers as indicative of a
disturbance in the regular working of the generators. This
odor, however, becomes perceptible only after the disturbance
has continued for some time, with the loss of a considerable
quantity of alcohol. Hence the control of the working of the
generators by a frequent determination of the acid becomes
necessary. Repeated observations of the thermometer also
furnish valuable hints about the progress of the chemical pro-
cess. The temperature in this case remains only for a short
time unchanged and soon falls, far less heat being liberated in
the mere conversion of alcohol into aldehyde than when oxi-
dation progresses to the formation of vinegar. These phe-,
nomena are indicative of the generator not being able to master
the alcoholic liquid introduced, and may be due to the pourings
being too large, or the temperature of the alcoholic liquid
poured in being too low, or finally to an insufficient draught
of air.
To restore the generator to a proper state of working, it is
best to try first the effect of smaller pourings, and then an in-
creased draught of air. If the disturbance was due to an in-
sufficient draught of air, the temperature soon rises and the
generator will be able to work up the regular quantity of alco-
holic liquid. By the use of alcoholic liquid of a somewhat
higher temperature the restoration of the normal conditions
can be accelerated.
A decrease in the content of acetic acid in the fluid running
off from the generators without the presence of alcohol being
shown, indicates a too vigorous process of oxidation, the alco-
hol being not only oxidized to acetic acid, but the latter further
DISTURBING INFLUENCES IN MANUFACTURE. 131
into carbonic acid and water. The temperature in the interior
of the generators rises considerably, about 45° F., above that
of the workroom.
In this case the restoration of the respective generator to a
proper state of working is not difficult and can be effected in
two ways, either by considerably decreasing the ventilation ot
the generator, or by pouring in a larger quantity of alcoholic
liquid than previously used.
Heating of the generators is generally due to faulty con-
struction. Generators of large dimensions, as a rule, become
too warm much easier than smaller ones, the phenomenon also
appearing more frequently in summer than in winter; and
" too warm " being just as injurious to the efficacy of the gen-
erators as " too cool," they must, during the warm season of
the year, be as carefully protected against too high a tempera-
ture as against cooling during the cold season. This is effected,
on the one hand, by a suitable ventilation of the workroom
during the night, and, on the other, by the use of alcoholic
liquid of a somewhat lower temperature during the hottest
season of the year. Moreover, disturbances from too high a
temperature of the exterior air need only be feared in coun-
tries with a very warm climate.
It has been frequently proposed to counteract a too vigorous
activity of the generators by the addition of a little oil of cloves
or salicylic acid which have the property of checking fermenta-
tion. Salicylic acid, especially,, is an excellent corrective for
the faulty working of a generator. It has to be used, however,
with great caution and only be added by the TTOOITO °f the
weight of the alcoholic liquid, and just in sufficient quantity
to attain the desired result. A large amount is injurious to
the ferment and might kill it.
" Sliming " of the Shavings in Generators. — This disturb-
ance sometimes occurs in a vinegar plant, and its progress gen-
erally ends in throwing the entire operation into complete
disorder so that finally no more vinegar can be produced.
After fruitless experiments nothing remains but to empty the
132 MANUFACTURE OF VINEGAR.
generator, wash the shavings with hot water and, after drying
and steeping them in hot vinegar, return them to the gen-
erator.
Sliming may be due to infection by foreign bacteria and
fungi, as well as to super-oxidation and the accumulation of
larger quantites of alcohol in the shavings which affects the
bacteria to such an extent that they have no longer the power
of forming acetic acid or only very sinall quantities of it, but
only aldehyde, the intermediate product between alcohol and
acetic acid.
The trouble begins to show itself by the generators commenc-
ing to work irregularly. While formerly a certain quantity of
alcohol was after a fixed number of pourings converted into
acetic acid, a large number of pourings are. now required to
attain the same result. The generators work slower and the
heat in their interior decreases. By heating the workroom
more strongly only a temporary improvement is brought about,
and the production of the generators becomes less and less, and,
finally, so low that work has to be interrupted. When the
disturbance has progressed thus far a disagreeable musty, in-
stead of the characteristic acid odor, is perceived in the work-
room. By allowing one of the faulty working generators to
stand for a few days without charging it with alcoholic liquid,
the temperature in the interior may rise considerably and pro-
ducts of putrefaction be developed to such an extent as to
taint the air of the workroom.
Long before this phenomenon becomes apparent, an altera-
tion takes place in the shavings. A shaving taken from a
normally working generator has the ordinary appearance of
wet wood ; but one taken from a generator working in the
above-mentioned faulty manner is coated with a slimy mass,
which is somewhat sticky, and can be drawn into short threads.
Viewed under the microscope this slimy coating presents a
structureless mass, throughout which numerous germs of vine-
gar ferment are distributed and sometimes the vinegar eels.
Independently of the presence of the latter, this slimy coating
DISTURBING INFLUENCES IN MANUFACTURE. 133
presents the same appearance as the so-called mother of vine-
gar. By placing a shaving coated with slime upright in a shal-
low dish, and filling the latter f the height of the shaving with
alcoholic liquid, the previously described delicate veil of vine-
gar ferment develops upon the surface, while the portion of the
shaving covered by the fluid is surrounded by flakes distin-
guished by nothing from mother of vinegar. Hence there can
scarcely be a doubt that the slimy coating actually consists of
the same structure to which the term mother of vinegar (see
p. 21) has been applied, and in searching for the cause of the
formation, it will generally be found to be due to conditions
similar to those which give rise to the formation of the latter.
An alcoholic liquid overly rich in young beer containing much
albumen, or one to which much malt extract or young fruit-
wine has been added, is apt to give rise to the formation of
mother of vinegar in the generators. The slimy coating thus
formed upon the shavings envelops the vinegar ferment and
prevents its immediate contact with the air ; consequently the
alcoholic liquid does not encounter as much ferment as is re-
quired for the complete oxidation of the alcohol, and the gen-
erators become weaker. This decrease in the production is, of
course, followed by a lower temperature in the generators, and
consequently by a decrease in the propagation of the ferment,
these unfavorable conditions finally becoming so great as to
bring the activity of the generators to a standstill.
The settlement of vinegar eels upon the surface of the mother
of vinegar has no connection with sliming. Should, however,
large masses of these animalcules happen to die in the genera-
tors for want of air, due to the constantly decreasing draught,
they quickly putrefy on account of the high temperature, and
give rise to the most disagreable odors.
A careful manufacturer will observe sliming at the com-
mencement of the evil, when it can be remedied without much
difficulty. First of all, the composition of the alcoholic liquid
must be changed by discontinuing the use of fluid containing
many carbohydrates and albuminous substances, such as
134 MANUFACTURE OF VINEGAR.
young beer, malt extract, young fruit-wine, it being best to
use alcoholic liquid of water, vinegar, and alcohol only until
the generators are entirely restored to a normal working
condition. The activity of the ferment is at the same time
increased by a stronger draught of air in the generators and
by raising the temperature of the workroom. In a few days
the generators will be again in a proper working condition,
which is recognized by the normal conversion of alcohol into
acetic acid.
If, however, the evil has progressed to a certain extent
FIG. 36.
nothing can be done but to empty the generators. Though
considerable labor is connected with this operation, there is
no further use of experimenting, since such nonsensical addi-
tions as beer-yeast, tartar, honey, etc., which have been pro-
posed as remedies, only accelerate the final catastrophe — the
entire cessation of the formation of vinegar. Should a dis-
turbance occur which cannot be accounted for by defective
nutriment of the ferment, want of air> or an incorrect state of
the temperature, the condition of the shavings should be at
once examined into, and if they show the first stages of sliming
DISTURBING INFLUENCES IN MANUFACTURE.
135
the evil should, if possible, be remedied by changing the com-
position of the alcoholic liquid. If the new alcoholic liquid
contains only water, vinegar, and alcohol, sliming cannot
progress, and the layers of slime upon the shavings will in a
short time disappear, they being partially utilized in the nu-
triment of the ferment, and partially mechanically washed
off by the alcoholic liquid running down.
Disturbances due to Vinegar Eels. In many factories filamen-
tous structures scarcely visible to the naked eye will frequently
be observed in the vinegar. When viewed under the micro-
FIG. 37.
scope they will be recognized as animalcules, to which the
term vinegar eel (Anguilla aceti) has been applied on account
of their form slightly resembling that of an eel. Fig. 36
shows a microscopical picture of a drop of vinegar swarming
with vinegar eeis slightly magnified, and Fig. 37 a vinegar
eel greatly magnified.
The animalcule consists of a cylindrical body running to a
sharp point. The mouth-opening is covered with small knots ;
the throat is globular and passes directly into the long intes-
tinal tube. The eggs are placed at about the centre of the
136 MANUFACTURE OF VINEGAR.
body in two tubes which unite to a plainly perceptible aper-
ture. The average length of the female is 0.0682 Paris inch
and that of the male 0.0486, the former being larger than the
latter in proportion of 1 : 1.3.
Vinegar eels can exist in dilute alcohol of the strength used
in making vinegar as well as in dilute acetic acid. In
alcoholic liquid containing much alcohol and acetic acid they
do not thrive as well as in weak liquid. Their part in the
manufacture ol vinegar is under .all conditions an injurious
one. The vinegar ferment can only carry on its function
correctly when vegetating upon the surface of the fluid and in
contact with air. The vinegar eel being an air breathing
animal always seeks the surface, and in an alcoholic liquid
which contains it, and upon whose surface an abundance of
ferment grows, actual combats between animalcule and fer-
ment can be observed, the former striving to force the latter,
which is inimical to its existence, under the surface and thus
render it harmless. (Submerged vinegar ferment, as is well
known, changes its conditions of existence aud becomes mother
of vinegar.) If the conditions are favorable for the develop-
ment of the animalcules, the latter overcome the ferment and
submerge it so that it can continue to exist only as mother of
vinegar, and consequently the process of the formation of
vinegar will be considerably retarded. Under conditions
favorable to the development of the ferment the reverse is the
case. The ferment floating upon the fluid consumes nearly
all the oxygen contained in the layer of air immediately above
the surface, and thus deprives the animalcules of a condition
necessary for their existence. A portion of them die and fall
to the bottom of the vessel, while another portion of them
escape to the sides of the vessel where they congregate imme-
diately above the surface of the fluid in such masses as to form
a whitish ring. These conditions can be readily induced by
pouring vinegar containing a large number of vinegar eels
into a flat glass dish and adding a fluid upon which vinegar
ferment has been artificially cultivated. In a few hours the
DISTURBING INFLUENCES IN MANUFACTURE. 137
ferment has spread over the entire surface and the animalcules
form the above-mentioned white ring on the sides of the vessel.
If by means of blotting paper the veil of ferment be removed
as fast as it propagates, the animalcules soon spread over the
entire fluid.
From the above explanation it is evident that the appearance
of vinegar eels in large masses threatens danger to the regular
working. When the animalcules reach the shavings the strug-
gle for existence between them and the ferment commences,
and their struggling to dislodge the latter may be the first cause
of the formation of slimy masses of mother of vinegar upon
the shavings. Since the vinegar eels consume oxygen, the air
in the generators becomes thereby less suitable for the nourish-
ment of the ferment, and consequently the generators will work
feebly. By accelerating the draught of air in the generators,
which is generally the first remedy tried, the development of
the ferment may again become so vigorous that a large portion
of the vinegar eels are killed, their bodies being found in the
vinegar running off. The dead vinegar eels remaining in the
generator, however, finally putrefy and give rise to the pre-
viously mentioned disagreeable odor. The processes of putre-
faction being also effected by bacteria capable of decomposing
nearly all known organic combinations (even small quantities
of such strongly antiseptic bodies as salicylic and carbolic
acids), it is evident that vinegar containing vinegar eels, can-
not possess good keeping qualities and must be subjected to a
special treatment, which will be referred to later on.
Several remedies for the suppression of vinegar eels in the
generators have been proposed, one of them consisting of the
introduction of vapors of burning sulphur, i. e., sulphurous
acid. Sulphurous acid, it is true, kills the vinegar eels, but
at the same time, the vinegar ferment, and if small remnants
remain, also the newly-introduced ferment. To restore a
generator thus treated, a large quantity of air must be blown
through it, which will remove the last traces of sulphurous
acid. An alcoholic liquid containing much living ferment is
then poured in.
138 MANUFACTURE OF VINEGAR.
The vinegar ferment can for many hours stand the exclusion
of oxygen without being destroyed, while the vinegar eels die
in a short time. This circumstance can be utilized for the de-
struction of the animalcules without recourse to other reme-
dies. The generator having first been brought into the high-
est state of activity by pouring in very warm alcoholic liquid
and opening all the draught-holes, is left to itself for 6 or 8
hours after closing all the draught-holes. The ferment in a
short time consumes all the free oxygen in the generators, and
the vinegar eels die from the want of it. By opening the
draught-holes and pouring in alcoholic liquid, the normal
formation of vinegar soon recommences.
The killing of a large number of vinegar eels in the above
manner is, however, of considerable danger to the regular
working of the factory, and the respective generators must be
watched with special care in order to meet at once any appear-
ance of putrefaction. It may sometimes succeed to keep up
the work undisturbed, the killed vinegar eels being gradually
removed from the generators by the vinegar running off. In
such critical cases, when the generator may at any moment
commence to work irregularly, the use of a very small quan-
tity of salicylic acid as an addition to the alcoholic liquid
would be advisable. The acid by checking putrefaction would
prevent the immediate decomposition of the killed vinegar
eels still present in the generators.
Should, however, signs of putrefaction appear, energetic
means should at once be taken to arrest its progress, it being
in this case best to sulphur the generator. This is effected by
closing all the draught-holes except one, and introducing into
the latter the nozzle of the apparatus whose arrangement is
shown in Fig. 38.
In a large clay vessel, best glazed inside, stands upon a tripod
a shallow dish. The cover of the vessel luted air-tight with clay
is provided with three openings. The opening in the center is
closed by a well-fitting clay stopper, while glass tubes bent at
a right angle and with a clear diameter of about J inch are
DISTURBING INFLUENCES IN MANUFACTURE.
139
cemented in the openings at the side. The tube reaching
nearly down to the plate is connected by means of a rubber
hose with a double-acting bellows, while the second tube lead-
ing directly from the cover is connected with a second clay
vessel. From the cover of this vessel a pipe leads to, and is
fitted into, the open draught-hole of the generator.
For use the apparatus is put together, as shown in the illus-
tration, and small pieces of sulphur are thrown through the
central aperture upon the dish. The sulphur is ignited by
throwing in a lighted sulphur match, and after closing the
aperture the bellows is put in operation. The product of the
FIG. 38.
combustion of the sulphur passes through the tube into the
generator, and in ascending dissolves the fluid adhering to the
shavings to sulphurous acid. The addition of sulphur and the
blowing-in of air are continued until the odor of burning sul-
phur is clearly perceptible in the upper portion of the genera-
tor. The second vessel which contains some water serves for
the condensation of the portion of the sulphur which is not
consumed, but only volatilized.
The sulphurous acid kills every living organism in the gen-
erator, and consequently all the germs of the vinegar ferment
are also destroyed.
After allowing the sulphured generator to stand a few hours,
140 MANUFACTURE OF VINEGAR.
fresh air alone is forced through it by means of the bellows.
The air-holes are then opened and the generator allowed to-
stand a few days for the sulphurous acid to be converted into
sulphuric acid by the absorption of oxygen. To bring this
generator again into operation, it is best to introduce at first a
number of pourings consisting only of vinegar, with a content
of acetic acid corresponding to that of the original acetification.
In consequence of the absorption of sulphuric acid by the
shavings, this vinegar becomes of no value as a commercial
article, but it can be used for the preparation of alcoholic
liquid.
The last traces of unchanged sulphurous acid having in this
manner been removed from the generator and the greater
portion of sulphuric acid adhering to the shavings washed out,
the generator is again acetified, this being best effected by
pouring in alcoholic liquid just run off from correctly working
generators.
Disturbances Due to Vinegar Lice (Vinegar Mites). — Unless
the most scrupulous cleanliness prevails, so-called vinegar lice
will always be found in the factory. They prefer places kept
constantly moist, and to which the air has access, for instance,
the draught-holes and the interior of generators beneath the
false bottom. As a rule, manufacturers do not pay much at-
tention to their presence, as they apparently exert no influ-
ence upon the regular working. That such, however, is not
the case, will be seen from the following occurrence : Some
years ago, the proprietor of a vinegar factory in Italy informed
Dr. Bersch, of Vienna, that millions of small animals had
appeared in the factory and penetrated into the generators,
the shavings to a certain height being covered with living
and dead animals, and by reason of the latter putrefying,
further operations had become impossible. Every drop of
vinegar running off from the generators contained one or more
of the mites. A small bottle half full of vinegar and closed
air-tight by a cork accompanied the communication. Al-
though the bottle had been sixty hours in transit, on opening
DISTURBING INFLUENCES IN MANUFACTURE.
141
it a number of living animals were found, congregated especi-
ally in the fissures of the cork. On examining them with the
microscope two forms (male and female?) could be clearly dis-
FJG.
tinguished, many being only one-quarter or one-half the size
of others. Figs. 39 and 40 show the two characteristic forms
FIG. 40.
of these animalcules. As far as it was possible to determine
their zoological position, they belong to the family Sarcoptidw.
142 MANUFACTURE OF VINEGAR.
No particulars as to their origin seem to be known, the manu-
facturer simply stating that they had come from the soil. under
the supports of the generators and gradually rendered the
latter ineffective. The generators were sulphured in the
manner above described, and again put into operation.
To prevent the vinegar mites from collecting in large masses,
scrupulous cleanliness must prevail in the factory. Especially
should the draught-holes be from time to time examined, and,
if mites be found, thoroughly cleansed with hot water, which
kills them. The mites might also be prevented from^ pene-
trating into the interior of the generators by rings of a sticky
substance (turpentine) around the draught-holes.
Vinegar- Flies. — Though, as far as known, the animals
known as vinegar-flies create no disturbance in the regular
working of the factory, they deserve mention because they
appear wherever a fluid passes into acetic fermentation. In
wine cellars, not kept thoroughly clean, these insects are fre-
quently found on the bung-holes of the wine-barrels, and in
factories in which the manufacture of wine vinegar is carried
on according to the old system, they often occur in great
swarms.
The vinegar-fly (Drosophila funebris, Meig) is at the utmost
0.11 inch long ; it is especially distinguished by large red eyes
sitting on both sides of the head and meeting in front. The
thorax and legs are red ; the abdomen, which is provided with
six rings, is black, with yellow stripes. The wings are longer
than the body. The larva is white, has twelve rings, on the
mouth two black hook-like structures, and on the back part of
the body four warts, two of which are yellow. In eight days
the larva is transformed into a yellow chrysalis.
The collection of these flies in large masses can be readily
prevented by keeping the factory thoroughly clean and being
especially careful not to spill any fluid.
SLOW PROCESS OF MAKING VINEGAR. 143
CHAPTER XIV.
SLOW PROCESS OF MAKING VINEGAR.
IN the manufacture by the slow process, barrels thoroughly
cleansed with boiling water and previously saturated with hot
vinegar are used. The bung-holes are left open or loosely
covered. Smaller barrels with a capacity of from 15 to 25
gallons are preferred, and earthenware pots holding only 3 to
5 gallons are also used, it being claimed that they are espe-
cially suitable for the preparation of very strong vinegar. The
barrels are arranged in tiers upon wooden supports in such a
manner that their contents can be readily withdrawn by means
of a faucet or a siphon. The heating apparatus may be either
stoves, a hot-air furnace, or an arrangement similar to that
employed in heating hot-houses. Due attention must be
given to the methods of maintaining an equable temperature.
For the induction of the formation of vinegar, finished
vinegar should be added to the dilute alcohol. By adding a
few slices of bread, or beer wort, or a decoction of resins, the
formation of vinegar can in many cases be accelerated, the
substances named offering nutriment to the vinegar ferment.
The mixture of weak alcohol and vinegar is called wash. It
is prepared from whiskey or alcohol, to which sufficient water
is added that the mixture shows a content of about 6 per cent,
of alcohol. To this weak spirit one-quarter or one-half of its
volume of vinegar is added. Suppose vinegar containing 4J
per cent, of acetic anhydride is to be made. Theoretically, the
wash should contain a little over 5 per cent, absolute alcohol,
but on account of the loss by evaporation of alcohol, a wash of
6 per cent, must be used. If in making this wash 80 per cent,
alcohol is employed, then the latter would have to be diluted
so that every gallon of it becomes 13f\ gallons. In other
words, to 100 gallons of 80 per cent, alcohol 1,250 gallons of
water are added, which makes 1,330 gallons of mixture, and
144 MANUFACTURE OF VINEGAR.
this, after the addition of 300 gallons of vinegar, becomes 1,630
gallons of wash. A portion of the water must be taken suffi-
ciently hot to give a temperature of 90° to 100° F. to the
wash. The resulting wash is placed in the fermenting barrels
to fill each one two-thirds full, and the temperature of the
apartment, observed by thermometers placed in different parts
of it, must be kept at between 75° and 100° F. At the mini-
mum temperature less fuel is required, but the time needed
for acetification is extended, and consequently more barrels
and a larger apartment are needed to make the same amount
of vinegar. With the maximum temperature the reverse is
the case.
Several days after the addition of the wash acetification be-
gins, and is indicated by a temperature in the barrels slightly
above that of the apartment. A piece of stone or slate, which
is usually laid over the bung-hole of each barrel to prevent too
great evaporation and consequent cooling, is bedewed with
moisture, and a pungent acid odor is perceived in the room.
As long as these indications continue, everything is going on
well, but every barrel must be examined by itself to at once
restore activity in any " lazy " one, lest putrefaction or mpuldi-
ness take place and spread to the neighboring barrels. When
this misfortune occurs, the bad barrels are at once removed
from the apartment, their contents thrown away, and the
barrels scoured well with brushes and water, and placed in the
sun. After they are dry they may be saturated with hot vine-
gar and brought into action again. If only " lazy," they are
excited by withdrawing a portion of their contents, which is
warmed in glass bottles, and with the addition of a little alco-
hol and vinegar is restored to the casks.
Too cool a location or a constant draught of air will some-
times put a cask out of action. This is remedied by re-
moval, after acetification is restored, to a warmer location, or
by covering with a non-conductor, such as heavy paper pasted
over it.
After a lapse of time dependent on the temperature which
SLOW PROCESS OF MAKING VINEGAR. 145
is kept somewhat higher towards the end of the operation,
acetification is complete. Otto gives the time generally re-
quired as follows :
With a temperature of Weeks required.
95° to 100° F. 2 to 4.
86° to 95° F. 4 to 8.
72° to 86° F. 8 to 16.
The close of acetification is indicated by the diminution of
the strong vinegar smell in the room, by the absence of vapor
condensing upon the slate covers of the bung-holes, and by
the temperature of the inside of the barrels becoming equal to
that of the room.
As soon as acetification in any one barrel is perfected, the
vinegar must at once be withdrawn, barreled and removed to
a cooler place than the vinegar room, in which its tendency
to spoil in the heated atmosphere is very great. The slimy de-
posit called " mother of vinegar " is removed, and the vinegar
with which it is imbued, employed in part for the next aceti-
fication. If the sediment from each barrel be placed in a cask,
the clear vinegar may be drawn off after the deposition of the
mother of vinegar. It is well before barreling the vinegar, to
allow it to stand for a short time in a cool room in a vessel
filled with beech shavings, which clarify it. When stored, a
pint of spirits should be added to each barrel.
As previously mentioned, the slow process above described
may be modified in various ways. Thus, instead of bringing
the fermentation to completion in all of the barrels at about the
same time, they may be divided into three or four groups, so
that J or J of the whole quantity of vinegar may be with-
drawn, and stored at intervals of J to J the time required for
the acetification of the whole quantity. This modification has
the advantage of a greater distribution of the work ; necessity
of a smaller quantity of vinegar stored for sale, and the pres-
ence of barrels in full action, emitting strongly acetic vapors,
which is of advantage in keeping up fermentation in barrels
10
146 MANUFACTURE OF VINEGAR.
just going into operation. The disadvantages consist in greater
need for entering and leaving the vinegar room, involving
loss of its heat, and requiring in consequence greater attention
to its fires. In addition to this the heat cannot be increased
towards the close of acetifi cation, which is useful in shortening
the time for manufacture.
Another modication consists in always keeping a large
quantity of vinegar in the fermenting barrels, and at short
intervals withdrawing small quantities of vinegar which are
replaced by fresh wash. This saves time, as acetification is
more rapid in the presence of large bodies of vinegar. It
involves loss of heat by a need for too frequently entering the
vinegar room. It involves also a loss of' interest upon the
value of the large quantity of vinegar kept in the fermenting
barrels. The intervals at which vinegar may be withdrawn
are closer in proportion to the heat of the apartment, which
bears a ratio to the amount of fuel consumed.
By this method only -J of the vinegar is removed at one time
from each barrel ; in other words, at intervals of one to two
weeks, according to temperature, one gallon of vinegar is with-
drawn from every 5 gallons in the fermenting barrels, and in its-
stead a gallon of wash is added. In a large factory, the latter
process requires a large number of barrels of vinegar to com-
mence operations. The vinegar must be either purchased or
made gradually in the fermenting barrels, not withdrawing any
until the barrels are sufficiently full. The advantage consists
in a smaller number of fermenting barrels being required than
by the method first described. Dr. Otto gives the following
calculation for the number of fermenting barrels required for
the slow process :
Suppose that it is required to furnish a barrel of vinegar per
day, excluding Sundays, which would equal 312 forty-gallon
barrels per year, the fermenting barrels would have each a ca-
pacity of J barrel, and since they are not filled with wash, and
on account of unavoidable loss, four such barrels may be allowed
to each barrel of vinegar made. What is added to make the
SLOW PROCESS OF MAKING VINEGAR. 147
wash is, of course, not accounted as manufactured vinegar, as
a like quantity must be added in the subsequent wash. From
every four fermenting barrels, one barrel of vinegar may be
sold, and hence 6 barrels of vinegar will require 24 fermenting
barrels. If the workroom be so heated that the operation is
completed in four weeks, 24 barrels of vinegar will have to be
drawn off, to do which 96 fermenting barrels will be required.
If, however, a lower temperature be maintained in the work-
room, say to complete the process in 16 weeks, 4 times 96 =
384 fermenting barrels, will be required. In the latter case
the expense of fuel is lessened, but that of the fermenting
barrels is increased. Besides, a larger apartment will be neces-
sary, which will involve a higher rent and greater expense for
fuel in heating it. If the process be modified, as described, so
that a large body of vinegar is always kept in the fermenting
barrels, their number may, as before stated, be proportionately
decreased.
This calculation affords the very best illustration of the
superiority of the modern quick process, over the old slow
method. To make one barrel per day by the quick process, a
small room and two generators are the only requisites.
Household Manufacture of Vinegar. — The following method
is to be recommended as simple, expedient, and furnishing a
constant supply of vinegar with scarcely any trouble and at
trifling cost :
Procure two barrels, the one for making, the other for stor-
ing the vinegar, barrels from which good vinegar has just been
drawn being preferable. The storage barrel is always kept in
the cellar, and the generating barrel in the house or cellar, ac-
cording to the season. At the top of one of the heads of the
storage barrel a small hole is bored for the circulation of air.
The barrels lie on their side, and each of them is furnished
with a wooden faucet. Their capacity is, of course, regulated
by the yearly demand.
Suppose that the generator, filled to the level of the venti-
lating hole, contains 10 gallons, the manufacture will then
148 MANUFACTURE OF VINEGAR.
be carried on as follows : Seven gallons of vinegar of a good
quality are placed in the barrel, and three gallons of warm
alcoholic liquid are added. This alcoholic liquid is made as
follows: If common 50 per cent, whisky be employed, have a
small measure of 3 pints and a large one (a bucket) of 3
gallons. If 86 per cent, alcohol is used, let the small measure
be for 2 pints. Put a small measureful of spirits in the large
measure ; fill quickly to the mark with boiling water, and
pour by means of a funnel into the generator. Every two or
three weeks, three gallons of vinegar are withdrawn from the
generator and added to the storage barrel, and three gallons of
alcoholic liquid are placed in the generating barrel as before.
Another method of working the casks consists in half filling
the generator with vinegar, and adding every week so much
of the alcoholic liquid that it fills the barrel in from 8 to 16
weeks, according to the season. Half the vinegar is then
added to the storage cask, and the process then recommenced
iri the generator. The warmer the season the more rapid
may be the manufacture.
Preparation of Vinegar with the Assistance of Platinum Black.
— In considering the theory of the formation of vinegar it was
mentioned that platinum in a finely divided state possesses the
property of converting alcohol into acetic acid. This property
of platinum has been utilized for the purpose of manufacturing
acetic acid on a large scale. The apparatus used for this pur-
pose consists of a small glass house, provided in the interior
with a number of compartments. The shelves forming these
compartments support a number of porcelain capsules. The
alcohol to be acetified is poured into these capsules, in each of
which is placed a tripod, also of porcelain, supporting a watch-
glass containing platinum black or spongy platinum. In the
roof and at the bottom of the apparatus are ventilators, so con-
structed as to admit of regulating the access of air. By means
of a small steam-pipe the interior of the house is heated to 79°
F. By this means the alcohol is gently evaporated, and com-
ing in contact with the platinum black or sponge is acetified.
TREATMENT OF FRESHLY-PREPARED VINEGAR. 149
So long as the ventilation is maintained, the platinum black
retains its property of oxidizing the alcohol. With an appa-
ratus of 52 cubic yards' capacity and with 37 pounds of plati-
num black, 150 quarts of alcohol can daily be converted into
pure vinegar. The drawbacks to this process are high prices
for alcohol, and the large quantity of the very expensive
platinum required for working on a manufacturing scale.
CHAPTER XV.
FURTHER TREATMENT OF FRESHLY-PREPARED VINEGAR.
THE vinegar running off from the generators is " finished "
in so far that it contains the quantity of acetic acid obtainable
from the content of alcohol in the alcoholic liquid, but it be-
comes a commercial article only by long storing and special
treatment.
The odor of freshly prepared vinegar is by no means agree-
able. It is very pungent and at the same time stupefying,
the latter property being no doubt due to small quantities of
aldehyde contained in it, which, however, volatilize or oxidize
by storing. The odor depends largely on the materials used
in the manufacture, that of vinegar prepared from an alcoholic
liquid composed of water and alcohol alone without an addi-
tion of beer being decidedly the least agreeable. By long
storing such vinegar acquires a somewhat finer odor, but never
especially agreeable properties.
The barrels for storing fresh vinegar should be filled up to
the bung-holes and closed air-tight, since when air is present
the ferment in the absence of alcohol consumes acetic acid,
thus reducing the strength of the vinegar ; and moreover, mold
ferment might develop.
The temperature of the vinegar running off from the gener-
ators being quite high, its volume diminishes on cooling, and
150 MANUFACTURE OF VINEGAR.
consequently the barrels when inspected later on will not be
quite full. When the vinegar is stored in barrels not made
air-tight by a suitable coating (lacquer, paraffin, etc.), the air
penetrates through the pores of the wood and a constant re-
ciprocal action takes place between it and the vinegar. The
very slow oxidation thus produced exerts a decidedly favorable
influence upon the odor of the vinegar, the processes thereby
taking place being somewhat similar to those which cause the
formation of the bouquet in wine. This similarity extends
also to the fact that the vinegar bouquet, if it may so be called,
is the finer the slower the effect of the oxygen, and this can
be reached by storing the barrels in a warehouse having a
temperature of from 57° to GO0 F., or in a cellar.
It has been sought to improve the odor of vinegar by various
additions, but that of volatile oils, such as oils of caraway,
fennel, anise, etc., which has been frequently proposed for the
purpose, cannot be recommended. These oils, to be sure, give
a specific, agreeable odor to the vinegar, but an expert can at
once detect such additions. More suitable for the purpose is
the use of a very small quantity (a few hundred-thousandths
of the weight of the vinegar) of potato or grain fusel oil, these
bodies forming with the corresponding quantity of acetic acid
the frequently mentioned odoriferous compound ethers. An
addition of J per cent, of very strong alcohol to the vinegar
has also a very favorable effect upon the odor of the latter,
acetic ether being formed in storing. In place of alcohol,
acetic ether or amyl acetate (pear essence) can be directly
added, but only in very small quantities and best in alcoholic
solutions of a determined content, for instance, 50 grammes of
pear essence to 1 liter of 95 per cent, alcohol. Of this solution
0.1 liter (= 100 cubic centimeters) contains 5 grammes of pear
essence, and if added to 100 liters of vinegar, which in round
numbers weigh 100 kilogrammes, the latter will contain Tooicro
of pear essence. By proceeding in this manner the correct
quantity required can be readily determined. Immediately
after the addition of one of the above-mentioned substances
TREATMENT OF FRESHLY-PREPARED VINEGAR.
151
its odor is disagreeably prominent, but becomes pleasant by
storing.
After lying for several weeks a muddy sediment forms on the
deepest place of the barrel. The vinegar can be carefully
drawn off from this sediment by means of a rubber hose ; or a
special apparatus, similar to that shown in Fig. 41, is used for
the purpose. It consists of the glass tube a, which is inserted
in the tap-hole of the barrel and reaches to the bottom, where
it is slightly bent 'upwards. In front of the bung-hole this
tube is provided with a bulb in which is fitted by means of a
cork a tube, b, bent at a right angle. While the vinegar is
stored, this tube stands upright as indicated by the dotted
FIG. 41.
lines, and is secured to a rubber hose reaching, up to the
bung-hole. By turning the tube downward, the fluid runs
out through the tube a, until its level has sunk to the dotted
line.
Sometimes the vinegar is not rendered perfectly clear by
storing, and filtering has to be resorted to. Before referring
to this operation a few words will be said in regard to the
storing of vinegar.
The vinegar brought into the storage barrels contains the
following constituents: Water, acetic acid, alcohol (very
little), aldehyde (very little), acetic ether, vinegar ferment
(living and dead), extractive substances (depending on the
152 MANUFACTURE OF VINEGAR.
nature of the alcoholic liquid used). Moreover, there are fre-
quently found alcoholic ferment (from the beer), and vinegar
eels and vinegar mites, if these animals exist in the factory.
By filling the storage barrels to the bung-holes and closing
them air-tight, the vinegar eels and vinegar mites die in a short
time for want of air, and fall to the bottom. The living vine-
gar ferment present in the fluid must assume the form in which
it can for some time exist without free oxygen, i. e., of mother
of vinegar. When in consequence of the shrinkage in the
volume of the vinegar by cooling, the air penetrates through
the pores of the wood, it is first utilized for the conversion of
the small quantity of aldehyde into acetic acid, and later on
enables the vinegar ferment to continue to exist upon the sur-
face and to slowly convert the small quantity of alcohol still
present into acetic acid.
If the barrels are not closed absolutely air-tight, the vinegar
ferment will develop quite vigorously upon the surface, and
when all the alcohol is consumed attack the acetic acid, so that
when the vinegar is tested a decrease in the content of acetic
acid is plainly perceptible. If the finished vinegar still con-
tains considerable quantities of albuminous substances in solu-
tion (vinegar from grain, malt, or fruit), or if it contains
tartaric and malic acids and at the same time only a small per-
centage of acetic acid, as most fruit vinegars do (seldom more
than 5 per cent.), Ihe mold ferment readily settles upon the
vinegar and finally dislodges the vinegar ferment from the
surface. The acetic acid is, however, very rapidly destroyed
by the mold ferment, and through a luxuriant growth of the
latter, which floats upon the surface as a white membranous
coating, the vinegar may in a few weeks lose one or more per
cent, of it. This happens so frequently, for instance with fruit-
vinegar, that the opinion that such vinegar cannot be made to
keep, is quite general.
Vinegar which, besides a considerable quantity of extractive
substances, contains the salts of certain organic acids (malic
and tartaric acids), for instance, vinegar prepared from apples
TREATMENT OF FRESHLY-PREPARED VINEGAR. 153
or wine, must be frequently examined, as it readily spoils, and
may suffer even if kept in barrels constantly filled up to the
bung. In fluids containing the salts of the above-mentioned
organic acids a ferment may frequently develop, even when the
air is excluded, which first decomposes the. tartaric and malic
acids, and though these acids are present only in a compara-
tively small quantity, they influence, to a considerable extent,
the flavor of the vinegar on account of their agreeable acid
taste. In vinegar in which this ferment has long existed a
diminution of acidity can be readily detected by the taste, and
by the direct determination of the acid a decrease in its con-
tent can be shown which, if calculated as acetic acid, may in
some cases amount to one per cent. Besides the loss of its
former agreeable taste, vinegar thus changed acquires a harsh
tang, due no doubt to the formation of certain products not
yet known formed by the ferment effecting the destruction of
the tartaric and rnalic acids. Moreover, wine or fruit-vinegars
in which this ferment has for a considerable time flourished,
lose their characteristic agreeable bouquet which may be con-
sidered the greatest damage.
In the presence of a large number of vinegar eels their bodies
may decay and impart to the vinegar a very disagreeable
putrid odor, even if stored in barrels closed air-tight.
The advisability of filtering the vinegar before bringing it
into the storage barrels will be readily understood from the
above statement. By filtration it is, however, only possible to
remove the vinegar eels and vinegar mites swimming in the
fluid and larger flakes of mother of vinegar. The ferments
and bacteria inducing putrefaction cannot be thus removed,
so that even filtered vinegar is liable to spoil when stored.
Heating the Vinegar. — In order to destroy all organisms
which might cause the spoiling of the vinegar, it is recom-
mended to heat the latter to about 140° F. before running it
into the storage barrels. A few moments exposure at this
temperature being sufficient for the purpose, a large volume
of vinegar can in a short time be heated with the use of a suit-
able apparatus, such as is shown in Fig. 42.
154
MANUFACTURE OF VINEGAR.
In the head of the barrel b is secured a pipe of pure tin with
very thin walls and a clear diameter of about j- inch. It is
-coiled in a boiler filled with water, which it enters at e/and
leaves at h. It then passes into the barrel b, in which it is also
coiled, and ends outside the barrel at g. At i it expands to a
bulb in which a thermometer, t, is placed. A vat, a, placed at
a certain height above the barrel is provided with a wooden
stop-cock, c, to which is secured a rubber hose, d, which enters
the barrel b above the bottom. The pipe k, which is secured
on top of the barrel b, is open on both ends and of sufficient
length to project above the vat a.
FIG. 42.
The boiler is filled with water and placed in an ordinary
hearth. The vat a is filled with the vinegar to be heated and
kept constantly supplied. The water being heated to boiling,
the stop-cock c is opened. The vinegar now runs through d
into the barrel b, and, after filling it, flows at e into the tin
coil and in passing through it in the direction of the arrows
is heated. The thermometer t dipping into the hot vinegar
indicates the temperature, and the inflow of vinegar is accord-
ingly regulated by opening or closing the cock c. As shown
in the illustration, the hot vinegar runs through the coil sur-
TREATMENT OF FRESHLY-PREPARED VINEGAR. 155
rounded by cold vinegar into the barrel b, whereby it is cooled
off and the vinegar in the barrel preparatorily heated. The
pipe k, open on both ends, allows the escape of the gases de-
veloped.
In consequence of the albuminous substances becoming in-
soluble by heating, the vinegar running off at g is, as a rule,
more turbid than before. It is brought into the storage bar-
rels, which need, however, not be closed air-tight, the subse-
quent processes taking place in the vinegar being of a purely
chemical nature and not caused by organisms. The latter
have been killed by heating, and, together with all other for-
eign bodies suspended in the vinegar, gradually fall to the
bottom of the barrel. If the vinegar after heating is allowed
to lie for a sufficiently long time, it clarifies completely and
€an be drawn off perfectly bright from the sediment.
Filtration of Vinegar. — The bodies suspended in the vinegar
and causing its turbidity being very small, it takes some time
before they settle on the bottom and the fluid becomes entirely
<?lear. To accelerate clarification the vinegar is filtered.
Fig. 43 shows a filter suitable for the purpose. It consists
of a small, strong wooden vat provided with two perforated
false-bottoms, s and b. Upon the lower false bottom is spread
a linen cloth and upon it fine sand, which is not attacked by
acetic acid, or small pieces of charcoal. Upon the smoothed
surface of the sand is spread a layer of paper pulp f to 1 inch
deep which is covered with a linen cloth and then placed upon
the false bottom b, the latter being forced down by means of
the screw k and the pieces of wood r. The vinegar to be fil-
tered is in the vat a which is connected with the filtering vat
by the stop-cock h and the rubber hose s, 8 to 10 feet long.
By opening the stop-cock h the filter stands under the pres-
sure of a column of fluid 8 to 10 feet high and the filtered
vinegar runs off through an aperture in the side of the filter-
ing vat. By filling the filter below the paper pulp with fine
sand, the latter retains the greater portion of the solid bodies
suspended in the vinegar, and it will be a considerable time
156
MANUFACTURE OF VINEGAR.
before the pores of the paper pulp become choked up to such
an extent as to require its renewal.
Sharp, fine-grained sand should be used for filtering. It
should be free from iron and sulphur and previous to use
freed as much as possible from lime and earthy constituents
by washing in pure water to which some hydrochloric or tar-
taric acid may be added. Fine white quartz sand is very
suitable for the purpose. White sea-sand is also highly
recommended for filtering vinegar, it being claimed that after
FIG. 43.
its use for several months not a single vinegar-eel was found
in the filtered product. When after long use the sand be-
comes so closely packed that the vinegar does not run off with
the rapidity desired, the layer of slime that has accumulated
upon the sand is carefully removed and the sand thoroughly
washed and dried, when it is again ready for use.
An arrangement suitable for filtering larger quantities of
fluid under an increased pressure is shown in Fig. 44.
It consists of a strong linen bag, 8, about 16 inches in diam-
TREATMENT OF FRESHLY-PREPARED VINEGAR.
157
FIG. 44.
eter, and a jute or hemp hose, R, open at both ends and about
6 inches in diameter. The bag is tied by means of pack-thread
to a cylindrical piece of wood which is secured to a suitable
support. The bag is then connected by means of the rubber
hose K with the reservoir B, which contains the vinegar to be
filtered, and is placed about 10 to 13 feet above the support
carrying the bag. The bag is folded so that it can be inserted
in the hose R, the latter being also secured to the cylindrical
piece of wrood.
By gradually opening the stop-cock on the reservoir the bag
is filled with vinegar, but being
enveloped by the hose R cannot
entirely expand but only so far
as permitted by the diameter of
R, so that though its entire
surface acts as a filter a large
number of folds are formed, and
it is thus protected from burst-
ing, even under the pressure of
a column of fluid of consider-
able height. The fluid filter-
ing through the bag runs down
on the hose and collects in a
vessel placed under it.
At first this filter generally
does not act entirely satisfac-
torily, the fluid running off tur-
bid ; and this continues until
the pores of the filter have be-
come sufficiently contracted to
retain the small bodies sus-
pended in the fluid. This can,
however, be remedied by stir-
ring some charcoal powder into
the first portion of vinegar to
be filtered. The charcoal powder adheres to the sides of the
158 MANUFACTURE OF VINEGAR.
bag and contracts the pores of the tissue so that the fluid runs
off entirely clear.
By subjecting the freshly-prepared vinegar to heating and
filtering, a commercial article is obtained which is perfectly
clear and does not spoil by keeping. By storing it, however,
for some time in barrels it gains considerable in fineness of
odor and taste. Wine-vinegar, cider-vinegar and fruit-vinegars
in general should positively be stored for some time, the
odoriferous bodies which make these varieties so valuable
developing only by that means.
Sulphuring of Vinegar. — Sulphuring has long been employed
as the most convenient method for the preservation of wine,
and, if correctly applied, can also be used for that of vinegar.
But as sulphurous acid readily dissolves in vinegar, the latter
must not be brought in direct contact with the gases arising
from the burning sulphur.
The sulphuring of vinegar is best executed as follows : The
barrel intended for the reception of the vinegar is thoroughly
rinsed and immediately placed in the storeroom. Then place
a sulphur match consisting of a strip of linen about 6 inches
long and f to 1 inch broad dipped in melted sulphur into a
perforated sheet-iron cylinder about 8 inches long and 1 inch
in diameter, secure this cylinder to a wire, and after igniting
the sulphur match, lower it from the bung-hole to the center of
the barrel. The sulphurous acid formed by the combustion
of the sulphur is at once dissolved by the water adhering to
the interior of the barrel. A sulphur match of the above size
suffices for a barrel of 100 to 125 gallons.
If the sulphured barrel be now immediately filled with vin-
egar, the sulphurous acid becomes distributed throughout the
fluid and kills the vinegar ferment as well as all other fer-
ments present, so that the vinegar cannot undergo any further
change except it come again in contact with living ferments.
The sulphurous acid dissolved in the vinegar is after some
time converted into sulphuric acid and its presence can be
readily detected. It may, however, be remarked that the
TREATMENT OF FRESHLY-PREPARED VINEGAR.
quantity of sulphuric acid which reaches the vinegar in the
above manner is exceedingly small, and, moreover, is partially
fixed to the mineral bases (lime and magnesia) contained in
the water used in the preparation of the alcoholic liquid.
Hence a manufacturer who sulphurs his barrels need not fear
being accused of having adulterated his vinegar by the direct
addition of sulphuric acid. Sulphured vinegar must be stored
at least several weeks before it is salable, the odor of sulphur-
ous acid adhering to it perceptibly, and disappearing only at
the rate at which the sulphurous acid is converted into sul-
phuric acid.
Fining Vinegar. — Similar to wine, vinegar can be obtained
bright by " fining " with isinglass. This method is employed
by a number of manufacturers though it offers no advantages
as compared with filtration. The isinglass to be used is pre-
pared as follows : Cut with a pair of scissors into narrow strips
J to 1 drachm of isinglass for every 20 gallons, and soak it in
water in a porcelain dish for 24 hours. The resulting jelly-
like mass is pressed through a linen cloth. A solution of J to
| drachms of tannin for every 20 gallons is then added to the
isinglass and the mass diluted with vinegar. The whole is
then thrown into the barrel and thoroughly mixed with th&
contents. The clarified vinegar is finally drawn off from the
sediment.
Coloring Vinegar. — Vinegar prepared from alcohol is limpid
as water or only slightly colored. Prior to the general intro-
duction of the quick process consumers "were accustomed to
the dark yellow product prepared from wine or beer, and many
are still prejudiced against slightly colored vinegar, consider-
ing it weaker. Unfounded as this prejudice is, the manufac-
turer is nevertheless obliged to recognize it, and to suit the
public taste, must color his vinegar by artificial means. Car-
amel or burnt sugar prepared from glucose is a simple and
perfectly harmless coloring. It is made by melting the glu-
cose in a shallow iron vessel over a fire, stirring constantly
with a long-handled spoon. The melted mass soon turns
160 MANUFACTURE OF VINEGAR.
brown and rises in the vessel. The conversion into caramel
being hastened in the presence of alkalies, the addition of a
small quantity of pulverized carbonate of ammonium — about
If to 2 per cent, of the weight of the glucose used — is of ser-
vice at this stage. The mass is now heated with constant stir-
ring until it becomes black, runs from the spoon in viscous
dark brown threads, and a sample dropped upon a cold sur-
face congeals to a black mass impervious to light except upon
the edges. The vessel is then lifted from the fire and the con-
tents poured out upon metal or stone plates. The taste of the
congealed mass should not be bitter, or at least only slightly
so. On exposure to the air, the caramel deliquesces to a thick
black fluid, and, therefore, it should immediately after its
preparation, be converted with water into a solution of the con-
sistency of syrup, such concentrated solution keeping better
than a dilute one which readily molds. Immediately before
use the solution is diluted with water, and enough of it added
to the vinegar to give it the desired coloration. Some manu-
facturers use molasses or dark syrup for coloring vinegar.
CHAPTER XVI.
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS.
SINCE acetic acid is formed by the oxidation of alcohol, vin-
egar can, of course, be prepared from every kind of fluid con-
taining alcohol, such as beer, wine, cider, as well as from the
juice of sacchariferous fruits which has passed into alcoholic
fermentation. By allowing grain to germinate, a body to
which the term diastase is applied is formed, which possesses
the property of converting starch into fermentable sugar and
dextrin when brought in contact with it under certain con-
ditions. Vinegar can, therefore, be prepared from starch —
though in a round-about way — by treating the latter with
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 161
grain containing diastase (malt), whereby it is converted into
maltose and dextrin. The fluid (sweet mash) is compounded
with yeast, and the sugar — and with a correct execution of the
process the dextrin also — is converted into alcohol by vinous
fermentation. The resulting alcoholic liquid can then be
used for making vinegar.
Alcohol or spirits of wine obtained in the above-described
manner from the starch contained in potatoes or grain being at
present the chief material used in the manufacture of vinegar,
the greater portion of the latter brought into commerce might
actually be designated potato or malt vinegar according to the
elementary material used. The great progress made in modern
times in the preparation of malt, brewing of beer, and in the
distilling industry has been accompanied by a constantly ex-
tending division of labor. While formerly every brewer and
distiller prepared his own malt, there are at present numerous
establishments exclusively engaged in this branch of the
industry which sell their product to the brewer and distiller.
The manufacturer of vinegar who did not use materials con-
taining finished alcohol (beer or wine) had to undertake the
laborious work of making the malt and preparing and ferment-
ing the mash in order to obtain an alcoholic liquid which he
•could finally convert into vinegar. With the present im-
provements in the preparation of malt and the production of
alcohol, the vinegar manufacturer can work more cheaply by
buying the alcohol, and the manufacture of so-called malt or
grain vinegar would pay only where heavy taxes prevent the
direct use of alcohol.
Formerly, when, in consequence of defective processes,
many a brewing or batch of malt spoiled, it was used for mak-
ing vinegar. But, as a rule, the vinegar obtained was not
of a fine taste and remained turbid, and besides, the operation
was frequently interrupted by all sorts of incidents, which
led to the opinion of malt-vinegar not possessing keeping
properties.
Beer-wort judged by its composition does not seem a suit-
11
162 MANUFACTURE OF VINEGAR.
able material for making vinegar. Besides a certain quan-
tity of fermentable sugar (maltose), it contains a considerable
amount of dextrin and other fermentable bodies. For the
purpose of making vinegar the maltose alone can be consid-
ered, it being the only fermentable constituent of beer-wort.
Hence, vinegar prepared from beer-wort always contains a
considerable quantity of dextrin and extractive substances,
and, consequently, is of a more thickly fluid nature than
belongs to vinegar, and clarifies with difficulty. Moreover,
this drawback exerts a disturbing influence upon the behavior
of the vinegar when stored, it being frequently changed by
further processes of fermentation into a slimy fluid, and ac-
quires an insipid taste and loses a large portion of its content
of acetic acid.
Alcoholic mashes containing in consequence of faulty prepa-
ration a considerable quantity of dextrin show, when used for
making vinegar, a behavior similar to that of beerwort ; the
vinegar obtained clarifies with difficulty and does not keep
well. Fermented whiskey-mashes properly prepared contain,
however, only very small quantities of dextrin and extractive
substances, and, when freed by filtration from admixed husks,
can be used as a material for the manufacture of vinegar and
yield an entirely normal product.
According to experience, the process of the formation of
vinegar proceeds in the most uniform manner by preparing
the alcoholic liquid from dilute alcohol, and, consequently, in
a vinegar factory connected with a distillery it would be best
to dilute ti on-rectified spirits of wine with the required quantity
of water and add from 10 to 20 per cent, of the weight of the
alcoholic liquid of fermented mash. The latter containing
salts and nitrogenous substances suitable for the nourishment
of the vinegar ferment serves, in this case, as a substitute for
the beer generally used in vinegar factories for the prepara-
tion of alcoholic liquid.
Manufacture of Malt or Grain Vinegar. — Under certain local
conditions the manufacture of vinegat from malt, with or with-
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 163
out an addition of grain, can be profitably carried on in con-
nection with that of compressed yeast. Such factories for
evident reasons not being established on an extensive scale, a
description of the preparation of vinegar in connection with
that of compressed yeast without the use of expensive machin-
ery will be given.
The preparation of the fundamental material, malt, requir-
ing much labor and knowledge, it will be best for the manu-
facturer to buy the article already prepared. Malt kiln dried
at as low a temperature as possible and yielding a light-col-
ored extract when treated with warm water should be chosen.
Many malt houses prepare such malt especially for distilling
purposes. Malt prepared for brewing purposes is after the
actual kiln-drying heated to a temperature frequently exceed-
ing 158° F. for the formation of certain aromatic combinations
and coloring substances which are to impart to the beer a
specific taste and dark color. Independently of the dark color
of the vinegar prepared from such malt, it contains a consider-
able quantity of dextrin, and consequently acquires an insipid
by-taste, clarifies with difficulty, and is readily subject to in-
jurious alterations. Malt, as is well known, contains diastase,
which in mashing with water effects the conversion of the
starch into maltose and dextrin. By kiln-drying at a very
high temperature a portion of the diastase is, however, rendered
ineffective, and in mashing comparatively little maltose but a
large quantity of dextrin is formed. Mashing, in this case,
would have to be continued for a long time in order to obtain
a larger quantity of maltose.
With the use of but slightly kiln-dried malt, in which the
efficacy of the diastase has not been injured by a high tem-
perature, the greatest directly obtainable quantity of maltose
and the smallest amount of dextrin are procured. The pro-
portion of maltose to dextrin is in this case as 4 : 1, or in other
words, the finished mash contains about 80 per cent, of mal-
tose and 20 per cent, of dextrin. The dextrin cannot be
directly converted into acetic acid by the vinegar ferment and
164 MANUFACTURE OF VINEGAR.
consequently would be found in the finished product. It is,
however, possible to treat the finished mash in such a manner
that the total quantity of dextrin contained in it can be con-
verted into maltose and the latter into alcohol, in this case
the theoretically calculated yield of vinegar from the malt
will be nearly approached in practice, arid the product thus ob-
tained contain only a small quantity of extractive substances
of the malt which are not decomposed by alcoholic or acetic
fermentation.
Before entering upon a description of the mashing process,
the theoretical part in mashing will be briefly discussed. Malt
contains starch and diastase. By bringing the comminuted
malt in contact with water of about 131° to 133° F., the starch
is formed into paste and the diastase passes into solution. By
the action of the diastase upon the starch, the latter is con-
verted into maltose and dextrin, the finished mass containing
80.9 per cent, of maltose and 19.1 of dextrin. For reasons
given later on, the finished mass is heated for a short time to
between 140° and 141.8° F., without, however, exceeding this
temperature, and then cooled off to the degree required for the
induction of alcoholic fermentation.
Mash prepared in this manner contains, besides the stated
quantities of maltose and dextrin, effective diastase, i. e., such
as possesses the power of liquefying starch. By heating to
above 158° F. the diastase entirely loses this property. By
compounding a mash of this nature with yeast, the diastase
with the simultaneous action of the yeast is able to convert all
the dextrin present in the fluid into maltose, and consequently
the total quantity of starch originally present is converted into
alcohol by this peculiar process, to which the term after-effect
of the diastase has been applied.
Unmalted grain being cheaper than malt and the latter
containing sufficient diastase to convert a very large quantity
of starch into maltose and dextrin, a mixture of malt and
unmalted grain (equal parts of both; f grain and J malt, etc.)
can be used instead of malt alone. The latter is, however,
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 1G5
preferable for the manufacture of vinegar, it yielding a product
of a finer taste than unmalted grain. The mode of preparing
the mash is exactly the same as for the distillation of alcohol,
and as the necessary information can be obtained from any
treatise on that subject, only a brief sketch of the operation
will here be given.
The malt carefully ground is mixed with cold water to a
thin paste, which is stirred until all small lumps are dissolved.
This mixing of the ground malt with water, dougldng in as
it is called, can be effected with the assistance of a crutch or
rake, but best in a vat provided with a mechanical stirring
apparatus.
Doughing-in being finished, water of 140° to 149° F. is per-
mitted to run in. until the mash shows a temperature of about
131° to 133° F. During this operation the mash should be
constantly stirred. The at first thickly fluid mass will soon
be observed to become thinly fluid by the starch paste being
converted into soluble bodies. Mashing is finished in 2 to 2J
hours, and will be the more complete the more accurately the
temperature is maintained at 131P to 133° F. The completion
of the process is recognized by a filtered sample cooled to the
ordinary temperature remaining colorless after the addition of
iodine solution.
The mash having reached this state, sufficient hot water is
added with constant stirring to raise the temperature to 140°
or 141.8° F. The purpose of this operation is to render all fer-
ments present in the mash ineffective. Lactic acid ferment and
frequently also butyric acid ferment always adhere to the malt,
and, if allowed to develop in the mash, would form lactic and
butyric acids during fermentation which would be injurious to
the process of alcoholic fermentation as well as to the proper-
ties of the vinegar to be manufactured. The mash is now re-
duced to a temperature of about 57° or 59° F. by bringing it
into the cooling-back or passing it through a system of refrig-
erating pipes. When working on a small scale the mash can
be suitably cooled by allowing cold water to pass through a
coil placed in a vat containing it.
166 MANUFACTURE OF VINEGAR.
The strength of the vinegar to be manufactured depends on
the concentration of the mash ; mashes showing a saccha-
rometer statement of 20 per cent, contain after fermentation
about 9J per cent, of alcohol which yields vinegar of about 8
per cent.; mashes showing 18 per cent, yield vinegar of about
7 per cent., so that 1 per cent, of acetic acid in the vinegar
may be calculated on for about every 2J degrees indicated by
the saccharometer.
The mash is now set with yeast, though the latter may be
added when the mash still shows a temperature of 71. 5° to
75° F., the yeast having then time to vigorously propagate.
Mashes prepared from malt alone are uncommonly rich in
nourishing substances for the yeast, the latter propagating
abundantly and inducing a very vigorous process of fermenta-
tion. This can be profitably utilized by combining the manu-
facture of vinegar and that of compressed yeast, a valuable
product being thus obtained without any extra expense and
with but little labor. At a certain stage of the alcoholic fer-
mentation the yeast comes to the surface of the fluid and can
be lifted off. By washing the yeast once or twice with cold
water and then freeing it from the excess of water by pressing,
compressed yeast is obtained which, with the exception of the
portion to be used for setting fresh mashes, can be sold.
Up to the completion of alcoholic fermentation the treatment
of the mash as can be seen from the preceding description,
does not essentially differ from that to which mashes for the
manufacture of alcohol are subjected. If, however, the com-
pletely fermented " ripe "mash is to be used for making vine-
gar, it should be subjected to a special treatment, the object of
which is to prepare a fluid containing no living yeast.
By filtering the mash through a closely woven linen cloth
the particles of malt-husks, etc., are retained but not the cells
of alcoholic ferment which may be present, and which, on ac-
count of their minuteness, are difficult to separate from the
fluid by filtration. It is, therefore, best to heat the mash be-
fore filtration to about 140° F. whereby the ferment is killed,
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 167
and at the same time a certain quantity of albuminous sub-
stances dissolved in the fluid is rendered insoluble and sepa-
rated. The heating of the mash is best effected by passing it
through a coil of tin-pipe placed in a boiler filled with water
kept constantly boiling. The temperature of the fluid can be
readily regulated by increasing or decreasing the velocity with
which it passes through the coil. If the fluid heated to 140°
F. were allowed to cool in the air, a large portion of the alco-
hol contained in it would be lost by evaporation, and it is there-
fore allowed, after heating, to pass through a second coil of
pipe which is surrounded by cold water whereby it is cooled to
at least 86° F. This fluid is then filtered through a linen bag,
is being repeatedly poured back into the filter until it runs off
sufficiently clear. It will not, however, be obtained perfectly
clear in this manner, the yeast cells being too minute to be re-
tained by such a filter, but having been killed by heating, their
presence in the fluid is connected with no disadvantage.
By mixing the filtered fluid with from 10 to 15 per cent, of
its volume of vinegar, an alcoholic liquid is obtained which
can be worked in the usual manner in the quick-process gen-
erators, and yields an agreeable aromatic vinegar which clari-
fies rapidly and improves byt storing.
According to the slow process, the fermented malt-wort is
run into casks placed in apartments called " stoves," since
they are heated by stoves or steam to a temperature ranging
from 70° to 80° F. The casks are arranged in parallel rows,
resting upon long wooden beams elevated about 18 inches
from the ground, and having their bungs uppermost while a
small hole on top of the front head of each causes the circula-
tion of air.
A large saving of labor will be effected by connecting ele-
vated tanks holding the fermented wort with pipes and mov-
able flexible hose which will allow of the rapid and easy filling
of the casks. The vinegar produced is siphoned off into in-
clined troughs, which deliver it to a central underground
tank, from which it is pumped into the storing tanks.
168 MANUFACTURE OF VINEGAR.
Malt vinegar generally contains a great deal of mucilaginous
matter which settles with difficulty, preventing its keeping,
while giving nourishment to vinegar eels. It is therefore
necessary to filter it, and for this purpose it is pumped into
the refining or rape vessels. These vessels are often filled with
wood shavings, straw, or spent tanner's wood, but nothing acts
as well in producing by filtration a clear bright vinegar as the
stalks and skins of grapes or raisins technically called " rape."
Where there is power and a large quantity of vinegar is man-
ufactured, the filtering is effected under a considerable hydro-
static pressure. The rape is placed in a closed vessel between
two false perforated bottoms. A circuit of pipes is connected
at the lower and upper part of the vessel, and by means of a
pump the vinegar is made to pass again and again through
the rape.
The mode of manufacture is frequently effected by " field-
ing." In this case, as the term implies, the process is con-
ducted in the open air. The casks rest on small frames 1J
feet high, being supported by firm pillars of brick-work or
wood. The operation generally begins in spring and continues
during the summer. The fermented liquor is run into the
casks by the bung-holes, the latt^fr being left open in dry, and
loosely covered with a tile in wet weather. Gradually the
alcohol of the "gyle," as the fermented liquor is called, be-
comes oxidized, and acetic acid is produced, of course simul-
taneously affording vinegar. The latter is then drawn off and
transferred, to the refining or rape vessels where it passes
through the process of filtration already described.
In some factories large quantities of sour ale and beer are
converted by similar processes into vinegar, but the product is
much inferior to the vinegar made from malt-wort. The large
amount of nitrogenous and other extractive substances which
those liquids contain undergoes a second or putrid fermenta-
tion after the alcohol has been oxidized into acetic acid, and
in doing so reacts upon the acid,, leaving a liquid of a dis-
agreeable odor slightly resembling very stale beer. By the
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 169
addition of sulphuric acid this second fermentation is post-
poned for some time, but the vinegar has nevertheless a
nauseous smell which renders it objectionable.
Vinegar from Sugar-Beets. — The juice of the sugar-beet con-
tains a considerable quantity of cane-sugar and is readily
brought into alcoholic fermentation, so that seemingly this
root would form a very suitable material for the manufacture
of vinegar. Sugar-beets contain on an average 12 percent,
of cane-sugar, the latter yielding, when completely fermented,
a fluid containing about 6J per cent, by weight of alcohol ; a
fluid with this percentage of alcohol yields vinegar with 6 per
of acetic acid.
In addition to sugar the juice of the beet-root contains,
however, a large number of other substances which exert an
influence upon the course of alcoholic fermentation, and, be-
sides alcohol, a large quantity of fusel oils is formed, so that
the alcohol has to be thoroughly rectified before it is fit for
use. The fermented beet-root juice itself has, however, a dis-
agreeable taste and odor, and the vinegar prepared from it
showing similar properties will not be fit for household pur-
poses until a remedy for these drawbacks is found. Numerous
experiments made for the purpose of freeing beet-root vinegar
from the substances which impart to it a disagreeable odor
and taste have given no favorable results. Filtering through
charcoal, and even distilling the vinegar and treating the dis-
tilled product with strongly oxidizing bodies, do not produce
the desired effect. From these experiments it would seem
impossible to directly obtain from sugar-beets vinegar fit for
household use.
Vinegar from Sugar, Fruits and Berries. — By fermenting
sugar solution with pure yeast and pouring off the clear alco-
holic fluid, the latter shows a slightly acid reaction (from suc-
cinic acid), but is not converted into vinegar even if standing
for several weeks in the most suitable temperature, because
the vinegar ferment is wanting. By adding, however, an
excess of yeast, so that it remains partially suspended in the
170 MANUFACTURE OF VINEGAR.
fluid, which can be effected by the addition of solution of gum
or starch paste, the nourishment for the spores of the vinegar
ferment reaching the fluid from the air is provided and
acetification takes place.
Cadet-Gassicourt advises the fermentation together of 124
parts of sugar, 868 of water, and 80 of yeast, and to filter after
one month. Or, according to another formula : Sugar 245
parts, gum 61, water 2145, yeast 20. Allow to ferment at
68° F. Fermentation begins the same day and is completed
in 15 days.
Doebereiner gives the following directions : Dissolve 10 Ibs.
of sugar in 180 quarts of hot water, add 6 Ibs. of pulverized
crude tartar (it dissolves only partially), and after .cooling to
77° F. induce fermentation by 4J quarts of beer yeast. In
about eight days, when fermentation is finished, add about 15
quarts of spirits of wine of at least 50 per cent. Tr. or 8 quarts
of alcohol of 90 per cent. Tr., and bring the mixture into the
acetifying vessel. This fluid would also be suitable for the
quick process.
For making vinegar on a small scale for domestic use, brown
sugar with water alone, or sugar with raisins, currants, and
especially ripe gooseberries, may be used. These should be
mixed in the proportion which would give a strong wine, put
into a small barrel filled to about three-fourths of its capacity,
and bunged very loosely. Some yeast should be put in and
the barrel set in the sun in summer or a little way from the
fire in winter, and fermentation will soon begin. This should
be kept up constantly, but moderately, till the taste and smell
indicate that the vinegar is complete. It should then be
poured off clear, and bottled carefully. It will keep much
better, if it is boiled for a minute, cooled, and strained before
bottling.
With the exception of apples and pears, the different varie-
ties of fruit cannot be had in such abundance as that they
could be used for the manufacture of vinegar on a large scale,
and hence only a brief description of their utilization for that
purpose will be given.
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 171
It is characteristic of most of our varieties of fruits, and
especially of berries, that in proportion to their content of
sugar they have a much greater content of free acids than
grapes, and this circumstance must be taken into considera-
tion, as otherwise wine would be obtained which contains a
considerable quantity of unfermented sugar. The following
table shows the average content of sugar and free acid in the
most common varieties of fruits : —
Free acid calculated
Sugar. as malic acid.
Cherries . . ;;„ . 10.00
Apples 6.25 to 13.99 0.691
Pears . . . .... .' . . . . . . 8.78
Currants 6.40 2.147
Strawberries. .'..':.. . . • . . . . 5.09 to 11.31 ' 1.363
Gooseberries . . - . ,< 6.93 1.603
Bilberries.. . . .V.*.;:.V. 5.78 1.341
Raspberries . . : ". ...... '.. 4.02 1.484
Blackberries . ....... . . 4.44 1.188
According to the above table, currants, gooseberries, rasp-
berries, etc., contain on an average scarcely 6 per cent, ol
sugar, and consequently their juice, after complete fermenta-
tion, would give a fluid with about 3 per cent, of alcohol, from
which vinegar with about 2J per cent, of acetic acid could be
obtained. Such vinegar being, however, too weak, those ber-
ries would not seem suitable for the direct preparation of vine-
gar. Moreover, the complete fermentation of the juice of most
berries is very difficult, the free acids, among which malic acid
preponderates, exerting an injurious influence upon the pro-
gress of fermentation.
Vinous fluids of an agreeable taste can, however, be pre-
pared from berries, and from them an aromatic and finely
flavored vinegar, by decreasing the content of acid in the juice
and increasing that of sugar. The juice of currants, as seen
from the above table, contains in round numbers 6 per cent,
of sugar and 2 per cent, of malic acid. By diluting this juice
with an equal volume of water a fluid containing 3 per cent.
172 MANUFACTURE OF VINEGAR.
of sugar and 1 per cent, of acid is obtained, and the content
of the former can be increased at will by the direct addition
of sugar.
By compounding, for instance, 100 quarts of currant juice
with 100 quarts of water and adding 34 Ibs. of sugar, the re-
sulting fluid contains about 20 per cent, of sugar and after
complete fermentation gives a fluid with about 9.5 per cent, of
alcohol, which yields vinegar of nearly 9 per cent, strength.
The taste of this vinegar is, however, stronger and more agree-
ably acid than that of vinegar from alcohol, it containing be-
sides acetic acid about 1 per' cent, of malic acid. Moreover,
vinegar obtained from berries contains a certain quantity of
extractive substances and odoriferous products of fermentation,
so that it possesses an agreeable bouquet and thus appears
more valuable than the ordinary product.
In many regions bilberries grow in abundance and can be
bought very cheap. Treated in the above manner, they yield
an excellent vinegar, possessing, however, a somewhat harsh
by-taste, due to the tannin contained in the berries. The latter
can be removed from the fermented fluid before using it for
the preparation of vinegar, by compounding the latter when
quite clear with gelatine solution or fresh white of egg, both
forming insoluble combinations with the tannin, which sepa-
rates in the form offtakes.
In regard to the preparation of vinegar from berries, it re-
mains to be remarked that, after pressing the bruised berries,
the juice is compounded with water and sugar and at once
brought into fermentation by the addition of yeast (best fresh
wine-yeast, or if this be wanting, compressed yeast divided
in water). Fermentation should take place at quite a high
temperature, 68° to 72° F. The separated yeast is carefully
removed from the fermented liquid and the latter stored away
in barrels kept constantly filled up to the bung, or at once used
for the preparation of vinegar. By converting fruit-wine into
vinegar by means of the vinegar ferment floating upon the
fluid a much finer product is obtained than by the quick
process.
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 173
Peaches as Vinegar Stock. Mr. H. C. Gore * has made ex-
periments regarding the value of peaches as vinegar stock.
The conclusions drawn by him from this work are, first, that
peaches contain sufficient fermentable sugar for use as vinegar
stock, and, second, that they can be successfully handled by
machinery already in use for making apple cider and vinegar.
Other points of interest are as follows : First, but little varia-
tion was found in the composition of the same variety of
peaches when obtained from different localities. Second, the
peach juices analyzed were found to be richer in sugar than
those which have been previously analyzed by others, but
they were about 1 per cent lower in sugar than average apple
juices. They were considerably richer than apples in suc-
rose and in acid. Third, it was found that the use of pure
culture yeasts was not necessary to insure rapid alcoholic fer-
mentation. Fourth, the ciders prepared from peaches were
considerably poorer in alcohol than apple ciders on Account of
the fact that peaches contain less total sugars than apples.
Fifth, the presence of brown rot was found not to inter-
fere with the alcoholic fermentation of the ground peaches,
but a large proportion of the sugars was wasted by allowing
the fruit to rot before fermenting. Sixth, well-flavored vine-
gars were produced by the use of a small quick-process gener-
ator. These vinegars were of acceptable quality, though tur-
bid, and did not possess the distinctive peach flavor.
Cider Vinegar. The manufacture of cider itself will be de-
scribed in another portion of this work and, hence, its utiliza-
tion for the preparation of vinegar will here only be given.
The preparation of vinegar from good cider is not difficult,
the process of acetification by means of the vinegar ferment
floating upon the surface yielding an aromatic product of a
fine flavor which is nearly of as good a quality as wine vine-
gar. On account of its content of malic acid, the vinegar is
* United States Department of Agriculture, Bureau of Chemistry — Circular
No. 51.
174 MANUFACTURE OP VINEGAR.
more acid than ordinary vinegar with the same content of
acetic acid. But in order to produce cider vinegar of the first
quality one must have good cider ; vinegar made of watered
cider will be thin and weak.
The cider extracted by the first pressing of the apples is
but in rare cases used for making vinegar, the juice obtained
by subjecting the pomace, with the addition of water or sugar
solution, to a second and third pressure being as a rule utilized
for the purpose. The juice thus obtained should be so consti-
tuted as to yield vinegar containing 4 J to 5 \ per cent, of acetic
acid. The cider to be converted into vinegar should be as
clear as possible and, if necessary, filtration over sand or storing
for some time is advisable.
The conversion of cider into vinegar is best effected in a
generator furnished with a tilting trough for the intermittent
supply of cider.
After the cider has been extracted and the cheese removed
from the press, the pomace may also be utilized for making
vinegar by treating it as follows : The pomace is piled up on
a platform of suitable construction and allowed to ferment.
In the course of a few days considerable heat will be devel-
oped, when a few pailfuls of warm water (not boiling) are
poured upon the pile, and in the course of twenty-four hours
the pomace will be in proper condition for grinding. It is
then run through a grater-mill and relaid upon the press in a
cheese in tlpe same manner as originally laid in cider making.
It is then subjected to heavy pressure until the liquid con-
tained in the cheese is extracted. This liquid may be ex-
posed in shallow open casks in a warm room, and in a short
time will be found good vinegar ; or it may be immediately
passed through a generator.
Mr. Walter G. Sackett * gives directions for home-made cider
vinegar as follows : " The sweet cider as it comes from the
* Bulletin 192, November, 1913. The Agricultural Experiment Station of the
Colorado Agricultural College.
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 175
press may either be placed at once in barrels, which should
not be filled more than two-thirds or three-fourths full, or if
one has suitable wooden tubs or vats, in a clean, cool place ;
it may be stored there from 12 to 24 hours to permit settling,
after which it should be transferred to barrels. The bung
should be left out and a loose stopper of cotton batting in-
serted in the hole to decrease evaporation and prevent dirt
from falling in. The barrels should not be tightly stoppered
until the vinegar contains at least 4 to 5 per cent, of acetic
acid, at which time they should be filled entirely full and
securely bunged. Throughout the entire period of vinegar
making, the casks should be placed on their side and not on
the end. This gives the cider a larger free surface exposed to
the air, which is quite essential to rapid vinegar formation.
It may also be of some advantage in admitting air to bore a
If inch hole in each end of the barrel along the upper edge.
If this is done, the holes should be covered with fine gauze
wire or two thicknesses of cheese-cloth to exclude small
vinegar flies.
" A few days after the cider is put into the barrels the char-
acteristic frothing appears at the bung-hole. To use a com-
mon expression, 'it is beginning to work.' This indicates
that the alcoholic fermentation, the first step in the vinegar-
making process, has begun, and the sugar of the apple juice is
being converted into alcohol and carbon dioxide gas. To de-
pend upon the wild yeast of the air to accomplish the fermen-
tation is too uncertain since many of them are able to convert
only a small part of the sugar into alcohol, while others act
so slowly that they are impracticable. Inasmuch as the per-
centage of acetic acid in the vinegar depenjds directly upon the
amount of alcohol produced, it is very essential to secure as
large a yield of alcohol as possible from the sugar present.
This means converting all of the sugar into alcohol in the
shortest time possible. The most satisfactory way of doing
this is to add one cake of compressed yeast, stirred up in a
little cooled, boiled water, to each five gallons of sweet cider.
176 MANUFACTURE OF VINEGAR.
In place of this, one quart of liquid wine yeast, propagated
from a pure culture, may be used for each thirty gallons of
cider.
" During the alcoholic fermentation, the cider should be
kept at a temperature of 05° to 80° F. Here is where many
make the very serious mistake of putting their fresh cider into
a cool cellar where the fermentation takes place entirely too
slowly. If the cider is made in the fall, the barrels should be
left out of doors for a while on the protected, sunny side of a
building and kept warm, unless a regular vinegar-cellar, arti-
ficially heated, is at hand.
" If yeast is added and the proper temperature is maintained,
the alcoholic fermentation should be completed in six weeks
to three months in place of seven to ten months as in the old-
fashioned way. Experiments along this line have shown that
when yeast is added and a temperature of 70° F. is held, the
cider at the end of one month contained 7.25 per cent, of alco-
hol as against .11 per cent, when no yeast was used and the
temperature was between 45° and 55° F. Cider kept in a
cellar at 45° to 55° F. with no yeast added required seven
months to make 6.79 per cent, of alcohol.
" Temperature, alone, is an important factor as shown by
an experiment wherein cider to which no yeast was added was
held for three months at 70° F. and yielded 6.41 per cent, of
alcohol.
"There is no question but that the time required for com-
pleting the alcoholic fermentation can be reduced at least one-
half by adding yeast and by maintaining the proper tempera-
tures. By hastening this operation, the loss of alcohol by
evaporation is reduced, and the acetic fermentation can be
started that much sooner.
" As soon as alcoholic fermentation is completed draw off
the clear liquid, being very careful not to disturb the sedi-
ment in the barrel. Wash out the barrel thoroughly and re-
place the hard cider. It is believed that removing this sedi-
ment permits the acetic acid to form somewhat more quickly,
PREPARATION OF VINEGAR FROM VARIOUS MATERIALS. 177
and furthermore, the sediment may undergo decomposition
and impart a disagreeable flavor to the cider. Again these
dregs may harbor living bacteria which either destroy acetic
acid or interfere with its formation.
" We are now ready to introduce the acetic acid germs.
This ma}7 be carried on in a number of different ways, but
preferably by means of a pure culture of a desirable organism
which has been selected because of its ability to produce strong
acetic acid and impart an agreeable flavor to the vinegar. In
place of the pure culture starter, one may add two to four
quarts of good cider vinegar containing more or less ' mother '
for each barrel. The introduction of a desirable organism is
left to chance in this case. A serious objection to the latter
method is that sometimes one introduces foreign organisms
with the ' mother' which may prove detrimental to the vine-
gar. Pure culture * is free from this objection.
" With the acetic fermentation, as with the alcoholic, the
higher temperatures favor the changes. Experimental work
shows that hard cider to which no acetic acid bacteria were
added other than those that came from the air, and kept at
65° F., when six months old, contained 7.03 per cent, of acetic
acid, while that held at 55° F. showed only 3.63 per cent.
" The addition of some kind of an acetic acid starter, either
as a pure culture of the acetic organism or as good vinegar,
hastens the fermentation and reduces appreciably the time
required for making marketable vinegar.
" For most satisfactory results we would recommend using
the pure cultures and holding the vinegar at a temperature of
65 to 75° F. Under these conditions, salable vinegar can be
obtained in three to six months in place of two to three years,
as is often the case. Theoretically, 100 parts- of alcohol should
give about 130 parts of acetic acid, but in actual practice this
will probably fall below 120.
* The pure cultures, both of yeast and acetic acid bacteria, for vinegar making,
here referred to, can be obtained by addressing The Bacteriological Department,
Experimental Station, Fort Collins, Colorado.
12
178 MANUFACTURE OF* VINEGAR.
" When the acetic acid has reached 4.5 to 5 per cent., fill
the barrels as full as possible and cork tightly. In this way,
contact of the air with the vinegar is cut off and the acetic
acid organisms soon cease their activity. If this is not done
and the acetic and other bacteria are allowed to develop in-
definitely, there is apt to be a reverse reaction resulting in a
partial or complete loss of the acetic acid. Such vinegar is,
of course, worthless."
CHAPTER XVII.
VINEGAR SPECIALTIES.
THESE specialties may be divided into two groups : Into
those with a specific odor, and those with a specific odor and
taste. As an example for both kinds tarragon vinegar may
be taken. If it is prepared by simply dissolving in the vine-
gar the volatile oil of dragon's wort (Artemisia dracunculus) ob-
tained by distillation with water, the product is simply per-
fumed vinegar, the odor of the volatile oil being mixed with
that of the acetic acid, but the taste remains unchanged. If,
however, the fresh leaves of the plant are macerated with vine-
gar, not only the volatile oil is dissolved, but also certain ex.
tractive substances peculiar to this plant, and the taste of the
vinegar is also changed, the product in this case being aro-
matized vinegar.
By dissolving in vinegar rose oil or rose water (perfumed),
rose vinegar is obtained. By treating raspberries with vinegar
the latter absorbs not only the odoriferous substances of the
raspberry, but also the non-odoriferous extractive substances,
and the product is aromatized vinegar.
By skillful manipulation every volatile oil can be dissolved
in vinegar, and consequently as many different varieties of
perfumed vinegar can be prepared as there are volatile oils.
VINEGAR SPECIALTIES. 179
In fact, perfumers prepare a number of such varieties which
contain one or more volatile oils whose odors harmonize and
are sold as volatile spirit of vinegar, fumigating vinegar, etc.
Such vinegars can be prepared in various ways, the finest odors
being, however, obtained by distilling the fresh parts of the
plants with water and mixing the distillate, which actually
represents a solution of the volatile oil in water, with strong
vinegar. The finest rose vinegar, orange blossom vinegar,
etc., are prepared in this manner.
For this rather tedious process of preparing perfumed vine-
gar, the one in which freshly prepared volatile oils are used
may be advantageously substituted. Td be sure the volatile
oils dissolve only sparingly in vinegar, but sufficiently so to
impart their characteristic odor to it. By using an excess of
volatile oil it does not dissolve; but distributes itself in fine
drops throughout the vinegar, rendering the latter opalescent,
so that fining with tannin and isinglass is necessary to make
it bright again.
This drawback can be avoided by a simple manipulation
which is based upon the fact that a body dissolving with diffi-
culty dissolves the more readily the greater surface it offers to
the solvent.
Prepare glass-powder as fine as the best wheat flour by heat-
ing pieces of glass, throwing them into cold water, and pulver-
izing and elutriating in a mortar. By the sudden cooling the
glass becomes so brittle that it can be readily converted into a
fine powder. Bring a suitable quantity of this powder into a
porcelain dish and drop volatile oil upon it with constant rub-
bing until it is uniformly moistened. Pour the vinegar to be
perfumed upon this glass powder and stir gently with the
pestle. The fluid is then poured into the barrel intended for
the reception of the perfumed vinegar and a fresh quantity of
vinegar poured upon the glass-powder, this being continued
until all the glass-powder has been brought into the barrel by
stirring and pouring over fresh vinegar. The barrel is then
entirely filled with vinegar, and after being securely bunged,
180 MANUFACTURE OF VINEGAR.
rolled in order to secure a uniform mixture of its contents.
It is then allowed to rest for a few days for the glass-powder
to settle. The entirely clear perfumed vinegar is then drawn
off into bottles, which are to be kept in a dark cool room, the
odor of the volatile oil being injured by light and heat.
For the preparation of volatile fumigating or toilet vinegars
it is best to dissolve the volatile oils in uncolored vinegar pre-
pared from alcoholic liquid. Where the remaining of a small
residue after the volatilization of the perfumed vinegar is of
no importance, pulverized sugar may be substituted for the
glass-powder, as it acts in the same manner ; the only differ-
ence is that the glass-powder being an insoluble body falls to
the bottom of the barrel, while the sugar dissolves together
with the volatile oil in the vinegar.
By the above-described process perfumed vinegar with the
odor of dragoii's-wort, peppermint, anise, rose, etc., etc., may
be prepared, and by a suitable mixture of those whose odors
harmonize, a great number of fumigating and toilet vinegars
may be obtained.
The preparation of aromatized vinegars by means of the ex-
tractive substances of plants is very simple. The parts of
plants to be extracted are placed in a suitable vessel, a barrel
or large flask, and after pouring vinegar over them and closing
the vessel, are allowed to rest for a few weeks in a moderately
warm room. In case glass vessels are used they have to be
kept in a dark room, light exerting an injurious influence upon
the odors. The vegetable substances used for aromatizing
vinegar containing, as a rule, a large quantity of water, strong
vinegar, with 10 to 11 per cent, acetic acid, should be used.
Below a few formulas for toilet and table vinegars are given :
TOILET VINEGARS.
Mohr's Volatile Spirits of Vinegar. — Equal parts of acetic acid
and acetic ether, perfumed with a few drops of oil of cloves.
Aromatic Vinegar. — Concentrated acetic acid 8 ounces, oil of
lavender 2 drachms, oils of rosemary and cloves each 1
drachm, oil of camphor 1 ounce.
VINEGAR SPECIALTIES.' 181
Bruise the camphor and dissolve it in the acetic acid, then
add the perfumes ; after standing for a few days with occa-
sional agitation it is strained and ready for use.
Henry's Vinegar. — Dried leaves of rosemary, rue, worm-
wood, sage, mint and lavender flowers each 1 ounce, bruised
nutmeg, cloves, angelica root and camphor each J ounce, alco-
hol (rectified) 8 ounces, concentrated acetic acid 32 ounces.
Macerate the materials for a day in the alcohol ; then add
the acid and digest for a week longer at a temperature of
about 59° F. Finally press out the now aromatized vinegar
.and filter it.
Vinaigre des Quatre Voleurs. — Fresh tops of common worm-
wood, Roman wormwood, rosemary, sage, mint and rue each
} ounce, lavender flowers 1 ounce, garlic, calamus aromaticus,
cinnamon, cloves, and nutmeg each 1 drachm, camphor J
ounce, alcohol or brandy 1 ounce, strong vinegar 4 pints.
Digest all the materials, except the camphor and spirit, in
a closely covered vessel, for a fortnight, at summer heat ; then
express and filter the vinegar produced and add the camphor
previously dissolved in the brandy or alcohol.
Hygienic or Preventive Vinegar. — Brandy 1 pint, oils of cloves
and lavender each 1 drachm, oil of marjoram J drachm, gum
benzoin 1 ounce.
Macerate these together for a few hours, then add 2 pints of
brown vinegar and strain or filter.
Cosmetic Vinegar. — Alcohol 1 quart, gum benzoin 3 ounces,
concentrated aromatic vinegar 1 ounce, balsam of Peru 1
ounce, oil of neroli 1 drachm, oil of nutmeg J drachm.
TABLE VINEGARS.
Anise Vinegar. — Convert into a coarse powder anise seed 5
parts, caraway seed f, fennel and coriander seed each J, pour
5 parts of alcohol and 45 parts of strong vinegar over the
powders, close the vessel air-tight and let the whole digest in
a warm place for 6 to 8 days, shaking frequently. Then strain
the liquid off, press out the residue, filter the vinegar, and put
it up in bottles.
182 MANUFACTURE OF VINEGAR.
Anchovy Vinegar. — Reduce 1 pound of boned anchovies to a
pulp in a mortar and pass the mass through a hair-sieve. The
bones and parts which do not pass through the sieve are
boiled for 15 minutes in a pint of water and strained. To the
strained liquor add 2J ounces of salt and the same quantity
of flour together with the pulped anchovies, and allow the
whole to simmer for 3 or 4 minutes ; as soon as the mixture
is cold add J pint of strong vinegar.
Tarragon Vinegar. — Pick the young tender leaves of dragon's-
wort (Artemisia dracunculus) when the first flower-buds ap-
pear. Bruise the leaves, place them in a suitable vessel, pour
good wine-vinegar over them, and let the whole stand for a
few days. Then strain the vinegar through a cloth, filter and
bottle. The bottles must be filled entirely full, as otherwise
the vinegar will not keep.
Compound Tarragon Vinegar. — Comminute leaves of dragon's-
wort 100 parts, common bean leaves 25, leaves of basil and
marjoram each 12J, bay leaves and orris root each 25, cloves
3J, cinnamon 6J, and shallots 25. Put all in a suitable ves-
sel, pour 700 to 750 parts of pure, strong vinegar over it, let
it stand in a warm place and digest 5 or 6 days, frequently
agitating it. Then strain the vinegar through linen, press
out the residue, add 25 parts of alcohol, and filter. Keep the
vinegar in well-corked bottles in a cool, dark place.
Effervescing Vinegar. — Dissolve 500 parts of loaf sugar in
5000 parts of water, add lemon juce and rind cut up in the
proportion of 1 lemon to 1 Ib. of sugar, 1J parts of the best
cinnamon, and 12 parts of beer yeast thoroughly washed.
Place the whole in a barrel, and after agitating it thoroughly
let it ferment at a temperature of 55° to 60° F. When fer-
mentation has ceased the vinous fluid is strained and mixed
with 1000 parts of best wine- vinegar, previously boiled up, and
yeast in the proportion of 1 spoonful to 5 Ibs. of sugar. The
fluid is then distributed in several earthenware pots and ex-
posed to a temperature of 77° to 88° F. until it has been con-
verted into strong vinegar. This, while remaining in the pots,
VINEGAR SPECIALTIES. 183
is mixed with 200 parts of French brandy and after two days
bottled in small bottles. To each pound of this vinegar are
added, f part of crystallized tartaric acid, pulverized, and J
part of bicarbonate of soda. The bottles, as soon as the re-
spective portion of the mixture has been added to each, must
be corked as quickly as possible and then stored in a cool
place.
Herb Vinegar. — Chop fine the leaves of marjoram and thyme
each 13J parts, common bean leaves 6J, leaves of mint, basil
and celery each 3 J, and fresh shallots 1 J. Pour 600 or 700
parts of good vinegar over the herbs and treat in the same
manner as given for compound tarragon vinegar.
Pine-apple vinegar. — This excellent vinegar soon- loses its
flavor, and it is therefore best to prepare a small quantity at
a time and keep in bottles closed air-tight.
Bruise the slices of pine-apple and pour over them a con-
siderable quantity of vinegar. Close the vessel air-tight and
let it stand 12 hours ; then pour off the vinegar and filter.
Celery Vinegar. — Celery seed 4J ozs., vinegar 1 pint. Digest
14 days ; filter.
Clove Vinegar. — Cloves 3J ozs., vinegar 1 pint. Digest 7
days and strain.
Mustard Vinegar. — Black mustard seed 2 ozs., vinegar 1
pint. Digest one week and filter.
Lovage Vinegar. — Lovage root 2 ozs., lovage seed 1 oz.,
vinegar 10 ozs. Digest one week and filter.
Raspberry Vinegar. — For the preparation of this vinegar it
is best to use the residue remaining after pressing the ripe and
crushed berries, as it contains sufficent aroma to impart to
vinegar macerated with it for some time an agreeable odor
and taste of raspberries. However, the juice may also be
used, but if the vinegar itself is not very strong it becomes
thereby too much diluted and consequently weak.
Crush the fresh berries to a paste and allow the latter to
stand a few days, stirring it frequently, for the small quantity
of sugar contained in the berries to ferment. By the alcohol
184 MANUFACTURE OF VINEGAR.
thus formed the pectin in the juice is to a great extent sepa-
rated. The paste is then brought into a small bag and
pressed.
The press-cake is crushed, made into paste with vinegar
and spread out flat, exposed to the air for a few days, being
frequently stirred. During this time the paste, at first pale
red, again acquires, in consequence of a process of oxidation,
a vivid red color. The quantity of vinegar required is then
poured over the paste. The whole is then allowed to digest
for a few days, when it is pressed and filtered. The flavor of
raspberry vinegar is improved by adding 10 drops of acetic
ether per quart. For 1 pound of pressed residue about 4 to 5
quarts of strong vinegar are used.
Preparation of Acetic Ether. — Among the numerous combi-
nations into which. acetic acid enters with other bodies, acetic
ether is of special value for the vinegar manufacturer, it being
directly used in the manufacture of vinegar. It is readily
formed on alcohol coming in contact with acetic acid, and it
would seem with special ease when the latter is in a nascent
state. Hence a small quantity of it is found in nearly all red
wines not prepared by fermentation in closed vats, its pres-
ence being due to the formation of a small quantity of acetic
acid from the alcohol, which immediately combines with the
ethyl oxide or ether.
In vinegar containing a small quantity of unchanged alco-
hol some acetic ether formed by the conversion of this alcohol
into acetic acid is always present, and imparting a very deli-
cate and agreeable bouquet to the vinegar, it is recommended
to conduct the production of a fine article so that it contains
a small quantity of it.
It is, however, not absolutely necessary to leave a small
quantity of alcohol in the vinegar, as either acetic ether or al-
cohol can be directly added to the finished product. But in
both cases the vinegar has to be stored for several weeks ; in
the first, for the purpose of harmonizing the odors of acetic
ether and of acetic- acid, and in the latter, for the formation of
acetic ether.
VINEGAR SPECIALTIES. 185
A fluid quite rich in acetic ether and very suitable for im-
parting bouquet to table vinegar can in a very simple manner
be prepared by mixing in a flask one volume of highly concen-
trated acetic acid with 95 or 96 per cent, alcohol, and after clos-
ing the flask air-tight, allowing the fluid to stand in a warm
room for several months. The resulting fluid is used as an ad-
dition to the vinegar whose odor is to be improved. Entirely
pure acetic ether is best prepared in the following manner : To
9 parts of concentrated sulphuric acid 3.6 parts of commercial
absolute alcohol are added by means of a funnel tube which
reaches to the bottom of the vessel, at the same time keeping
the liquid well stired. After standing for 24 hours this mix-
ture is added to 6 parts of sodium acetate which has previously
been fused and broken in small fragments, and after 12 hours
the mixture is distilled. Thus 6 parts of pure acetic ether are
obtained, from which, by rectifying over calcium chloride, all
traces of water are removed.
0 IT O ^
Pure acetic ether or ethyl acetate has the composition p**
and represents a fluid clear as water with an agreeable but
stupefying odor. Its specific gravity is 0.932 and it boils, at
165.2° F. On account of its volatility it has to be kept in
well-stoppered bottles, best in a cool place.
About 3J to 7 ozs. of acetic ether suffice for the improve-
ment of the odor of 100 quarts of vinegar.
186 MANUFACTURE OF VINEGAR.
CHAPTER XVIII.
MANUFACTURE OF WINE VINEGAR.
Since wine contains between 6 and 14 per cent, of alcohol,
it evidently furnishes an excellent material for vinegar making.
Both white and red wines may be used for the purpose, but as
white wine vinegar is as a rule preferred, the product obtained
from red wine is generally not salable until it has been decol-
orized, and the process of decolorizing impairs its flavor and
aroma. Vinegar may also be made from grapes which are
unsuitable for drying, shipping or wine making, and this may
be the most profitable use, in some cases, to which even the
best grapes can be put. If grapes are used they must of course
be first made into wine by the usual process. According to
Bioletti* one ton of grapes of 20° Balling should on the aver-
age yield 135 gallons of vinegar of 9.8 per cent, acetic acid.
It may be greater or less than this according as the grapes
contain more or less sugar. This yield may be diminished by
imperfect crushing and pressing of the grapes whereby more
must is left in the pomace. Alcohol may be lost by imperfect
or improper fermentation in which case the vinegar will be
weaker. The greatest difference between the theoretical and
the actual yield is in the change from wine into vinegar.
This is because one or two percent, of alcohol remains uncon-
verted in the vinegar, and because during the process there is
a considerable loss of alcohol and acetic acid by evaporation,
and by reactions within the liquid which produce other sub-
stances at the expense of the alcohol and acetic acid. If the
temperature during acetification is too high, or if the acetic
bacteria are allowed to act too long, this loss may be much
increased.
* Grape Vinegar. By Frederic T. Bioletti. University of California Publica-
tions. Bulletin No. 227, 1912.
MANUFACTURE OF WINE VINEGAR. 187
By allowing the crushed grapes to ferment on the skins
before pressing, a somewhat larger volume of wine and there-
fore of vinegar may be obtained. This may amount to 150
or 160 gallons of vinegar from a ton of grapes. The vinegar,
however, will be darker colored and, in the case of red grapes,
red. This color can be removed, but the decoloration is diffi-
cult and involves some loss of quality.
Fermentation for twenty-four hours on the skins will much
facilitate the extraction of the juice without, except in the
case of grapes very rich in coloring matter, reddening the juice
very much.
The question, what constitutes the superiority of wine vine-
gar over the ordinary product obtained from alcohol is not
difficult to answer for those who have an accurate knowledge
of the constitution of wine. Besides the ordinary (ethyl) alco-
hol, wine vinegar contains very small quantities of other
alcohols, for instance, amyl alcohol, which in the same man-
ner as ethyl alcohol is converted into acetic acid, are changed
into acids possessing a peculiar odor. Moreover, wine very
likely contains a series of odoriferous substances which pro-
duce its peculiar aroma termed bouquet or flower, the cenan-
thic ether found in every wine forming, so to say, the keynote
in the harmony of the odoriferous substances constituting the
bouquet. In the conversion of wine into vinegar these bou-
quet substances are also changed in such a manner that
bodies distinguished by a characteristic odor are formed.
Furthermore, wine contains glycerin, a series of non-volatile
organic acids, tartaric, malic, succinic acids, etc., and finally
the so-called extractive substances. What changes these bodies
undergo is not accurately known, but all of them are very
likely subject to certain modifications because a smaller quan-
tity of extractive substances and of non-volatile acids is found
in the vinegar than in the original wine. The following table
shows the composition of wine and of the vinegar formed
from it :
188 MANUFACTURE OF VINEGAR.
Wine contains— Wine-vinegar contains —
Water, Water,
Ethyl alcohol, Ethyl alcohol (none or very little)
Other alcohols, Other alcohols (changed),
Glycerin, Glycerin (less?)
Acetic acid, (traces), Acetic acid (much newly formed),
Tartaric acid, Tartaric acid (less),
Tartar, Tartar (less),
Malic acid, Malic acid (less),
Snccinic acid, Snccinic acid (less),
Tannin, Tannin (changed),
(Enanthic ether, (Enanthic ether (changed and unchanged),
Bouquet substances, Bouquet substances. >
Extractive substances, Extractive substances I changed,
Coloring substances Coloring substances J
Acetic ether and other compound \ newly
ethers / formed.
The above comparison shows the thorough modification
wine undergoes in being converted into vinegar, and that the
resulting product must have a bouquet or flower having a
certain connection with that of wine.
Potable wine can be profitably used for making vinegar
only in localities where in consequence of a very abundant
harvest it can be bought at a very low price. The chief sup-
ply for making vinegar is derived from wines, especially from
varieties with from 8 to 9 per cent, of alcohol, which have
deteriorated on account of incorrect treatment in the cellar, and
consequently have become unsalable as a beverage.
The term " sick " is generally applied to wines in which
alterations take place by the activity of a certain ferment which,
when progressed to a certain degree, renders the wine unfit for
a beverage. " Turning sour " is, for instance, a sickness fre-
quently occurring in wines poor in alcohol. It manifests itself
by the development of large masses of a certain ferment which
quickly destroys the tartaric acid contained in the wine. An-
other sickness chiefly, occurring in red wines is the so-called
" turning bitter," the wine, as the term implies, acquiring in a
short time by the action of a peculiar ferment such a disagree-
able bitter taste as to render it absolutely unfit for drinking.
MANUFACTURE OF WINE VINEGAR. 189
Such wine cannot be used even for vinegar, the latter showing
the same disagreeably bitter taste. Wine attacked by what is
called " lactic acid degeneration " can be used for the manufac-
ture of vinegar, but yields a product of very inferior quality,
because on the wine being subjected to acetic fermentation the
lactic acid contained in it is readily converted into butyric acid,
which possesses a disagreeable rancid odor completely killing
the pleasant aroma of the bouquet substances. There only re-
mains as a material actually fit for the preparation of wine-
vinegar, wine attacked by " acetic degeneration," i. e., wine al-
ready so much changed by the vinegar ferment as to render
it unfit for a beverage, and, further, wine which though not
sick is unsound, showing a taste of mold, of the barrel, etc.
Wine no longer young and not overly rich in alcohol is
especially adapted for the nutriment of the vinegar ferment.
Such wine need only be exposed to a somewhat higher tem-
perature in order to induce acetic fermentation, which if not
disturbed in its progress, will finally convert all the alcohol in
the wine to acetic acid.
It may be here remarked that every normal wine always con-
tains, besides the bodies belonging to the series of fatty acids,
acetic acid, though only about a few ten-thousandths of its
weight. By storing the wine, the acetic acid does not increase,
but becomes rather less, it being consumed in the formation of
compound ethers. Hence, a rapid increase of the acetic acid
is an indication of the wine being attacked by acetic degenera-
tion, and if examined with the microscope the ferment charac*
teristic of acetic fermentation will be found upon its surface.
Many remedies have been proposed for the cure of acetic de-
generation, but none of them is of any value except heating
the wine to about 140° F., whereby the vinegar ferment is
killed and the further progress of acetic fermentation checked.
There is, however, absolutely no remedy for the removal or
neutralization of the acetic acid already present in the wine.
Heating the wine can only be recommended when the evil has
been in existence but a short time and the increase of acetic
190 MANUFACTURE OF VINEGAR.
acid can be detected only by a very sensitive tongue. Mixing
wine attacked by acetic degeneration with sound wine in order
to cover the acid taste is especially unadvisable, since nothing
can be attained by it except a short delay in the reappearance
of the evil and the transmission of the infection to the sound
wine. There are but two ways in which wine attacked by
acetic degeneration can be in any wise profitably utilized : By
employing it for the preparation of cognac or converting it into
wine-vinegar. For the first a distilling apparatus is required,
and, consequently, cannot be effected by every wine grower,
while for the latter nothing is necessary but a few vessels read-
ily procured.
Young wine attacked by acetic degeneration is also fit for
nothing else than the preparation of vinegar. On account of
its large content of albuminous substances it is, however, more
suitable for the nutriment of the mold ferment than for that
of the vinegar ferment, and consequently many difficulties oc-
cur in its conversion into vinegar. These difficulties can, how-
ever, be largely overcome by introducing large quantities of
air into such wine and storing for some time in barrels filled
up to the bung, or heating after the introduction of air to about
140° F., the separation of the albuminous substances being
effected by either means, though more rapidly by the latter.
Before further working the wine has to be filtered to remove
the albuminous substances rendered insoluble by the treatment
described, since their presence might give rise to injurious com-
plications.
The so-called after wine obtained from grapes once pressed,
by a process introduced by Petiot, is a very suitable material
for making wine vinegar, since after fermentation its composi-
tion as regards alcohol and extractive substances is very advan-
tageous. For successfully carrying out the process it is abso-
lutely necessary to work the marc fresh from the press.
According to Paul Hassack * there are used for the purpose,
* Gahrungs-Essig, 1904.
MANUFACTURE OF WINE VINEGAR.
191
FIG. 45.
400 Ibs. fresh marc,* 150 Ibs. glucose and 1000 quarts of
water.
The glucose is dissolved in about 400 quarts of hot water,
and after making the whole up to 1000 quarts by the addition
of 600 quarts of cold water, the solu-
tion is thoroughly stirred.
In the meanwhile 400 Ibs. of fresh
marc are brought into a fermenta-
tion-vat Fig. 45, and the sugar solu-
tion at a temperature of 72° to 75°
F. is poured over them. The marc
should be broken up, and not
brought into the vat in large lumps.
Fermentation as a rule commences
after six hours and as by it the marc
is forced to the surface, the vat, as
will be seen from the illustration, is
furnished with a perforated head B,
by which the marc is kept below the level of the liquid.
Fermentation is effected under exclusion of the air, a hydraulic
ventilating bung g being used, which permits the escape of
carbonic acid but does not allow air to enter. Fermentation
is best carried on at a temperature of 68° to 75° F., and the
fermenting liquid is allowed to remain in the vat till but a
very weak current of carbonic acid escapes through the venti-
lating bung (about 6 to 8 days). The young wine is then
as quickly as possible racked off into barrels for the second or
after-fermentation. In filling the barrels it is advisable to
pass the wine through a medium fine hair- sieve. The wine
should not come in contact with the air any more than can
possibly be avoided to prevent it from acquiring a darker
color. The marc is taken from the fermentation-vat and
pressed.
* An addition of 1 Ib. or more of crushed quinces per 100 Ibs. of marc imparts
to the wine and indirectly to the vinegar a very agreeable aroma, and the large
content of tannin effects a more rapid clearing of the wine.
192 MANUFACTURE OF VINEGAR.
An addition of tartaric acid to wine prepared by the above-
described process is seldom required, and in any case a solu-
tion of crystallized acid per 100 quarts of the wine when
racked off for the second fermentation will be sufficient. The
treatment of the young wine in the cellar is the same as that
of original wine. The barrels should be kept full up to the
bung. During the first two weeks of the second fermentation
it is of advantage to have a ventilating bung in each barrel.
By taking into consideration the sugar solution that has been
added to the marc and the sugar contained in the latter itself,
the wine, when fermentation is finished, will contain about 7
to 8 per cent, alcohol, 5 to 10 per cent, acid, 0.5 per cent,
sugar and l.G to 2.3 per cent, extract free from sugar, and
would yield vinegar with 5.6 to 6. 5 per cent, acetic acid.
The wine thus obtained when carefully made is dark yellow,
has an agreeably pure taste, and its odor is aromatic and rich
in bouquet. When made with the exclusion of air, it is
durable, easily managed, and clarifies readily. After racking
off several times into clean, slightly sulphured barrels, it is
clarified by means of isinglass solution or filtering through a
linen or paper filter. For fining with isinglass J to J oz. of
isinglass is sufficient for each 100 gallons of wine. Pound
the isinglass, cut it into small pieces and soak it for 12 to 24
hours in fresh water. When taken from the water, squeeze
it thoroughly and bring it into a vessel together with 1 gallon
of water in which f oz. of tartaric acid has previously been
dissolved. The isinglass swells up and is converted into a
thin jelly-like mass. Dilute this solution with 40 gallons of
wine, add it to the wine to be fined and stir thoroughly.
Very young turbid after-wine is not fit for making wine
vinegar. After-wine for vinegar making should be perfectly
bright, and at least 4 to 6 months old.
Before entering upon a description of the various methods
of making wine vinegar it may be mentioned that a product
of actually fine quality can only be obtained by a slow pro-
cess of acetification, wine treated by the quick process yielding
a product very poor in bouquet.
MANUFACTURE OP WINE VINEGAR. 193
The oldest method for making wine vinegar is that to which
the term " boiling of wine vinegar" (Weinessig Siederei) has
been applied. A barrel was filled f full with wine to be con-
verted into vinegar ; a portion of the fluid was then heated to
boiling and poured back into the barrel. Upon the wine
thus heated to about 8(3° F., the development of the vinegar
ferment commenced, and in the course of a few months the
greater portion of the alcohol was converted into acetic acid.
The greater portion of the contents of the barrel was then
drawn off as " ripe wine vinegar," the barrel again filled f
full with wine, and a portion of this heated. The operation
was continued in this manner until so much slimy sediment
had accumulated in the barrel as to render it necessary to
entirely empty and clean it. This crude process, which, as
mentioned, was known in Germany as " vinegar boiling," was
similar to the method formerly in general use in France, and
which, being still partially practised there in some large wine-
vinegar factories, for instance in Orleans, may be designated
as the
Orleans or old French Process of Making Wine Vinegar. The
casks, called mothers, which are employed, hold not more
than 22 gallons, each cask being filled | full. Immediately
above the level of the fluid a hole is bored in the surface of
the front end of each cask, this hole as well as the bung-hole
remaining open ; a stop-cock for the discharge of the fluid is
placed in the lower part of the cask. The casks are placed in
rows in the open air, eight, ten. fifteen, or twenty such rows
constituting what is termed a vinegar field. This so-called
fielding, which is carried on from spring to fall, may be suitable
for the southern part of France, but cannot be recommended
for more northern regions, as the temperature may fall very low
during the night and rise very high during the day. Exper-
ience has shown that the propagation and efficacy of the fer-
ments are very much injured by great variations of tempera-
ture, and consequently it is decidedly preferable to keep the
casks in a room the temperature of which can be maintained
13
194 MANUFACTURE OP VINEGAR.
at, at least 68° F. The wine remains in these casks until it is
converted into vinegar. The latter is then drawn off by means
of the above-mentioned stop-cock and the casks are again filled
with wine, etc. The hole in the front end of the cask and the
bung-hole permit the free access of air to the surface of the
wine. In other French factories the work is carried on accord-
ing to a method somewhat different from the one just described.
Casks having a capacity of up to 100 gallons are used, each
cask having in the surface of the front end a square aperture,
which serves to charge the casks with wine as well as for the
entrance of air. The casks are placed in three rows one above
another in a room which can be heated. In the beginning of
the operation a certain quantity of strong vinegar is brought
into the casks ; about one-fourth of its volume of wine is then
added, and at intervals of eight days about 10 quarts more.
When the cask is nearly filled up to the above-mentioned aper-
ture, the regular process of drawing off vinegar and filling up
again with wine is commenced. If, for instance, 10 quarts of
finished vinegar are drawn off, the same quantity of wine is re-
placed in the cask, and suppose that, according to the manner
of working, 7, 8, or 10 days are required for the conversion of
this quantity into vinegar, 10 quarts of vinegar are again drawn
off after the expiration of that time, this being continued until
a disturbance occurs.
In the course of time large masses of slimy matter consist-
ing of albuminous substances, vinegar ferment vegetating
below the surface (the so-called mother of vinegar), decayed
vinegar ferment, etc., form a deposit in the cask, and finally
accumulate to such an extent as to occupy half the volume of
the cask, so that the latter has to be emptied and thoroughly
cleansed. Sometimes the operation has to be interrupted
much sooner on account of the contents of the cask acquiring
a disagreeable, putrid odor. The appearance of putrefaction
is generally due to vinegar eels settling in the interior of the
cask — as a rule, immediately above the level of the fluid —
and developing to such an extent that they form a slimy coat-
MANUFACTURE OF WINE VINEGAR. 195
ing on the cask and upon the fluid and suppress the develop-
ment of the vinegar ferment. These animalcules are de-
stroyed by being deprived of air, and, hence, when the vinegar
ferment is brought to vigorous development it withdraws so
much of the oxygen from the air in the cask that many of
them die and their bodies sink to the bottom, where they
sooner or later putrefy. If this putrefying process takes place
before a cleansing of the casks is considered necessary, it pro-
gresses to such an extent that the entire contents of the cask
are converted into a stinking mass which has to be removed
as quickly as possible. The casks in which such disturbances
takes place must of course be carefully cleansed by sulphuring
and washing with boiling water before they are again used.
The above-described method of making vinegar is full of
defects. The presence of vinegar in a fluid which itself is to
be converted into vinegar promotes, to be sure, the formation
of acetic acid, but is not absolutely necessary, as has been fre-
quently asserted, for the induction of the process. If such
were the case, it would evidently be impossible for an alcoholic
liquid, such as beer or wine to pass on its own account into
acetic fermentation. The acetification of the casks with boil-
ing vinegar is irrational, because by heating the vinegar and
pouring it boiling hot into the casks, not only the vinegar fer-
ment contained in it, but also that present in the cask or wine,
is, if not absolutely killed, at least weakened to such an extent
as to be incapable of converting alcohol into acetic acid.
That acetic fermentation nevertheless takes place is very likely
due to the following causes.
The hot fluid in the cask gradually cools off and is finally
reduced to a degree of temperature most favorable to the de-
velopment of the vinegar ferment ; in the same proportion as
cooling-off takes place the air contracts in the cask and air
enters from the outside. The latter, however, carries with it
germs of vinegar ferment which rapidly develop upon the
fluid when reduced to the proper temperature and cause its
acetification. The air penetrating into the cask may, how-
196 MANUFACTURE OF VINEGAR.
ever, accidentally contain no vinegar ferment, or that con-
tained in it may not reach the wine ; in such case the wine
may for weeks remain in the cask without any perceptible
acetification taking place until the latter finally appears by an
accidental development of the vinegar ferment. This uncer-
tainty 'can, however, be readily avoided by the direct cul-
ture by the vinegar ferment upon the. wine to be acetified.
Milk, as is well known, turns sour on exposure to the air by
the milk sugar being converted into lactic acid by the action
of a ferment frequently occurring in the air, this souring
taking place in several hours or several days according to the
temperature 'to which the milk is exposed. It is further a
well-known fact that the addition of a few drops of sour to
sweet milk suffices to immediately induce the formation of
lactic acid in the latter; the ferment of lactic acid fermenta-
tion being in the true sense of the word sowed upon the milk.
The ferment develops very rapidly, converts the sugar into
lactic acid, and in a short time turns the entire quantity of
milk sour.
Exactly the same course may be pursued as regards the
vinegar ferment, it being only necessary to mix the wine with
a fluid containing living vinegar ferment and place it in a
sufficiently warm room in order to immediately start the pro-
cess of the formation of acetic acid. In this case the vinegar
ferment is sowed upon the wine, or in other words, the wine
is impregnated with vinegar ferment and intentionally made
" sick." This method of transmitting ferment to the fluid to
be fermented has for a long time been in use in the prepara-
tion of beer and of alcohol. In the brewery the wort, and in
the distillery, the mash, is brought into fermentation by " set-
ting" it with yeast, i. e., alcoholic ferment is intentionally
added. The " setting of wine" with vinegar ferment is the
only correct method for the preparation of vinegar from wine.
Pasteur's, or Modern French Method of Preparing Wine Vine-
gar. Pasteur, as previously mentioned, made exhaustive in-
vestigations regarding the conditions essential to the life of
MANUFACTURE OF WINE VINEGAR.
197
the vinegar ferment, and found that it thrives especially well
upon a liquid which in addition to water, alcohol and vinegar,
contains a trace of phosphates. The latter is absolutely neces-
sary for the propagation of the ferment; if wanting, the fer-
ment cannot attain vigorous development. Pasteur recom-
mends a liquid consisting of boiled water 100 per cent., pure
alcohol 2, crystallized glacial acetic acid 1, phosphate *-0. As
an inorganic combination that contains all the substances re-
quired for the nutriment and development of the vinegar fer-
ment, Pasteur gives the following mixture of phosphate : Po-
FIG. 46.
tassiurn phosphate 1 part by weight, calcium phosphate 1,
ammonium phosphate 2, magnesium phosphate 1.
The liquid prepared according to the above directions is
exposed to the action of the air at a temperature of 68° to 77°
F. In a short time the surface of the liquid becomes covered
with the vinegar ferment and by the agency of the latter the
alcohol present is converted into acetic acid. In the mean-
while a corresponding quantity of wine has been sterilized by
198 MANUFACTURE OF VINEGAR.
heating it to between 158° to 176° F. This process is called
"Pasteurization" and may be effected in various ways, an
apparatus for that purpose being shown in Fig. 46.* Upon
the furnace C sits a vessel F filled with boiling water. In
this vessel lies a coil of pipe tinned, or better, silvered inside.
A similar coil also tinned inside lies in the preparatory heater
and cooler B. The wine to be heated is contained in the vat
A. It passes through g, /, o, d, to B, and when the latter is
full, passes through e into the coil in F, where it is heated, the
temperature of the liquid being indicated by the thermometer
h. From the coil in F, the pasteurized liquid is cooled by
passing through a through the coil in B, heating at the same
time the wine in B, and finally runs off at d. By regulating
the cocks 6, e, and a, the quantity of wine passing through the
apparatus can be readily controlled so that the thermometer
h constantly indicates a temperature between 131° and 140° F.
Various methods based on the researches of Pasteur have
been devised, but before entering upon a description of the
process, it will be necessary to discuss a few undesirable phe-
nomena which may appear in the conversion of wine into
vinegar. A thick white skin having the appearance of a ruffle
may frequently form upon the surface of the wine to be aceti-
fied, the wine in this case becoming constantly poorer in alco-
hol, but does not show acidity. Sometimes the previously
steady increase in the content of acid in the wine suddenly
ceases and a very rapid decrease in the content of acid takes
place, the development of the white skin upon the surface
being also in this case observed.
The formation of this white coating upon the surface is due
to the development of mold ferment which in a short time
propagates to such an extent as to form a thick membranous
layer, the folds being formed by the superposition of the cells.
The mold ferment has the property of converting alcohol as
well as acetic acid into carbonic acid and water, and conse-
* Gahrungs-Essig by Paul Hassack.
MANUFACTURE OP WINE VINEGAR. 199
quently if it settles upon the wine the latter becomes poorer
in alcohol, and if upon wine containing already a certain
quantity of acetic acid the latter is also decomposed. The
mold ferment requires, however, considerable quantities of
nitrogenous combinations for its vigorous development, and
therefore, readily settles upon young wine which contains a
large quantity of albuminous bodies in solution. This fact
explains the reason why young wine is seldom attacked by
acetic degeneration, but it readily becomes moldy, and, con-
sequently cannot be recommended as vinegar material except
the albuminous substances be first separated by heating the
wine to 140° F., which is best effected by means of the appa-
ratus shown in Fig. 42.
Another serious annoyance in making wine-vinegar is the
appearance of vinegar eels, which, if not checked in time, may
lead to the interruption of the entire process. These animal-
cules are seldom found in factories working with pump or well
water, but frequently in those using river water, and conse-
quently their introduction is likely due to such water. In
case of their appearance in large masses it is best to interrupt
the process in time in order to prevent the previously men-
tioned phenomena of putrefaction. The fluid containing the
vinegar-eels should be drawn off into a thoroughly sulphured
barrel. The sulphurous acid kills the vinegar eels as well as
the vinegar ferment, and the filtered fluid, after standing a
few weeks, whereby the sulphurous acid is converted into sul-
phuric acid, can again be used as alcoholic liquid. The ves-
sels in which the vinegar eels have settled must also be
thoroughly sulphured and then repeatedly washed with water
before being re- used for making vinegar.
Throughout the entire factory the greatest cleanliness should
prevail ; in fact one cannot be too scrupulous in this respect,
as otherwise by-fermentations readily take place, and another
plague, the vinegar lice, or more correctly vinegar mites (see
p. 140) may appear. Should either of these drawbacks happen,
the workroom, fluids, and vessels should be thoroughly disin-
fected by means of sulphurous acid.
200 MANUFACTURE OF VINEGAR.
As previously mentioned the Orleans method of making
wine-vinegar cannot be recommended, it being slow and la-
borious, and besides there is considerable loss of material by
evaporation and by the formation of large masses of gelatinous
" mother of vinegar," which depreciates the quality and ne-
cessitates expensive cleaning of the casks.
Claudon's Method of Making Wine Vinegar. This is one of
the methods based on the researches of Pasteur. The appara-
tus used, Fig. 47 is described by Frederic T. Bioletti * as
follows: " It consists essentially of a wide, shallow, covered,
rectangular vat, furnished with numerous openings near the
top, a by which the entrance of air can be facilitated and
Fig 47.
Da a a Da a a .a Da
regulated. This vat is filled to near the bottom of the air
vents with a mixture of 4 parts of good new wine and G parts
of wine which has been pasteurized at 140° F., and when ne-
cessary filtered. On top of this liquid is floated a light wooden
grating /, which helps to support the bacterial film and pre-
vents its breaking and submerging during the various opera-
tions. When filled, the process is started by placing a small
quantity of a good bacterial film on top of the liquid which
soon becomes completely covered when the proper conditions
of temperature and aeration are maintained.
"Each acetifying vat is connected with a small measuring
vat R from which the proper amount of liquid is taken every
* " Grape Vinegar." University of California Publications College of Agricul-
ture, Agricultural Experiment Station. Bulletin No. 227, 1912.
MANUFACTURE OF WINE VINEGAR. 201
day after a corresponding amount of vinegar has been removed.
These two vats constitute a unit, several of which, usually six,
are united in a battery. A factory includes several of these
batteries.
" The batteries are fed from a large vat or reservoir, where
the mixture of wine and vinegar is prepared and stored. The
vinegar drawn from the batteries runs directly to filters, from
there to a pasteurizer, and thence to the storage casks. The
output of these batteries is from two to five times as great
per square yard of acetifying surface as that of the old methods;
the cost of operation is considerably less, the loss by evapora-
tion much reduced, and the quality equal and much more
under the Control of the manufacturer."
Rersch's MetJtod of Making Wine- Vinegar. The essential part
of the entire process is the impregnation of the wine in suitable
vessels with pure vinegar ferment under conditions suitable
for the rapid propagation of the ferment. The vessels are so
arranged that the finished vinegar can be removed and replaced
by wine to be acetified without disturbing the ferment, one
being thus enabled to uninterruptedly continue the process of
the formation of vinegar for a long time, and producing
vinegar unsurpassed by any other product as regards delicacy
of taste and odor. According to the above statement, the
operation includes the culture of the vinegar ferment on a
small scale and on a large scale, the former for the production
of pure ferment and the latter for obtaining wine-vinegar.
The culture of pure vinegar ferment on a small scale is best
effected by heating wine in a porcelain or glass dish to between
140° and 150° F., then mixing it with an equal volume of vine-
gar and pouring the resulting fluid into shallow porcelain plates,
which are placed in a warm room. In a short time, generally
in 24 to 30 hours, the veil-like layer of vinegar ferment pre-
viously described is observed upon the surface of the fluid. If,
besides the dull spots which are characteristic of pure vinegar
ferment, spots of pure white color are formed, it is an indica-
tion of the development of mold ferment. The contents of
202 MANUFACTURE OF VINEGAR.
the plates showing this phenomenon have to be boiled and
then again exposed to the air.
The wine to be acetified is in large, shallow vats, and is
brought to fermentation by carefully submerging in it one of
the above-mentioned plates containing pure vinegar ferment,
so that the latter is distributed upon the surface ; the plate is
then withdrawn. The ferment propagates very rapidly, so
that, in 24 hours, the surface of the wine in the vat is entirely
covered with a thin veil of it. By keeping the temperature
of the room in which the vats are placed at about 68° F., the
acetification of the wine proceeds rapidly, tests repeated at in-
tervals of 24 hours showing a constant increase in the content
of acid, until in about 8 days all the wine is converted into
vinegar when it is drawn off. To avoid the necessity of es-
pecially impregnating the next quantity of wine the finished
vinegar is not entirely drawn off, a small quantity, (about f to
an inch deep), upon the surface of which the vinegar ferment
floats, being allowed to remain in the vat. By now introduc-
ing'a fresh lot of wine the vinegar ferment propagates upon
it and after some time converts it into vinegar.
With sufficient care the process of the formation of vinegar
could thus be uninterruptedly carried on for any length of time
by transferring the vinegar ferment from the finished vinegar
to the wine, if a cleansing of the vat were not from time to
time required, on account of the accumulation on the bottom
of the vessel of decayed vinegar ferment and flakes of albumen
which have become insoluble. When the vat is to be cleansed
the last batch of vinegar is to be drawn off as long as it runs off
clear, and the turbid remainder in the bottom of the vat is
collected in a special cask, where it is allowed to clarify. The
vat is then thoroughly cleansed with water, and after filling
it again with wine, the latter is mixed with pure vinegar
ferment in the manner already described.
If, as may happen in very rare cases, mold ferment in the
form of the above-mentioned white spots appears upon the
surface besides vinegar ferment, the vat must at once be
MANUFACTURE OF WINE VINEGAR. 203
emptied. The process should also be interrupted in case of the
development of the so-called mother of vinegar. The latter
appears generally in the form of a soft gelatinous mass sub-
merged in the fluid, and consists of vinegar ferment, which,
however, on account of not being in direct contact with the
air, does not produce acetic acid. The fluid to be acetified
can be readily separated from the mother of vinegar by filter-
ing through a close cloth, the mother of vinegar remaining
upon the latter and finally drying to a whitish mass resemb-
ling very thin tissue paper.
From.the above description it will be seen that the rational
preparation of wine-vinegar is a very simple matter ; but there
are some difficulties which can, however, be entirely prevented
or readily overcome. The vinegar ferment is very sensitive
towards sudden changes in the composition of the fluid upon
which it lives, as well as towards rapid changes in the tem-
perature. The sudden change in the composition of the fluid
is prevented by not drawing off all the finished vinegar, but
allowing a small portion of it to remain in the vat. The
fresh supply of wine entering from below then lifts up the re-
mainder of vinegar, together with the ferment floating upon
it, and the mixture of both fluids is effected so gradually that
the change in the composition of the nourishing fluid proceeds
very slowly. A sudden change in the temperature of the work-
room can, of course, be readily prevented by proper heating.
Ripe wines with not much above 6 per cent, of alcohol are
the best to use, as they yield vinegar with about 5J per cent,
of acetic acid. Stronger wines with a content of alcohol up to
10 per cent., are, however, best reduced to about 6 per cent.,
either by water or ordinary vinegar. The strength of the
latter must be so chosen that the wine-vinegar prepared from
a mixture of wine and vinegar contains 5J to 6 per cent, of
acetic acid. The proportions in which vinegar and wine are
to be mixed for this purpose are found by a simple calculation
after an accurate determination of the content of alcohol in
the wine and that of acetic acid in the vinegar.
204 MANUFACTURE OF VINEGAR.
The workroom should be so situated as to be protected
against sudden changes in the temperature and provided with
a furnace or self- regulating stove. The vessels for the forma-
tion of vinegar are placed upon suitable supports, and tables
for holding the plates for the culture of the vinegar ferment
should be provided. If the size of the room permit, it is ad-
visable to store in it a few barrels of the material to be worked,
the fluid thereby gradually acquiring the proper temperature.
For the formation of the vinegar very shallow vats, best with
a diameter of 3 J to 5 feet and a depth of 9 to 14 inches, are
used.
The iron hoops are protected from the action of the acid
vapors by a coat of asphalt lacquer. The vats are placed in
FIG. 48.
H
the position they are to occupy in the workroom and filled
with water up to about If to 3} inches from the top, the
height of the level of the fluid being marked on the inside wall.
At distances of 3 j inches apart, and 5} in large vats, holes,
I, Fig. 48 of 0.39 inch diameter are then bored in the wall of
the vat. One hole, however, is bored in a place about 0.39
inch deeper than I, and in this hole is fitted a glass tube, g,
bent at a right angle, under which is placed an ordinary tumb-
ler. In the bottom of the vat is a tap-hole, Z, closed by a
stopper.
If the vat be filled during the operation with wine, the latter
can only rise until it begins to run off at g. The level of the
fluid being but little below the holes I, an uniterrupted change
MANUFACTURE OF WINE VINEGAR. 205
in the layer of air above the fluid takes place. A wooden
spigot, //, is fitted in the vat about { to 1 inch above the
bottom. In the centre of the lid D, which lies loosely upon
the vat, is an aperture, 0 ; in a second aperture a thermometer,
r, is inserted, whose bulb dips into the fluid ; and in a third
aperture is fitted a glass funnel, R, reaching nearly to the bot-
tom of the vat.
The operation in such a factor}^ commences with the cul-
ture of the vinegar ferment. For this purpose as many shal-
low porcelain plates as there are vats are placed upon the
table, and wine to the depth of J to f inch is poured in each.
The room should be heated and kept at a temperature of 86°
F. The manner of the development of the vinegar ferment
upon the fluid in the plates as well as the precautions which
have to be taken has already been described. In the com-
mencement of the operation the culture of the ferment requires
great attention, it being frequently disturbed by the develop-
ment of mold ferment, but when the factory is once in proper
working condition it is readily effected because the air of the
workroom then contains a large quantity of the ferment, which
rapidly propagates on coming in contact with a fluid favor-
able for its development.
The vats are charged by allowing the fluid to be converted
into vinegar to run in until it begins to pass out through g.
The impregnation with ferment is then effected by carefully
emptying the contents of one of the plates upon the surface of
the fluid, so that the greater portion remains floating upon it.
Finally the lid is placed upon the vat and the latter left to
itself.
The ferment soon covers the entire surface of the fluid in
the vat, and the commencement of the process of oxidation is
in a short time recognized by the rise of the thermometer dip-
ping into the fluid. As long as the quantity of alcohol in the
fluid is comparatively large, the process of the formation of
acetic acid and the propagation of the ferment takes place
very rapidly and the thermometer rises constantly ; but with
206 MANUFACTURE OF VINEGAR.
an increase in the quantity of acetic acid these processes become
slower, which is indicated by a fall in the temperature of the
fluid. The energy of the process must, however, not be al-
lowed to sink below a certain limit, care being taken to keep
it up by raising the temperature of the workroom, but not
higher than is absolutely necessary for the correct working,
as otherwise there would be a loss of acetic acid or alcohol by
evaporation.
The most convenient and business-like manner of operating
a factory arranged as above described is to simultaneously
charge all the vats with alcoholic liquid, it being then entirely
in one's power to regulate the heating of the workroom accord-
ing to the indications of the thermometer dipping into the
fluid. If, for instance, the operation commences at 77° F., the
thermometer will soon be observed to rise even if the tempera-
ture of the workroom remains unchanged. By the oxidation
of the alcohol sufficient heat is liberated to increase the tem-
perature of the fluid to above 95° F. It is, however, advisable
not to allow it to rise above 86° or 90° F., as otherwise the
losses by evaporation are too great. Hence, if the fluid reaches
this limit of temperature the heating of the workroom is so
regulated as to prevent a further rise of the thermometer, and
a constant temperature is maintained for several days until it
commences to fall almost simultaneously in all the vats. This
fall in the temperature, as previously mentioned, is an indica-
tion of the fluid now containing a comparatively large amount
of acetic acid and of the slow oxidation of the remaining alco-
hol. In order to maintain the most favorable conditions for
the efficacy of the vinegar ferment and to smoothly and rapidly
complete the process the workroom is now so heated as to
show a constant temperature of 86° F. as long as the fluid re-
mains in the vat.
Side by side with the observation of the statements of the
thermometer a chemical examination of the fluid has to be
carried on, this examination gaining in importance the further
the formation of vinegar progresses. If the content of alcohol
MANUFACTURE OF WINE VINEGAR. 207
in the wine to be worked is known, the test is up to a certain
stage limited to the determination of the acetic acid, but if the
process has so far advanced that the fluid contains scarcely 1
per cent, of alcohol, the latter has also to be determined by
means of the ebullioscope which will be described later on.
From this moment on the course of the process must be very
carefully controlled, and interrupted when still 0.15 or at the
utmost 0.2 per cent, of alcohol is present. This small amount
of unchanged alcohol exerts a favorable effect upon the quality
of the vinegar, acetic ether being formed from it and a corre-
sponding quantity of acetic acid during the time the vinegar
has to be stored.
The interruption of the process is best effected by separating
the fluid from the layer of ferment floating upon it. The stop-
cock, H, Fig. 48, is opened and left open as long as fluid runs
out. A layer of vinegar about j to 1 inch deep upon which
floats the vinegar ferment, remains in the vat, and the stop-
cock being closed a fresh supply of alcoholic liquid is intro-
duced through the funnel R until it begins to run out through
g. The process then commences anew in the manner above
described.
Theoretically unlimited quantities of wine could be con-
verted into vinegar by means of such an apparatus, as the
vinegar ferment which floats upon the fluid that remains in
the vat, rapidly propagates upon the fresh supply of wine and
converts it into vinegar. In practice an occasional short in-
terruption of the process is, however, necessary. During the
conversion of the wine the greater portion of albuminous sub-
stances held in solution in it separates as flakes, and, further,
a portion of the vinegar ferment sinks below the level of the
fluid and assumes the form of the flaky masses called mother
of vinegar. The result after a number of operations is a slimy
sediment, which finally accumulates to such an extent that it
has to be removed. This is effected, after the finished vinegar
is drawn off, by opening the tap-hole Z, and removing the
slimy mass by means of a broom or crutch. The vat is then
208 MANUFACTURE OF VINEGAR.
thoroughly washed with water and can be immediately re-
charged with wine. The slimy mass is best collected in a tall
vat and allowed to rest. In a few days it separates into two
layers, the upper one consisting of quite clear vinegar which
can be used for filling up storage-barrels, and the lower one of
a thickly-fluid mass from which a certain quantity of vinegar
can be obtained by filtration.
The vinegar drawn off from the vats is brought into storage
barrels which are filled up to the bung and closed air-tight.
The volume of the vinegar decreasing by cooling, the barrels
must from time to time be examined and kept filled up to the
bung-hole. While stored in the barrels the vinegar almost
completely clarifies^ and by carefully siphoning off the clear
portion, it can be at once brought into commerce without
further treatment. When a considerable quantity of slimy
sediment has collected in the storage-barrels, it is drawn off
and brought into the above-mentioned clarifying vat,> or is
clarified by filtration.
In case of disturbances in the production by the appearance
of mold ferment or vinegar eels, the process once commenced
must be carried through as well as possible, and then the en-
tire operation interrupted for the purpose of thoroughly cleans-
ing the vessels by washing with boiling water or steaming.
Under no circumstances should it be attempted to continue
working with vats infected with mold or vinegar eels, as it
would only lead to a considerable loss of material, and the
cleansing of the vessels which would have to be finally done,
would be more difficult.
If the vinegar has been made from clear, ripe wine, it will
generally come quite clear from the apparatus used for its pro-
duction. Should it be turbid, as may sometimes happen, it
has to be filtered through a bag or other filter as described on
p. 156. The turbidity is caused by various substances sepa-
rated during the formation of the vinegar. Vinegar is much
more difficult to fine than wine and for this reason alone, only
clarified, ripe wines should be used for its production. The
MANUFACTURE OF WINE VINEGAR. 209
simplest method to clarify the vinegar is to store it for several
weeks in a cool cellar in casks filled up to the bung. The
•greater portion of the vinegar can then Tbe drawn off perfectly
clear and only the last portion will require filtering.
The filtered vinegar is brought into clean casks and stored
in a cool cellar. However, while thus stored it may some-
times depreciate in quality and strength by unfavorable con-
ditions of temperature or handling, such depreciation being
indicated by a change in the aroma, and the acid taste loses
its sharpness and shows a peculiar insipidity. The cause of
this alteration may be attributed to the decomposition of the
tartaric and malic acids in the vinegar by a ferment. The
only sure remedy for this and all other alterations is to steri-
lize the vinegar by heating to 140° F. The apparatus, Fig.
46, p. 197, for pasteurizing wine, or any other form of pasteur-
izer may be used for the purpose. The vinegar should come
out of the pasteurizer cool and the storage-barrels should be
completely filled, bunged tight and placed in a cool cellar.
Wine vinegar acquires its special aroma only by being stored
for several months. French manufacturers store their best
quality of it for at least one year before offering it for sale and,
of course, charge a good price.
When the wine vinegar has acquired a fine taste and aroma
by storing it should be bottled, this being the most profitable
way of selling it. As the vinegar should be perfectly bright
before racking it into bottles it must first be filtered or fined.
Many manufacturers pasteurize the bottled vinegar. An ap-
paratus for this purpose * is shown in Fig. 49. It consists of
an iron receptacle furnished with a cover fitting air-tight, and
in the interior with a perforated false bottom. The apparatus
is about 5 feet long, 3 feet 6 inches wide and 1J feet deep.
Between the perforated false bottom and the actual bottom is
a pipe-system which is connected by two iron pipes with the
furnace. The bottles are placed alongside each other upon the
* German patent No. 17970 granted to Boldt & Vogel, Hamburg.
14
210
MANUFACTURE OF VINEGAR.
perforated false bottom. Before placing them in the appara-
tus, water is admitted into the latter so as to fill the space
below the perforated false bottom and cover the latter. Fire
is then started in the furnace and the water commencing to
circulate, steam is in a short time evolved in the apparatus.
The temperature prevailing in the interior is indicated by a
thermometer on top of the apparatus, and pasteurization can
thus be carried on to any desired degree. Cooling is effected
by discontinuing heating and opening the cover.
Pasteurized wine-vinegar does not spoil if exposed to vary-
FIG. 49.
ing temperatures or even if kept in open or improperly closed
receptacles. It is free from all kinds of ferments and vinegar
eels, and is not attacked by the spores of the vinegar ferment
suspended in the air, because the nutriment required for their
further development has been withdrawn.
Wine-Vinegar by the Quick Process. — Although in making
wine vinegar of fine quality, the best results are without doubt
obtained by one of the slow methods above described, a very
good product can be made from clear wines in one of the gen-
erators previously described, that furnished with a tilting
MANUFACTURE OF WINE VINEGAR. 211
trough being by some manufacturers preferred for the purpose.
The process is the same as for ordinary vinegar, the principal
conditions for smooth working being a limited admission of
air below the perforated false bottom, the use of perfectly clear,
pasteurized wine, correct measuring of the quantity to be
poured and its uniform distribution, absolute cleanliness,
cleansing the perforated head every week or two, according to
the accumulation of slime, and finally continuous working.
The last condition — continuous working — is necessary to pre-
vent the product from being impaired during the rest at night
by a decomposition — a decrease of its most valuable properties.
Wine-vinegar made by the quick process has less aroma
than that prepared by the other method. However, by stor-
ing it for about three months it gains in quality and aroma
so that it can scarcely be distinguished from vinegar made by
the Orleans method.
Wine Vinegar from Marc — The marc left after the wine has
been pressed consists of the stems, skins and seeds of the grapes
and contains a not unimportant quantity of must. As, pre-
viously described, by subjecting the marc with the addition of
water or sugar solution to fermentation a wine is obtained
which forms an excellent material for making vinegar. How-
ever, the marc may also be directly used for the purpose.
The mass of marc as it comes from the press is broken up
and put in a pile where it is left to itself until it becomes warm
and acquires the odor of alcohol and acetic ether. The mass
is then shoveled into a vat and gently pressed together with a
shovel. For every 220 Ibs. of marc used, about 10 quarts of
water are now sprinkled over the mass by means of a watering-
pot. By the entrance of air while shoveling the pile of marc
into the vat the action of the vinegar ferment has been accel-
erated and a considerable quantity of alcohol converted into
acetic acid, which is indicated by the stronger vinegar odor.
The water permeating the marc almost completely displaces
the fluid containing the alcohol and acetic acid, the latter run-
ning off through an aperture in the bottom of the vat. It is
212 MANUFACTURE OF VINEGAR.
collected in a shallow vessel placed in an apartment having
the ordinary temperature of a living-room, and is allowed to
rest. The vinegar ferment present in abundance in the fluid
rises to the surface, where it quickly propagates and converts
the remainder of the alcohol in the fluid into acetic acid. The
only difficulty to be overcome in preparing the vinegar ac-
cording to this method is the appearance of the mold ferment
upon the surface of the fluid. This can, however, be met by
removing the growth of this ferment, which is recognized by
its pure white color, by means of a spoon as soon as it has at-
tained the thickness of a few millimeters. The vinegar fer-
ment then commences to propagate and suppresses the further
growth of the mold ferment.
If the grapes originally used contained from 18 to 20 per
cent, of sugar, the vinegar from the marc prepared according
to this method shows, if not too much water has been used, a
content of at least 4 or 5 per cent, of acetic acid, and conse-
quently is immediately fit for table use. By long storing in
barrels kept filled up to the bung-holes, it acquires a flavor
resembling that of vinegar prepared from wine.
On account of the simplipity and the slight expense con-
nected with it, the above-described process is especially adapted
for making vinegar for household use. For industrial pur-
poses it is, however, more advantageous to prepare wine from
the marc as described on p. 190, and convert the product thus
obtained into vinegar.
CHEMICAL EXAMINATION OF RAW MATERIALS. 213
CHAPTER XIX.
CHEMICAL EXAMINATION OF THE RAW MATERIALS AND CON-
TROL OF THE OPERATIONS IN A VINEGAR FACTORY.
Determination of Sugar. — The sacchariferous materials used
by the vinegar manufacturer are either whiskey-mashes, malt-
extracts, or must prepared from wine-marc, apples, etc. The
determination of sugar contained in these fluids is effected by
means of various instruments, which are really hydrometers,
with different names and graduations. The instruments mostly
used for the determination of sugar in whiskey-mashes and
malt worts are known as saccharometers, and directly indicate
the content of sugar in the fluid in per cent. A similar in-
strument, known as the must-aerometer, serves for the determi-
nation of the content of sugar in grape-must. According to
the arrangement of their scales, the must-aerometers indicate
either direct sugar per cent., 'or degrees ; in the latter case the
use of special tables accompanying the instrument is required
for finding the per cent, of sugar corresponding to a certain
number of degrees.
No special saccharometer for fruit-must having as yet been
constructed, the determination of the content of sugar has to
be effected either by a tedious method unsuitable for practice,
or, what can be more quickly done, by fermenting a sample
of the respective must, and after determining the quantity of
alcohol, ascertaining from it tha content of sugar.
In place of special saccharometers or must-areometers, an
ordinary areometer indicating the specific gravity can also be
used, and the content of sugar corresponding to a certain
specific gravity found from a reducing table. Tables X to
XIII at the end of this volume give the content of sugar espe-
cially for wine-must, but also with sufficient accuracy for apple
or pear-must, according to the statements of the respective
must-aerometers.
214 MANUFACTURE OF VINEGAR.
Determination of Alcohol. — In a factory using commercial
spirits of wine as the fundamental material for making vine-
gar, the percentage of absolute alcohol contained in it has to
be accurately determined in order to enable one to correctly
calculate, in the manner explained on p. 109, the quantity of
water required for the preparation of alcoholic liquid of de-
termined strength.
For the determination of the content of alcohol in pure
spirits of wine consisting only of water and alcohol, instru-
ments called alcoholometers are generally used, they indicating
the volumes of alcohol contained in 100 volumes of the spirits
of wine. They are, however, not suited for this purpose when,
as is frequently the case in a vinegar factory, the spirit of wine
contains other bodies besides water and alcohol. In this case,
either the alcohol contained in a sample has to be distilled off,
and after determining its strength by the alcoholometer, the
content of alcohol in the total quantity of fluid ascertained by
calculation, or the determination is effected in a short time
and with sufficient accuracy for practical purposes by the use
of a special apparatus.
Determination of the Alcohol with the Alcoholometer. — For the
vinegar manufacturer the alcoholometer is an important in-
strument in so far as it serves for quickly ascertaining the de-
grees of the spirits of wine used. It is best to use an instru-
ment which is combined with a thermometer, one being thus
enabled to ascertain the temperature of the fluid simultane-
ously with reading off the statement of the alcoholometer.
Tables I to VIII appended to this work give the necessary as-
sistance for the determination of the actual content of alcohol
in a fluid whose temperature is above or below the normal
temperature (59° F.).
For examining fluids with a very small content of alcohol,
alcoholometers have been constructed which accurately indi-
cate at least 0.1 percent. For the manufacture of vinegar,
four alcoholometers will, as a rule, suffice. They should be
so selected that one is to be used for fluids with from 0 to 4
CHEMICAL EXAMINATION OP RAW MATERIALS. 215
per cent, of alcohol, the second for indicating 4 to 8 per cent.,
the third 8 to 12 per cent., and the fourth 12 to 1C per cent.
The scale of such alcoholometers comprising only 4 per cent,
each, is sufficiently large to allow of the easy reading off of
one-tenth per cent. These instruments serve for the determi-
nation of the content of alcohol in alcoholic liquid consisting
only of spirits of wine and water, and are used in examining
the progress of the formation of vinegar during manufacture.
Determination of the Alcohol by the Distilling Test — The con-
tent of alcohol in a fluid containing other bodies besides alco-
hol and water cannot be directly determined by means of the
alcoholometer, as the statement of the latter would be incor-
rect on account of the foreign bodies exerting a considerable
influence upon the specific gravity. Hence, the content of
alcohol in alcoholic liquid containing a certain quantity of
acetic acid, or fermented whiskey-mash, beer, wine, etc., can-
not be ascertained by immersing the alcoholometer in the re-
spective fluid. In order to determine the content of alcohol
in such a fluid a determined volume of it is subjected to dis-
tillation, and the latter continued until it may be supposed
that all the alcohol present is volatilized and again condensed
in a suitable cooling apparatus. By diluting the fluid distilled
over with sufficient water to restore it to the volume of the
fluid originally used and immersing the alcoholometer the
content of alcohol is determined.
A rapid and at the same time accurate execution of all ex-
aminations being of great importance in practice, a suitable
apparatus should be used for the distilling test. Such an ap-
paratus is shown in Fig. 50. It consists of a glass boiling
flask, K, having a capacity of \ liter in which sits by means
of a perforated cork a glass tube, E, which is about f inch in
diameter and 7f inches in length. On top this tube is closed
by a perforated cork. From the latter a glass tube bent twice
at a right angle leads to a cooling-coil, which is placed in a
vessel F, filled with water, and terminates over a graduated
cylindrical glass vessel G. The uppermost mark on G indi-
216
MANUFACTURE OF VINEGAR.
cates the height to which the vessel must be filled to contain
^ liter = 500 cubic centimeters. Generally vessels are used
which are so 'graduated that the distance between two marks
is equal to 2-V liter or 50 cubic centimeters. The boiling-flask
stands upon a plate of thin sheet-iron (to prevent bursting
from an immediate contact with the flame), and together with
the cooling vessel is screwed to a suitable support.
In distilling a fluid containing acetic acid the vapors of the
latter pass over together with those of alcohol and water, and
consequently, the statement of the alcoholometer would be in-
FIG. 50.
correct. This is overcome by placing a few pieces of chalk
the size of a hazelnut in the tube R. By the vapors coming in
contact with the chalk the acetic acid is fixed to the lime con-
tained in it, not a trace reaching the cooling vessel.
The manner of executing the test with this apparatus is as fol-
lows : Fill the vessel G to the uppermost mark with the fluid
whose content of alcohol is to be examined, then pour it into
the boiling flask K, rinse out G with water, and after pouring
the rinsing water into K, put the apparatus together as shown
in the illustration. The contents of K are then heated to boil-
CHEMICAL EXAMINATION OF RAW MATERIALS. 217
ing by a spirit or gas flame under the sheet-iron plate upon
which Crests, the flame being so regulated that the distillate
flows in drops into G(. By too strong heating the contents of
K might foam up and pass into (r, which would necessitate a
repetition of the experiment with another quantity of fluid.
Wine, beer, and whiskey-mashes frequently foam up on heat-
ing, which can, however, be almost completely overcome by the
addition of a small quantity of tannin solution to the contents
inK.
The heating of the boiling flask is continued until sufficient
fluid is distilled over into G to fill it from one third to one half
full, this being a sure indication of all the alcohol present in
the fluid having passed over. The flame is then removed, the
vessel G filled to the uppermost mark with distilled water, and
the fluids intimately mixed by shaking, the mouth of G being
closed by the hand. The fluid now contained in G consists
only of water and alcohol, and its volume is equal to that of
the fluid originally used. By testing the fluid with an alco-
holometer the content of alcohol found corresponds exactly
to that possessed by the fluid examined — alcoholic liquid,
beer, fermented whiskey-mash, etc.
Determination of the Alcohol by Means of the Ebullioscope.
Many determinations of the content of alcohol in the alcoholic
fluid having to be made in a well-conducted vinegar factory,
the above-described distilling test is objectionable on account
of the time (about twenty minutes) required for its execution.
Good results are, however, obtained by the use of the ebullios-
cope and, but a few minutes being required for the test with
this apparatus, it can be frequently repeated, and thus even a
more accurate idea of the working of the generators obtained
than is possible with a single determination by the distilling
test. The apparatus is very simple, is easily managed, and
allows, without the use of an sero meter or table, of the direct
reading-off of the content of alcohol in a fluid containing not
much over 12 per cent. It is much used in France for the ex-
amination of wine. The principle of the apparatus is based
218 MANUFACTURE OF VINEGAR.
upon the initial boiling point of the fluid to be examined, an
alcoholic fluid boiling at a lower temperature the more alcohol
it contains. For instance, wine with —
12 per cent, by volume of alcohol boils at 196.7° F.
10 " " 198.3° F.
8 " 201.0° F.
5 " 203.3° F.
Fig. 51 shows Vidal-Malligaud's ebullioscope. To a round
cast-iron stand is screwed a thick-walled brass cup which ex-
pands somewhat towards the top ; a screw-thread is cut in the
upper edge. A hollow-brass ring is soldered into the cup near
its base, the one end of the ring entering it somewhat higher
than the other. On filling the cup with the fluid to be ex-
amined this hollow ring also becomes filled. On the one side
the ring carries a small sheet-iron chimney, and by placing a
small spirit lamp under this the fluid in the cup is heated,
this arrangement securing a quick circulation of the fluid
during heating. Upon the upper edge of the cup a lid is
screwed, in which a thermometer is inserted air-tight. The
mercury bulb of the thermometer is on the lower side of the
lid and, in determining the boiling-point, dips into the fluid.
The tube of the thermometer is bent at a right angle outside
the lid, the latter carrying the scale, which is divided not into
degrees but in per cent, by volume of alcohol. The scale can
be shifted upon a supporting plate so that it can be fixed at
any desired place, and, consequently, also so that the ther-
mometer when dipped into boiling water indicates 0. The
scale is secured by small screws. Into a second aperture in
the lid is screwed the cooling-pipe, which is surrounded by a
wide brass tube for the reception of the cooling water. During
the determination of the alcohol, which requires about ten
minutes, the cooling water need not be renewed, the boiling
point remaining constant during the short time (one or two
minutes) necessary for making the observation. In heating
wine, the gases and besides a few light volatile varieties of
CHEMICAL EXAMINATION OF RAW MATERIALS.
219
ether, as acetic ether, aldehyde, etbylamine, propylamine, and
similar combinations escape through the cooling pipe, which
is open on top, and in heating beer, carbonic acid. For the
determination of the alcohol in sacchariferous wines, the ebul-
lioscope is less adapted, nor does it give accurate results with
the use of dilute wines.
It has been ascertained by the French Academy that the
FIG. 51
JL
statements of the ebullioscope as regards the quantity of alco-
hol in the wine differ on an average J per cent, from those
found by accurate distillation. The entire apparatus with the
exception of the thermometer being of metal, it is not liable to
breakage. The mercury bulb of the thermomter is compara-
tively large. For the vinegar manufacturer the ebullioscope is
a very valuable instrument, as it enables him to accurately
220 MANUFACTURE OF VINEGAR.
determine to within % per cent, the content of alcohol in a fluid
in a shorter time than is possible with any other instrument.
Its use is especially recommended when the working of one or
more generators is to be ascertained in a short time, perfectly
reliable results being obtained in connection with the deter-
mination of the acid by titration.
Determination of the Content of Acetic Anhydride in Vinegar
or Acetometry. The content of acetic acid in vinegar is some-
times ascertained by a species of hydrometer termed an
acetometer. The statements of these instruments are, however,
very unreliable. Vinegar made from dilute alcohol or ripe
wines in which no great excess of albuminous or other matter
is present might to a certain limit be tested with sufficient
accuracy by the acetometer, but vinegars made from malt,
poor wines, and such liquids as contain an excess of organic
matters, do not admit of being tested with the required degree
of accuracy by this method, since the apparent quantity of
real acetic acid is increased by the presence of foreign bodies
which add to the density of the liquid. In some cases the
vinegar is saturated with chalk or milk of lime, the solution
filtered, and the specific gravity of the acetate of lime liquor
ascertained, by which a nearer approximation is arrived at
than by the direct testing of the vinegar, yet implicit reliance
cannot be placed on either of these two methods.
The best method of ascertaining the percentage of acetic
acid in vinegar is by titration or volumetric analysis. For
the execution of the test a few instruments are required,
namely, a burette and pipette. The latter is filled by dipping
the lower end of it into the fluid and sucking on the upper
end with the mouth until the fluid has ascended nearly to the
. top. The upper end is then quickly closed with the index
finger of the right hand. By slightly lifting the finger the
liquid is then allowed to flow off by drops until its level has
reached a mark above the convex expansion of the instru-
ment, when it will contain exactly the number of cubic centi-
meters indicated opposite to the mark.
CHEMICAL EXAMINATION OF RAW MATERIALS. 221
The burette is a cylindrical glass tube open on the top. It
is graduated, commencing from the top, into whole, one-tenth
and one-fifth cubic centimeters. The lower end of the tube is
drawn out to a somewhat distended point so as to allow a
rubber tube to be drawn over it and securely fastened. In
the lower end a glass tube drawn out to a fine point is inserted.
The rubber tube is compressed in the center by a pinch-cock
or clip, whereby the lower end is closed. The burette is filled
with fluid from above by means of a small funnel. By a
quick, strong pressure upon the handle-joint of the clip, some
liquid is then allowed to flow in a jet into a vessel. By this
the tube below the clip is filled with liquid and the air con-
tained in it expelled. By a slight or stronger pressure the
liquid can, after some experience, be ejected in drops or in a
stronger jet. The number of cubic centimeters which have
been allowed to flow out can be readily read off by keeping
the surface of the fluid in the tube on a level with the eye.
The test liquor generally used is normal caustic soda solution,
one cubic centimeter of it corresponding to 0.06 gramme of
acetic anhydride, and for especially accurate determinations
decinormal solution, one cubic centimeter of it corresponding
to 0.006 gramme of acetic anhydride and -^ cubic centimeter
to 0.0006 gramme.
For determining the acetic acid the burette is filled to the 0
point with soda solution. A corresponding quantity of vinegar
is then accurately measured off by means of the pipette, and
after bringing it into a beaker, colored red by the addition of
one or two drops of litmus tincture and diluted with four or six
times its quantity of distilled water. The beaker is placed upon
a white support under the burette and the soda solution in the
latter ejected in a strong jet by pressing with the right hand
the handle-joint of the clip, the fluid being constantly agitated
by gently swinging the beaker with the left. The inflow of
soda solution is interrupted as soon as a blue coloration on the
point where it runs in is observed. After thoroughly stirring
the fluid with a glass rod, the soda solution is again allowed to
222
MANUFACTURE OF VINEGAR.
FIG. 52.
run in, but now drop by drop, the fluid being stirred after the
addition of each drop. This is continued until the fluid has
acquired a violet color with a strong reddish shade, and the
addition of one drop more of soda solution changes the color
to blue. The appearance of the violet coloration is called the
neutralizing point, while the change of color from violet to blue
indicates that the fluid is now neutral, i. e., contains neither
free acetic acid nor an excess of caustic soda. The determina-
tion is based upon the coloring substance of litmus appearing
red in acid, violet in neutral, and blue in alkaline solutions.
Instead of soda test liquor, a solution of ammonia is some-
times used to saturate the acid. The solution is prepared by
adding water to concentrated ammonia till the specific gravity
is 0.992 ; 1000 grains of this dilute ammonia
contain one equivalent of ammonia, which is
capable of saturating one equivalent of acetic
acid. The application of this test is similar
to that already described.
There is some difficulty in preserving the
dilute ammonia of the same strength, which
is an objection to its use ; but a uniformity of
concentration may be insured by introducing
into the bottle two glass hydrometer bulbs so
- adjusted that one remains barely touching at
the bottom, and the other floats just under
the surface of the liquid as long as the test-
liquor retains the proper strength. If a part
of the ammonia volatilizes, the specific gravity
of the liquor will become proportionately
greater, and the glass bulbs rise ; the lower one
higher from the bottom, and the upper one
partly above the surface. When this happens,
more strong ammonia is added, till the hydro-
static drops are properly readjusted.
Determinations of acetic acid by titration having to be fre-
quently executed in a vinegar factory, it is advisable to
CHEMICAL EXAMINATION OP RAW MATERIALS. 223
use an apparatus which will facilitate the operation. Such
an apparatus is shown in Fig. 52. Upon a table stands a
two-liter flask holding the normal soda solution. The flask is
closed air-tight by a cork provided with three perforations.
In one of these perforations is inserted a glass tube, A, in
the lower end of which is a stopper of cotton upon which
are placed small pieces of burnt lime. On top, the tube is
closed by a glass tube drawn out to a fine point. Through
another of these perforations passes a glass tube, R, bent twice
at a right angle and reaching to the bottom of the flask. The
portion of this tube outside of the flask, as will be seen in the
illustration, is somewhat longer than that in the flask, and,
consequently, the tube forms a siphon. The outside portion
of this tube is connected by a short rubber tube with the upper
portion of the burette B. The latter is secured in a vertical
position by two rods placed on the stand holding the flask.
Below the burette is connected with a short rubber tube in
which is inserted a glass-tube drawn out to a fine point. On
the side near the top of the burette is a small tube bent at a
right angle, which is connected by a short rubber tube with the
tube L, the latter reaching only to below the edge of the cork.
Above and below the burette is closed by the clips Q andQ,.
For working with the apparatus the flask is filled with nor-
mal soda solution and the cork inserted air-tight after remov-
ing from it the tube A, and substituting for it a small glass-
tube. Now open the upper clip Q and blow vigorously through
the glass-tube substituted for A, whereby the fluid is forced
through the tube R into the burette. This being done, cease
to press upon Q, whereby the latter closes and stops a further
discharge of the fluid. The tube, A, is then placed in position.
By now pressing on the clip Q the fluid passes into the burette,
the air contained in the latter entering the flask through the
tube L. The burette being emptied by the discharge of the
fluid through Qlt it .is refilled for another determination of
acid by simply pressing on Q, and this can be repeated as
long as the flask contains soda solution.
224 MANUFACTURE OF VINEGAR.
In discharging the fluid from the burette by opening Qv air
from the outside passes into the apparatus through A. In
doing so it must, however, pass through the lime which fixes
the carbonic acid contained in it, so that the fluid in the flask
remains free from carbonic acid even after standing for months.
The calculation of the quantity of acetic acid present in the
vinegar examined is made as shown by the following exam-
ple : —
For 10 cubic centimeters of vinegar were consumed 70 cubic
centimeters of decinormal soda solution.
One cubic centimeter of decinormal soda solution being
equal to 0.006 gramme of acetic acid, hence 70 cubic centi-
meters=0.42 gramme. '
Now, as 10 cubic centimeters contain 0.42 gramme of acetic
acid, 100 cubic centimeters contain 10 times 0.42 gramme =
4.2 grammes .of acetic acid ; or the vinegar examined contains
4.2 per cent, by weight of acetic acid.
For the determination of the strength of vinegar with suffi-
cient accuracy for manufacturing and commercial purposes an
instrument called a vinegar tester is largely used. In the form
shown in Fig. 53, as described by Frederic T. Bioletti,* the
acetic acid is determined by the volume of gas given off by
bicarbonate of soda when treated with a measured volume of
vinegar.
" The requisite volume of vinegar is measured in the small
glass tube A and poured into the bottle B. A sufficient
amount of bicarbonate is then taken with the spoon E and in-
troduced carefully into the bottle. As soon as the bottle is
tightly closed with the cork the bicarbonate is shaken gradu-
ally into the vinegar and immediately carbonic acid gas com-
mences- to be given off. This gas passing through the rubber
tube forces the water in the bottle D to rise in the large glass
tube C. The stronger the vinegar, the more gas will be given
* Grape Vinegar. University of California Publications, College of Agricul-
ture Experiment Station. Bulletin No. 227.
CHEMICAL EXAMINATION OF RAW MATERIALS.
225
off and the higher the water will rise in the tube G. This
tube is marked with numbered lines. By reading the num-
ber of the line nearest the level reached by the water and add-
ing the estimated height above or below this line, the strength
of the vinegar is obtained directly in per cent. If the vinegar
is made from wine 0.5 per cent, must be deducted from the
observed reading to allow for the tartaric acid of the wine.
FIG. 53.
" To insure sufficient accuracy with these instruments cer-
tain precautions are necessary. The bicarbonate of soda sold
for cooking purposes is sufficiently pure. In placing it in the
bottle care should be taken that none gets into the vinegar
until the bottle is securely corked. There must be no leak in
the apparatus. This is determined by allowing the column
15
226 MANUFACTURE OF VINEGAR.
of water to remain for a few minutes in the cylinder after
making a determination. If the column does not fall in this
time there is no leak of importance.
"The instruments are adjusted for water of ordinary tem-
perature. If the water is either very cold or very warm the
results are inaccurate. The following table shows some of the
variations due to the use of too warm water."
KESULTS OF VJNEGAR TESTER COMPARED WITH ACCURATE ANALYSES
TT- True
Reading
of vinegar
tester
VmeSar- acidity.
. •
1
65° F.
75° F.
86°
F.
1 . .
.
3.02
1
2.9
3.2
3.
3
2 .
3 . .
•-.'. . . . 1 4.55
6.50
4.4
6.4
4.6
6.6
4
6
7
9
4 . .
........ 1 7.04
7.0
7.4
7
7
5 - .
6 . .
, 1 8.49
; . . . ... 10.15
8.5
10.1
8.7
10.7
9
11
1
2
" No temperature correction is possible as the variations are
irregular. At 65° F!, as shown by the table, the determina-
tions agree very closely with the results of more accurate tests.
There are other sources of error such as the atmospheric pres-
sure, the pressure of the column of water and the absorption
of gas by the water, but they are none of them large enough
to be of any significance to the vinegar maker."
EXAMINATION AS TO PRESENCE OF FOREIGN ACIDS. 227
CHAPTER XX.
EXAMINATION OF VINEGAR AS TO THE PRESENCE OF FOREIGN
ACIDS AND OF METALS, AS WELL AS TO ITS DERIVATION.
Detection of Acids. — Some unscrupulous manufacturers, in
order to pass off weak or inferior vinegars, adulterate them
with mineral acids. Such adulteration is not only a fraud,
but dangerous to health, and it is necessary to indicate the
means by which such additions can be detected.
Sulphuric Acid. — Add to a sample of the vinegar a few drops
of a solution of barium chloride. If the vinegar becomes
slightly cloudy, the impurities are due to sulphates naturally
present in the water or in the substances from which the
vinegar has been made. A heavy white cloud slow in subsid-
ing will indicate free sulphuric acid in small proportion. If
the quantity of sulphuric acid is more than a thousandth, the
sulphate of baryta produces a precipitate and falls rapidly to
the bottom of the test-glass.
The presence of free sulphuric acid in vinegar can also be
determined by coating a porcelain plate with strong sugar
solution and allowing the latter to dry up. By bringing a few
drops of the vinegar to be examined upon the plate and placing
the latter in a moderately warm place, pure vinegar evapo-
rates, leaving a slightly brownish stain ; vinegar containing
free sulphuric acid leaves a dark-brown stain which on heating
the plate turns black.
The presence of free sulphuric acid in vinegar can be deter-
mined with still greater sharpness by the following test : Divide
a piece of starch the size of a grain of wheat in 50 cubic centi-
meters of vinegar arid reduce the fluid one-half by boiling. To
the clear fluid cooled to the ordinary temperature add a drop
of a solution of iodine in spirits of wine. Vinegar containing
no free sulphuric acid at once acquires a blue coloration ; if
free sulphuric acid be present, the fluid remains colorless.
228 MANUFACTURE OF VINEGAR.
This test is based upon the fact that starch by continued boil-
ing with sulphuric acid is converted into dextrin and finally
sugar. Neither of these bodies reacts upon iodine, while a
very small quantity of starch gives with iodine the charac-
teristic blue coloration.
Hydrochloric Acid. — Take about 100 cubic centimeters of
the vinegar to be tested and distil off one-half by means of the
apparatus Fig. 50, p. 216. Compound the fluid distilled off
with a few drops of solution of nitrate of silver. In the pres-
ence of hydrochloric acid a white, caseous precipitate is
immediately formed, which consists of chloride of silver and
dissolves in liquid ammonia added in excess.
Nitric acid is not a frequent adulteration. It is detected
by saturating with carbonate of sodium or of potassium
several ounces of vinegar, and evaporating the whole to dry-
ness. The addition of sulphuric acid and copper turnings
will cause the evolution of nitrous vapors if nitric acid be
present.
Lactic Acid. — In many varieties of vinegar small quantities
of lactic acid occur, which can be detected by slowly evaporat-
ing 100 cubic centimeters of vinegar in a porcelain dish until
but a few drops remain. If these drops show a very strong
pure acid taste, the vinegar examined contains lactic acid. The
presence of lactic acid is, however, not due to an intentional
addition, but to the material used in the manufacture of the
vinegar, that prepared from grain, malt or beer always
containing it.
Sulphurous Acid. — This acid occurs only in vinegar pre-
pared by fermentation when stored in freshly sulphured bar-
rels. It may, however, occur in vinegar whose content of
acetic acid has been increased by the addition of high-grade
acetic acid prepared from wood-vinegar. The most simple
method of detecting the presence of sulphurous acid is by
placing 100 cubic centimeters of the vinegar to be examined
in a glass distilling apparatus, and connecting the latter by a
glass-tube with a vessel containing 50 cubic centimeters of
EXAMINATION AS TO PRESENCE OF FOREIGN ACIDS. 229
pure water compounded with about 10 drops of nitric acid.
After distilling over -jfc of the vinegar the acidulated water is
heated to boiling for a few minutes and solution of barium
chloride added. If the vinegar contains sulphurous acid, a
heavy white precipitate is formed.
Detection of Metals. — The occurrence of metals in vinegar is
due to the vessels employed in the manufacture or the storage,
and, hence, the use of metallic utensils, such as stop-cocks,
pumps, etc., should be avoided as much as possible. Besides
iron, other metals such as copper, zinc and tin are occasionally
found in vinegar. y -
Iron. — The presence of this metal imparts a black color to
the vinegar, which is increased by a few drops of tincture of
gall-nuts. If the color of vinegar compounded with a few
drops of solution of tannin is not changed after standing a few
hours, the vinegar contains no iron, or only so small a quan-
tity as to be of no importance.
Copper. — While the presence of a small quantity of iron is of
little importance in hygienic respect, that of copper, zinc, or
tin is more serious, the combinations of these metals having a
poisonous effect upon the organism. Copper in vinegar can
be detected by evaporating to dryness about 1 quart of the
vinegar to be examined and dissolving the residue in a few
drops of nitric acid. By compounding a portion of this solu-
tion with ammonia in excess, the fluid acquires a perceptible
blue coloration in .the presence of copper. The latter can be
shown with still greater sharpness by dipping polished iron
into another portion of the fluid. If the iron becomes coated
with a perceptible red film (consisting of actual copper), the
presence of this metal is shown.
Tin — Evaporate to dryness at least 2 or 3 quarts of the
vinegar ; dissolve the residue in hydrochloric acid, and con-
duct sulphuretted hydrogen through it until the fluid has
acquired a strong odor of the latter. If a precipitate is formed,
it is filtered off, dissolved in strong hydrochloric acid, and the
solution divided into several portions. Compound one of these
230 MANUFACTURE OF VINEGAR.
portions with dilute solution of chloride of gold ; if after some
time it becomes red and precipitates red flakes, the vinegar
contains tin. The presence of tin is also indicated if another
portion of the solution of the precipitate in hydrochloric acid
does not acquire a blue color after the addition of potassium
ferrocyanide. The behavior of the fluid towards solution of
potassium permanganate may serve as a controlling test ; if
the fluid contains tin, the solution of potassium permanganate
becomes discolored.
Determination of the Derivation of a Vinegar. — The examina-
tion of a vinegar as regards the materials used in its prepara-
tion is generally effected by the- senses of odor and taste.
There are, however, a number of tests of ready execution which
assist the judgment of the tongue and nose.
Vinegar prepared from dilute spirits of wine is colorless or
only colored slightly yellowish. If such vinegar has a dark
yellow color resembling that of wine, it is generally due to the
addition of caramel, the addition being chiefly made on ac-
count of the erroneous opinion prevailing among the public
that vinegar clear as water or only slightly colored lacks
strength.
Vinegar prepared from spirits of wine, when carefully evap-
orated in a porcelain dish, leaves a very small residue of a
whitish or very slightly yellow color, which chiefly consists of
the salts contained in the water used for the preparation of the
alcoholic liquid, an accurate examination showing it to consist
of calcium acetate, gypsum, and a very small quantity of
sodium chloride. If the residue is of a dark brown color,
swells up when heated, and leaves a lustrous black coal, the
vinegar has been colored with caramel.
Beer and malt vinegars are dark yellow, generally with a
reddish shade. On account of their content of dextrin they
foam when shaken, and, when carefully evaporated, leave a
brown, gum-like residue. The latter consists chiefly of dex-
trin, and contains, besides the other extractive substances
occurring in beer and malt vinegar, such as salts of ashes,
EXAMINATION AS TO PRESENCE OF FOREIGN ACIDS. 231
especially much phosphoric acid. On heating strongly an
odor calling to mind that of toasted bread is evolved. At a
still higher temperature the residue turns black and finally acts
like caramel ; it evolves pungent vapors and leaves a lustrous
coal.
The great content of phosphoric acid characteristic of malt
or beer-vinegar may also serve for the determination of the
derivation of such vinegar. By compounding beer or malt-
vinegar with some nitric acid and a solution of ammonium
molybdate and heating, the fluid, after standing, separates a
yellow precipitate, which contains the phosphoric acid present
in the fluid.
Wine-vinegar is best recognized by its characteristic odor,
the latter becoming especially perceptible by rinsing out a
large tumbler with the vinegar, and after allowing it to stand
for a few hours examining the odor of the few drops remaining
in the tumbler. The greater portion of the acetic acid having
then volatilized, the vinous odor becomes more prominent.
Cider-vinegar, the odor of which is somewhat similar to that of
wine-vinegar, can in this manner be plainly distinguished from
the latter, the residue in the tumbler having an entirely differ-
ent odor.
The presence of potassium bitartrate is a characteristic sign
of wine-vinegar. By evaporating wine-vinegar to a brownish
syrupy mass, boiling the latter with some water, rapidly filter-
ing the boiling fluid into a test tube, and adding double its
volume of strong spirits of wine, a sand-like precipitate falls to
the/ bottom of the test-tube, which consists of very small
crystals of tartar. This, however, does not prove the sample
to be genuine wine-vinegar, tartar also being contained in imi-
tations. With a sufficiently sharp sense of smell this is, how-
ever the surest means of distinguishing genuine wine-viriegar
from a spurious article.
In case the derivation of a vinegar is to be established with
absolute certainty, it has to be subjected to an accurate chem-
ical analysis, and this being better made by an analytical
232 MANUFACTURE OF VINEGAR.
chemist, only a few hints are here given which may serve as
a guide for such analyses.
In vinegar prepared from a fermented fluid a certain quan-
tity of glycerin and succinic acid will, as a rule, be present,
these bodies being always formed by the fermentation of a sac-
chariferous fluid, and consequently when found the vinegar in
question cannot have been prepared from an alcoholic liquid
consisting only of spirits of wine and water. If they are found
only in very small quantities, the alcoholic liquid used for the
production of the vinegar consists very likely of spirits of wine
and water with the addition of beer or fermented whiskey-
mash, and in this case small quantities of dextrin and of phos-
phates will also be found. The total absence of tartaric acid
and the presence of malic acid indicate the derivation of the
vinegar under examination from fruit, though not necessarily
from apples or pears, other sacchariferous fruits also containing
malic acid. A content of tartaric acid is, however, no proof of
genuine wine-vinegar, as its presence may be due to an inten-
tional addition, and it is very difficult to arrive at a certain
conclusion as to the genuineness of a pretended wine-vinegar,
especially in the case of cider-vinegar to which tartaric acid
has been added.
Should pepper, chillies, etc., be added to vinegar for the
purpose of conferring more pungency, they may be detected
by neutralizing the acid with carbonate of soda and tasting
the liquor; if these bodies be present, the solution will still
retain the sharpness peculiar to such spices.
WOOD VINEGAR AND OTHER, BY-PRODUCTS.
233
CHAPTER XXL
WOOD VINEGAR AND OTHER BY-PRODUCTS OBTAINED IN THE
DESTRUCTIVE DISTILLATION OF WOOD.
Constitution of Wood. — Wood essentially consists of woody
fiber, small quantities of salts and sap and a varying quantity
of hygroscopic water. Woody fiber or cellulose constitutes
about 96 per cent, of dry wood, and is composed of C6H1005 ;
100 parts containing 44.45 parts carbon, 6.17 hydrogen and
49.38 oxygen. The vegetable sap consists chiefly of water,
but contains organic as well as inorganic matters, partly in
solution and partly in suspension. The inorganic constituents
— the ash left after the incineration of the wood — are the same
in all kinds of wood. The quantity of water in wood is gen-
erally larger in the soft than in the hard varieties. One hun-
dred parts of wood recently felled contain, according to
Schubler and Neuffler, the following quanties of water :
Beech 18.6
Birch 30.8
Oak 34.7
Oak (quercus pedunculata) . 35.4
White fir. . 37.1
Common fir 39.7
Red Beech 39.7
Alder ... 41.6
Elm 44.5
Ked fir. . 45.2
The branches always contain more water than the trunk.
Wood is called air-dry when its weight no longer changes
at an ordinary temperature ; in this state it contains still 17 to
20 per cent, of water. The latter can be expelled by con-
tinued heating at 212° F., but wood thus dried re-absorbs
about 20 per c'ent. of water from the air.
When felled, nearly all kinds of wood are specifically lighter
than water. A few varieties are heavier, but these are the
harder kinds in which the cellulose is so compactly packed as
to leave very little space for the retention of air. The table
here given exhibits approximately the specific gravity of the
different woods :
234 MANUFACTURE OF VINEGAR.
Larch
. . .0.47
Ash . . .
Fir and pine . .
. . 0.55
Oak . . .
Beech ..'
. . 0.59
Hornbeam
Birch .
062
0.64
0.70
0.76
The content of ash is not the same in all woods ; it varying
considerably in different parts of the same tree and also with
its age. According to Violet, in the cherry tree the content of
ash is greatest in the leaves (about 7 per cent.), next in the
lower parts of the roots (5 per cent.) ; considerably greater in
the bark than in the wood, in the former from 1.1 to 3.7
per cent., and in the latter 0.1 to 0.3 per cent. Saussure
found in the bark of the oak 6 per cent., in the branches
0.4 per cent., and in the trunk 0.2 per cent, of ash. The ash
consists chiefly of carbonates of calcium, potassium, and sodi-
um, further of magnesia and the phosphates of different bases.
The average composition of 100 parts of air-dry wood is :
Carbon 39.6 parts, hydrogen 4.8, oxygen and nitrogen 34.8,
ash 0.8, hygroscopic water 20 ; and that of artificially dried
wood : Carbon 49.5, hydrogen 6, oxygen and nitrogen 43.5,
ash 1.
Decomposition of wood. — Cellulose when carefully treated re-
mains unchanged for a long time, even thousands of years.
Wood is, however, subject to greater changes, though under
especially favorable circumstances it may last for several cen-
turies. In the presence of sufficient moisture and air the ni-
trogenous .bodies of the sap are, no doubt, first decomposed,
and the decomposition being next transferred to the woody
fiber, the latter loses its coherence, becomes gray, then brown,
and finally decays. Hence, wood rich in water decays more
rapidly than dry wood.
Wood to be preserved should, therefore, be as dry as pos-
sible, and the nitrogenous bodies, which can be but incom-
pletely removed by lixiviation, be converted into insoluble
combinations ; tar and one of its most .effective constituents —
creosote — mercuric chloride, blue vitriol, chloride of zinc, and
many other substances having been recommended for this
WOOD VINEGAR AND OTHER BY-PRODUCTS. 235
purpose. Moreover, it has been successfully attempted to
produce certain insoluble bodies, such as aluminium and cop-
per soaps, in the interior of the wood by saturating it with soda
soap and then with aluminium chloride, or blue vitriol, or such
as barium phosphate, by saturating with sodium phosphate
and then with barium chloride, etc.
By heating to 212° F. wood remains unchanged, it yielding
up only sap constituents. If, however, the temperature be in-
creased, for instance to 392° F., a small quantity of sugar is,
according to Mulder, formed from cellulose in a closed vessel,
and from" wood, according to G. Williams, an acid not yet
thoroughly known, methyl alcohol (see further on), an oil
boiling between 277° and 421° F., and a small quantity of
furfurol.
In the presence of water, wood in a closed vessel is, however,
already decomposed at about 293° F. If this temperature be
kept up for a long time, for instance, a month, the wood,
according to Sorby, is converted into a lustrous black mass
with the formation of acetic acid and gases.
According to Daubree, pine, when heated for some time with
water in an entirely closed vessel to 752° F., is converted into
a mass having the appearance of stone-coal and approaching
anthracite in its behavior. Baroulier made similar observa-
tions, masses resembling stone-coal being formed by pressing
saw-dust, stems and leaves together in moist clay and heating
continuously to from 392° to 572° F., so that the vapors and
gases could only escape very slowly.
By avoiding all heating, concentrated sulphuric acid converts
cellulose into a gum-like body — dextrin — which by diluting
with water and long digesting is converted into sugar (starch
sugar). When heated, the wood, however, turns black and is
completely destroyed, sulphurous acid being at the same time
evolved. With concentrated sulphuric acid, cellulose swells
up and gradually dissolves, being precipitated by water in
white flocks. The starch-like body thus obtained is called
amyloid. It is an altered cellulose and is colored blue by
236 MANUFACTURE OF VINEGAR.
iodine. At the ordinary temperature, wood is but little
affected by dilute sulphuric aci.d, while at a higher tempera-
ture a certain quantity of sugar — glucose or dextrose — is
formed, water being, absorbed at the same time. This be-
havior has been utilized for obtaining alcohol by fermenting
the sugar .thus obtained with yeast after neutralizing the acid
by calcium carbonate, for instance, chalk. The woody fiber
remaining unattacked can be used as material for paper.
Concentrated hydrochloric acid colors wood rose color to
violet-red and rapidly destroys it. Dilute hydrochloric acid
on heating, forms sugar ; but, according to Zetterlund, the
quantity of absolute alcohol obtainable in this manner is very
small, amounting to about 2.3 per cent, of the weight of the
wood.* By macerating wood with dilute hydrochloric acid at
an ordinary temperature, the cellulose is not changed, but the
so-called lignin seems to be dissolved. By forcing dilute hy-
drochloric acid by a pressure of two atmospheres into trunks
provided with the bark, and subsequent washing out in the
same manner with water, and drying by means of a current of
air at 98.6° F., wood acquires great plasticity. In a moist
state wood thus treated can be pressed together to one-tenth of
its original volume.
Hydriodic acid reduces wood to various hydrocarbons, water
being formed and iodine liberated.
Concentrated nitric acid, or, still better, a mixture of it and
sulphuric acid, converts cellulose, for instance, cotton, into
gun-cotton, while wood is colored yellow and partially dis-
solved. Dilute nitric acid, for instance, of 1.20 specific gravity,
has no effect in the cold, and but little when heated.
By bringing cellulose in contact with dilute aqueous solu-
tions of alkalies, it is colored blue by iodine, and consequently
a starch-like substance is formed, but no humus-like bodies ;
* According to prior experiments by Bachet, it is, however, claimed that up ta
23 per cent, of sugar can be obtained from wood%by boiling 10 to 12 hours with
water containing one-tenth of hydrochloric acid.
WOOD VINEGAR AND OTHER BY-PRODUCTS. 237
from wood only the lignin is extracted, the woody fibre remain-
ing unchanged. By heating with strong alkaline lyes, or, still
better, by fusing with solid caustic alkalies, acetic acid is, ac-
cording to Braconnot, first formed and then oxalic acid. The
latter acid is frequently obtained by this process.
On heating shavings with sodium sulphide an abundant
quantity of acetic acid (sodium acetate) is formed, the addition
of sulphur to caustic soda apparently having the effect of pre-
venting the formation of oxalic acid.
Products of Destructive Distillation, — Besides charcoal, there
are formed in the decomposition of wood under exclusion of
air, a great number of products, the kind and quantity of
which depend on the temperature to which the wood has been
exposed, as well as on whether that temperature has been slow-
ly raised to a certain point, or as rapidly as possible.
The products obtained by gradually increasing the heat are,
at the ordinary temperature, either gaseous, liquid or solid.
In speaking of the gases, which will be first considered, a dis-
tinction has to be made between those which must be accepted
as actual products of decomposition of wood, and those which
are formed by certain volatile fluids which are liquid at the
ordinary temperature, but at higher degrees of heat suffer de-
composition and yield gaseous products.
Gaseous products of distillation. — At the commencement of
decomposition, between 320° and 374° F., carbonic acid, CO2,
mixed only with very small quantities of carbonic oxide, CO,
is chiefly found, the quantity of the latter increasing with the
rise in the temperature. At between 392° and 428° F. the
quantities of carbonic acid and carbonic oxide are nearly equal,
and small quantities of methane or marsh gas, CH4, appear.
At between 608° and 680° F., carbonic acid and carbonic
oxide become less prominent, and methane appears in larger
quantities. Above this temperature the content of carbonic
acid in the gas mixture becomes small, while that of methane,
mixed also with hydrogen, increases, and heavier hydro-
carbons make their appearance.
238 MANUFACTURE OF VINEGAR.
By igniting the gases escaping from the distilling apparatus,
a conclusion can be drawn from the appearance of the flame
as to the kind of products which are developing. At first
the flame is slightly luminous and shows the characteristic-
pale blue color of the carbonic acid flame. Later on, in con-
sequence of the increase in the formation of methane and
heavier hydrocarbons, the flame exhibits periodically a pure
white color, while the blue coloration gradually becomes less
prominent, until finally the gases burn with the luminous
pure white flame of heavy hydrocarbons.
The following table shows the order in which the gaseous
combinations are formed at different temperatures :
Temperature. Name. Composition.
{Carbonic acid CO2 ]
Carbonic oxide CO
'55: ,
Ethy'lene C2H, lre'
From 680° to 812° F.
Propylene
(above this temperature ] Butylene C4H8
only a very small quan- | Benzene C6H6 ~)
tity of gas is evolved).
Toluene (-7^8 I Liquid at the or-
Xylene C8H]0 }• dinary temper-
Cumene C9H12 | ture.
Napthalene C]0H8
Pettenkofer found the composition of wood gases as follows :
Carbonic Carbonic Heavy
Air. acid. oxide. Methane. Hydrogen, hydrocarbons.
Up to 680° F. . . 5 54.5 38.8 6.6
Above 680° F. . . 0 18-25 40-50 8-12 14-17 6.7
The process by which the above-mentioned bodies, of which
the products of benzene caught by cooling may also be vola-
tilized, are formed is of a very complicated nature, and while
as regards the formation of many of these bodies only hypoth-
eses can be advanced, that of others is readily explained.
Before entering upon this explanation, it is well to remem-
ber that in the execution of carbonization and destructive dis-
tillation on a large scale, it is impossible to maintain the same
WOOD VINEGAR AND OTHER BY-PRODUCTS. 239
temperature in all parts of the apparatus, and that consider-
able differences in temperature will occur. Furthermore cer-
tain volatile bodies when highly heated, i. e., in contact with
hot places of the distilling apparatus, possess the property of
undergoing decomposition, new combinations being formed.
This explains the origin of many bodies which appear among
the products of the decomposition of wood.
When wood substance is heated, its elementary constituents
act at first upon each other in such a manner that water is
formed, and consequently steam is evolved, when the wood,
after being freed from all moisture, is heated to 320° F.
However, at a higher temperature the affinity of carbon for
oxygen and hydrogen asserts itself, and at first combinations
composed of the three constituents of wood are formed.
At a certain temperature the affinity of carbon for oxygen
becomes so potent that the two bodies enter into combina-
tion, and carbonic acid — the combination of carbon richest in
oxygen — is formed so long as an abundance of oxygen is
present. At a later stage of decomposition, when the quan-
tity of oxygen in the mass has decreased and the temperature
has become higher, carbonic oxide — the combination of car-
bon poorer in oxygen — appears in larger quantity. It is due
to the affinity of hydrogen for carbon that two hydrocarbons
are formed. So long as hydrogen is present in abundance,
methane CH4 — a combination of carbon with hydrogen com-
pletely saturated with hydrogen — is first formed, and then, at
a somewhat higher temperature, ethylene C2H4,a combination
poorer in hydrogen.
The gases above mentioned, namely : Carbonic acid, carbonic
oxide, methane and ethylene, are very possibly those combi-
nations which may originate directly from the decomposition
of the wood substance. When these gases are brought in
contact with glowing coal, or are highly heated — two cases
which always occur in destructive distillation — they suffer
decomposition, and new bodies appear in the products of
distillation.
240 MANUFACTURE OF VINEGAR.
Carbonic acid in contact with glowing coal changes to car-
bonic oxide, C02-|-C=2CO, and it is very likely that the con-
stant increase of the content of carbonic oxide in the gases
with an increasing temperature, is partly due to this reciprocal
action.
Hydrogen appears only when the temperature has reached
a point at which methane and ethylene are formed in abun-
dance, the hydrogen being split off from these combinations.
So long as the temperature is not much above 750° F., acety-
lene, C2H2, and hydrogen are chiefly formed from methane,
while at a red heat, methane is directly decomposed to its
elementary constituents.
Hence at lower degrees of heat is formed :
2CH4 = C2H2 -I- H6
methane = acetylene + hydrogen.
and at higher degrees of heat : CH4 = C + H4.
On the portions of the iron distilling vessels, which are
highly heated in the distillation of wood, a graphite-like layer of
carbon is found which adheres quite firmly and is very likely
formed by the decomposition of methane and other hydrocar-
bons in coming in contact with the hot surface, carbon being
thereby separated.
Ethylene C2H4 is decomposed at a comparatively low tem-
perature to acetylene and methane.
3 C2H4 = 2 C2H2 + 2 CH4
ethylene = acetylene + methane.
At a higher temperature, ethylene is decomposed so that the
above mentioned products are formed, carbon, however being
at the same time separated.
4 C'H4 = 2 C2H2 -1- 3 CH4 -f C.
The above-mentioned decompositions of methane, however,
are not the only ones which may occur, and according to the
temperature, there may be formed from these gases a series of
WOOD VINEGAR AND OTHER BY-PRODUCTS. 241
other combinations. The appearance of propylene may, for
instance, be explained by the reciprocal action of methane and
carbonic oxide.
2 CH4 + CO = C3T76 -J- H2O
methane + carbonic oxide = propylene + water.
Besides the processes of decomposition above represented,
there are others which are a source of the formation of gaseous
bodies. At a temperature of between 392° and 536° F. a con-
siderable quantity of acetic acid and methyl alcohol is already
formed, and the vapors of this combination are entirely or par-
tially decomposed when highly heated, and this explains why
in heating the wood very rapidly, very little acetic acid and
methyl alcohol are formed, but, on the other hand, a very large
quantity of gaseous and tar products.
Wood contains in its sap constituents small quantities of
nitrogenous combinations and the nitrogen forms with hydro-
gen, ammonia, which, on coming together with hydrocarbons,
forms at once substitution products, of which, for instance,
methylamir.e, in which a portion of the hydrogen in the am-
monia is replaced by methyl, appears in proportionally largest
quantity.
CH40 + IT3N CH5N -f H20
methyl alcohol + ammonia = methylamine + water.
Since in the destructive distillation of wood a large quantity
of gases is evolved, the apparatuses in which the products of
distillation, liquid at the ordinary temperature, are to be con-
densed must be quite- large, as otherwise the seams might open
in consequence of the pressure of the gases ; or at least a large
quantity of bodies which might be condensed would be carried
away by the powerful current of gases.
By destructive distillation 100 kilogrammes of wood yield
on an average 24.97 cubic meters of gas. This quantity, how-
ever, corresponds only to the conditions prevailing when dis-
tillation is carried on slowly. When the heat is rapidly raised
' 16
242 MANUFACTURE OP VINEGAR.
nearly 50 per cent, more of gas is obtained and of course the
yield of liquid products of distillation and of charcoal is cor-
respondingly reduced. F. Fischer made thorough investiga-
tions regarding the gases formed in the destructive distillation
of wood. He found that the average yield from 100 parts of
beech is 45 kilogrammes wood vinegar (with 4 kilogrammes
acetic anhydride and 1.1 kilogramme wood spirit), 23 kilo-
grammes charcoal, 4 kilogrammes tar, 28 kilogrammes gases
and steam.
Liquid Products of Distillation. — The products of destructive
distillation of wood which can be condensed by cooling, sepa-
rate, when at rest, into two layers, the upper lighter one, which
is of an acid nature, forming the wood vinegar, while the lower,
denser one, is termed tar. Since these fluids are formed at
temperatures widely apart and there is considerable difference
in the chemical constitution of the bodies contained in them,
it is best to consider them separately.
Wood Vinegar. — At the lowest temperature at which the de-
composition of wood commences — according to Violette be-
tween 302° and 312° F., and according to Gillot, even be-
tween 216.6° and 244.4° F. — the three elementary constituents
of wood act upon each other, and, besides a number of acids
of the fatty acid series and methyl alcohol, there are formed
certain products of the decomposition of these bodies. The
formation of fatty acids, amongst which acetic acid appears in
largest quantity, commences, according to Gillot, at 255° F.,
and reaches its maximum at 437° F. At higher temperatures
considerable quantities of products of decomposition of the
fatty acids appear, so that, according to the temperature and
duration of distillation, there may be considerable variation, as
regards the quantities of bodies contained in it, in the composi-
tion of wood vinegar gained on a large scale. The presence of
the following fatty acids in wood vinegar has been definitely
established :
WOOD VINEGAR AND OTHER BY-PRODUCTS. 243
Formic acid ' . CH2O2
Acetic acid C2H4O2
Propionic acid C3H6O2
Butyric acid C4H8O2
Valeric acid '. C5H]0O2
Caproicacid C6Hi2O2
Formic acid boils at 212° F., and since the boiling-point of
the succeeding members of this series of acids lies about 68°
higher, it may be supposed that the lower members of this
series of acids are found in the portion of the wood-vinegar
which distils over at a comparatively low temperature. This
has been fully confirmed by experience, and for this reason the
wood should be very slowly heated if the largest possible yield
of acetic acid is to be obtained.
Methyl alcohol, CH4O, may be produced from marsh -gas by
subjecting that compound to the action of chlorine in sunshine,
whereby chloromethane, or methyl chloride, CH3C1, is pro-
duced, and then distilling with potash. In the destructive
distillation of wood it is very likely formed by the action of
carbonic acid upon methane :
CH4 + CO2 CH40 + CO
methane + carbonic acid = methyl alcohol + carbonic oxide,
so that the appearance of constantly increasing quantities of
carbonic oxide beside carbonic acid would appear to be ex-
plained by this process.
Acetone, C3H60, is formed directly from acetic acid by con-
ducting the vapors of the latter through a red-hot tube whereby
carbonic acid and water are formed :
2(C2H402) = C3H60 + C02 + B20
acetic acid = acetone + carbonic acid -f water.
It may, however, be also formed from methyl alcohol and
acetic acid, or from methyl alcohol and carbonic oxide. The
occurrence of methyl acetic ether, CH3,C2H302, in wood vine-
gar is due to acetic acid and methyl alcohol in a nascent state
acting upon each other, while the presence of aldehyde,
244 MANUFACTURE OP VINEGAR.
C4H1002, may be explained by tbe reciprocal action of methyl
alcohol and acetic acid, two molecules of methyl alcohol with
one molecule of acetic acid being transformed to dimethyl
acetal (= aldehyde) while water and oxygen are liberated, the
latter being immediately fixed by other products.
2(CIT40) +C2H402 = C4H100, + H,0 + O
methyl alcohol + acetic acid = aldehyde -f water + oxygen.
Further products of the reciprocal action of the fatty acids,
methane and carbonic oxide, are: Metacetone, C6H100, and
allyl alcohol or furfurol, C3H60. The small quantities of
nitrogen originating from the sap constituents of the wood,
which are present in destructive distillation, appear in the
form of methylamine C3H2N, and ammonia.
There is such a variation in the quantities of the bodies of
which wood vinegar is composed that it is impossible to give
figures of general value in regard to them, the time during
which heating takes place being of great influence in this re-
spect, so that from the same variety of wood, by rapid heating,
only a few tenths of the quantity of products are frequently
obtained, which would result by slow heating. This fact is of
the greatest importance for the practical manufacture of wood
vinegar and wood spirit, and will be more fully discussed later
on. It may here only be mentioned that from air dry wood,
with not too rapid distillation, 30 to 53 per cent, (from most
varieties of wood on an average 40 to 45 per cent.) of wood
vinegar may be obtained, the specific gravity of which varies
between 1.018 and 1.030, and which contains between 2.5 and
'8.5 per cent, acetic anhydride, calculated from the gravity of
the wood vinegar.
Tar. The products which occur in wood tar are still more
numerous than those which originate during the period in
which there is still considerable oxygen in the heated mass.
Among the combinations which may be termed tar products
in the actual sense of the word, are only a few containing
oxygen, and these occur only in smaller quantities. The
WOOD VINEGAR AND OTHER BY-PRODUCTS. 245
larger quantity of the tar products consist of hydrocarbon
combinations and must be considered as having been formed
by the elements, carbon and hydrogen, grouping themselves
in various ways at different temperatures. Ethylene very
likely breaks up into a series of hydrocarbon combinations, at
a slightly higher temperature than that at which it originates,
as is, for instance, shown for naphthalene
ethylcne = naphthalene + methaner
8(C2H4) = <J10H8 +G(CH4),
and the formation of all the other hydrocarbons might in the
same manner be explained. When derived from hard wood,
wood-tar consists chiefly of parafins,* toluene, xylene, cresol,
guaiacol, phenol, and methyl derivatives of pyrogallol.
Since a portion of these combinations is already formed at a
temperature at which acetic acid is still evolved from the wood,
certain quantities are found dissolved in wood vinegar, the tar
products being jointly condensed with the wood-vinegar.
While, according to Pettenkofer, the heavy hydrocarbons ap-
pear only at a temperature of above 680° F., according to Gil-
lot, tar in abundance is already formed at 565° F. Practical
experience, however, has shown that the largest quantities of
tar are formed only at a higher temperature, and the boiling-
points of tar products also indicate a high temperature of for-
mation, naphthalene, for instance, boiling at 413.6° F. and
paraffin only at over 572° F.
Besides the above-mentioned combinations, various chemists
have established in wood-tar the presence of a long series of
combinations, but up to the present time they have not been
more closely examined, or they appear in such small quantities
that their occurrence is only of theoretical interest. In this
series may be mentioned : Iridol/ citriol, rubidol, benzidol ;
further, retene, pittacall, cedriret, and pyroxanthogene ; and
* Under the name paraffin are very likely comprised many combinations which,
though having the same percentage composition, possess different physical and
chemical properties, i. e., are isomeric.
246 MANUFACTURE OP VINEGAR.
further, the combinations established by Reich enbach, kapno-
mar, picamar, creosote and xylite, and finally mesite, prepared
by Schweizer.
The yield of tar obtained in the destructive distillation of
wood depends on the time and temperature used, but also
essentially on the nature of the wood itself, resinous woods
yielding larger quantities of tar than the varieties free from
rosin. By slow distillation, the former yield 9 to 14 per cent.,
and the latter, 5 to 11 per cent, of tar. The more quickly the
process of distillation is conducted the greater will be the yield
of tar and gas, while that of acetic acid is less. The table
below shows the bodies appearing in the destructive distillation
of wood and the limits of temperature of technical importance,
within which they are very likely formed :
GASES. WOOD VINEGAR. TAB.
Carbonic acid . ) Formic acid ) Qt.AO f^ KWO TT Benzene 1 ^ *i
Carbonic oxide U20° to 680° F. Acetic acid j" d< 0/z * ' Toluene
Methane j Propionic acid i Xylene
Hydrogen 1 Butyric acid ! QQ.,o +„ '«cno i? < 'umene
Acetylene | Valeric acid f °92 to 68° F" Naphthalene
Ethylene }>6800 to 809.6° F.Caproic acid J Paraffin
Propylene | Methyl alcohol 392° to 683° F. Phenol
Butylene J Acetone 1 Anisol .
Metacetone .. .
Acetic acid and
methyl ether
Dimethyl acetate
Aldehyde
Methylamine acetate J
Phenetol .... j r
482° to 680° F.
At present only a comparatively small number of the pro-
ducts originating in the destructive distillation of wood are
utilized. Of the combinations which belong to the series of
tar bodies, the only products which have actually found indus-
trial application, are creosote, which consists chiefly of phenic
acid, and the light and heavy oils which can be obtained by
distillation from the tar.
It is, however, possible to separate from wood tar the various
combinations contained in it, as has been successfully done
with coal tar. Benzene, toluene, naphthalene, etc., can be pre-
pared, and coloring matters manufactured from these hydro-
carbons. The reason why this is not done is very likely to be
sought in the fact that in the manufacture of illuminating gas
WOOD VINEGAR AND OTHER BY-PRODUCTS. 247
from coal, a sufficiently large quantity of coal tar is obtained
to supply the demand of the manufacturers of coal tar colors.
Paraffin might also bs obtained from wood tar, but its manu-
facture would not pay in competition with the article obtained
from the by-products gained in the purification of crude pe-
troleum.
Hence there is nothing left in the destructive distillation but
to work wood free from rosin into charcoal, acetic acid and
methyl alcohol as chief products, and to consider all other
products as by-products, to be utilized as opportunity offers and
eventually to be used as fuel in the factory. When working
with wood rich in rosin, it is best first to obtain acetic acid and
wood spirit at a low temperature, and then to raise the heat to
such a degree as is required to gain the total quantity of tar,
since from this tar, by subjecting it to further treatment, tar
oil can advantageously be prepared. *
Wood-tar varies in character with the kind of wood from
which it is obtained, that derived from resinous woods being
considered the more valuable on account of its content of
rosin. When wood is distilled in retorts, the portion of tar
separated from the crude wood-vinegar by settling and that
skimmed off of the top of the neutralized wood-vinegar are
united, and, after washing with water, may be sold in the
crude state as u raw tar" or as " retort tar." It is used for
preserving wood, for making roofing felts, as an antiseptic, and
for the preparation of wagon grease and other low-grade lubri-
cants. In addition to the tar separated by settling, the crude
wood-vinegar contains considerable tar held in solution by the
acids and alcohol present, which is recovered when the wood-
vinegar is distilled, and constitutes what is known as " boiled
tar." It may be sold as such or burned under the retort, or
it may be mixed up with the raw tar and subjected to any
desired treatment.
By the destructive distillation of resinous woods tar oil con-
taining turpentine is also obtained, but less wood vinegar,
eventually calcium acetate. From 50 cubic meters of air-dry
248 MANUFACTURE OF VINEGAR.
resinous wood are obtained about 4600 to 4750 kilogrammes
charcoal, 1500 kilogrammes tar, 400 kilogrammes tar oil, 450
kilogrammes calcium acetate, 75 to 100 kilogrammes wood-
alcohol.
Properties of the Combinations formed in the Destructive Distil"
lation of Wood. — Of the many bodies formed in the destructive
distillation of wood, only a few are of importance, these being
especially acetic acid, wood spirit and the combinations and
products of decomposition originating from these two bodies ;
further the combinations which can be obtained from the tar,
namely : Creosote and tar oils.
Acetic acid. — The physical and chemical properties of acetic
acid have already been described on p. 27. Of the products of
decomposition which acetic acid may yield, those formed by the
action of heat are here of special interest. Heated by itself,
acetic acid can stand comparatively very high temperatures
without suffering decomposition, and acetic acid vapor can, for
instance, be conducted through a red-hot porcelain tube without
being decomposed. However, decomposition takes place al-
ready at a slight red heat when the vapor comes in contact with
glowing coal, as is the case in the destructive distillation of wood.
If acetic acid vapor remains for some time in contact with such
coal, a gas mixture, consisting of methane, carbonic acid' and
carbonic oxide is formed, the latter originating from the action
of the coal upon the carbonic acid :
C2H4O2 = CH4 -f CO2.
acetic acid, methane, carbonic acid.
Acetone. At a less high temperature, acetone, CH3CO.CH3, is
formed by the decomposition of acetic acid ; its formation is
illustrated by the following equation :
2(C2H402) = CaTT60 4- C02 +H2O.
acetic acid acetone carbonic acid water.
Acetone is always found in wood vinegar, and in a pure state
is a liquid boiling at 132.8° F., of specific gravity 0.814, of a
WOOD VINEGAR AND OTHER BY-PRODUCTS. 249
pleasant aromatic odor and a pungent taste. It burns with a
brilliant flame and is miscible in all proportions with water,
alcohol and ether. It is an excellent solvent for fats, resins,
camphor, volatile oils, gun cotton, etc., and in modern times
quite large quantities of it are employed in the manufacture of
smokeless gunpowder.
Methyl acetate is in the chemical sense an acetic methyl ester.
This ester is formed by the combination of acetic acid with
methyl alcohol, water being withdrawn :
CH,.CQQ£I + CH3OH = CH3.COO.CH3 -|- H2O.
By treatment with alkalies such esters are saponified, whereby
the alcohol and the salt of the acid are again formed. This is
also the case with the methyl acetate contained in crude wood-
vinegar when it is distilled with the addition of lime. But,
as a rule, small quantities of it escape saponification, and for
this reason the presence of acetic methyl ester can always be
established in crude wood-vinegar.
Aldehyde or acetaldehyde has already been described on page
24. It is a constant constituent of the products of the
destructive distillation of wood.
Methyl alcohol or wood spirit, CH3OH, in a pure state, is a
colorless, mobile liquid having a peculiar odor and burning
taste. When ignited it burns with a slightly luminous flame.
It boils at 149° F. and has a specific gravity of 0.798 at 32° F.
It is a solvent for resins and essential oils, and for this reason
is used in the manufacture of lacquers and varnishes. It may
also be employed as fuel in place of ordinary alcohol. In
modern times it has become an important article of commerce,
it being largely used in the manufacture of aniline colors and
for many other purposes.
Crude wood spirit as originally obtained from wood-vinegar
is a mixture of methyl alcohol, acetic methyl ester, all the
readily volatile products of decomposition of acetic acid (ace-
tone, aldehyde, dimethyl acetate) and the readily volatile
250 MANUFACTURE OF VINEGAR.
hydrocarbons. The preparation of pure methyl alcohol, which
will be referred to later on, is therefore connected with certain
difficulties.
Tar Products — Hydrocarbons of the series CnH2n-6. There
is considerable variation in the properties of the products oc-
curring in tar, as far as they are hydrocarbons. Those which
are liquid at the ordinary temperature are of slight specific
gravity but have different boiling-points and belong to differ-
ent series composed according to a certain type. The best
known are those of the series CnH2n_6) mentioned below.
Benzene boils at . . - . 179.6° F, Specific gravity . . . .0.850
Toluene " .... 231.8° F. " " . . . . 0.870
Xylene " .... 282.2° F. " " . . . . 0.875
Cumene " .... 330.8° F. " . . . . 0.887
Cymene " . . . . 345.2° F. 'k ... .0.850
These bodies possess the property of yielding by substitu-
tion bases which by treatment with oxidizing bodies can be
converted into coloring matters, the so-called tar or aniline
colors. As an example may here be mentioned the conver-
sion of benzene. Benzene has the formula C6H6. By con-
r\ TT "|
version of benzene into nitro-benzene = 6 5 > and treat-
N02 J
ment of the latter with hydrogen at the nascent moment,
aniline is formed :
°«E« j+6H==C6N6.NHa
Nitre-benzine. Aniline.
According to the same scheme, nitro-combinations and
amines can be prepared from toluene, cumene, and from all
other hydrocarbons belonging to this series which can by suit-
able treatment be converted into coloring matters.
At present aniline colors are exclusively obtained from coal
tar, but there is no doubt that they can also be prepared from
wood tar, though thus far only experiments have been made
WOOD VINEGAR AND OTHER BY-PRODUCTS. 251
in this direction, which, however, have proved highly suc-
cessful.
Besides the hydrocarbons, benzene, toluene, etc., boiling at a
higher temperature, the presence in wood tar of a few others,
distinguished by very low boiling points and slight specific
gravity, has been established. Such are:
Iridol boils at , . . 116.6° F. Specific gravity 0.660
Citriol " . . . 125.60 F. tfc " 0.700
Kubidol" . . .134. 60 F. "• " 0.750
Coridol " ... 140° F. " " 0.800
Benzidol1' - . .158° F. " " 0.850
By treatment with nitric acid, these hydrocarbons can also
be converted into nitro-combinations from which, by reduc-
tion, amines can be prepared, which may be converted into
colored combinations. However, thus far these bodies have
not been thoroughly examined.
Naphthalene and Paraffin. — These two hydrocarbons, which
also occur in wood tar, are solid at the ordinary temperature
and are distinguished by high boiling points. Naphthalene
crystallizes in white rhombic leaflets with a peculiar odor and
burning taste. It fuses at 174.2° F. and boils at 424.4° F.
Its composition is C10H8. By treating with nitric acid,
naphthalene may be converted into nitronaphthalene,
C10H7N02, and from the latter naph thy lamine is prepared,
which serves for the manufacture of yellow and red coloring
matters.
The hydrocarbons with boiling points of 680° to 752° F.,
which occur in wood tar, are designated paraffins and belong
very likely to the series CnH2n. According to the material
from which they are obtained, the melting points of the par-
affins vary, and all the combinations belonging to this group
are distinguished by their great chemical indifference.
Many varieties of wood tar are of a viscous and gritty
nature, which indicates a large content of paraffin. In fact,
paraffin was first prepared from beech-wood tar by Reichen-
252 MANUFACTURE OF VINEGAR.
bach. However, as previously mentioned, there is at present
little prospect of the preparation of paraffin from wood-tar
proving remunerative, on account of the competition with the
article obtained from crude petroleum.
Besides the hydrocarbons mentioned, there occur in wood-
tar small quantities of the following : Chrysene, C12H8, retene,
C18H18, and pyrine, C15H15.
Tar Products Containing Oxygen (Creosote). — The combina-
tions containing oxygen which occur in wood-tar are either
members of the phenol series or belong to the guaiacol series.
The liquid known as wood-tar creosote consists of a mixture
of combinations belonging to both series, the compounds be-
longing to the phenol series being :
Phenic acid or carbolic acid °6]^5 | O C6H7O.
Creosote C6H4<°^ C7H8O.
/OH
Ethyl phenate or phenetol C6H3— CH3 C8H10O.
Among these acids, carbolic acid occurs in smallest quan-
tity. The combinations belonging -to the guaiacol series,
which are found in wood tar are :
OTT
Pyrocatechin or oxyphenic acid C6H4<^ C6H6O2.
OP FT
M ethyl-pyrocatechin or guaiacol C6H4<^rT 8 C7H8O2.
/CHS
Creosol 06H3— OOH2 C8H10O2.
Creosote may also be prepared from coal-tar ; chemically,
however, this creosote consists almost exclusively of carbolic
acid, and cannot be used for medicinal purposes.
Wood-tar creosote is a fluid of a peculiar penetrating smoky
odor. Applied to a mucous membrane or to the raw cuticle,
it excites severe burning pain, coagulates the albumen of the
WOOD VINEGAR AND OTHER BY-PRODUCTS. 253
secretion, and may even produce ulceration. It preserves
meat probably in consequence of its behavior with albumen,
and the preserving action of smoking meat is due to a content
of this body in wood-smoke.
Since the introduction of the manufacture of illuminating
gas from wood, wood-tar creosotes very rich in carbolic acid
are found in commerce, and this may be explained by the
conditions under which the tar from which the creosote has
been obtained has been formed.
When illuminating gases are to be obtained from wood, the
latter must as quickly as possible be heated to a high temper-
ature, and under these conditions an abundance of carbolic
acid is formed which passes into the creosote. If, on the other
hand, destructive distillation is carried on at a slowly increasing
temperature, tar is obtained which chiefly contains creosol and
guaiacol. Since carbolic acid is comparatively quite a poison-
ous body, creosote intended for medicinal use should only be
prepared at factories which carry on the destructive distillation
of wood chiefly for the purpose of obtaining acetic acid.
Besides the above-described constituents, various chemists
have mentioned a complete series of compounds as occurring
in wood-tar. It can scarcely be doubted that several, but lit-
tle known, bodies which have not yet been prepared in a pure
state occur in wood-tar, but those which have been called
eupione, picamar, kapnomar, pittacal, cedriret, pyroxantho-
gene, mesite, xylite, etc., consist very likely of mixtures of
various bodies. As far as these compounds are known they
must be considered as hydrocarbons belonging to various series
of combinations. A few of them, like cedriret and chrysene,
give with acids characteristic color reactions, and pittacal is
itself of a beautiful dark blue color. On heating it evolves
ammonia, and hence it contains nitrogen very likely in the
form of combinations known as substituted ammonias.
None of these combinations have thus far become of any
technical importance, but they are occasionally observed in
the purification of sodium acetate. The melt of the crude salt
254 MANUFACTURE OF VINEGAR.
when not yet sufficiently roasted yields, when treated with
water, solutions of a beautiful blue, violet, red to orange color,
these colorations being produced by the products of decompo-
sition of the tar substances.
CHAPTER XXII.
PREPARATION OF CHARCOAL, WOOD VINEGAR AND TAR
IN CLOSED VESSELS.
IN installing a plant for the purpose of utilizing wood in a
thermo-chemical way, i. e.} a factory in which chiefly pure acetic
acid and wood spirit, and eventually the tar-products — tar oils
and creosote — are to be produced, apparatus will evidently
have to be selected, the arrangement of which is as complete as
possible, and which, besides the gaining of all products liquid
at the ordinary temperature, allows also of the utilization of the
large quantities of gas evolved in the destructive distillation of
wood. Hence, according to the object in view in distilling
wood, the arrangements for obtaining the products of distilla-
tion may be of very varying nature, the most simple being a
few suitably-fitted pipes and barrels. Retorts in which the
temperature can be accurately regulated are the most compli-
cated and complete, but also the most expensive, apparatus.
What kind of apparatus has to be used and what kind of
products are to be prepared, depends entirely upon local condi-
tions. Since the value of a product increases in proportion to
the labor expended in the production of it, a manufacturer who
prepares, besides pure acetic acid and wood spirit, also tar oils
and creosote, will thus realize the greatest profit from the
wood, but to attain this object the establishment of a plant
with all the apparatus required for this purpose is necessary.
However, many a proprietor of woodland does not care to
manufacture pure products in a special factory, but desires,
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 255
by the expenditure of a small sum, to obtain from his wood,
besides charcoal, also wood-vinegar and eventually tar, in order
to realize, by the sale of these raw products, a larger profit
from his wood than is attainable by charring alone. In such
a case the principle of division of labor, and eventually associ-
ation deserves recommendation, so that the proprietors of the
woodland would prepare charcoal besides wood-vinegar and
tar and sell these products, or what is still better, work them
further in a factory erected at joint expense.
Some readers may ask the question whether it is possible to
utilize large quantities of wood by employing them for the
manufacture of products of destructive distillation. This ques-
tion may be unconditionally answered in the affirmative, since
in consequence of the high and steadily increasing tax on alco-
hol levied in most countries, the price of table vinegar must
constantly rise.
There are but two processes by which acetic acid on a large
scale can be prepared, namely, from alcohol and from wood.
Up to the present time alcohol can only be obtained from the
products of agriculture, the chief raw materials being grain
and potatoes, and eventually grapes and certain varieties of
fruit, especially apples.
By taking into consideration the great expense of labor re-
quired to obtain these products of the soil and to manufacture
alcohol and acetic acid from them, it will be evident that the
price of this acetic acid must be greater than of that which can
in a short time be prepared from wood. Furthermore, vinegar
prepared from alcohol is never pure, i. e., it does not consist
only of acetic anhydride and water, but always contains quite
a quantity of foreign substances in solution, and besides is very
poor in acetic acid. To obtain the latter pure and in a highly
concentrated state, vinegar has to undergo almost exactly the
same chemical manipulations to which wood vinegar has to be
subjected in order to prepare from it pure concentrated acetic
acid, but the expense of preparing such acetic acid would be
very great.
256 MANUFACTURE OF VINEGAR.
Pure concentrated acetic acid is at present used on an ex-
tensive scale in the chemical industries, and is also more and
more employed in the preparation of table vinegar, since there
is no difference between pure acetic acid prepared from wood
and that prepared from alcohol. Wood vinegar, however, can
be utilized for other purposes besides the preparation of pure
acetic acid, it being in consequence of its content of tar pro-
ducts, which have an antiseptic effect, an excellent preserva-
tive of wood, and the process of impregnating the latter with
it is decidedly cheaper than most methods in which other
bodies are employed for the purpose. •
When only acetic acid, wood spirit and tar are to be pro-
duced, wood waste of all kinds, for instance, saw-dust, ex-
hausted shavings of dye-woods, spent tan, can be advanta-
geously worked. If the charcoal obtained from such material
is to be used as fuel, it must, on account of the smallness of
the pieces, be moulded to briquettes by a machine constructed
for the purpose.
Kilns or Ovens and Retorts. — The chief object of the oldest
method of charring wood, as still carried on in some localities,
is the production of charcoal without regard to the recovery of
the available by-products. For this purpose the wood under
a moveable covering is burnt with the access of air in heaps
or pits in the immediate neighborhood of where it is cut. The
attempt to obtain all the products simultaneously, with a
greater amount of charcoal, probably first led to the substitu-
tion of stationary apparatus, either of brick-work or iron, in
place of the covered heaps. Some of these arrangements are
calculated, like the heaps, to produce the necessary tempera-
ture for charring, by the combustion of a portion of the wood,
and the admission of a little air, such as kilns, the sides of
which form a fixed covering for the substances to be charred.
In others the portion of the wood destined to produce the heat
is entirely separated from that to be charred, the latter being
placed inside, the former outside, the kiln. The yield of ace-
tate and alcohol is very low even in the best of kilns, and the
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 257
use of the latter has been almost entirely abandoned, they be-
ing now only employed in localities where charcoal is prac-
tically the only product recovered. For the sake of complete-
ness a few of the older constructions will be described.
Schwartz's Oven. — The oven introduced by Schwartz into
Sweden is based upon the principle that the hot gases furnished
by a special furnace must pass through the wood piled in a
closed space and heat it sufficiently for destructive distillation.
The construction is shown in Figs. 54, 55 and 56. Fig. 54 is
a ground plan, Fig. 55, a section of the elevation following the
lines dd, and Fig. 56, another section following the lines cc.
In the illustrations A A is the space where the wood is carbon-
ized, b, apertures through which the wood is brought into the
oven, and the charcoal withdrawn ; c c, the fire-places for heat-
ing the oven ; d d, openings through which the smoke, car-
bonic acid, acetic acid, oleaginous and tarry substances pass off
through the pipes g g, and thence through the condensers into
the chimney ; e e are knee-pipes which convey the tar condensed
into the vessels// — Fig. 55. The bend in the pipes prevents
the access of air into the apparatus. H H H H are wooden
channels wherein the acid and oleaginous matters condense ; i
is the chimney and k a small opening in the chimney, where a
fire is lighted to establish a powerful draught. The oven walls
are of fire-brick or may be of two rows of ordinary brick, the
interspace being filled with clay and sand. The oven is first
charged with the heaviest blocks of wood, and between these
smaller wood is introduced, for the purpose of making the in-
terior more permeable to the action of the fire. All the orifices
of the oven are then closed, and the fires at c c lighted, the
current of air being instituted in i by lighting a fire at k as
above mentioned. The blaze of the fire traverses the oven
and carbonizes the charge of wood, and the smoke and other
vapors from the oven pass by the exit pipes d d into g g,
whence they escape to the condensers H H, and thence to the
chimney i. The charge is known to be completely carbonized
when the smoke issuing at i, which is at first black and heavy,
17
258
MANUFACTURE OF VINEGAR.
becomes bluish and light. The chimney passage is then
closed, and the opening of the pipes d d stopped up with
FIG. 54.
FIG. 55.
FIG 56.
wooden plugs and then well luted with plastic clay ; the fire-
doors are closed and the oven left to cool. At the end of the
second day, two holes in the top of the oven which hitherto
WOOD VINEGAR AND TAR IN CLOSED VESSELS.
259
had been closed air-tight, are opened, and water is introduced
to extinguish the red-hot charcoal. The openings are again
closed for a longer period, and when the oven gets a little
cooler, more water is added. If any red sparks are observed r
the openings and pipes must be carefully stopped up, so as to-
prevent the formation of a current of air, as this would occa-
sion the combustion of the charcoal and consequently lessen
the product.
Great care has to be exercised in accurately regulating the
access of air, since the smallest quantity of atmospheric oxygen
which passes through the fire-room without being consumed
causes a corresponding loss of material in the space where the
FIG. 57.
wood is carbonized. Since notwithstanding the utmost care
and attention, the access of oxygen can never be entirely
avoided, this oven will seldom be used where the chief object
is to obtain as large a quantity of acetic acid as possible. An
essential improvement in the oven might be made by intro-
ducing generator gases in the heating places and burning
them by the admission of just a sufficient quantity of air, which
could readily be accurately regulated, so that a slight reduc-
ing atmosphere would always prevail in the oven.
Reichenbach' s oven, Fig. 57, is a square construction with
double walls, the inner wall of fire-brick and the outer of
ordinary brick. The space between the two walls is filled
260
MANUFACTURE OF VINEGAR.
with sand. The oven is heated by pipes about 2 feet in diam-
eter which run from one end of the wall to the other, and are
seen in the illustration at a, 6, c, d and m, n. o, p. The appa-
ratus having been filled with wood, the upper portion is cov-
ered with a layer of sods and earth, or with iron plates, the
joints of the latter being carefully luted with clay. A fire is
then lighted in the fire-places in front of p and d, which raises
the temperature of the pipes so high as to cause them to glow.
The wood in the surrounding spaces of the oven abstracts the
heat and is thereby carbonized, the volatile products of which
pass off at the bottom of the oven through the openings at x,
into the conduit/, #, h, and through y at the opposite side into
a similar conduit. Both products intermix in the pipe ki,
where the tar is partly deposited. From the pipe ki, the
acetic acid vapors are carried off to the condenser.
Swedish oven. This oven is shown in Fig. 58. The space
G where the wood is carbonized is vaulted and is provided on
top with an aperture for charging the wood, which after the
vault is filled, is closed by a heavy lid luted with clay. The
pipe A serves for carrying off the products of distillation. The
bottom of the vault is conical, and in the center is provided with
thetgrate R, below which is the ash-pit C, which can be closed
by an accurately-fitting slide S. The door Tt which is bricked
WOOD VINEGAR AND TAK IN CLOSED VESSELS. 261
up during the process of carbonization, serves for withdrawing
the finished charcoal, and also for the introduction of a portion
of the wood. It is immediately closed after the introduction
through it of some glowing coals. The effect of the latter is to
ignite a portion of the wood, and combustion is conducted by
setting the slide 8 so that the vapors are cooled with a certain
uniformity. In a short time the wood and the walls of the
oven become so thoroughly heated that combustion can be
entirely interrupted by closing the slide S, distillation being
completed by the heat accumulated in the oven.
An oven of a somewhat different construction is shown in
cross-section in Fig. 59, and in ground plan in Fig, 60. The
FIG. o9.
FIG. 60.
space in which the wood is carbonized is in the form of a cyl-
inder and passes above into a vault closed by a heavy iron lid
a. The brick work of this space is surrounded by another
brick work 6, and the fire which is ignited at the opposite side
d circulates between the two walls in the space c c. On the
upper portion of the oven, at d, are apertures provided with
slides, which serve for regulating the fire. The products of
distillation escape through the pipe e on the bottom of the
carbonizing space.
The oven is heated so that the interior wall becomes red-hot.
Firing is interrupted when no more vapors escape from* the
pipe e. The slide at d is then closed and the oven left to cool
:262 MANUFACTURE OF VINEGAR.
'until the charcoal is sufficiently cooled off to allow of it being
withdrawn without fear of ignition.
*Carbo-oven. — In this oven carbonization is effected in a
WTo-ught-iron vertical cylinder with a capacity of 300 to 400
cubic meters of wood. The wood is introduced through open-
ings in the wrought-iron cover of the cylinder. The products
of distillation pass out through a pipe branching off from the
lowest part of the bottom. An outlet on the side of the cyl-
inder serves for emptying the latter.
Heating is effected by tire-gases produced in a separate
furnace, which pass through spiral flues surrounding the
wrought-iron cylinder. The lower portion of the cylinder is
protected by brickwork from the direct action of the fire-gases.
In the center of the cylinder stands a large vertical heating-
pipe divided into halves by a partition. The non-condensable
gases, as well as the air required for their combustion, can
pass in through two pipes entering the lower part. The
smoke-gases coming from the last flue may also be conducted
through this heating pipe and, mixed with the combustion
products of the wood-gases, escape to the chimney.
Retorts. — The various forms of apparatus for the destructive
distillation of wood previously described are of such a con-
struction as to exclude uninterrupted operation. When a
charge has been distilled off, the kiln or oven has to stand till
the charcoal is sufficiently cooled off to allow of its being with-
drawn. When this has been done the oven must be again
charged, heated and so on. This is evidently connected not
only with considerable loss of time, but also of heat, and it
has been endeavored to overcome this drawback by the use of
retort-ovens.
By heating wood in a retort closed air-tight with the ex-
ception of an opening for the escape of the products of distil-
lation, and by fitting to this opening a condenser of suitable
•construction, an apparatus is obtained with which all vapor-
iform products escaping from the wood can be recovered.
Such an apparatus, though the most expensive, is the best for
the production of wood vinegar.
WOOD VINEGAR AND TAR IN CLOSED VESSELS.
263
'a. Horizontal retorts. — The arrangement of an apparatus for
the distillation of wood is very similar to that used for the
production of illuminating gas from coal, the essential differ-
ence being that the retorts for the distillation of wood must
lie in fire-places which allow of the heat being slowly and
uniformly raised, while in making illuminating gas rapid
raising of the heat is required. Clay being a worse conductor
of heat than iron, the use of retorts of this material would
apparently seem advisable for the destructive distillation of
wood. However, clay retorts have the drawback of being
fragile and besides cracks are readily formed through which a
FIG. 61.
FIG. 62.
portion of the vapors would escape. For this reason iron retorts
are as a rule used. Cast iron retorts do not readily burn
through and are but little affected by the vapors of the acid,
but they have the drawback of great weight, and defective
places are difficult to repair. The best material for horizontal
as well as vertical retorts is hot-riveted boiler plate about 8
millimeters thick. Defects in such a retort can be readily
repaired by riveting a piece of boiler plate upon the defective
place.
A wrought-iron retort of very suitable construction is shown
in Figs. 61 and 62. It consists of a cylinder 2.2 meters long
and 1 meter in diameter. On the back end the retort passes,
264
MANUFACTURE OF VINEGAR.
as seen in the illustration, into a pipe of such a length that
about 30 centimeters of it project from the brick work of the
oven. In front the retort is secured to a cast-iron ring, in the
groove of which fits a sheet-iron door. This door is pressed
against the ring by a screw and the joint is made air-tight by
luting with clay. For the rapid withdrawal of the charcoal,
the interior of the retort is furnished with a sheet-iron disk
supported by two rods riveted to it. To the center of this disk
a chain is fastened which lies upon the bottom of the retort.
When the door of the retort is opened the chain is seized with
a hook and on being drawn forward the sheet-iron disk pushes
the charcoal out.
To protect the portion of the retort which comes in direct
contact with the flame it is advisable to apply to it repeatedly
FIG. 63.
a mixture of clay and cow hair. This prevents quite well the
formation of burnt iron which scales off from the portions
directly heated.
Fig. 63 shows the manner of bricking in six retorts, two
being placed in one fire place. In this construction, as will
be seen from the illustration, the fire-gases pass directly into
the chimney which is equivalent to a waste of heat. How-
ever, this heat can be completely utilized either by placing
upon the retort-oven a pan in which the solution of crude
sodium acetate may be evaporated, or the fire-gases may be
used for heating a room in which the wood for the next oper-
ation is dried. In working wood very poor in water, a smaller
WOOD VINEGAR AND TAR IN CLOSED VESSELS.
265
quantity of wood vinegar is to be sure obtained than with the
use of ordinary air-dry wood, but it is correspondingly richer
in acetic acid.
FIG. 64.
In Figs. 64 and 65, a a a are the wrought-iron retorts, b the
hearth, c c the flues, d the chimney. Over the somewhat
conical neck of the retort is pushed an elbow pipe e which
FIG. 65.
dips into the receiver F. The latter is a cast-iron pipe 1 to 2
feet in diameter according to the number of retorts, and ex-
tends the entire length of the oven. For the neck of each re-
tort it carries a tubulure 5} to 7} inches long. The object
•266
MANUFACTURE OF VINEGAR.
of the receiver is to receive the products of distillation from all
the retorts and at the same time to hydraulically close the
-elbow-pipe of each receiver. Hence the vapors not precipi-
tated in the receiver can continue their way through g to the
other condensing apparatus h, but cannot re-enter the retorts.
This is of no slight importance, for if there were no water-
joint and the vapors should from any cause suddenly cool off,
the external air might penetrate into the retort, and the latter
being filled with inflammable gases and vapors of a high tem-
perature, an explosion would necessarily follow. For making
the water-joint it suffices for the elbow-pipes to dip f to 1 inch
FIG. 66.
into the fluid into the receiver. But as the fluid constantly
increases, provision must be made for its discharge through a
pipe, placed below or on the side, into a collecting vessel
located in another apartment.
In many plants the gases escaping from the condenser are
utilized for heating by conducting them under the retorts
through a suitable pipe system. However, the pipe-system
should be so arranged as to allow of the gas being conducted
under any one of the retorts or being shut off from it in case
of necessity, because if distillation progresses too rapidly, the
fire under a retort may have to be entirely removed in order
to moderate the chemical process in the retort. It is advisable
to arrange the gas conduit so that the gas can also be used for
heating other apparatus, for instance, evaporating pans, etc.
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 267
In this country what is known as the oven-retort, Fig. 66,
is largely used in equipping plants for hard-wood distillation.
This retort is a rectangular wrought-iron chamber, a common
size being 6 feet wide, 7 feet high and from 27 to 50 feet long,
according as it is intended for two or more cars loaded with
wood. The oven is set in brickwork or is made with double
iron walls with an air space between. It is provided with a
large door closing air-tight, and is heated by wood, charcoal,
coal or gas.
When distillation is finished the cover of the retort is re-
moved, and the glowing charcoal is with the assistance of the
FIG. 67.
previously-described contrivance emptied into cans, which are
immediately closed with tightly-fitting covers, the latter being
luted with clay or sand to prevent ignition of the glowing coal
by the entrance of air. If such retorts as shown in Fig. 66
are used, coolers, Fig. 67, similar in shape are employed, in
which the coal is allowed to remain until thoroughly cool.
b. Vertical Retorts. — The principal drawback of horizontal
retorts is that, on the one hand, charging them is connected
with some difficulty in case they are longer than two lengths
of the wood, and, on the other, that defects in them cannot
as a rule be immediately detected, and that when repairs have
to be made they have to be taken from the oven. In addi-
268
MANUFACTURE OF VINEGAR.
tion a certain number of sheet-iron cans have to be provided'
for the reception of the charcoal drawn from the retorts.
The arrangement of the retorts so that they can be lifted
from the oven and replaced by others has many advantages.
The operation can be carried on without interruption by re-
moving a retort in which distillation is finished and replacing
it by another, in which distillation at once recommences, be-
cause the hot brickwork throws out heat continuous!}', and
heating need to be interrupted only during the time required
for lifting out the retort and replacing it by another.
The accompanying illustrations show the arrangement of the-
FIG. 68.
retort-ovens and the lifting apparatus as devised by Dr. Josef
Bersch. Fig. 68 shows a retort 12 feet high with a diameter of
3 feet and 3 inches. It is constructed of boiler-plate 0.315
inch thick, the bottom, i. e., the portion which is exposed
directly to the fire, being of plate 0.394 inch thick. The
upper portion of the retort is provided with a cast-iron ring
K which, when the retort is lowered into the oven, rests upon a
flat cast-iron ring P placed upon the brickwork. On this
ring are four eyes $ which serve for fastening the lifting tackle,
and the lid of the retort is secured by four pins pushed through
the openings in the ring. The lid of the retort consists of a
sheet-iron disk, provided in the center with a conical head-
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 269
piece D which terminates in the pipe H leading to the con-
denser.
Figs. 69 and 70 show the retorts placed in the oven and the
mechanical contrivance for raising and lowering the retort R.
On top of the ovens is a track (7, upon which runs a crane with
a head-piece having the form of a truncated cone. The track is
continued from the last oven to a brick wall upon which it rests,
and beneath this track is another one, which runs to the place
where the charcoal is to be emptied and the retort is to be re-
filled with wood. The function of this mechanical contrivance
Fig. 69.
is as follows : The retort, after the contents have been distilled,
is, while hot, lifted from the oven by pushing the crane over it
and drawing it into the hollow pyramid. The crane is then
pushed over the opening 0, upon which stands a carriage K
upon the other track E. The carriage is provided with a
basket-like arrangement for the reception of the retort. The
retort having been lowered into the basket, the latter is brought
into a horizontal position by turning a screw without end. The
carriage, which is actually a dumping-car, is pushed over the
pit for the reception of the charcoal, and the retort, the lid of
which is now taken off, is sufficiently inclined to allow the char-
270
MANUFACTURE OF VINEGAR.
coal to fall into the pit. The charcoal is protected from igni-
tion by being covered with wet charcoal dust. The empty
retort is then again brought into a horizontal position and
refilled with wood.
While the retort just coming from the oven is thus handled,
and the first dumping-car has been pushed away, another
dumping-car is immediately brought from a side track &' under
Fig. 70.
the crane, the retort lifted in, the crane pushed over the empty
oven, and the retort lowered.
Since towards the end of distillation the greatest heat must
be applied in order to obtain the last remnants of acetic acid
and tar, the sides of the oven are hottest at this period. If
now immediately after a retort with charcoal has been taken
out, another one charged with wood is brought into the oven,
the heat radiating from the sides of the oven suffices to induce
distillation, and the fire need only be slightly stirred to unin-
terruptedly carry on the operation.
One crane and two dumping-cars are sufficient for attend-
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 271
ing twelve to eighteen ovens arranged one alongside the other.
For a larger number of retorts it is advisable to have two-
cranes, and to arrange the coarse of the operation as follows :
One crane, in the pyramid of which is suspended a retort
filled with wood, which has been lifted from a dumping-car
standing, for instance, on the right-hand end of the series of
ovens, is immediately pushed over the oven as soon as the re-
tort filled with charcoal has been lifted out, and the retort is
then lowered. The other crane is pushed to the left-hand
end of the series of ovens, where the retort is lowered, and
so on.
By the employment of these contrivances the time required
for distillation is reduced to a minimum, the operation can be
carried on without interruption, and it is not necessary to pro-
vide sheet-iron cylinders for cooling the charcoal, since the-
latter is dumped from the retorts directly into pits between the
rails upon which the dumping cars run, where it is cooled by
covering with wet charcoal dust.
Distilling apparatus for wood waste. — In working wood and
bark in the various trades a large quantity of waste results
which, in most cases, is used as fuel. Such waste can, however,
be utilized to greater advantage by subjecting it to destructive
distillation for the purpose of obtaining wood-vinegar, tar and
charcoal.
Halliday's apparatus for the production of acetic acid, etc.,
from sawdust, spent bark from tan-yards and dye woods ex..
hausted of their coloring matter, is shown in Fig. 71. The
waste to be treated is introduced into a hopper B placed above
the front end of an ordinary cylinder C, in which a vertical
screw or worm revolves, conveying the material, and in proper
quantities, to the cylinder, placed in a horizontal position,
and heated by means of a furnace H. Another revolving
screw or worm D keeps the material introduced into the retort
by C in constant agitation, and at the same time moves it
forward to the end. During its progress through the retort
the materials are completely carbonized and all the volatile
•272
MANUFACTURE OF VINEGAR.
products disengaged. Two pipes branch off from the ulterior
part of the retort, one .F passing downward and dipping into
-an air-tight vessel of cast-iron, or a cistern of water G, into
which the carbonized substance falls. The other ascending
pipe E carries off the volatile products of the distillation into
the condenser, consisting of pipes of copper or iron immersed
in or surrounded by water.
The arrangement of the cylinder A with the screw is sim-
ilar to the worms used for moving grain, malt, etc., in a
-horizontal direction. According as the screw revolves with
Fig. 71
greater or less rapidity, the materials can for a shorter or
longer time be exposed to the action of the heat, and accord-
ing to well authenticated statements, the quantity of acetic
acid obtained from the wood substance distilled in this appa-
ratus is larger than that derived from blocks of wood stacked
in other retorts.
This fact, however, cannot be ascribed to the construction of
the apparatus, which is not particularly favorable, but is ex-
clusively due to the condition of the wood. From the small
particles of wood the products of distillation escape with far
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 273
greater rapidity than from the large blocks, which must be
very hot on the surface before their interior is sufficiently
heated for distillation to commence. Hence the products of
FIG. 72.
distillation must pass through the strongly-heated carbonized
parts, whereby a considerable portion of the acetic acid is de-
composed.
Another apparatus suitable for the distillation of sawdust,
18
274 MANUFACTURE OF VINEGAR.
spent tan-bark, exhausted dye woods and waste of wood in
general, is shown in Fig. 72. It consists of an iron cylinder,
18 feet high and 5} feet in diameter, which contains a number
of bell-shaped rings placed one above the other. In this man-
ner a kind of annular cylinder is formed which below termin-
ates in a conical space.
The materials thrown in at the top are heated in the cylin-
der, and the vapors in the cavities of the bell-shaped rings pass
upwards, while the charcoal falls down and is from time to
time removed. In removing the charcoal, the lower portion
of the cylinder is closed by a slide, so that by introducing
material on top of the cylinder, distillation can be carried on
without interruption.
The small charcoal resulting in the destructive distillation
of wood waste, may be utilized in various ways. A portion
burned upon a grate of suitable construction, for instance,
a step-grate, serves as fuel in the factory itself, while the re-
mainder, especially that from sawdust, forms in the finely
divided state in which it is turned out, an excellent disinfect-
ing agent.
The various apparatus employed in the destructive distilla-
tion of wood having now been described, it may be stated that
it is impossible to say which is to be preferred, this depending
largely on local conditions. The decision must particularly be
influenced by the fact whether the charcoal is of value or not.
In the first case it will evidently be of advantage to employ
smaller apparatus, so arranged that besides thoroughly car-
bonized charcoal, all the wood-vinegar and tar are obtained,
and further, that the resulting gases can be employed for
heating the retorts.
But where the conditions are such as to make it difficult to
realize on the charcoal, the principal profit of the plant will be
in the yield of acetic acid and wood spirit, and for this reason
it is best to carry on the destructive distillation of wood in
very large retorts, since with their use the temperature can be
raised very slowly, whereby wood-vinegar very rich in acetic
acid is obtained.
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 275
Coolers. — The products which escape in the destructive dis-
tillation of wood consist, in addition to acetic acid, water and
other very volatile products, of very large quantities of gas.
Since the current of gas is the carrier of vapors, and consider-
able quantities of gas are evolved at certain stages of the pro-
cess, provision must be made for the thorough condensation of
the vapors to prevent the escape into the air of large quanti-
ties of valuable products of distillation, or their being burned
with the gases.
In plants working with a number of retorts, the discharge
pipes of the latter enter into a common pipe of large diameter,
and in this condensing pipe, which in a short time after the
commencement of the operation becomes very hot, the vapors
and gases entering it are cooled off to a considerable extent,
since the condenser in consequence of its large surface yields
considerable heat to the surrounding air. A portion of the
heavier volatile tar products is already condensed in the con-
denser, and is drawn off by means of a faucet in the lowest
portion of the pipe. It might be suitable to place over the-
condenser a pipe with numerous small perforations, so that a
spray of water in such quantity that it immediately evapo-
rates, falls constantly upon the condenser.
By the use of this contrivance not only a large portion of
the vapors are liquefied, but another advantage is attained.
Since by this cooling the tension of the vapors and gases in
the condenser is diminished, the vapors formed in the retorts
pass out with great rapidity. This is of great advantage,
since by the vapors remaining for a long time in the retort a
considerable quantity of acetic acid is decomposed. Further-
more, the volume of non-condensed vapors is considerably de-
creased, so that a cooler of smaller dimensions can be used,
than would be possible if all cooling had to be done in it.
Counter-current Pipe Cooler. — The arrangement of such a
cooler is shown in Fig. 73. The pipe J9, containing the vapors
to be cooled, is surrounded by another pipe W, filled with
water. From the reservoir placed at a higher level, cold water
276
MANUFACTURE OF VINEGAR.
is conducted through the pipe Z to the lowest part of IF, and
passing through the latter, runs off at A. Since the vapors in
the lowest part of D have already been cooled off to a great
•extent, they yield but little heat to the water. As the water
•reaches the higher portions of W,-it constantly acquires a
higher temperature from the heat withdrawn from the vapors,
.and rinally runs off at A. With a sufficient length of the cool-
ing pipes and a powerful current of water, the vapors are so
completely condensed that but very small quantities of acetic
^icid and wood spirit are carried away by the current of gas.
To obtain this acetic acid, the gas before being burned is
FIG. 73.
allowed to pass through a cylinder d, see Fig. 76, which is from
3J to 4 feet high and filled with limestone. The acetic acid
contained in the gas is fixed by the limestone and the calcium
acetate thus formed can be obtained by lixiviation.
The cooling pipes should be of considerable length. With
six retorts in operation at the same time, the length of the
pipes should be about 130 feet and their diameter 5} inches,
since otherwise great pressure is caused in the apparatus by
back pressure of the gases, which results in a decrease in
'the yield of acetic acid. Hence it is advisable to arrange the
upper portion of the cooling apparatus so that the pipe TFhas
WOOD VINEGAR AND TAR IN CLOSED VESSELS.
27T
an elliptical cross section and contains two pipes D, one along-
side the other, which in passing out from this portion combine
to one pipe.
To prevent obstruction in the pipes by the collection of vis-
cous tarry substances, it is recommended to give them consid-
erable inclination and to connect them so that, in case of neces-
sity, the interior of each pipe can be cleansed with a brush.
Fig. 74 shows the most suitable way of connecting two pipes.
The upper pipe is connected writh the lower one by means of
a curved joint secured by screws.
To prevent the fluid running off from the cooler from being
Fig. 74
Fig 7o
forced by fits and starts from the lower pipe by the current of
gas, the contrivance shown in Fig. 75 may be used. The pipe
D, coming from the cooling apparatus, is cut off at an acute
angle, and extends nearly to the bottom of a cylindrical vessel
C, to which is fixed a U-pipe R at such a height that the fluid
in C can rise to the upper edge of the cut end of D. The pipe
G, fixed in the lid of the cylinder, carries away the gas from C.'
Since with an increase in the development of gas, the latter, in
order to escape, needs only to press down a layer of liquid of
very moderate height, it can pass off without impediment,
while the distillate which collects in C runs off through R.
278 MANUFACTURE OF VINEGAR.
If neither liquid nor gas escapes through D, the discharge of
wood-vinegar from R ceases at once, and the uiouth of D is
•closed.
Box-cooler. — In place of the counter-current cooler, the box-
cooler shown in Fig. 76 is used in some establishments. In a
long, narrow trough or box of wrought-iron or wood lies a
series of straight, wide, copper pipes with a gradually decreas-
ing diameter. The pipes are slightly inclined, so that the fluid,
running in at the highest point, flows out at the lowest. Out-
side the trough the pipes are connected by movable elbow
joints. One end of each pipe is firmly fixed to the wall of the
trough, while the other, to prevent free expansion, sits loosely
FIG. 76.
in a slightly conical socket. The lower end of the last pipe
divides into two branches, one of them leading downward and
dipping into the receiver, while the other, as a rule, conducts
the gases directly under the fireplace. There should be but a
small space between the collecting pipe a, which conducts the
vapors to the condenser, and the first condensing pipe, as
otherwise obstructions might readily be formed by the deposit
of tar dried by the hot vapors. A constant stream of water is
conducted through b, along the bottom of the trough, the
heated water running off at c.
The development of gas from the wood being very irregular
and by no means in the proportion desirable for the heating
of the retorts, it is preferable to collect it in a gasometer and
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 279
distribute it from there as may be necessary, instead of con-
ducting it directly into the fire. But little gas is developed in
the beginning of the operation, and much towards the end,
while the reverse proportion is desirable.
In case condensation is not very complete, the pipe leading
to the hearth or gasometer is more or less attacked by acetic
acid precipitated in it by the access of air. To prevent this
evil it is advisable to place on the pipe small receptacles pro-
vided with cocks for the collection and discharge of any fluid
deposited. These receptacles may also be filled with quick
lime, which at least fixes the acetic acid, thus rendering it
harmless for the pipe. The lime is from time to time extracted
with water to regain the soluble calcium acetate.
To further cool off the current of gas and render the vapors
of acetic acid carried along with it harmless for the pipe, Vin-
cent uses a cylindrical copper receptacle, d, Fig. 76, provided
with a false bottom, upon which is placed a layer of crystal-
lized soda from 2J to 2J feet deep. The vapors of water and
acetic acid dissolve the soda, and the temperature thereby
being lowered, a further portion of the volatile bodies, especi-
ally wood spirit, is precipitated. By distilling the fluid thus
obtained, the wood spirit is regained, and the residue in the
still used for the preparation of sodium acetate.
For a condenser for four retorts of a capacity of 141.26
cubic feet each, Gillot gives the following approved dimensions,
provided the period of distillation is 72 hours : The diameter
of the pipe at its entrance into the water trough is 15} inches,
and at its exit 5} inches ; its total length is 164 to 180 feet,
this length being divided between 6 straight pieces and their
elbow-joints. The vat is 26J feet long with a depth of 5J
feet.
Reservoirs for the Product of Distillation. — For storing the
liquid products of the destructive distillation of wood, wooden
vats 6 or more feet high with a capacity depending on the
quantity of the daily distillate are generally used, it being ad-
visable to have them of such a capacity that at least one ol
280
MANUFACTURE OF VINEGAR.
them is filled every day. The U-pipe through which the fluids
run off from the cooling apparatus terminates over a funnel
fixed to a pipe which runs alongside the vats, and is provided
FIG. 77.
on the corresponding places with stop-cocks by means of which
the fluid can be discharged into any vat desired.
Each vat is placed so as to incline slightly forward, and on
the lowest place is provided with a cock, beneath which is a
gutter. About 8 to 10 inches above the bottom of each vat is
a cock with a gutter underneath. Figs. 77 and 78 show the
arrangement of the vats. The pipe E serves for filling the
FIG. 78.
vats with the products of distillation; the cocks Tand the
gutter Tl for discharging the tar into the brick reservoir H
sunk in the floor ; the cocks E and the gutter Ei for drawing
WOOD VINEGAR AND TAR IN CLOSED VESSELS. 281
off the wood vinegar into the small vessel G, to which is-
secured the suction pipe /S of a pump for the further convey-
ance of the wood vinegar.
It is advisable to coat the vats and iron hoops with hot wood
tar.
Collecting boxes. — When working on a large scale quite a
number of vats are required, which involves considerable ex
pense, together with the disadvantage of occupying considera-
ble space. It is therefore advisable to use in place of vats
collecting boxes sunk in the ground.
Such boxes are best and cheapest constructed of about 3-
inch wooden planks, every kind of wood being suitable for the
purpose, since the products of distillation with which the boxes
become saturated preserves them even in moist soil. From the
planks prismatic boxes, each about 13 feet long, 13 feet wide
and 8 feet deep are constructed. The boxes are sunk in the
ground, and in the corner of each box is placed a small barrel
F, Figs. 79 and 80, into which can be dipped the suction pipe
of a pump. The spaces between the planks and the walls of
the pit are filled with earth, and the joints between the planks
with pitch. On top each box is provided with a frame, upon
which is placed a lid made of planks.
The requisite number of boxes are placed alongside each
other so that about 3 feet of ground remain standing between
the sides of every two boxes. The products of distillation run-
ning off from the cooling apparatus are conducted through a
pipe running the length of the boxes into the vessel to be
filled. To prevent a box from being filled too full, all the
boxes are connected by the wooden pipe R, placed about 15
inches below the edge.
When a box has been several times filled with the products
of distillation, the layer of tar deposited on the bottom is of
sufficient depth to be pumped out. The suction pipe of the
pump is then lowered to the bottom of the small barrel in the
corner of the box, and the tar, with the exception of a small
portion, can be separated from the wood vinegar by pumping.
MANUFACTURE OF VINEGAR.
Figs. 79 and 80 show the arrangement of several such collect-
ing boxes in ground plan and elevation.
Since the separation of the tar from the wood vinegar takes
place the more completely the longer the fluids are allowed to
repose, it is advisable to first fill all the boxes in turn with
products of distillation and then to work further the contents
of the box filled first.
Utilization of the Gases. — The gases evolved in the destructive
distillation of wood may advantageously be used as fuel. In
the commencement of the operation a gas mixture, very rich
FIGS. 79-80.
in carbonic acid, is obtained, which is of little value as fuel,
but latter on less carbonic acid is evolved and the gas contains,
besides carbonic oxide, hydrogen and hydrocarbons, which are
of considerable value as fuel.
The most suitable plan would be to catch the gases by
means of a pump from the pipe £, Fig. 75, and collect them
in a gas holder of ordinary construction, and to conduct them
from the latter by means of pipes to the fire-place. However,
a gasholder of sufficient capacity to hold the large quantities
of gas evolved would be rather an expensive affair for a plant
•engaged in the distillation of wood, and it is therefore gener-
DESTKUCTIVE DISTILLATION OF WOOD. 283
ally preferred to conduct the gas directly to the fire-places
where it is to be burnt.
When working with a large number of retorts, the operation
may be so conducted that the wood or coal fire under the
retort just placed in the oven is allowed to go out entirely, and
to fire only with gases escaping from retorts in which distilla-
tion is in full progress, and from which a large quantity of gas
is constantly evolved. In factories devoted to the further
working of the wood vinegar, it is best to conduct the gases of
distillation under an apparatus which has to be heated almost
without interruption, for instance, under the pans in which
the crude sodium acetate is evaporated to crystalization.
Care should be taken not to ignite the gas escaping from the
retorts before all the air has been displaced from the entire
apparatus — retorts, condenser and cooler — since otherwise an
explosion might take place by the flame spreading into the
pipe conduit, which would not only be dangerous, but suffi-
ciently heavy to tear apart the lute of clay on the pipes for
the vapors, the condensers, etc. When the vapors escaping
from a retort condense on cooling to a yellowish colored fluid,
all the air has been displaced from the apparatus, and the gas
may be ignited without fear of danger.
CHAPTER XXIII.
EXECUTION OF THE DESTRUCTIVE DISTILLATION OF WOOD.
No matter what the arrangement of the apparatus may be
in which the destructive distillation of wood is to be carried
on, the course of distillation as regards the succession of phe-
nomena remains the same, and a distinction has only to be
made in reference to the kind of product desired, and the dura-
tion of time for the operation. The latter depends on the
quantity of wood used at one time ; the larger the latter is, the
284 MANUFACTURE OF VINEGAR.
longer the operation will have to be continued, and under
otherwise equal conditions, more time will be required for the
complete distillation of a charge of wood, if wood vinegar, tar
and black charcoal are to be obtained.
When working with a larger number of retorts, the opera-
tion should be so arranged that it is carried on uninterrupt-
edly, this being advisable on account of the division of labor,
and also to prevent being forced to adopt special expedients
by reason of the vast quantity of gas evolved at a certain stage
of the operation.
With the use of vertical retorts and a suitable lifting tackle,
the retorts are placed open in the oven and a gentle fire is
started. At first only steam evolves from the wood, which is
allowed to escape into the air, and only when a peculiar aro-
matic odor indicates the commencement of distillation, are the
lids placed upon the retorts and connected with the cooling-
apparatus. To make the lid steam-tight, a roll of clay is laid
upon the edge of the retort and the lid pressed down upon it,
the clay forced out thereby being smoothed down with an
elastic steel blade.
The time during which distillation has to be continued de-
pends on the size of the retorts, but, as a rule, the operation
is so conducted that distillation is finished in 12 hours. Of
course, with the use of very large apparatus in which a great
quantity of wood is carbonized at one time, distillation re-
quires several days, since the heating of such a large quantity
of wood to the temperature of decomposition takes consider-
able time. When the temperature — about 393° F. — has been
reached at which the wood begins to yield more abundant
quantities of products of distillation, care must be taken to
keep the fire under the retorts so that the temperature increases
gradually and reaches 662° F. only in the last period of dis-
tillation, so that with a distilling time of 12 hours, the tem-
perature in the retorts remains for about ten hours below
662° F. To gain practical experience in regulating the tem-
perature in heating, which is of special importance with new
DESTRUCTIVE DISTILLATION OF WOOD. 285
ovens, it is advisable to place a thermometer on one of the re-
torts as follows : In a small aperture in the lid of the retort
is screwed an iron pipe closed below and open at the top. The
length of the pipe should be such that the lower end reaches
to the center of the retort. In this pipe is lowered by means
of a wire a thermometer graduated to 680° F. (the boiling
point of mercury). By from time to time consulting this
thermometer, a conclusion can be drawn as to the degree of
heat prevailing in the retort. Experienced men can accurately
judge of the progress of distillation from the quantity of distil-
late running off, and of the gases escaping simultaneously.
When, for instance, 5 cubic meters of wood — the contents
of two retorts — are to be distilled at one time, the first distil-
late, in a jet about the thickness of a lead pencil, is obtained
with correct firing, in about 1 J to '2 hours after the commence-
ment of heating. The thickness of the jet of fluid does not
change for hours, and it retains its original yellow color.
The gas issues in a moderately strong current from the re-
spective pipe and burns with a pale blue flame, the latter be-
coming more luminous only later on at a higher temperature
when hydrocarbons are mixed with the gas.
When a temperature of about 662° F. has been reached, the
quantity of distillate suddenly becomes smaller, and the quan-
tity of escaping gas also decreases. In order to obtain the
last remnants of the product of distillation, which consist pre-
dominantly of tar products, the fire is increased, when a more
abundant quantity of distillate is obtained. However, the jet
of fluid running off from the cooler is henceforth of nearly a
black color, due to numerous drops of dark-colored tar pro-
ducts. The volume of gas becomes larger and these gases
burn with a very luminous, pure white flame. In this last
stage of distillation certain precautions have to be observed in
reference to raising the temperature. If it is raised too
rapidly at once, such a large quantity of gas is evolved from
the retorts as to cause a high pressure in the apparatus, which
is recognized by the force with which the current of gas issues
286 MANUFACTURE OF VINEGAR.
from the pipe entering the fire-place. Since in this stage of
the process the retorts are hottest and their bottoms not seldom
red hot, there is danger of the riveted places becoming leaky,
so that in the succeeding operations a considerable quantity of
products of distillation is lost by 'its escape in the form of vapor
through these leaky places and being burned.
When the volume of gas is observed to becoTne greater,
about 1J hours before the end of distillation, the fire under
the retort may be allowed to go out entirely, since the heat
developed in the retorts in consequence of decomposition in
conjunction with that radiating from the sides of the ovens,
suffices to finish the operation. When the temperature in the
retorts rises to 806° F., the evolution of products of distillation
ceases almost suddenly and the retorts now contain only black
charcoal.
Since antimony melts at 809.7° F., this metal may be used
for determining the commencement of the end of distillation.
For this purpose the thermometer is removed from the pipe
previously mentioned, and a small crucible containing a piece
of antimony is lowered by means of a wire into the pipe.
When the antimony is melted, distillation may be considered
finished and the retort be at once lifted from the oven.
The fluid which runs off during distilation is at first wax-
yellow, but later on oecornes of a darker color, red brown, and
finally nearly black, and is quite turbid. When allowed to re-
pose it separates into two — or perhaps more correctly into
three — layers, sharply separated one from the other. The low-
est layer is tar, a thick fluid of a dark, generally pure black
color; the middle layer, which comprises the greater quantity,
is wood vinegar, and is of a red yellow or red brown color.
The upper layer is again of a dark color, and possesses the
properties of tar, but, as a rule, this tarry mass is present
in such small quantities that it even does not cover the entire
surface, but swims upon it like flakes.
It is advisable to allow the distillates to repose for a consid-
erable time, the tar thereby separating more completely from
DESTRUCTIVE DISTILLATION OF WOOD. 287
the wood vinegar, and the latter is obtained as an entirely clear
red brown fluid, which can be manufactured into acetic acid
with greater facility than wood vinegar mixed with larger
quantities of tar.
By giving the vats intended for the reception of the distillate
such a size that one vat is filled by the distillate obtained in
one day, and arranging twelve such vats as shown in Fig. 78
the contents of the vat filled first can be allowed to repose for
11 days before the manufacturer is forced to empty it in order
to make room for fresh distillate. When the wood vinegar and
tar are to be worked further in the factory itself, the appara-
tuses intended for this purpose should be of such dimensions
that the quantity of wood vinegar produced daily can be
worked up at one time. The quantity of tar being considera-
bly smaller than that of wood vinegar, it is collected in the res-
ervoir H, Fig. 78, and larger quantities of it are worked in one
operation.
When the liquid products of distillation are caught in boxes
sunk in the ground, described on p. 281, the operation may be
so arranged that the distillate is allowed to run uniterruptedly
into the first box until it is filled with tar to such an extent
that not only wood vinegar, but also tar commences to run off
through the pipe R, Figs. 79 and 80. The tar is then allowed
to repose for some time, whereby it still better separates from
adhering wood vinegar, and the larger quantity of pure tar
thus obtained is then worked up at one time.
Experience has shown that it is of advantage to allow the
tar also to repose as long as possible, it having been observed
that if kept for some time in special reservoirs, a permanent
separation of the products according to their specific gravitie&
takes place. On the bottom of the reservoir tar of a very
viscous gritty nature collects, which is of such thick consist-
ency that it can scarcely be raised by a pump. The higher
layers of the tarry mass are of thinner consistency, the upper-
most being almost oleaginous, and upon them floats a layer of
-288 MANUFACTURE OF VINEGAR.
wood vinegar, which can from time to time be taken off and
worked together with that drawn from the vats.
Yield of Products. — The quantities of wood vinegar and tar
which are obtained from a given quantity of wood depends on
several factors, namely, on the kind of wood, its content of
water, and the manner in which distillation itself has been
conducted. Since these three factors vary very much, it is
evident that there must be considerable differences in the
statements regarding the quantities of products of distillation,
and especially the quantities of acetic anhydride and wood
.alcohol which can be obtained from crude wood vinegar, be-
cause by careless manipulation a large quantity of the acetic
&cid present in wood vinegar is lost.
In order to obtain accurate data regarding the quantities of
wood vinegar and tar which can be obtained from a variety
of wood when working on a large scale, it is necessary to weigh
the wood worked during a certain time, to determine its con-
tent of water, to ascertain in a sample of the wood vinegar re-
sulting from each distillation the quantity of acetic acid and
wood alcohol, and finally to accurately ascertain the volume
of vinegar. From the results of such a series of tests and
from the quantities of pure acetic acid and wood alcohol fur-
nished by the factory itself, it would be possible to obtain re-
liable data regarding the quantities of products of distillation
which may be obtained from a given variety of wood.
Stolze has published experiments made with the greatest
care to show the amount and strength of the products obtained
from the distillation of several kinds of wood. The quantity
of each kind of wood submitted to destructive distillation was
one pound, a quantity suitable, in most cases, to form a prece-
dent for the manufacture on a large scale. The woods were
all collected at the same time of the year (towards the end of
January) and only those of nearly the same growth were
chosen. From Stoltze's table the following figures for the
most important -varieties of wood have been calculated :
DESTRUCTIVE DISTILLATION OF WOOD.
289
**
Therein
Wood
acetic
Char-
Gases,
vinegar,
anhydride,
Tar,
coal,
cubic
pounds.
pounds.
pounds.
pounds.
meters.
100 pounds of birch
100 pounds of beech
44.9
44
8.9
8.6
also
8.6
9.5
24.4
2J.6
9.8
10.8
100 pounds of hornbeam.
100 pounds of oak
42.5
43
7.H
7 7
i(
11.1
9 1
23.9
26 1
10
10
100 pounus of fir
423
4 2
H
11 9
266
12.5
The results obtained by Assmus in manufacturing on a
large scale are as follows :
100 pounds of—
Yield
wood
vinegar,
pounds.
Which
yield
calcium
acetate,
pounds.
Or
acetic
an-
hydride,
pounds.
Tar,
pounds.
Char-
coal,
pounds.
Crude
light
oil,
pounds.
Crude
heavy
oil,
pounds.
Birch 25 to 40 years old ....
Birch-bark, first extract
Birch-bark, second extract.
Oak
46
22
20
42
5.2
0.6
0.7
60
3.9
0.4
0.5
4 5
8
30
20
8 8
23.5
18.5
22
27 5 (f\
12
21.6
12
0 8
4.5
3.0
4.7
33
Fir
42
3 2
2 4
10 5
22
1 3
5 7
Pine
44 5
3 0
2 3
9 5
22 6
0 6
q c
According to Roth's experience, the trunk-wood of birch
from 60 to 80 years old and grown upon a high dry soil with
a limestone sub-soil surpasses the best red beech in the yield
of acetic acid. He obtained from 100 pounds of this kind of
wood dried at 140° to 158° F., with heating for 48 hours, at
a temperature not exceeding 750° F., 40 pounds of wood vin-
egar of 25 per cent, acetic anhydride, also 2 or 3 per cent, of
tar, and 30 per cent, of red charcoal suitable for the manufac-
ture of powder.
Klar * gives the following yields obtained with retorts.
The figures refer to anhydrous wood of 100 per cent., expressed
in per cents, by weight.
19
Technologie der Holzverkohlung, 1910.
290
MANUFACTURE OF VINEGAR.
Calcium
.Crude
Charcoal.
acetate
of 80 per
wood spirit
of 100 per
Tar.
Tar oil.
cent.
cent.
3
a
8
a -
a
g
a
a
a
S
p
p
3
p
p
P
p
B
§
§
1
a
a
a
a
a
a
9
|
X
B
x
oS
"S
M
cS
q
|
g
S
i
M
i
S
3
g
a
a
S
33
35
33
36
28
28
33
10.5
8
2.5
3.6
8
2.3
3
2.5
2
0.42
0.8
1.7
o'.28
0.6
6
7
20
12
5
'e
1
5
6.'4
Very resinous fir
European fir
Sawdust from conifera. . . .
33
..
3
0.6
10
Olive kernels
35
4
1.2
4
CHAPTER XXIV.
TREATMENT OF THE WOOD VINEGAR.
Wood vinegar in the state it is obtained from wood finds but
a limited application. Without further treatment it can in a
crude state be used only for impregnating wood or for the
preparation of ferric acetate (red liquor), because a portion of
the tar products impart to it a penetrating empyreumatic odor
rendering its use for other purposes impossible. It is also not
possible to free the wood vinegar from these tar products sim-
ply by distillation. By repeated rectification highly concen-
trated acetic acid remaining almost colorless in the air is to be
sure finally obtained, but it has always a more or less empy-
reumatic odor which makes it unavailable for comestible pur-
poses.
'The acetic acid can, however, be separated in a perfectly
pure state from the wood vinegar, and upon this is based not
only the preparation on a large scale of the various acetates,
but also, what is perhaps of still greater importance, the pro-
duction of absolutely pure acetic acid suitable for comestible
purposes.
TREATMENT OF THE WOOD VINEGAR. 291
No matter how the wood-vinegar is to be used, it is of great
importance to separate it as' much as possible from the tar-
Freshly prepared wood-vinegar is a turbid red-brown fluid.
By allowing it to stand quietly in a tall vessel a quite thick
layer of tar separates on the bottom, over which stands the per-
fectly clear wood-vinegar; a thin, oleaginous layer of light tar
products also floats sometimes upon the surface of the vinegar.
As in the further treatment of the wood-vinegar the presence
of tar causes many disturbances, care must be taken to sepa-
rate it as much as possible by mechanical means, this being
effected by allowing the products of distillation to stand in the
vats for several days — the longer the better.
It has been proposed to heat the wood vinegar by placing a
copper coil in the vat, and thus effect a more complete sepa-
tion of vinegar and tar. But independent of the expense, the
result of this treatment is less favorable than that obtained by
allowing the products of distillation to stand for a long time,,
and besides, by heating too much, a portion of the readily
volatile wood spirit .is evaporated.
There are several ways by which concentrated acetic acid
can be obtained from crude wood-vinegar, the one to be selected*
depending on what the acetic acid is to be used for. When it
is to be employed for the production of acetates where a slight
empyreumatic odor is not detrimental, it is best to prepare
from the crude wood-vinegar distilled wood-vinegar, and work
the latter into acetates. Crude lead acetate can, for instance,
be prepared in this manner.
If the distilled wood-vinegar should be directly used for the
preparation of the various acetates, salts would be obtained
which on exposure to the air would turn brown in consequence
of the oxidation of the tar-products. However, the behavior
of some acetates in the heat is made use of to obtain from
them chemically pure acetic acid. While nearly all salts of
the organic acids are decomposed at a comparatively low tem-
perature, some salts of. acetic acid can without suffering decom-
position be heated to almost 750° F. But at this temperature
292 MANUFACTURE OF VINEGAR.
all the tar products adhering to the salt are completely vola-
tilized or destroyed, so that by recrystallizing the heated mass,
salts are obtained which are free from empyreumatic substances,
and chemically pure acetic acid can then be made.
Distilled wood vinegar. — Since crude wood vinegar always
contains tar in solution it is absolutely necessary to get rid of
it before neutralizing the vinegar and preparing calcium ace-
tate. High-grade " grey acetate " can only be produced from
wood vinegar freed from tar, otherwise " brown acetate" con-
taining at the utmost 67 per cent, calcium acetate is obtained.
This separation is effected by distillation, the tar remaining
in the still.
For this purpose the crude wood vinegar is subjected to dis-
tillation in a simple still heated by steam, whereby about 7
per cent, of tar remains in the still. The distillate, called clear
vinegar, still contains small quantities of volatile oils. They
are removed mechanically by allowing the clear vinegar to
stand, or the latter is separated in vats arranged one after the
other in the manner of Florence flasks.
Besides acetic acid the clear vinegar contains wood spirit, i. e.
a mixture of methyl alcohol, methyl acetate, aldehyde, acetone
and allyl-alcohol, and can be separated from it by repeated
fractional distillation, whereby the methyl acetate, however,
passes over into the woodspirit, thus causing losses of acetic
acid. It is, therefore, better to first neutralize the distilled
wood vinegar with milk of lime, whereby the greater portion
of the methyl acetate is saponified, i. e. split into calcium ace-
tate and methyl alcohol, and then distil it. The crude wood
spirit is then subjected to rectification and the solution of cal-
cium acetate is evaporated and allowed to crystallize.
This method is obviously inexpedient in so far that distilla-
tion takes place twice. The heat used for the first distillation
of the crude wood vinegar is therefore lost. Proceeding from
this point of view, M. Klar has devised the so-called "three
still system". The mixture of vapors .appearing in the first
distillation of the crude wood vinegar is at once conducted
TREATMENT OF THE WOOD VINEGAR. 293
into milk of lime where calcium acetate which remains in
solution is formed from the acetic acid. The vapors again
pass into a still filled with milk of lime where any acetic acid
which has been carried along is fixed. The vapors pass finally
into a cooler where the wood spirit is condensed. Since the
boiling point of wood spirit is lower than that of acetic acid,
the former does not pass over up to the end of the operation.
The cooler may therefore be previously disengaged and the
vapors be allowed to escape or be used for other purposes. A
special advantage of this method is the complete utilization
of the latent heat of the vapors coming from the first still.
Moreover the milk of lime in the second and third stills gets to
boiling whereby the solution of calcium acetate is at the same
time concentrated. The milk of lime in the still has of course
to be renewed before it is completely saturated with acetic
acid. When working according to this method three advan-
tages are consequently gained in one operation, the crude
wood vinegar is freed from tar, the wood spirit is separated and
the solution of calcium acetate is concentrated. A solution
of calcium acetate of 20 to 35 per cent, is obtained, and a dis-
tillate with about 10 per cent, wood spirit.
A great saving in fuel, steam and space is effected by F. H.
Meyer's system (German patent, 193,382) of distilling the
crude wood vinegar in multiple evaporators in vacuum. It
is based upon the fact that all fluids under a decreased air-
pressure boil at a lower temperature. Hence if vapors with
a lower temperature than the boiling point of the fluid to be
evaporated are at disposal for heating purposes, they may be
used for distillation by correspondingly decreasing the air-
pressure over the fluid to be evaporated.
Freshly-prepared distilled wood vinegar is a colorless, very
acid fluid with an empyreumatic odor. On exposure to the
air it acquires a brown coloration in consequence of the oxi-
dation of the empyreumatic bodies. Although a number of
expedients have been suggested for freeing the distilled wood
vinegar from the empyreumatic odor and taste, none of them
294 MANUFACTURE OF VINEGAR.
have answered the purpose so far as to make it possible to use
the vinegar for comestible purposes. The surest proof of the
inexpediency of these methods is found in the fact that none
of them has been adopted in practice, though by direct con-
version of the distilled vinegar, table vinegar could be pro-
duced at a very low price.
The distilled wood vinegar may, however, be directly used
for technical purposes, for instance, in the preparation of lead
acetate, copper acetate, etc. When it is desired to obtain a
pure preparation, precaution should be taken to change the
receiver of the apparatus in which the crude wood vinegar
is distilled when about 80 to 85 per cent, of the total quantity
of vinegar which can be obtained has passed over, experience
having shown that the last portions of the distilled vinegar
are far richer in empyreumatic substances than those passing
over first.
Stolze has proposed several methods for the purification of
wood vinegar, the most simple and cheapest being to add 5
pounds of finely pulverized pyrolusite to every 100 quarts of
vinegar, keeping it at nearly a boiling heat for 6 hours, then
digesting it in the same manner with 40 pounds of freshly
glowed charcoal pulverized and sifted while hot, and finally
distilling off to dryness in a shallow cast-iron still. But on
account of its tediousness and the necessarily large consump-
tion of fuel, this process, though frequently modified, has been
almost entirely abandoned.
According to Tereil and Chateau, the wood-vinegar is puri-
fied by compounding it, according to its more or less dark color,
with 10 or 5 per cent, of concentrated sulphuric acid, whereby
the greater portion of the tar separates in 24 hours. By dis-
tilling the decanted acid it is obtained almost colorless, but it
darkens somewhat on exposure to the air, and by saturation
with soda a slightly colored salt is obtained which can, how-
ever, be discolored by a small consumption of animal char-
coal.
Rothe employs a peculiar method for the purification of
TREATMENT OF THE WOOD VINEGAR. 295
wood-vinegar. The greater portion of tar being separated by
standing, the wood-vinegar with an addition of charcoal is
rectified from a copper still. The pale yellow watery wood-
spirit is caught by itself, and the succeeding clear, but strong-
ly empyreumatic, distillate is pumped into a vat, placed at a
considerable height, from which it runs into a purifying ap-
paratus. The latter consists of a cylindrical pipe of stout tin-
plate. It is about 26 feet high and 1J feet in diameter, and
is filled with pieces of coke about 0.122 cubic inch in size,
which rest upon a heavily tinned iron grate placed about 1J
feet above the bottom of the pipe. Over this column of coke
the wood-vinegar is poured in an uninterrupted fine spray,
while in the space between the bottom and the grate a slow
current of air heated to 104° F. is constantly blown in through
a nozzle. The empyreumatic oils mixed with the wood-vine-
gar are oxidized by the oxygen of the warm air, and, in con-
sequence, the temperature in the interior of the column of
coke rises to 122° F., and over. The pipe is protected from
cooling off by a thick layer of felt. The products of the oxi-
dation of the empyreumatic oils are partially of a resinous
nature and adhere to the coke, and partially volatile. The
acetic acid running off through an S-shaped pipe on the bot-
tom of the pipe is clear, of a pure acid taste, and suitable for
the preparation of all the acetates as well as of acetic acid.
The very slight empyreumatic odor disappears by forcing the
product through a pipe filled with pieces of animal charcoal
free from lime. The vinegar thus obtained is claimed to be
suitable for table use. Though a quantity of acetic acid is
carried off in the form of vapor by the warm dry current of
air, this loss can be prevented by passing the air through an-
other pipe filled with calcined soda or lime.
Experiments have shown that the method above described
cannot be recommended for practice, because by the resinous
oxidation-products deposits are soon formed upon the pieces
of coke which obstruct the free passage of the current of fluid
and air, necessitating a frequent renewal of the charge of coke.
296 MANUFACTURE OF VINEGAR.
Besides a portion of the oxidation-products remains dissolved
in the vinegar itself, rendering it for this reason alone unfit
for table use.
The only way to prepare perfectly pure acetic acid from the
wood vinegar is to fix the acetic acid to strong bases, strongly
heat the resulting salts so that all tar substances are volatilized
or decomposed, and to separate from the salts thus purified
acetic acid by distillation with strong acids. According to this
process crystallized acetic acid — the chemically pure prepara-
tion— can finally be prepared.
Production of pure acetic acid from wood vinegar. — The basic
bodies employed in the practice to fix the acids contained in
wood vinegar are, according to the object in view, either lime
or sodium, the former being used for the preparation of acetic
acid suitable for technical purposes, and the latter for that of
absolutely pure acetic acid fit for comestible use. In many
plants not equipped with the apparatus required for the pro-
duction of pure acetic acid, the crude wood spirit is distilled
off from the wood vinegar and the residue in the still used for
the preparation of crude calcium acetate, these two raw pro-
ducts being sold to chemical factories. This course is of
special advantage where the charges for transporting the
chemicals are very high, the weight of the crude wood spirit
and that of the crude calcium acetate being very likely scarcely
10 per cent, of the weight of the wood used. Besides working
up the calcium acetate for acetone has also to be taken into
consideration.
Since calcium acetate aiid sodium acetate are the technically
most important salts of acetic acid their preparation will be
somewhat fully described.
Preparation of calcium acetate. — For the neutralization of the
crude wood vinegar freed by distillation from wood spirit,
burnt and slaked lime is generally used, though as acetic acid
is a strong acid and can with ease displace carbonic acid from
salts, lime stone i. e. carbonate of lime may also be employed
for the purpose. The limestone must, however, be quite pure,
TREATMENT OF THE WOOD VINEGAR. 297
especially as free as possible from organic substances, and'
neutralization has to be effected in large vessels, as the calcium
acetate solution foams very much in consequence of the escaping
carbonic acid ; this drawback is avoided with the use of burnt
lime.
The neutralized fluid should be allowed to stand several
days so that the tarry substances contained in the wood vinegar
can collect on the surface and be removed. It is of importance
to only just neutralize the wood vinegar with lime and not
use lime in excess, because then a portion of the acid tar-
products passes already into the layer of tar collecting on the
surface and can be separated together with it from the calcium
acetate solution. When this has been done the solution is
mixed with 1 J to 1 J per cent, by volume of crude hydrochloric
acid and allowed to rest. The mass which thereby separates
on the surface consist chiefly of those substances in which creo-
sote occurs. It is collected and worked by itself for creosote.
The clear calcium acetate solution is evaporated in shallow
iron pans, which may be heated by the fire gases escaping
from the retort ovens. The tarry substances which separate
during evaporation in the form of pitch-like masses are care-
fully removed. Evaporation- is continued till the specific
gravity of the hot fluid is = 1.116 or 15° Be. When this
point has been reached, the boiling hot, highly concentrated
solution of the salt commences, on being further evaporated,
to separate crusts of salt. These crusts are removed and com-
pletely dried in smaller pans, whilst being constantly stirred.
In plants having power 'at their disposal, evaporation and
drying can be effected in one vessel, a circular pan in which
a stirrer moves uninterruptedly being used in this case.
When, as previously mentioned, the fire gases escaping from
the retort ovens are utilized for heating the evaporating pans,
there is no danger of the decomposition of the calcium acetate
by overheating of the salt mass, since by simply pushing a
slide the fire gases can be immediately given another direc-
tion. Overheating of the mass in drying is indicated by the
298 MANUFACTURE OF VINEGAR.
•characteristic odor of acetone. ' While calcium acetate is de-
com posed at between 426° and 428° F., acetone being evolved
and carbonate of lime remaining behind, the process com-
mences already at about 302° F.
It is most expedient to evaporate the calcium acetate solu-
tion only to a doughy mass which can be lifted out with a
shovel, and to effect the complete drying of this mass upon
iron plates forming the bottom of a flat arch and heated by
the fire gases escaping from the retort ovens. The tempera-
ture in the arches should be so regulated as to never exceed
302° F., but the crude salt should be exposed for several hours
to this temperature, because by long-continued heating at a
lower temperature a great many more tarry substances are
destroyed and volatilized than by stronger heating for a
shorter tim.e, which besides is accompanied by the danger of
decomposing a portion of the calcium acetate.
In heating the evaporating pans by a direct fire there is
always danger of overheating. Besides, the pans soon become
covered with a crust of calcium acetate, which renders the
transmission of the heat very difficult. For this reason round
or square pans heated by steam are as a rule used in large
modern plants. These pans have a double bottom into which
steam is conducted. Copper pans are preferable to iron ones,
since the acetate burning to the pans can be more readily re-
moved from copper. The use of such pans is, however, only
advisable for the evaporation of solutions already concen-
trated. For dilute solutions it is better to first concentrate
them in multiple evaporators in vacuum, F. H. Meyer's sys-
tem, German patent 193,382, previously referred to. In this
apparatus the solution is brought to 30 to 35 per cent, dry
substance and then transferred to the open pans mentioned
-above.
To avoid the tedious and disagreeable work of completely
evaporating and drying the calcium acetate in pans, M. Klar
has devised a continuously-working apparatus. It consists of
a. revolving hollow iron cylinder heated inside by steam or
TREATMENT OF THE WOOD VINEGAR. 299
waste gases. In revolving, the heated cylinder dips into the
•calcium acetate solution and becomes coated with a thin layer
of it, which dries quickly and is removed by scrapers. With
this apparatus gray acetate with 80 per cent, can be prepared
from acetate solution in one uninterrupted operation. Since,
however, the acetate is obtained in the form of a fine, light
powder, Klar carries on the drying process only far enough to
-obtain a product which is no longer sticky. This is dried in
a closed band heated by warm air, and at the same time
granulated.
The crude gray acetate thus obtained forms a gray odorless
mass. It consists of about 80 per cent, calcium acetate and
is a commercial article. In addition to calcium acetate it
contains calcium butyrate and propionate, as well as certain
empyreumatic bodies, and the acetic acid prepared from it
also contains butyric acid, propionic acid, etc. Hence this
acetic acid cannot be directly used for comestible purposes,
but is suitable for most technical uses. Calcium acetate is
largely used in print works and in dyeing, and also serves for
the preparation of acetone.
Preparation of Sodium Acetate. — Sodium acetate in a pure state
can be obtained according to several methods which, however,
differ from each other only in a certain stage of the operation,
the latter beginning always with the neutralization of the wood
vinegar freed from wood spirit. For this purpose sodium car-
bonate is preferably used, as crystallized soda, in consequence
of its content of water of crystallization, entails high charges
for transport.
Neutralization is effected by adding gradually the sodium
carbonate to the wood vinegar, as otherwise the escaping car-
bonic acid causes strong foaming and the fluid would run over
even with the use of a very tall vessel. Enough soda should
be added to the wood vinegar for the fluid to contain a very
small excess of sodium carbonate, because the sodium acetate
crystallizes with greater ease from a slightly alkaline fluid
than from a perfectly neutral one.
300 MANUFACTURE OF VINEGAR.
After adding the soda the fluid is allowed to rest for one
day for the separation of the tarry substances, and after remov-
ing the latter, the fluid is evaporated in shallow pans, which
are heated by the fire gases escaping from the retort ovens or
over an open fire. Evaporation is continued until the hot
fluid shows a specific gravity of 1.23 = 27° Be. The fluid is
then emptied into the crystallizing boxes, in which, after the
separation of the crystals of crude sodium acetate, remains the
mother-lye. The latter is returned to the evaporating pans.
The mother-lye is at the ordinary temperature a saturated
solution of sodium acetate, mixed, however, with the bulk of
sodium butyrate and sodium propionate contained in the
wood vinegar used. When these mother-lyes are continually
returned to the evaporating pans, the quantity of sodium buty-
rate and sodium propionate finally accumulates to such an
extent that in cooling the fluid evaporated to specific gravity
1.23, a granular crystal mass is no longer formed, but a soft
paste is separated. In this case the fluid in the pans has to be
entirely removed and treated as will be described later on.
It is of great importance as regards the purification of the
crude crystals to cool the evaporated fluid very rapidly in
order to obtain small crystals which retain but little mother-
lye. For this purpose oblong sheet-iron crystallizing pans
with slightly inclined sides are used. When the contents of
the crystallizing vessels have cooled to the ordinary tempera-
ture, they form a dark-colored paste of crystals which holds
the entire quantity of mother-lye.
To separate the crystals as completely as possible from
mother-lye one of two methods may be adopted, namely,
draining and washing, or by means of a centrifugal. Accord-
ing to the first method the crystallizing pans are placed in a
slanting position, whereby a great portion of the mother-lye
runs off and is returned to the evaporating pans. The mass of
crystals is brought into a vat with a false bottom, below which
is a discharge pipe. When the vat is filled with the mass of
crystals, water is poured in. The water dissolves a certain
TREATMENT OF THE WOOD VINEGAR.
301
Fig. 81
quantity of sodium acetate, and this solution in sinking down
displaces the mother-lye, a salt of a quite pale brown color
remaining behind.
However, as this method requires considerable time and
leaves the salt in a wet state, it is preferable to free the salt
from the mother-lye by means of a centrifugal, it being then
obtained perfectly dry. In distilling this salt with sulphuric
acid, an acid is obtained which to be sure is still empyreu-
matic, but which can be directly used for many manufacturing
purposes.
To obtain pure sodium acetate, the crude salt is dissolved in
water by means of steam so that a nearly boiling solution of
15° Be. is obtained, which is then filtered in a hot state through
animal charcoal in a filter which can be heated. The filter,
Fig. 81, consists of an iron cylinder, C, 10 to 13 feet high, en-
closed in a somewhat larger iron cylin-
der C. The inner cylinder is filled with
granulated animal charcoal, and steam
circulates in the space between the two
cylinders. To avoid the necessity of
charging a filter in too short a time
with fresh animal charcoal, four to six
of such filters are arranged in a battery.
When the first filter becomes ineffec-
tual, it is emptied, charged with fresh
animal charcoal and placed as the last
in the battery. Filtration of the hot
solution should progress only with such
rapidity that a colorless fluid runs off
from the last filter. This fluid when
rapidly cooled deposits small colorless
crystals which after having been freed from mother-lye by
means of a centrifugal and dried, pass in commerce as pure so-
dium acetate.
However, even to the salt purified in this manner adhere
certain, though only very small quantities, of sodium butyrate
302 MANUFACTURE OF VINEGAR.
and sodium propionate, and the acetic acid prepared from it
contains the corresponding quantities of butyric and propionic
acids. The odor of butyric acid is, however, so penetrating
that its presence in the acetic acid can be immediately detec-
ted by the sense of smell. By rubbing such impure acetic
acid upon the palm of the hand, the disagreeable odor of
butyric acid becomes conspicuous as soon as the more volatile
acetic acid has evaporated.
Hence for the preparation of perfectly pure acetic acid such
as is demanded for comestible purposes, a different course ha&
to be adopted which to be sure is somewhat more troublesome
than the previously described process but surely accomplishes
Fig. 82.
the object in view. It is based upon the fact that sodium ace-
tate may be heated to nearly 752° F. without suffering decom-
position, while sodium butyrate and sodium propionate are
decomposed and the tarry substances volatilized at a considera-
bly lower temperature.
The salt obtained from the first crystallization purified by
washing or by means of a centrifugal is used for this purpose.
It is melted in a cast-iron boiler, Fig. 82, about 5 feet in di-
ameter and about 8 inches deep, equipped with a stirrer
furnished with two curved blades. The salt at first melts
very rapidly in its water of crystallization, yielding the latter
with heavy foaming, so that finally a crumbly yellow-brown
TREATMENT OF THE WOOD VINEGAR. 303
mass remains behind which constantly emits tar vapors. The
fire under the kettle is kept up uniformly for about one hour
and is only sufficiently increased for the mass to melt when
no more vapors rise from the latter. The melted mass is lifted
from the kettle with shallow shovels and poured upon sheet-
iron plates where it congeals to a gray-white cake full of small
blisters.
When the operation above described has been correctly
carried on, the congealed melt contains sodium acetate, car-
bonaceous matter and such a small quantity of tarry substances
that, when brought into water, it yields a solution of a very
pale yellow color. If the heat has been raised too high, a
portion of the sodium acetate is also decomposed, acetone being
evolved and soda remaining behind. It may sometimes
happen that the whole mass takes fire ; the latter is extin-
guished by throwing crude crystals upon it.
The melted mass is dissolved in boiling water. The boiling
hot solution, which is colored dark by suspended particles of"
carbonaceous matter, is filtered through a filter filled with
sand and heated by steam, and then quickly cooled in order
to obtain small crystals which after treatment in a centrifugal
should be perfectly colorless. Since it is next to impossible
to heat every portion of the melting mass exactly so long
until all the coloring matters have been destroyed, solutions-
of a yellow color yielding yellow crystals are sometimes ob-
tained. By redissolving these yellow crystals in boiling water
and passing the solution through an animal charcoal filter
entirely colorless crystals are also obtained.
The sodium acetate thus obtained forms colorless crystals of
the composition NaC2H302-f 3H2O, which effloresce on exposure
to the air. At the ordinary temperature the salt dissolves in
about three times its quantity by weight of water. With an
increasing temperature, its solubility becomes much greater
and the saturated solution, boiling at 255.2° F., contains for
100 parts of water 208 parts of the salt. When heated the
salt melts at 172.4° F., yields its water of crystallization, and;
304 MANUFACTURE OF VINEGAR.
•congeals. It then melts again only at 606.2° F., and in a
melted state can be heated to between 716° and 752° F., with-
out suffering decomposition. When heated above this tem-
perature it evolves acetone, becomes readily ignited in the air,
and finally leaves a residue consisting of sodium carbonate
and coal.
The mother-lyes which in the course of time accumulate in
the pan and finally no longer crystallize are evaporated to the
•consistency of syrup and stored in vats. In a few weeks they
are separated from the crude salt and further worked. In
most plants this is done by evaporating the lye to dry ness and
incinerating the residue whereby calcium carbonate mixed
with coal remains behind, which is again used for the neutra-
lization of wood vinegar.
When 100 parts of the strongly inspissated lye are mixed
with 20 parts by weight of strong alcohol and 70 parts by
by weight of sulphuric acid are gradually added, a black, oily
layer separates on the surface of the fluid. This layer con-
sists of crude acetic, butyric and propionic ethers besides
small quantities of formic, valeric and capric ethers and from
these raw products all the mentioned acids can be prepared in
a pure state.
The purification of the sodium acetate by filtration through
animal charcoal is at present only seldom practised, the melt-
ing process being more simple to manipulate and yielding
better results.
Sodium acetate can also be prepared from calcium acetate
by transposition with a soluble sodium salt, the acid of which
forms with the calcium an insoluble combination. By mixing,
for instance, a solution of calcium acetate with one of sodium
sulphate (Glauber's salt), insoluble calcium sulphate is formed
and sodium acetate remains in solution. The calcium
sulphate (gypsum) is, however, not entirely insoluble and it is
therefore far better to effect transposition with the use of
sodium carbonate whereby calcium carbonate dissolving with
greater difficulty is formed.
TREATMENT OF THE WOOD VINEGAR. 305
Preparation of acetic acid from the acetates. — For the prepara-
tion of acetic acid in a free state the calcium acetate is decom-
posed by an acid and the acetic acid separated by distillation.
Hydrochloric acid was formerly generally used for the purpose?
it having the advantage of forming with the calcium, calcium
chloride which is readily soluble in water and in distilling pre-
sents fewer obstacles than the calcium sulphate (gypsum)
formed by the decomposition of the acetate with sulphuric acid,
but the latter is now almost exclusively used, this process being
preferable because, on the one hand, the apparatus required
for it has been greatly improved and, on the other, the gray
acetate with 80 to 82 per cent, acetate furnishes a better and
purer raw material. The further manipulation of the acetic
acid is then effected in a distilling column which renders it
possible to prepare at once from the crude acid, perfectly pure
acetid acid and also glacial acetic acid.
Hydrochloric Acid Process. — The decomposition of the cal-
cium acetate may be effected by aqueous, as well as by gaseous
hydrochloric acid. As previously mentioned, the hydrochloric
acid process has been generally abandoned, it being now in
use only where brown acetate with about 67 per cent, acetate
is to be worked. This product being far more impure is for
that reason not suitable for decomposition with sulphuric acid,
because the resinous and tarry substances which are present
in abundance exert a reducing action upon the sulphuric
acid.
The quantity of calcium acetate to be treated is brought in-
to a vat and after pouring the requisite quantity of hydro-
chloric acid over it, the mass is thoroughly stirred and then
allowed to rest for 24 hours. During this time it liquifies and
tarry substances separate on the surface. These substances
have to be carefully removed before bringing the contents of
the vat into a still.
The quantity of hydrochloric acid required for the decom-
position of the calcium acetate could ver}^ readily be accurately
determined if the combinations contained in the salt, which are
20
306 MANUFACTURE OF VINEGAR.
decomposed by hydrochloric acid, were exactly known. But
this can only be learned from a complete analysis of a sample
of the calcium acetate. However, in the practice this trouble-
some work is generally avoided and the required quantity of
hydrochloric acid is determined by pulverizing a portion of
the calcium acetate and, after adding to every 100 grammes of
salt 90 or 95 grammes of hydrochloric acid, distilling the mass
in a small glass still. The distillate is tested for the presence
of hydrochloric acid by the addition of solution of nitrate of
silver. If after a short time the fluid commences to opalesce
or a caseous precipitate is formed in it, hydrochloric acid is
present.
A content of hydrochloric acid renders the acetic acid un-
suitable for many purposes, and, hence, the use of a small ex-
cess of calcium acetate is advisable. When the operation is
carefully conducted and especially too rapid distillation con-
nected with squirting of the mass avoided, the acetic acid then
obtained contains only traces of hydrochloric acid, and can be
freed from them by rectification over some calcium acetate.
With the use of crude hydrochloric acid of 1.16 specific gravity,
an acid is obtained from the calcium acetate which contains
between 47 and 50 per cent of acetic anhydride, and possesses
a yellowish color and a slightly empyreumatic odor and taste.
Distillation is effected in a copper still which is protected
from the direct action of the fire by an iron shell. The worm
may be made of lead and should below be furnished with a
U-shaped piece which, when distillation begins, becomes
immediately filled with acetic acid and prevents the entrance
of air into the worm. By thoroughly washing the worm with
water after each distillation it is not attacked by the acetic
acid, or only so slightly that the quantity of lead which by
these means reaches the acetic acid is insignificant in a product
intended for technical purposes.
If rectification of the acetic acid is effected over potassium
dichromate instead of over calcium acetate, an acid is to be
sure obtained which contains no hydrochloric acid and is
TREATMENT OF THE WOOD VINEGAR. 307
colorless, but has still a very perceptible empyreumatic taste.
Since potassium dichromate, 1 to 1J Ibs. of which -has to be
used for every 100 Ibs. of acid, is quite expensive, its use for
the preparation of acetic acid from calcium acetate cannot be
recommended, since the resulting acetic acid, on account of
its empyreumatic taste, cannot be used for comestible purposes.
The decomposition of the acetate can, as previously men-
tioned, be also effected with gaseous hydrochloric acid, the
advantage of this process being that concentrated acetic acid
is at once obtained. The operation is carried on by bringing
a sufficient quantity of finely pulverized calcium acetate into
vertical retorts which can be heated from the outside. Gaseous
hydrochloric acid, previously heated, is conducted through
the retorts and the escaping vapors of acetic acid are condensed.
However, with the use of this process, the crude acetic acid
obtained is very much contaminated with hydrochloric acid,
especially towards the end of the operation when the greater
portion of the calcium acetate has already been decomposed.
Sulphuric acid process. — At present the decomposition of the
calcium acetate is, as previously mentioned, almost exclusively
effected with sulphuric acid, insoluble calcium sulphate being
separated which forms a viscid, pasty mass, and finally
becomes solid. In order to attain complete decomposition the
mass has to be thoroughly shaken, a work which requires
considerable expenditure of power. Gypsum is a bad conduc-
tor of heat, and although heat is liberated during the progress
of the reaction itself whereby a portion of the acetic acid
evaporates, to obtain the last remnants of acetic acid which
are tenaciously held by the gypsum, is connected with diffi-
culties. With the use of higher temperatures than attainable
with direct firing the mass can to be sure be so far heated that
all the acetic acid finally passes over, but a heavy reduction
of sulphuric acid then also takes place. For this reason the
more modern processes work with the use of a vacuum and
steam for heating, far better yields and a purer acid being
thereby obtained.
308 MANUFACTURE OF VINEGAR.
Below a description of an older plant arranged according
to Biihler for the sulphuric acid process will first be given,
IFig. 83 a to d.
:From the lime kiln the roasted calcium acetate is directly
'thrown through the funnel o into the storage receptacle p,
which serves also as a measuring vessel for one charge. De-
•composition is effected in shallow cast-iron pans a, equipped
•with stirrers, and the covers of which are furnished with man-
liole, exhaust pipe, safety valve and inlet for acid. From the
reservoir I, concentrated sulphuric acid is allowed to run in
through a lead pipe conduit. For 100 parts of calcium acetate
GO parts of sulphuric acid are, as a rule, allowed. Decompo-
sition at first progresses by itself and about J of the acetic acid
•present distils over. Slight heating then becomes necessary.
'The stirrers must be kept constantly in operation. The acetic
acid vapors pass from a into a clay condenser c?, and run
through c into a storage-reservoir d of clay ; all other mater-
ials would in a short time be destroyed.
The crude acid still contains impurities, such as sulphurous
acid, traces of sulphuretted hydrogen, etc., which by its par-
tial decomposition the sulphuric acid has yielded together with
the tar of the crude acid ; besides it contains resinous and tarry
substances and coloring matter which are removed by rectifi-
•cation over potassium chromate.
For this purpose acid is allowed to run from the reservoir d
•into the still, and after the addition of water is rectified. The
-apparatuses used at the present time at once furnish a product
of 09 per cent, and more. In the illustration, e is the column,
/a pipe condenser with return pipe, and g a condenser for the
acid-. For the preparation of vinegar for comestible purposes
the acid is again rectified in the still h, with the addition of po-
tassium chromate, a perfectly clear product without detrimen-
tal odor being obtained from the clay condenser i. The still
h may be of enameled cast iron and is provided with a heating
jacket. The movement of the fluid is effected by means of
-compressed air and the munte-jus m, d, and L
TREATMENT OF THE WOOD VINEGAR. 309^
FIG. 83.
1. Engine-house ; 2. Fire passage; 3. Boiler-house; 4. Lime Kiln ; 5. Storage-
for calcium acetate ; 6. Lime kiln.
The preparation of glacial acetic acid is effected by decom-
posing the sodium salt by means of sulphuric acid. By the
introduction of sodium sulphate (Glauber's salt) into the calr-
310 MANUFACTURE OF VINEGAE.
cium acetate solution, the latter is converted into sodium ace-
tate solution, saturation being attained when a clear filtered
sample no longer yields a precipitate of calcium sulphate on
the further addition of sodium sulphate.
The solution is drawn off from the sediment and the latter
lixiviated until exhausted. Concentration to a specific gravity
of 1.3 is effected in directly heated boilers. The excess of so-
dium sulphate crystallizing out is brought into perforated bas-
kets from which the mother-lye again runs into the boilers.
It is then allowed to settle and clarify for 8 to 10 hours when
it is drawn of. The sediment consists of admixtures of the
raw materials which have become insoluble, t.ar and other con-
stituents. In coolers or crystallizing vessels the greater portion
of the sodium acetate is deposited in three to five days, and
the crude salt is frequently directly sold. The mother-lye is
drawn off, is again concentrated, crystallized, and so on until
exhausted. The residue is then evaporated and heated to a
red heat in order to obtain sodium carbonate, or heated to
melting to remove the tar, the sodium acetate thus obtained
being separated from the coal by dissolving in water. The
tarry admixtures, tar oils of various kinds, adhere with great
tenacity to all the products of distillation, even the crystals
first obtained being not perfectly pure. They are purified by
again dissolving them, concentrating the solution and crystal-
lizing. The crystals are then melted in an iron boiler in the
water of crystallization and, after evaporating the latter, heated
until melted the second time. The salt is now anhydrous and
great care is required to prevent it from burning. It is then de-
composed by concentrated sulphuric acid in glass retorts in a
sand bath. For 92 parts salt 98 parts sulphuric acid are used.
From the distillate the glacial acetic acid separates, on cooling,
in the form of crystals.
At the present time the vacuum process is generally employed,
it yielding at once a highly concentrated acetic acid. The
apparatus used for this purpose as constructed by the firm of
J. H. Meyer, at Hanover-Hainholz, Germany, consists of cast
TREATMENT OF THE WOOD VINEGAR. 311
iron boilers which according to the size of the plant, have
a capacity of from 240 to 3300 Ibs. of calcium acetate. Each
boiler is equipped with a stirrer. The charge is introduced
through a manhole in the cover and the boiler is emptied, as
a rule, through an aperture in the bottom through which the
gypsum can be pushed out by the stirrer.
When the gray acetate is uniformly distributed in the boiler,
the calculated quantity of sulphuric acid is allowed to run in.
Decomposition then commences, so much heat being thereby
liberated that a large portion of the acetic acid distils over
without the use of a vacuum. When distillation slackens,
vacuum is applied and distillation carried on to the end, the
bottom of the boiler being at the same time heated by steam.
From 220 Ibs. of acetate and 132 Ibs. of sulphuric acid, 165
Ibs. of crude acetic acid with 80 per cent, acid are under
normal conditions obtained. The crude acid contains small
quantities — 0.005 to 0.05 per cent. — of sulphurous acid.
For the preparation of acid intended for technical purposes
only, the crude acetic acid is further purified by subjecting it
once more to distillation in more simple copper stills generally
provided with a worm silvered inside. For the preparation
of high-graded, entirely pure acid and of vinegar essence suit-
able for comestible purposes, the crude acetic acid is decom-
posed in a column apparatus.
In order to finally prepare chemically pure vinegar (99 to
100 per cent.) from that fraction which contains 96 to 98.5
per cent, of acetic acid, the distillate is further treated with
potassium permanganate for the oxidation of contaminating
admixtures still present, and then distilled from the " fine acid
apparatus ". This apparatus has a still of copper, but a head
and worm of silver to prevent contamination by copper acetate.
Generally the first and last runnings only are removed, the
middle running being perfectly pure acetic acid.
Glacial acetic acid, of the highest concentration, acidum
aceticum glaciale, can also be prepared as follows : Freshly de-
hydrated sodium acetate is distilled with concentrated sulphuric
312 MANUFACTURE OF VINEGAR.
acid, or water is withdrawn from high-graded acetic acid by
rectifying it over fused calcium chloride.
In the first case 9J parts by weight of sulphuric acid are
slowly poured upon 100 parts by weight of sodium acetate free
from water to prevent the escape, without being condensed,
of a portion of the acetic acid vapors' evolving with great vigor.
Heat is applied only after the introduction of the total quan-
tity of sulphuric acid, and the first four-fifths of the distillate
are caught by themselves, because the last portion of it has an
empyreumatic odor, while the first portions contain only sul-
phurous acid which is removed by rectifying the acid over
potassium dichromate.
According to the second process glacial acetic acid may
even be prepared from 50 per cent, acetic acid by distilling
the latter with fused (anhydrous) calcium chloride. The gla-
cial acetic acid thus obtained contains considerable quantities
of hydrochloric acid. It is freed from it by rectification over
anhydrous sodium acetate, a still with a silver head and worm
being used, and the precaution taken not to cool the worm too
much as otherwise the acetic acid might crystallize in it.
The calcium chloride containing water which remains be-
hind is dehydrated by heating in shallow vessels and then
heated to red hot fusion, this being necessary for the destruc-
tion of all organic substances present. The preparation of gla-
cial acetic acid should, if feasible, be undertaken in the cool
season of the year. The distillate running from the condenser
is collected in stone-ware pots which are covered and exposed
to a low temperature, the greater portion of the fluid congeal-
ing thereby to a crystalline mass. The position of the pots is
then changed so that the portion which has remained fluid can
run off ; this is added to the next rectification over calcium
chloride. By placing the pots in a heated room the anhydrous
acetic acid is melted and then filled in bottles. Glacial acetic
acid thus prepared will stand the test usually applied in com-
merce. It consists in bringing the acetic acid together with
lemon oil. Anhydrous acetic anhydride dissolves lemon oil
ACETATES AND THEIR PREPARATION. 313-
in every proportion, but in the presence of even a very small
quantity of water solubility decreases in a high degree.
Another commercial test consists in compounding the acetic
acid as well as the glacial acetic acid and the diluted acid,,
with solution of potassium permanganate till it appears rasp-
berry red ; pure acid remains permanently red, while if em-
pyreumatic substances are present, t-he red color disappears-
rapidly.
However, an acid free from empyreumatic substances, but
containing sulphurous acid, may also exert a discoloring effect
upon the potassium permanganate solution. It is, therefore,
advisable before making the test for empyreumatic substances-
to test the acid for sulphurous acid. This is done by com-
pounding the acid with potassium permanganate, allowing it
to stand until discolored and then adding barium chloride
solution ; sulphurous acid, if present, has now been changed
to sulphuric acid, the fluid is rendered turbid by barium chlo-
ride, and after standing for some time a white precipitate is-
separated. Such acid should again be rectified.
CHAPTER XXV.
ACETATES AND THEIR PREPARATION.
The acetates, particularly those of calcium, potassium, so-
dium, barium, lead, copper, aluminium and iron are exten-
sively used in the industries and are produced in large quan-
tities. Calcium acetate and sodium acetate are as previously
explained initial products for the preparation of acetic acid and
acetone, for which barium acetate may also be used.
All the acetates are more or less readily soluble in water.
By the addition of sulphuric acid the acetic acid is liberated
without perceptible evolution of gas. The solutions of the
acetates are precipitated by nitrate of silver ; the precipitate
,314 MANUFACTURE OF VINEGAR.
of acetate of silver is crystalline and soluble in 100 parts of
water.
When mixed with equal parts of alcohol and double the
weight of sulphuric acid, acetic ether is evolved, which is
recognized by its characteristic fruit-like odor.
Ferric chloride imparts to the very dilute aqueous solution
an intense bright-red color.
From other similar combinations the acetates are distin-
guished by yielding acetone when subjected to destructive
distillation, and marsh-gas when distilled with caustic potash.
When heated with arsenic the very peculiar and disagreeable
odor of cacodyl is evolved.
Potassium acetate, KC2H3Or Dry potassium acetate forms a
snow-white, somewhat lustrous, not very heavy, laminate or
foliated crystalline, pulverulent mass. It has a warming,
slightly pungent salty taste, and its odor is not acid. It turns
red litmus paper slightly blue, but does not redden phenol-
phthalein. It rapidly absorbs moisture from the air and deli-
quesces. At the ordinary temperature it is soluble in about
J part of water or 1 J parts of alcohol. Boiling water dissolves
eight times the quantity of its weight of potassium acetate,
such a solution boiling at 329° F. The dry salt when tritur-
ated with iodine yields a blue mixture, the latter giving with
water a brown solution.
When heated, potassium acetate melts, without suffering
decomposition, at 557.3° F., and on cooling congeals to a
radiated crystalline mass. On heating to 780° F. acetic acid
escapes and, after incineration, potassium carbonate colored
gray by coal remains behind.
By adding ferric chloride solution to potassium acetate
solution, a liquid of a blood-red color is obtained which besides
potassium chloride contains ferric acetate. By heating the
solution to boiling a red precipitate of basic ferric acetate is
separated, the supernatant liquid becoming colorless, provided
sufficient potassium acetate was present and the ferric chloride
solution did not contain too much hydrochloric acid.
ACETATES AND THEIR PREPARATION. 315
Potassium acetate is prepared by bringing into a vat or boiler
purified wood vinegar and adding potash in small quantities.
The liquid foams, and the tarry substances that separate on
the surface are removed by means of a perforated ladle. The
addition of potash is continued till the solution is neutralized
when it is allowed to settle. The clarified solution is then
evaporated todryness in an iron pan, the tarry substances ap-
pearing during this operation being removed. When the
product is dry, the fire is increased and the salt melted in the
water of crystallization. When the mass has acquired a but-
yraceous appearance, the fire is withdrawn and the salt allowed
to cool, otherwise it would change to potassium carbonate.
When cold the melt is again dissolved in water, filtered and
further worked.
Another method of producing potassium acetate is by decom-
posing normal acetate of lead (sugar of lead) with pure
carbonate or sulphate of potassium. To detect the presence
of lead it should be tested with sulphuretted hydrogen, which
in the presence of this metal produces a slightly brown pre-
cipitate. To obtain a pure product the decanted liquid is
treated with sulphuretted hydrogen, and, after separating
from the precipitate and adding a small quantity of acetic acid,
is evaporated in a stone-ware vessel.
Chemically pure potassium acetate is prepared by bringing
400 parts of 30 per cent, acetic acid into an acid-proof enameled
boiler and gradually introducing 138 parts of pure potassium
carbonate or 200 parts of potassium bicarbonate until the
solution is finally neutral or shows but a slight alkaline reac-
tion. Solution has finally to be assisted by heating.
The solution is then acetified with acetic acid and evaporated
to a small volume on a steam-bath or better over an open fire.
Some acetic acid is next added and the mass is then evaporated
till it is dust-dr}', being constantly stirred with a porcelain
spatula during this operation. The resulting dust-dry, crumbly
powder is brought into dry hot vessels, which are immediately
closed with corks and the latter are coated with paraffine.
316 MANUFACTURE OF VINEGAR.
Too strong heating should be avoided, otherwise decomposition-
takes place, acetone being formed.
Pure potassium acetate should dissolve in two parts of water
and the solution must not redden phenol phthalein, otherwise
it contains more than traces of potassium carbonate. A 5 per
cent, aqueous solution should not be rendered turbid or colored
(presence of metals) by hydrogen sulphide, and not altered by
barium nitrate after the addition of dilute nitric acid, other-
wise it is contaminated with sulphate.
Potassium acid acetate or potassium diacetate, KC2H302C2H402,
is formed by evaporating a solution of the neutral salt in excess
of acetic acid ; it crystallizes by slow evaporation in long, flat-
tened prisms. It is very deliquescent and decomposes at 392°
F., giving off crystallizable acetic acid.
Sodium acetate, NaC2H302. — The manner of preparing this
salt in the manufacture of wood vinegar has already been de-
scribed. It can be obtained in a manner similar to that of the
potassium salt by dissolving carbonate of soda in acetic acid,
evaporating the solution, and setting the liquid aside to crys-
tallize. The crystals form large, colorless, oblique rhombic
prisms. Their composition is NaC2H302 -f 3H20 ; they are
soluble in 3 parts of cold, in a less quantity of boiling, water,
and in 5 of alcohol.
The taste of sodium acetate is cooling and saline. When
exposed to dry air it loses its three equivalents of water, but
regains them in a moist atmosphere. After being melted it is
deliquescent and takes up 7 equivalents of water. It becomes
a liquid, supersaturated solution which crystallizes, with evolu-
tion of heat, immediately after a fragment of dry or crystallized
sodium acetate is thrown into it.
Sodium acetate is used for the preparation of acetic acid,
acetic ether, and in medicine. It has also been recommended
for the preservation of animal and vegetable tissues, it being
used in the form of a powder in place of common salt.
Ammonium acetate, neutral acetate of ammonia, NH4C8H302.
-This substance is obtained by neutralizing acetic acid with
ACETATES AND THEIR PREPARATION. 317
carbonate of ammonia, or better, by saturating glacial acetic
acid with dry ammonia gas. It is very difficult to obtain in
the crystalline form on account of its aqueous solution giving
off ammonia when evaporated, thus becoming converted into
the acid salt. When subjected to dry distillation ammonia gas
escapes first; above 330° F. there is formed, besides water,
chiefly acetamide (C2H5NO), a white crystalline body which is
also formed, besides alcohol, on heating acetic ether with liquid
ammonia in a closed vessel to about 266° F.
In medicine ammonium acetate has long been used as a
diaphoretic.
Calcium acetate, Ca (C2H302)2. The preparation of calcium
acetate has already been described under wood vinegar.
The crystals of the pure salt form white acicular prisms
which effloresce in the air and are soluble in water and in al-
cohol ; they have a bitter, salty taste. They are decomposed
by heat into acetone and calcium carbonate. A mixture of
this salt and of potassium oxalate gives, on heating, propylene
(C3H6), while a mixture of carbonates remains behind. By
destructive distillation of equal equivalents of acetate and ben-
zoate of calcium, acetophenone (C8H80) is obtained, which by
treatment with nitric acid is converted into nitro-acetophenone
(C8H7N03). By heating the latter with zinc-dust and soda-
lime, Emmerling and Engler claim to have obtained artificial
indigo-blue. But the quantity of the latter thus obtained is
always very small, and it appears to be very difficult to ascer-
tain the precise condition under which the transformation
takes place.
Barium acetate, (C2H302)2Ba+l J H20, finds at present exten-
sive application in the industries, especially in the preparation
of acetone, as it is decomposed at a lower temperature than
calcium acetate, and leaves a residue — barium carbonate —
which can again be used for the preparation of the acetate,
while the residue from calcium carbonate is of no value.
Barium acetate is prepared from the mineral witheritefin a
manner similar to calcium acetate, the only difference being as
318 MANUFACTURE OF VINEGAR.
to whether the witherite is used in lumps or in the form of pow-
der. In the first case the wood vinegar is allowed to act for
some time upon the witherite by allowing it to run over the
mineral, or after filling several vessels (a battery) with the
witherite, dissolving it by conducting gaseous acetic acid
through the vessels. Provisions must of course be made for
carrying off the carbonic acid that is evolved.
The use of witherite in the form of powder instead of in
lumps, is more advantageous ; but as the powder, in conse-
quence of its own specific gravity has a tendency to settle on the
bottom, a powerful mixing and stirring apparatus has to be
provided. When used in the form of a fine powder the with-
erite must be sifted upon the surface of the fluid containing
the acetic acid, as it readily forms lumps, which drop to the
bottom and are dissolved only with difficulty. As the evolu-
tion of carbonic acid is by no means tumultuous the vessels
used can be kept quite full.
The barium acetate solution obtained by either method may
be neutral but should never show an acid reaction. It is
passed through a filter press and then evaporated in the usual
manner, care being taken not to let it boil up ; for this reason
it is advisable to effect evaporation in a vacuum.
Crystallization is effected in the customary manner. The
resulting crystals are freed from the mother-lye and, if not
colored too dark (by empyreumatic substances), can be imme-
diately used. Purification is effected by recrystallization, dis-
solving the crystals in water, by treatment with animal char-
coal, china clay or bole, but best by a small addition of sulphuric
acid, whereby barium sulphate is formed which falls to the
bottom, carrying with it the empyreumatic substances. After
settling the clear liquor is drawn off or the mixture is passed
through a filter-press. The clear solution is evaporated in
the customary manner and, after crystallization, the mother-
lye is separated and the crystals, if necessary, are once more
purified. The mother-lyes are utilized by adding them to the
solutions first obtained. If they contain too many foreign
ACETATES AND THEIR PREPARATION. 319'
substances, they are evaporated to dry ness, dried, ignited and
used for solution in acetic acid.
According to another method barium acetate is prepared
by allowing equivalent quantities of barium chloride and so-
dium acetate to act upon each other. For this purpose the ade-
quate quantity of barium chloride is dissolved in water so that,
if feasible, an oversaturated solution is obtained, and to this
solution, whilst boiling vigorously, sodium acetate in fine-
crystals is gradually added. During this reaction the contents
of the boiler must constantly be kept boiling vigorously.
Decomposition progresses quite rapidly. The sodium chloride
which is separated is removed and the progress of reaction
watched by taking samples. When decomposition is complete,
the contents of the boiler are allowed to settle, and the solution
drawn off from the sediment is crystallized. The crystals are
then separated from the mother-lye and the last remnants of
the latter removed either by suction or by means of a centri-
fugal, the crystals being at the same time washed with water
and, if required, recry stall i zed from pure water. The mother-
lye always contains common salt and is again utilized for
dissolving the barium chloride.
The crystallized barium acetate obtained at the ordinary tem-
perature contains 1 molecule of water, while that crystallized
at 32° F. possesses 3 molecules of water and is amorphous with
lead acetate. On exposure to the air the crystals effloresce
and the solutions show an alkaline reaction. The salt is sol-
uble in 1.5 parts of cold, and 1.1 parts of boiling water, and
in 67 parts of boiling, and in 100 parts of cold, alcohol.
Strontium acetate. — This salt is prepared in a manner similar
to that of the preceding. The crystals obtained at 32° F. con-
tain 5 equivalents of water and those at 59° F. 1 equivalent.
With strontium nitrate it gives a double salt forming beau-
tiful crystals which contain 3 equivalents of water. On heat-
ing they first yield their water of crystallization and then
detonate, a beautiful purple flame being formed.
Magnesium acetate is prepared by dissolving magnesia alba
.320 MANUFACTURE OF VINEGAR.
or usta in acetic acid. It crystallizes with difficulty and is
readily soluble in water and spirits of wine. Only a very small
portion of the solution is decomposed by ammonia. By de-
structive distillation it yields acetic acid, while magnesia
remains behind.
Aluminium acetate. — Large quantities of aluminium acetate
-are used under the name of red mordant in dyeing, as well as
for water-proofing tissues.
Three combinations of aluminium with acetic acid are
•known, namely, normal f aluminium acetate, and two basic
acetates which according to their content of acetic acid it is
•customary to distinguish as f and £ aluminium acetates.
The normal or f aluminium acetate, A]2(CH3C02)6 is obtained
by decomposing aluminium sulphate with barium acetate, or
by dissolving aluminium hydrate in the calculated quantity
of acetic acid. It is only known in a liquid form. When
•evaporated even at below 100° F. it is decomposed to basic-
acetates of different compositions. In boiling the solution in-
soluble basic aluminium acetate is separated, the composition
of which is not yet accurately known.
The basic aluminium f acetate, A12(OH2)(CH3C02)4 is obtained
by dissolving aluminium hydrate in the calculated quantity
•of acetic acid. By evaporating the solution at below 100° F.,
it is reduced to a hornlike mass which gives a clear solution
with water, especially if the latter has been acidulated* with
acetic acid. By heating above 100° F. insoluble basic alum-
inium acetate is separated.
The bade aluminium J acetate, A12(OH4)(CH3C02)2 separates
on heating or evaporating the solutions of the abovementioned
combinations.
For the preparation of aluminium acetate in larger quantities,
aluminium hydrate is seldom used as the initial material,
-aluminium sulphate or ordinary alum being generally decom-
posed by means of a carbonate, lead acetate or calcium acetate.
The aluminium hydrate thus obtained is then dissolved in
-acetic acid.
ACETATES AND THEIR PREPARATION. 321
Aluminium sulphate is as a rule preferred to alum, it being
cheaper and can also be obtained free from iron, which is of
great importance as regards the use of aluminium acetate in
Turkey red dyeing (for alazaririe colors) as iron imparts a
brown tinge to the red.
Aluminium acetate is generally prepared by dissolving 30
parts by weight of aluminium sulphate in 80 parts of cold
water, then adding 36 parts by weight of 30 per cent, acetic
acid (of 1.041 specific gravity), and introducing into this mix-
ture, whilst stirring constantly, 13 parts by weight of whiting
triturated with 20 parts by weight of water.
Decomposition does not proceed as smoothly as would ap-
pear from the chemical equation ; it must be effected so that
heating of any kind is excluded.
By reason of the evolution of carbonic acid the decomposi-
tion-vessel must be of such a size that it is filled only two-
thirds full. It should be furnished with a stirrer to keep the
heavy whiting suspended, and thus cause uniformity of de-
composition.
The whiting should be intimately stirred together with 'the
water and in order to retain admixed impurities such as sand,
straw, etc., poured in small quantities through a fine-mesh
sieve. When all the whiting has been introduced the stirrer is
kept running for 5 or 6 hours longer, and the mass is then al-
lowed to stand quietly. Since decomposition is not completely
finished in 24 hours, it is accelerated after that time by again
running the stirrer for six hours, when the mixture is brought
into a filter-press and the heavy solution collected by itself.
The press-cakes are thoroughly washed and the wash- water is
used for dissolving fresh portions of aluminium sulphate.
The cakes remaining in the frame of the filter-press may, if
pure white, be dried and sold as gypsum ; otherwise they can
be utilized as fertilizer.
In place of whiting some manufacturers use sodium bicar-
bonate ; 667 parts by weight of aluminium sulphate are dis-
solved in 15000 parts by weight of warm water. Into this
21
322 MANUFACTURE OF VINEGAR.
solution are introduced very slowly and whilst constantly
stirring, 504 parts by weight of sodium bicarbonate, the bicar-
bonate product of the manufacture of ammonia-soda being
suitable for the purpose. Alumina in a gelatinous form is
precipitated. It is allowed to settle, washed free from salt
and pressed to a weight of 1750 parts. 200 parts by weight of
the gelatinous aluminium hydrate are dissolved in 150 parts
by weight of 50 per cent, acetic acid. One liter of the mordant
thus obtained contains 35.3 grammes of alumina. In place
of, sodium bicarbonate, ammonia-soda may be used in the
proportion of 1 part by weight of aluminium sulphate to 3.6
parts by weight of soda.
Many manufacturers prefer to effect the decomposition of
the aluminium sulphate with lead acetate instead of with
whiting or sodium carbonate. Since lead sulphate is insoluble
the decomposition of the aluminium sulphate solution is more
perfect. In practice it is found advantageous to employ equal
parts of aluminium sulphate and acetate of lead, or even a
rather less quantity of the latter. The aluminium sulphate
is dissolved in boiling water, and the powdered lead acetate
added to the solution. About one-tenth of crystallized carbon-
ate of soda, or a little carbonate of lime, is added to the alum
to combine with the free acid. The three following receipts
serve to indicate the proportions employed :—
I. Dissolve 100 pounds of aluminium sulphate in 50 gallons
of boiling water, and add 10 pounds of acetate of lead in fine
powder, stirring the mixture well at first, and likewise several
times during cooling.
II. Dissolve 100 pounds of aluminium sulphate in 50 gallons
of boiling water, add slowly 10 pounds of crystallized carbonate
of soda, and then stir in 50 pounds of acetate of lead in
powder.
III. Dissolve 100 pounds of aluminium sulphate in 50
gallons of boiling water, and add in small portions 6 pounds
of crystallized carbonate of soda, and then stir in 50 pounds
of acetate of lead, in powder, as before.
ACETATES AND THEIR PREPARATION. 323
The cheapest method of preparing aluminium acetate is
from calcium acetate and aluminium sulphate, the principal
condition being not to use a too tarry gray acetate as other-
wise the final product turns out too dark and can be decolor-
ized only with difficulty. Calcium acetate contains, as a rule,
a larger quantity of calcium carbonate, and this quantity has
previously to be accurately determined in order to calculate
the quantity of aluminium sulphate required. In practice
this calculation is avoided by having always on hand clear
solutions of both salts and, when an excess of one or the other
salt is found in the aluminium acetate solution, correcting it
by the addition of one or the other solution, so that a pure
aluminium acetate solution results.
As a rule 100 parts by weight of calcium acetate and 70
parts by weight of aluminium sulphate are dissolved, each by
itself, in sufficient water to obtain solutions of 5 to 6° Be.
The solutions are filtered and after bringing the separate solu-
tions into the vessels located over the precipitation vat, pre-
cipitation is effected. On account of the evolution of carbonic
acid, the vat should not be kept too full.
When a determined quantity of fluid has been consumed
and evolution of gas has ceased, a small quantity of the fluid
in the vat is filtered in a small glass cylinder, the filtrate di-
vided into two halves, one of which is tested with barium chlor-
ide solution for sulphuric acid, and the other with ammonium
oxalate or sulphuric acid for lime. If in one or the other case
a white precipitate is formed enough of one or the other clear
solution previously mentioned is added until after taking other
samples no precipitate or turbidity is formed in them ; the
aluminium acetate solution then contains only slight traces of
calcium acetate or aluminium sulphate.
The contents of the precipitation-vat are passed through a
filter-press and the residue is washed. The cakes of gypsum
are not suitable for fertilizing purposes ; by adding air-slaked
lime and ashes the)7 may be utilized for repairing roads, etc.
Manganese acetate, Mn(C2H302)2. This substance is pre-
324 MANUFACTURE OP VINEGAK.
pared by dissolving freshly precipitated mangauous carbonate
(MnC03) in heated acetic acid, evaporating the solution and
•crystallizing. The crystals are rhombic prisms, and occasion-
ally in plates of an amethystine color ; they are permanent in
the air, soluble in alcohol, and in about three times their
weight of water.
On a large scale this salt is manufncturedby precipitating a
-solution of manganous sulphate * by one of lime acetate and
.agitating the liquor to decompose the whole of the manganese
salt.
It sometimes happens that a portion of the manganese salt
is not acted upon by the acetate of lime, and in this case a
concentrated solution of acetate of lead is employed towards
the end of the process to effect complete decomposition. The
mixed precipitate of sulphate of lime and lead is filtered off,
and the filtrate evaporated and crystallized. The best acetate
of manganese is made by adding to 4 parts of manganous sul-
phate dissolved in 3 parts of water, 7 parts of crystallized
acetate of lead dissolved in 3 parts of water, agitating the solu-
tion, and drawing off the clear liquor for use.
Acetate of manganese is used in dyeing and calico-printing
to give a brown color to fabrics. Its principle of action de-
pends upon the further oxidation of the manganese.
Iron acetate. — Acetic acid combines with ferrous oxide
(FeO) as well as with ferric oxide (Fe203), but only the
ferrous acetate crystallizes in small greenish-white needles, very
prone to Oxidation, while ferric acetate is a dark, brownish
red, uncrystallizable liquid, of powerful and astringent taste.
Both salts dissolve freely in water, and are of importance for
dyeing and calico-printing.
Ferrous acetate, Fe(C2H302)2. Black mordant. For dyeing
* Manganons sulphate is prepared by mixing the dioxide (pyrolusite) with half
its weight of concentrated sulphuric acid and heating in a Hessian crucible until
no more vapors escape. The residue is dissolved in water, filtered, and allowed
to crystallize at an ordinary temperature. The solution of the salt when decom-
posed with crystallized soda gives a precipitate of manganous carbonate.
ACETATES AND THEIR PREPARATION. 325
purposes this salt is prepared by dissolving wronght-iron
turnings in wood-vinegar, care being had that some iron
remains undissolved, as otherwise the salt, on exposure to the
air, is gradually partly converted into the ferric salt. This
oxidation proceeds, however, but slowly, the empyreumatic
substances contained in the wood vinegar rendering the con-
version rather difficult. The pure salt oxidizes with great
rapidity. For commercial purposes this compound is manu-
factured as follows : Into a large wooden vat or into barrels a
quantity of iron turnings, hoops, or nails are introduced, and
hot crude wood- vinegar, freed by distillation from wood-spirit,,
is poured upon them. During the solution of the iron much
tarry matter separates, which is skimmed off, and the solution,
is frequently agitated to free it as much as possible from, the
tar. After 24 hours the solution is drawn off. The iron*
being entirely coated with tar so that it can not be again at-
tacked by the wood-vinegar, it is taken from the vat and the
tar ignited. The iron is freed from the oxide formed by
sifting and can be again used. The solution thus obtained
shows 13° or 14° Be.
The pure salt is obtained by dissolving iron in acetic acid or
by double decomposition from ferrous sulphate (14 parts) and
lead acetate (19 parts) ; and cheaper, but less pure, from
ferrous sulphate and calcium acetate.
If crude calcium acetate instead of wood-vinegar is to be used
in the preparation of this salt, a solution of the calcium acetate
of specific gravity 1.08 is mixed with half its weight of ferrous
sulphate dissolved in 2J times its weight of water. On agitat-
ing the mixture, the decomposition is rendered complete, the
clear liquor which is siphoned off after the subsidence of the
sulphate of lime showing 13° Be. It is kept in a closed barrel
in which is hung a bag containing a quantity of iron turnings..
In some factories the ferrous acetate is manufactured by de-
composing the carbonate of iron (FeCOJ with lead acetate;:
lead carbonate precipitates, and the blackish supernatant liquor
is the acetate of iron in a very pure state. It is kept from ox-
320 MANUFACTURE OF VINEGAR.
idizing by immersing in it some bright iron filings. The lead
salt formed repays the cost of the manufacture of the acetate.
Solution of ferrous acetate is used as a mordant by dyers, for
staining wood and leather and in the manufacture of ink. The
commercial article generally shows a specific gravity of 1.10
(12° B.).
On account of the avidity with which ferrous acetate absorbs
oxygen, it is of great value as a reducing agent. It is, for in-
stance, used in the preparation of aniline from nitrobenzole
and for similar reducing processes.
Neutral ferric acetate, sesquiacetate of iron, Fe(C2H302)3. —
For technical use this combination is obtained by dissolving
wrought-iron in wood-vinegar so that it has a chance to oxi-
dize in the air. For this purpose wood-vinegar is poured over
iron turnings in a vat, and after drawing off the solution in a
few days, the iron is for some time left to the action of the ox-
ygen of the air. It quickly oxidizes, and by pouring back the
solution and several times repeating the drawing off and pour-
ing back, a quite concentrated solution of dark red brown,
nearly black color is in a short time obtained. Heat must
not be employed in the preparation of this salt, as in such case
it readily decomposes.
Neutral ferric acetate may be obtained in the pure state by
decomposing a solution of lead acetate by adding ferric sul-
phate in slight excess. In the course of 24 hours the excess
of ferric sulphate precipitates as a basic salt. It is also pro-
duced, though more slowly, by dissolving ferric hydrate or
ferric carbonate obtained by precipitation, in strong acetic
acid. This method occupies more time, but affords better
guarantees for the purity of the compound.
By dissolving one part of nitric acid or aqua regia, precipi-
tating the solution with ammonia and dissolving the washed
ferric hydrate in 10 parts of acetic acid of 1.042 specific grav-
ity, and evaporating the solution at between 140° and 17G° F.
an amorphous salt soluble in water and alcohol remains, which
is, however, not neutral, as it contains only two instead of 3
ACETATES AND THEIR PREPARATION. 327
equivalents of acetic acid for 1 equivalent of ferric oxide. By
dissolving this amorphous salt in acetic acid and exposing the
dark red solution to a low temperature, the neutral salt crys-
tallizes out in hydrated, lustrous, dark red laminse.
On heating the strongly diluted solution of this salt to
nearly the boiling point its color becomes more intense and it
evolves a distinct odor of acetic acid without, however, produc-
ing a precipitate. The salt has nevertheless become more
basic, and an addition of any soluble sulphate or even of free
sulphuric acid immediately precipitates the whole of the iron
as insoluble basic ferrous sulphate. By heating, however, the
dilute solution of the pure acetate to boiling, it disengages
acetic acid and separates a basic salt, which, if boiling be con-
tinued, also loses its acid so that ferric hydrate remains behind.
The properties of this hydrate differ, however, from those of
ordinary ferric hydrate, it dissolving in concentrated hydro-
chloric acid only by long-continued digestion or boiling, and is
scarcely attacked by boiling concentrated sulphuric acid. In
acetic acid or dilute nitric acid it dissolves, however, to a red
fluid, transparent to transmitted, but opaque to reflected, light.
By adding the slightest quantity of a sulphate or of concen-
trated nitric or hydrochloric acid, a granular precipitate is
formed, which, however, redissolves on diluting the fluid with
water. If a solution of ferric acetate is heated in a closed ves-
sel to 212° F. for a few hours, the fluid seen by reflected light
appears opaque and opalescent. It has also lost its metallic
taste and no longer shows the other reactions of ferric salts, i.e.,
addition of ferrocyanide produces no precipitate nor does the
sulphocyanide augment its red color. A trace of sulphuric
acid or any alkaline salt suffices to precipitate the whole of the
iron in solution as ferric hydrate, of red color, which is totally
insoluble in all acids at an ordinary temperature ; dilute min-
eral acids do not, however, produce a similar 'precipitate. It
is remarkable that this ferric hydrate dissolves in water to a
dark red fluid which can be again precipitated by concentrated
acids or alkaline salts (Pean de St. Giles).
MANUFACTURE OF VINEGAR.
From the iron acetates the iron is precipitated as black fer-
rous sulphide by sulphuretted hydrogen.
With ferric nitrate, ferric acetate yields a crystallizable
double salt, Fe(C2H302)2N03 + 3H20, the solution of which
decomposes on boiling, nitric and acetic acids being disengaged.
A similar combination exists between the acetate and ferric
chloride.
Chromium acetates. — Acetic acid enters into combination
with chromous (CrO), as well as .with chromic, oxide (O203).
The salts are not used in the industries and are only of
scientific interest.
Chromous acetate, (C2H302)2Cr + H20, is prepared by mixing
a solution of chromous chloride with sodium acetate. The salt
separates out in small, lustrous red crystals which are sparingly
soluble in water and alcohol, and quickly oxidize to a greater
degree on exposure to the air, the succeeding salt being formed.
Chromic acetate. — A neutral salt is known and there are very
likely several basic ones. The solution of the neutral salt,
which is obtained by dissolving chromic hydrate in heated
acetic acid, forms a red fluid, green in a reflected, and red in
a transmitted, light. It is not decomposed by boiling, but by
ammonia. The precipitate, however, redissolves, on adding
ammonia in excess, to a violet-red fluid because the hydrate is
soluble in ammonium acetate. Hence, a solution of the salt
acidulated with acetic acid is not precipitated by ammonia.
There are also known crystallized combinations of this salt
with chromic chloride and sulphate and nitrate of chromium.
If the solution of the neutral salt is for some time digested
with chromic hydrate, it acquires a darker color, the acid
reaction disappears, and on evaporating, a green powder
soluble in water remains behind. Ordway has described a
purple busic salt.
Nickel acetate forms small green crystals soluble in water,
but not in alcohol.
Cobalt acetate forms small red crystals, the concentrated
solution of which turns blue on heating but again red on cool-
ing, and can, therefore, be used as sympathetic ink.
ACETATES AND THEIR PREPARATION. 329
Zinc acetate, Zn(C2H302)2. — This salt may be prepared by
dissolving metallic zinc, zinc oxide or zinc carbonate in acetic
acid, or by the decomposition of zinc sulphate by acetates of
lime or lead similar to the acetate of manganese. The acetate
is in the first three instances simply obtained by evaporation,
and in the latter, after agitating the mixture, filtering and
evaporating the filtrate. The salt crystallizes in flexible, opal-
escent, six-sided tables which effloresce slightly in the air.
Technically the best receipt is to dissolve 4 parts of the sul-
phate of zinc and 7J parts of acetate of lead each in 3 parts-
of hot water, mixing the solutions, agitating, and after the
sulphate of lead has deposited, drawing the clear liquid off to-
crystallize.
Copper acetates. Cuprous acetate, Ca2(C2H302)2. — This salt is-
produced by subjecting crystallized verdigris to dry distillation.
It is a white substance crystallizing in fine needles, which are
decomposed by water into yellow cuprous hydrate and cupric
acetate.
With cupric oxide acetic acid forms a normal and several
basic salts.
Neutral cupric acetate; crystallized verdigris, Cu(C2H302)2.
— The normal cupric acetate may be prepared by dissolving
pure cupric oxide or cupric hydrate in pure acetic acid or by
employing, instead of the pure oxide, copper scales whose con-
tent of metallic copper and of cuprous oxide is converted into
cupric oxide by moistening with nitric acid and gentle glow-
ing. The cupric oxide thus obtained .is washed to remove
foreign substances. The conversion of the cuprous oxide into
cupric oxide is especially essential when the acetic acid is not
entirely free from hydrochloric acid, as otherwise cuprous-
chloride is formed which dissolves with difficulty.
If copper scales cannot be obtained, hydrated basic carbon-
ate of copper can be prepared by precipitating sulphate of
copper with soda, and, after washing and pressing, dissolving
in acetic acid. Sulphate of soda remains dissolved in the
water, and this solution can eventually be utilized for the
330 MANUFACTURE OF VINEGAR.
conversion of crude calcium acetate into sodium salt. Instead
of soda, milk of lime can also be used for the decomposition
of the sulphate of copper, a mixture of calcium sulphate and
cupric hydrate being precipitated. By adding acetic acid the
latter is redissolved while the calcium sulphate remains sus-
pended. When the latter has settled the solution is drawn off
and evaporated. The calcium sulphate is repeatedly washed
with small portions of water, and the wash-waters are used for
dissolving fresh quantities of sulphate of copper.
In case the sulphate of copper contains iron, the latter is re-
moved by digesting the solution for several days with basic
carbonate of copper. The presence of iron is recognized by
the sulphate not dissolving entirely in ammonia in excess, but
leaving behind a red-brown residue (ferric hydrate).
The neutral acetate can also be prepared by dissolving the
basic salt, verdigris (described below), in acetic acid. The so-
lution is filtered and evaporated until a crystalline film is
formed. This method is, however, expensive.
The method by double decomposition may be recommended
for preparing the neutral acetate on a small scale, but not for
manufacturing purposes. Sulphate of copper (125 parts) and
sodium acetate (136 parts) decompose each other, neutral
cupric acetate crystalizing out, while sodium sulphate remains
in solution. The yield is, however, somewhat smaller than
theoretically might be expected, because the sulphate of cop-
per is not entirely insoluble in sodium sulphate solution. By
this process the object is quickly accomplished, and for this
reason is decidedly to be preferred to the following : Sulphate
of copper (125 parts) and normal lead acetate (190 parts)
decompose completely only in dilute, but not in concentrated,
solutions. Hence strong evaporation is required, whereby
acetic acid is lost. Further, with the use of lead acetate some
of the newly-formed lead sulphate is obtained in solution ; but
the lead cannot be separated with sulphuretted hydrogen
because the latter would also decompose the copper salt. The
disadvantage of substituting calcium acetate for the lead ace-
ACETATES AND THEIR PREPARATION. 331
tate is that it is not crystallized and hence furnishes no exter-
nal criterion of purity ; in fact it always varies slightly in
composition. If a small excess of calcium salt has been used,
the latter, after the calcium sulphate is filtered off and the
solution evaporated, does not remain in the mother lye, but
crystallizes out as double salt (see below), together with the
copper salt. Since these acetates create difficulties, and as
each of them must first be prepared by the manufacturer by
means of acetic acid, it would seem more rational to directly
use this acetic acid for dissolving the cupric oxide, whereby
no by-products of little value, such as sulphate of lead, calcium
and sodium, are formed.
The evaporation of the solution of cupric acetate obtained
by any of the above methods is effected in a copper boiler over
an open fire, or, still better, by steam. It is recommended to
close the boiler so that the escaping vapors of water and acetic
acid are condensed in a worm. Independently of the fact that
by these means the escaping acetic acid is regained and can be
used for other purposes, a great advantage is that the air of
the workroom is thereby not contaminated by flying particles
of salt.
Crystallization is generally effected in stoneware pots into
which dip a number of slender wooden rods. The pots are
placed in a warm room. Crystallization is finished in about 14
days. The crystals turn out especially beautiful when the acid
somewhat preponderates and the solution is cooled very slowly.
The salt forms dark green * rhombic prisms of a nauseous
metallic taste, which dissolve in 14 parts of cold, and 5 parts
of boiling, water; and are also soluble in alcohol. Heated in
the air the crystals burn with a green flame.
Neutral cupric acetate contains in 100 parts: Cupric oxide
39.8, anhydrous acetic acid 51.1, water 9.
On heating, the dilute solution of the neutral salt yields
* There is also another salt of a beautiful blue color, which contains, however,
o equivalents of water (VVohler). It is prepared by exposing a solution of the salt
mixed with free acetic acid to a low temperature. At 95° F. it passes into the
ordinary green salt.
332 MANUFACTURE OF VINEGAR.
acetic acid and deposits a basic salt ; hence the use of strongly
diluted acetic acid or even distilled vinegar is not suitable for
the preparation of crystallized verdigris. By long-continued
digestion with freshly glowed charcoal the dilute solution
yields its entire content of copper to the latter ; hence vinegar
containing copper can be purified in this manner (2 or 3 per
cent, of charcoal being sufficient). The crystals of normal
cupric acetate, after drying in vacuo, lose more water at 212°
F., but give off 9 per cent, of their water between 230° and
284° F. By destructive distillation cupric acetate yields strong
acetic acid which contains acetone and is contaminated with
copper. Cuprous oxide (Cu20) is obtained in red octahedral
crystals when the neutral salt is heated with organic substances,
such as sugar, honey, starch, etc. „ With the acetates of potas-
sium, sodium, and calcium, normal cupric acetate gives double
salts of a vivid blue color, which form fine crystals.
The chief use of normal cupric acetate in the arts is in
making pigments and for resisting the blue color which the
indigo would communicate in the indigo bath of the calico
printer. In the latter case its mode of action depends on the
readiness with which it parts with oxygen, whereby the indigo
is oxidized before it can exert any action on the cloth, being
itself reduced to the state of acetate of suboxide of copper.
Crystallized verdigris is occasionally employed as a transparent
green water color or wash for tinting maps. In medicine it
is used for external application. It is poisonous, like all
soluble copper salts.
Basic cupric acetates. Sesquibasic cupric acetate (Cu(C2H302)2).
CuO-f- 6H20. — This compound is obtained pure by gradually
adding ammonia to a boiling concentrated solution of the nor-
mal acetate until the precipitate, which is at first formed, is
redissolved. As the liquor cools the new salt then crystallizes
out in beautiful blue-green scales, which at 212° F. lose 10.8
per cent, of their water. Their aqueous solution is decom.
posed by boiling, acetic acid being given off and the black
oxide of copper precipitated.
ACETATES AND THEIR PREPARATION. 333
Dibasic cupric acetate, Cu(C2H302)2CuO-|-6H20, constitutes
the greater part of the blue variety of verdigris. It forms
beautiful, delicate, blue, crystalline needles and scales, which
when ground form a fine blue powder. When heated to 140°
F. they lose 23.45 per cent, of water and become transformed
into a beautiful green, a mixture composed of the neutral and
tribasic acetates. By repeated exhaustion with water the
dibasic, is resolved into the insoluble tribasic, salt, and a solu-
tion of the normal and sesquibasic cupric acetates.
Tribasic cupric acetate, Cu(C2H302)22CuO+3H20.— This corn-
pound is the most stable of all of the acetates of copper. It is
prepared by boiling the aqueous solution of the neutral acetate,
by heating it with alcohol, by digesting its aqueous solution
with cupric hydrate, or by exhausting blue verdigris with
water as above mentioned. The first methods yield the salt
in the form of a bluish powder composed of needles and scales,
the last as a bright green powder. This salt yields all its
water at 352° F. ; at a higher temperature it decomposes and
evolves acetic acid. Boiling water decomposes the solid triba-
sic acetate into a brown mixture of the same salt with cupric
oxide.
Under the name of verdigris two varieties of basic cupric
acetates are found in commerce: French verdigris which occurs
in globular, bluish-green, crystalline masses, but also in amor-
phous masses, and English verdigris of a pure green color and
crystalline structure, which is, however, also manufactured in
Germany and Sweden.
The first variety is chiefly manufactured in the region around
Montpellier, France. The refuse of grapes, after the extraction
of the juice, is placed in casks until acetous fermentation takes
place. The casks or vessels are covered with matting to pro-
tect them from dirt. At the end of two or three days the fer-
menting materials are removed to other vessels in order to
check the process, to prevent putrefaction. The limit to which
fermentation should be carried is known by introducing a test-
sheet of copper into the mass for 24 hours; if, on withdrawing
334 MANUFACTURE OF VINEGAR.
it at the end of that time, it is found covered with a uniform
green coating, the proper degree of fermentation has been
reached.
Sheets of copper are prepared by hammering bars of the
metal to the thickness of about ^ of an inch (the more com-
pact the copper sheets the better), and they are then cut into
pieces of 6 or 8 inches long by 3 to 4 broad. Sometimes old
ship-sheathing is used and cut into pieces of the required size.
The sheets are immersed in a concentrated solution of verdegris
and allowed to dry. When the materials are all found to be
in proper condition, the copper sheets are laid on a horizontal
wooden grating in the middle of a vat, on the bottom of which
is placed a pan of burning charcoal, which heats them to about
200° F. In this state they are put into large stoneware jars
with alternate layers of the fermenting grape lees ; the vessels
are covered with straw mats and left at rest. At the end of 10
to 20 days they are opened to ascertain if the operation is
complete. If the upper layer of the lees appears whitish and
the whole has worked favorably, the sheets will be covered
with silky crystals of a green color. The sheets are then taken
from the jars and placed upright in a cellar, one against the
other. At the end of two or three days they are moistened
with water and again placed to dry. The moistening with
water is continued at regular intervals of a week for six or eight
times. This treatment causes the sheets to swell and become
incrusted with increased coatings of the copper salt, which are
detached from the remainder of the sheets by a copper knife.
The scraped plates are submitted to a fresh treatment till the
whole of the copper is converted into verdigris. The salt
scraped off is made into a consistent paste by kneading with a
little water, and in this state is packed into leathern bags which
are placed in the sun to dry until the mass hardens and forms
the tough substance which constitutes the commercial article.
In England, Germany and Sweden copper sheets are moist-
ened with a solution of verdigris in vinegar and placed in a
warm room, or woollen cloths moistened with the above solu-
ACETATES AND THEIR PREPARATION. 335
tion are used, which are placed alternately with the copper
sheets in a square wooden box. The woollen cloths are moist-
ened with the solution every three days for 12 or 15 days,
when small crystals commence to form on the sheets. The
sheets are then drawn every six days through water and re-
placed in the box, but not in direct contact with the woollen
cloths, small disks of copper or small pieces of wood being
placed between each cloth and sheet. The woollen cloths are
now more thoroughly saturated than before, but with a weakei
solution. With a temperature of from 54° to 59° F., 6 to 8
weeks are required before the verdigris can be scraped off.
The product is not identical with that obtained by the French
method, it being somewhat poorer in acetic acid, and hence its
color is not bluish-green, but almost pure green.
Lead Acetates. — With plumbic oxide acetic acid gives a
neutral, as well as several basic, salts. The most important of
these combinations are the neutral salt, known in commerce
as sugar of lead, and a basic salt by means of which white
lead is obtained.
Neutral Acetate of Lead (Sugar of Lead), Pb(C2H302)2+3HO.
— According to Volkel's method, acetic acid prepared from
wood-vinegar and rectified over potassium dichromate is satu-
rated with litharge, filtered or decanted, and after a further
addition of acetic acid until a slightly acid reaction takes place,
evaporated to the crystallizing point.
By saturating acetic acid with litharge, a solution of basic
salt is obtained, which is later on converted into neutral salt
by the addition of acetic acid. This is more suitable than
using only as much litharge as the acetic acid requires for
the formation of the neutral salt, because the litharge dis-
solves with greater ease in solution of sugar of lead than in
acetic acid.
Solution of sugar of lead, like solution of neutral cupric ace-
tate, permits of the evaporation of acetic acid in boiling ; and,
hence, it is best to use strong acetic acid, because less will have
to be evaporated and the loss of acetic acid be consequently
336 MANUFACTUKE OF VINEGAR.
smaller. By taking, for instance, acetic acid of 1.057 specific
gravity, for 100 Ibs. of it 82 Ibs. of litharge are required for the
formation of the neutral salt. A larger quantity is, however,
taken (from 100 to 180 Ibs.), so that a basic salt is formed, or,
with 100 Ibs., a mixture of neutral and basic salts. To recog-
nize the point of neutralization in the subsequent addition of
acetic acid, litmus paper is used, or, still better, dilute solution
of corrosive sublimate (1 part of corrosive sublimate in 100 of
water), which does not change the neutral salt, but produces
turbidity in the basic (Buchner). Hence, by from time to
time testing the lead solution with this reagent, the point of
neutralization is reached the moment turbidity ceases. This
test is better than with litmus, considerable experience being
required to hit the right point with the latter on account of
solution of sugar of lead showing a slight, but perceptible acid
reaction.
The solution of litharge in acetic acid is promoted by heat,
and is effected either in a copper pan, the bottom and sides of
which are brought in contact with a few bright sheets of lead
(to prevent the copper from being attacked), or in a lead pan
over an open fire, or in a wooden vat into which steam is in-
troduced. The clear solution is evaporated. If this is to be
done over an open fire, it is recommended to have a prepara-
tory heating pan for each evaporating pan, as described in the
preparation of calcium acetate, the preparatory heating pan,
which is heated by the escaping gases, being used for the solu-
tion of the litharge in acetic acid. Lead pans, if used, should
rest upon strong cast-iron plates. The dimensions of the pans
vary very much. According to Assmus, they are 6J feet long,
4 feet wide, and from 12 to 14 inches deep, while the depth
of the preparatory heating pans is from 24 to 28 inches. From
the latter, which stand at a higher level, the clear solution is
discharged, through a stop-cock just above the bottom, into
the evaporating pans. Evaporation should be effected at a
moderate heat; actual boiling must be strictly avoided, as
otherwise large losses of acetic acid are unavoidable and the
solution readily acquires a yellow coloration.
ACETATES AND THEIR PREPARATION. 337
According to the degree of evaporation (to 36° B. or to 46°
B. or more) of the sugar of lead solution, distinct crystals are
obtained or only a radiated crystalline mass. With a perfectly
pure solution the first method is the best, since crystals bring
a better price. The mother-lye, after being again acetified, is
once more evaporated and acetified and yields more crystals.
Stein recommends the conducting of the vapors of acetic
acid or of vinegar into litharge mixed with a very small quan-
tity of water. This method is in general use in Germany. But
as the extract remaining iri-the still retains a considerable
quantity of acetic acid, especially if beer had been added to the
liquid used in the preparation of the vinegar, it is advisable to
increase the boiling point of the latter by the addition of one-
third of its weight of common or rock salt. At first the water
condenses in the receiver and the volume of the fluid containing
the litharge increases, but when the boiling point is reached in
the condensing vessels, only the acetic acid is retained, while
the litharge is first converted into sexbasic and then into tri-
basic acetate. To obtain neutral salt, however, either the
vapors must be somewhat expanded or several condensing
vessels be placed one after the other.
Fig. 84 shows the distilling apparatus, consisting of a still,
a, of sheet-copper. The vapors pass through a copper pipe, 5,
into the wooden vat, c, lined with lead, and about 35 inches
in diameter and (>7 inches deep. In this vat are four bottoms,
d, of thick lead provided with fine perforations. Short lead
pipes, soldered into these bottoms and arranged as shown in
the figure, serve to conduct the vinegar vapors in the vat to
and fro in the interspaces between the lead bottoms. For each
still at least three of such vats are connected with each other.
Upon the lead bottoms is first placed a layer of linen or of
flannel, and next a layer of litharge 2 to 4 inches deep. To
prevent the litharge from packing, it is mixed with an equal
volume of pebbles, about the size of a pea. The vats are pro-
vided with lids of sheet-copper lined with lead. From the lid
of the last vat a pipe leads to a worm surrounded with cold
22
338 MANUFACTURE OF VINEGAR.
water. The stop-cocks on the bottoms of the vats permit the
discharge of the collected lead solution, which is effected (with
the use of acetic acid) when it shows a specific gravity of at
at least 36° Be. The solution being, however, basic, it is aceti-
fied with strong acetic acid, and brought into the crystallizing
vessels.
This method is decidedly the best, because the evaporation
of the solution is entirely or almost entirely omitted and the
air of the workroom is not contaminated by particles of sugar
of lead, which is very injurious "to the health of the workmen.
FIG. 84.
Furthermore, this taethod does not require the use of pure
acetic acid, since the impurities remain in the still. This, how-
ever, holds good only for non-volatile impurities. For the
production of colorless salt, the crude acetic acid from wood-
vinegar must necessarily be purified, as above mentioned,
by potassium chromate and sulphuric acid.
The crystallizing pans are either of stone-ware or of wood
lined with lead or thin copper, to which is soldered a strip of
lead down the sides and across the bottom, with the idea of
rendering the metal more electro-negative, so as to prevent the
ACETATES AND THEIR PREPARATION.
339
acetic acid from acting on it. The wooden crystallizing pans
are about 4 feet long by 2 feet wide, and from G to 8 Indies
deep, sloping inwards at the edges. Shallow, slightly conical
copper vessels. 6 inches deep, with a diameter of 29J inches
at the bottom and 31 J inches at the top, are also used. The
stone-ware pans are placed upon a slightly inclined level cov-
ered with lead. In these small pans crystallization is complete
in 24 hours, while from 48 to 72 hours are required with the
use of the larger wooden vessels. Crystallization being com-
plete, the mother-lye is removed, and the vessels are placed
upon a wooden frame over a gutter of sheet-lead to drain off,
as shown in Figs. 85 and 8G.
FIG. 85.
FIG. 86.
If especially beautiful crystals are to be obtained, the first
crystals, which are not very distinct, are again dissolved in
the water obtained by the condensation of the vapors escaping
from the still. The solution being evaporated to the proper
density is again allowed to crystallize. The crystals, after
sufficient drainage, are placed upon linen spread over wooden
hurdles and dried at a moderate heat, not exceeding 75° F.
In some factories the heated air of a stove, placed outside the
drying-house, is conveyed through pipes passing round the
interior; at other places steam heat is employed for this pur-
pose, which is much to be preferred, on account of its being
more easily regulated.
When working on a large scale a centrifugal is advantage-
ously employed for the separation of the mother-lye, in the
340 MANUFACTURE OF VINEGAR.
same manner as recommended for the preparation of sodium
acetate.
Litharge being a quite impure lead oxide never dissolves
entirely, and frequently contains over 10 per cent, of impuri-
ties, consisting of sand, clay, red lead or minium (Pb304),
metallic lead, traces of silver, cupric and ferric oxides. The
cupric oxide passes into the sugar of lead solution and colors
it slightly blue. To separate the copper, bright sheets of lead
are dipped into the solution, the copper separating upon them
in the form of a dark slime. The sheets of lead must be fre-
quently cleansed (scraped), as otherwise they lose their effect.
When there is a large accumulation of litharge residue, it can
be worked for silver.
Sugar of lead can also be prepared from metallic lead, the
process having been recommended first by Berard, and is said
by Runge to yield a good product with great economy. Gran-
ulated lead, the tailings in the white lead manufacture, etc.,
are put in several vessels, say eight, one above the other, upon
steps, so that the liquid may be run from one to the other.
The upper one is filled with acetic acid, and after half an hour
let off into the second, after another half hour into the third,
and so on to the last or eighth vessel. The acid causes the
lead to absorb oxygen so rapidly from the air as to become
hot. When the acid runs off from the lowest, it is thrown on
the uppermost, vessel a second time and carries off the acetate
of lead formed. After passing through the whole series the
solution is so strong that it may be evaporated at once so as to
crystallize.
Apparently this method has a considerable advantage over
that with litharge, metallic lead being cheaper and producing
more sugar of lead (entirely free from copper) than litharge,
because 103.5 Ibs. of pure lead yield 189.5 Ibs. of sugar of lead,
while the same quantity is only obtained from 111.5 Ibs. of pure
litharge. Furthermore, commercial lead is always purer than
litharge. On the other hand, this process has the disadvan-
tage of a considerable quantity of acetic acid being lost by
ACETATES AND THEIR PREPARATION. 341
evaporation on account of it having to pass through several
vessels. The manufacture of sugar of lead is most suitably
combined with that of white lead, it being thus possible to
utilize the tailings, etc., to greater advantage than, as is fre-
quently done, by melting them together and remelting, which
always causes considerable loss.
Sugar of lead is further formed by boiling lead sulphate
with a very concentrated solution of barium acetate, barium
sulphate (permanent white) being thereby precipitated. For
100 parts of lead sulphate 84 parts of anhydrous or 100 of
crystallized barium acetate are required, the yield being 125
parts of sugar of lead. Sulphate of lead is obtained in large
quantities as a by-product in the preparation of aluminium
acetate.
For many purposes of dyeing and printing the use of pure
sugar of lead is not necessary, the brown acetate of lead an-
swering all requirements. For its preparation ground litharge
is introduced in small portions, stirring constantly, into dis-
tilled wood vinegar in a vat until red litmus paper is colored
blue, and, hence, a basic salt is formed. The impurities sep-
arating on the surface are removed and the clear fluid is then
transferred to a copper pan equipped with strips of lead, and is
evaporated to about two-thirds its volume, the brown smeary
substances rising to the surface during evaporation being con-
stantly removed. By again diluting and slightly acidulating
the concentrated fluid a further portion of the foreign sub-
stances can be removed. Finally evaporation is carried to
the crystallizing point, i. e., until a few drops congeal when
allowed to fall upon a cold metal plate. The addition of
animal charcoal for the purpose of discoloration is of no ad-
vantage. The coloration is not completely removed, and the
little effect produced is attained at a considerable loss of salt,
which is absorbed by the animal charcoal.
. By disturbing crystallization by constant stirring during
cooling, a nearly amorphous mass, having the appearance of
yellow wax, is obtained, which is much liked by many con-
342 MANUFACTURE OF VINEGAR.
sutners. The product thus obtained is not always a neutral
salt, but sometimes a mixture of neutral and basic salts (be-
sides empyreumatic substances). After cooling it must, there-
fore, be quickly and well packed, in order to protect it from the
moisture and the carbonic acid of the air. The sugar of lead
solution may, however, also be evaporated only so far that
some mother-lye remains after cooling, the crystallized mass
being then for some time allowed to stand in a moderately
warm room. In consequence of capillarity, the impurities,
which occur chiefly in the mother-lye, gradually rise up be-
tween the crystals, a slight coating of yellow, or brown, smeary
substance being finally formed upon the mass of crystals,
which can be readily removed.
The linen upon which the crystals are dried must be care-
fully protected from fire, as it ignites from the slightest spark
and burns like tinder.
If the hot solution be set aside to cool rapidly, the sugar of
lead crystallizes in clusters of fine needles ; but if evaporation
be conducted slowly the crystals are truncated and flattened,
quadrangular and hexahedral prisms derived from a right
rhombic prism. Acetate of lead has a sweet astringent taste,
is soluble in 1 J parts of water and in 8 parts of ordinary alco-
hol. The crystals are permanent in the atmosphere, but are
apt to effloresce and become anhydrous if the temperature
ranges between 70° and 100° F.
Acetate of lead consists of:
Plumbic oxide 58.9
Anhydrous acetic acid 26.9
Water . . . 14.2
100.00
Aqueous solution of sugar of lead slightly reddens litmus-
paper, but shows an alkaline reaction upon turmeric, brown-
ing it.
At 167° F. the crystals of acetate of lead melt, and slowly
yield up their water ; by heating the entirely dephlegmated
ACETATES AND THEIR PREPARATION. 343
salt more strongly it fuses at 536° F. to a clear, oil-like, color-
less fluid and decomposes above this temperature, evolving all
the compounds usually obtained in the destructive distillation
of the acetates of the heavy metals, while a residue of metallic
lead in a very minute state of division, with some charcoal, is
left behind. When this distillation is conducted in a glass
tube closed at one end and having the other drawn out for
convenience of sealing at the end of the operation, the well-
known lead pyrophorous is made. The particles of metallic
lead are so small that, when thrown into the air, oxygen mole-
cules come into such intimate contact with them that ignition
is effected from the rapidity with which lead oxide is formed.
A slight decomposition occurs when the neutral salt is ex-
posed to an atmosphere of carbonic acid, carbonate of lead
being formed ; the portion of acetic acid thus liberated pro-
tects the remainder from further change.
Cold solution of sugar of lead is not immediately changed
by ammonia ; by adding, however, a large excess of it, sexbasic
acetate of lead is gradually separated ; on boiling, yellow-red
crystalline lead oxide is precipitated.
The introduction of chlorine gas into a solution of sugar of
lead produces in a short time a brown precipitate of plumbic
dioxide. Bromine acts in a similar manner, but on account
of its insolubility, iodine produces scarcely any effect.
Solution of calcium chloride at once produces a yellow
precipitate, which gradually becomes brown.
Sugar of lead containing considerable copper has a bluish
appearance. If the content of copper is small, it is recognized
by the solution acquiring with ammonia a blue coloration, or,
still better, by mixing the solution of sugar of lead with an ex-
cess of solution of Glauber's salt and testing the filtrate with
potassium, ferrocyanide. A dark-red precipitate indicates
copper.
Sugar of lead, as well as the basic lead salts to be men-
tioned further on, possesses poisonous properties.
Sugar of lead is chiefly used for the preparation of alum-
344 MANUFACTURE OP VINEGAK.
inium acetate, as well as of other acetates. Considerable
quantities of it are consumed in the manufacture of colors, for
instance, of neutral and basic lead chromate, chrome yellow,
chrome orange, and chrome red. Upon the cloth-fibre (espec-
ially wool) chrome yellow and chrome orange are produced
by means of sugar of lead, particularly with the brown variety ;
the latter product being also very suitable for the production
of the so-called chrome green, which is obtained by the joint
precipitation of chrome yellow and Berlin blue.
Neutral lead acetate gives crystallizable double salts with
potassium acetate and sodium acetate as well as with lead
nitrate, lead chloride, lead bromide, etc.
Basic lead acetates. — Several of these compounds are known.
Those with 2 and 3 equivalents of lead oxide to 1 equivalent
of acetic acid are soluble in water, show a strong alkaline reac-
tion, and with carbonic acid the solutions yield at once and
in every degree of concentration, abundant precipitates of
white lead (basic carbonate of lead), while, when the operation
is at a suitable moment interrupted, neutral salt remains in
solution. In this manner white lead is manufactured accord-
ing to the so-called French method (of Thenard and Hoard)
at Clichy and other places in France, as well as in different
German factories. If however, the introduction of carbonic
acid be continued until no more precipitate is formed, a part
of the lead of the neutral salt is also precipitated as carbonate,
which, however, is neutral, and an acid solution remains
behind.
The soluble salt known as lead vinegar or extract of lead is
prepared by digesting 2 parts of sugar of lead dissolved in 5
of water with 1 of finely powdered litharge. The propor-
tional quantities of sugar of lead, litharge and water prescribed
by the Pharmacopoeias of the different countries vary very
much, and, consequently, also, the compositions and specific
gravities (from 1.20 to 1.36) of the solutions of lead prepared
in accordance with them. The litharge dissolves very readily
in the sugar of lead solution, in fact with greater ease than in
ACETATES AND THEIR PREPARATION. 345
acetic acid, and especially with greater rapidity if the sugar of
lead solution be heated in a silver dish to the boiling point
and the litharge gradually introduced. For the manufacture
on a large scale, the sugar of lead solution and the litharge
may be brought into a barrel revolving around its axis. If
the operation is to be conducted at the ordinary temperature,
the barrel must be closed to prevent the access of the car-
bonic acid of the air. Very remarkable is the behavior of the
tribasic acetate towards hydrogen dioxide ; plumbic dioxide
being first formed. But in a short time this exerts a decom-
posing influence upon the hydrogen dioxide which may be
present in excess, so that both dioxides' now lose one-half of
their oxygen, which evolves in the form of gas, and water
and plumbic oxide are formed.* Now, as freshly precipitated
plumbic dioxide possesses the further property of decomposing
solution of potassium iodide, Schoenbein recommends tribasic
acetate of lead, together with paper coated with paste prepared
with potassium iodide, as the most sensitive reagent for hydro-
gen dioxide.
Lead Sesquibasic Acetate, Triplumbic Tetracetate. — This salt is
obtained by heating the diacetate until it becomes a white,
porous mass ; this is redissolved in water and set aside to
crystallize. Sesquibasic acetate is soluble in both water and
alcohol ; its solutions are alkaline.
Tribasic acetate of lead is prepared by digesting 189.5 Ibs. of
sugar of lead with 223 Ibs. of plumbic oxide (pure) or 3 Ibs.
of sugar of lead to 4 Ibs. of litharge ; or, according to Payen,
into 100 volumes of boiling water are poured 100 volumes of
aqueous solution of sugar of lead saturated at 86° F., and
afterwards a mixture of pure water at 140° F., with 20 volumes
of ammonia liquor free from carbonate. The vessel is then
immediately closed, and in a short time an abundance of the
tribasic acetate crystallizes out. The salt presents itself under
the form of long needles. It is insoluble in alcohol, very solu-
* Schoenbein in Wagner's Jahresbericht, 1862.
346 MANUFACTURE OF VINEGAR.
ble in water, its solution being alkaline. Tribasic acetate is
the most stable of all the subacetates of lead. It takes a lead-
ing part in the manufacture of white lead by the Clichy pro-
cess. It is, in point of fact, a solution of this salt, which is
decomposed by the carbonic acid, and gives rise to the carbon-
ate of lead, being itself at the same time converted into lead
diacetate. In the Dutch process the formation of lead carbon-
ate is, according to Pelouze, also due to the formation of tri-
basic acetate on the surface of the sheets of lead, which is, in
its turn, decomposed by the carbonic acid.
Sexbasic Acetate of Lead. — This body is prepared by digest-
ing any of the preceding salts with lead oxide. It is a white
powder slightly soluble in boiling water, from which it crys-
tallizes out in silky needles which consist of two equivalents
of the salt combined with three equivalents of water.
Uranium Acetate. — With uranous oxide, acetic acid combines
to a dark green crystallizable salt, and with uranic oxide to a
yellow basic salt, which, combined with water, appears in two
different forms of crystals. It is remarkable for giving, with
many other acetates, well crystallizing salts, of a beautiful
color, and partly showing magnificent dichroism (Wertheim
and Weselsky).
Tin acetate is prepared by dissolving stannous hydrate * in
heated strong acetic acid, or by mixing stannous chloride
(SnCl2) with acetate of sodium or calcium. It forms small
colorless needles, which have a strong metallic taste and
readily decompose in the air. The salt is used to discharge
azo-dyestuffs in calico printing.
Bismuth Acetate. — Bismuth nitrate prepared by gradually
introducing pulverized metallic bismuth into cold dilute nitric
acid is mixed with pure concentrated sugar of lead solution.
The salt separates in small, colorless needles.
Mercurous acetate can be prepared by dissolving pure mer-
*The hydrate is obtained by precipitating stannous chloride with soda lye and
washing the precipitate.
ACETATES AND THEIR PREPARATION. 347
curous oxide or its carbonate in acetic acid, or by mingling
hot solutions of mercurous nitrate and acetate of sodium or of
potassium. The pure mercurous carbonate is heated to boiling
with 8 parts of water, and concentrated acetic acid added until
all is dissolved ; the hot, filtered liquid free from oxide being
allowed to cool. Or, acidulated nitrate is diluted with 6 to 8
parts of water, heated and mixed with one equivalent of acetate
of sodium or potassium, dissolved in 8 parts hot water con-
taining a little free acid, and cooled. The salt, when sepa-
rated, is washed with a little cold water, dried in the dark at
a gentle heat, and kept from the light in covered bottles.
It crystallizes in fine, white, silvery scales, flexible and unc-
tuous to the touch, with a nauseous metallic taste, easily de-
composed by light. It dissolves with difficulty in cold water,
requiring 33 parts at the ordinary temperature. It is par-
tially decomposed by boiling water into acid and basic salts of
both oxides and metallic mercury. It is used in pharmacy.
Mercuric Acetate. — Dissolve red oxide of mercury in concen-
trated acetic acid at a gentle heat and evaporate to dry ness,
or partially to crystallization, or by spontaneous evaporation.
When obtained by the first process it is a white saline mass ;
by the second it forms crystalline scales; and by the third,
four-sided plates, which are partly transparent, partly pearly
and translucent, anhydrous, of a nauseous metallic taste, fusi-
ble without decomposition, solidifying to a granular mass, but
the point of decomposition of the latter is near that of fusion.
It dissolves in 4 parts of water at 50° F., in 2.75 at 66.2° F.,
and in 1 at 212°, but by boiling it is partly decomposed,
red oxide being separated. Even in the air its solution suf-
fers the latter change and contains a basic salt. With free
acetic acid it is not decomposed. One hundred parts of alco-
hol dissolve 5f of this salt, and this solution behaves like the
aqueous one. It generally contains, except when carefully
crystallized, some mercurous oxide.
Silver Acetate. — This salt is obtained by precipitating a con-
centrated solution of silver nitrate with a concentrated solution
348 MANUFACTURE OF VINEGAR.
of sodium acetate. It forms a white crystalline precipitate.
ft dissolves in about 100 parts of cold, but readily in hot,
water, and only sparingly in alcohol. On exposure to light it
acquires a dark color, being partially reduced. On heating,
it yields acetic acid, metallic silver remaining behind.
If the salt be heated with disulphide of carbon in a closed
glass tube to 329° F., silver sulphide, carbonic acid and anhy-
drous acetic acid are formed (Broughton).
On treating the dry salt with iodine, lively decomposition
takes place, whereby silver iodide, some metallic silver and coal
remain behind, while methyl oxide, acetic acid, acetylene and
hydrogen appear. With iodine a solution of this salt yields
acetic acid, silver iodide and iodate of silver (Birnbaum).
CHAPTER XXVI.
PREPARATION OF PURE WOOD SPIRIT OR METHYL ALCOHOL, AND
OF ACETONE, AND WORKING THE WOOD TAR.
Preparation of Wood Spirit. — The crude wood-spirit solu-
tions collected during the distillation of the wood vinegar
contain, according to their method of production, from 9 to 10
per cent, wood spirit. They are subjected to repeated distil-
lation and rectification over milk of lime to fix the acetic acid
present and to saponify the methyl acetate. In this manner
wood spirit is produced, i. e.} a mixture that besides methyl
alcohol contains other combinations such as aldehyde, methyl-
acetic ether, acetone and similar combinations, amines, higher
alcohols, etc.
The crude wood-spirit of commerce contains besides the
above-mentioned constituents. 75 per cent, of methyl alcohol.
It is clear as water to dark brown and can be mixed in every
proportion with water without becoming turbid.
Wood spirit for denaturing purposes is produced from the
PREPARATION OF PURE WOOD SPIRIT. 349
crude wood spirit by further rectification. It contains 95 per
cent, methyl alcohol, and while the higher alcohols and the
acetone have been removed, aldehyde, methyl acetate, etc.,
are still present.
Pure wood spirit contains 98 to 99.5 per cent, wood-spirit
constituents, among which methyl alcohol, however, pre-
ponderates so that they are almost entirely pure. Such pure
wood spirit contains only very small quantities of acetone—
0.01 to 0.5 per cent. It does not discolor bromide solution
and when mixed with concentrated sulphuric acid acquires an
only slightly yellower color.
The rectification of the crude wood-spirit solutions collected
during the distillation of the wood vinegar is effected in a
columnar still. The crude wood-spirit solution is brought
into the still and, after adding slaked lime, the fluid is allowed
to rest for several hours. After the addition of the lime the
fluid soon becomes strongly heated in consequence of the free
acids combining with the lime, and of the formation of cal-
cium acetate and methyl alcohol from the methyl acetic ether,
small quantities of ammonia being also evolved.
After having rested for several hours the fluid is subjected
to distillation. In Fig. 87, a represents the copper still, b an
ellipsoidal or egg-shaped vessel which serves as a receiver, and
c the rectifying apparatus, consisting of a series of Pistorius's
basins into the uppermost of which a moderate current of
water is conducted ; d is the condenser.
The still a has a capacity of 1000 to 1200 quarts ; the steam
pipe placed in it is 2 inches in diameter and 32 feet long.
The vapors pass out through the wide pipe in the cover, and
what is condensed in b runs back through a narrower pipe
into a. In the rectifying vessel or rather dephlegmator, the ris-
ing vapors are forced to pass around a copper disk placed in
each basin, and thus to come in contact with the surface of
the basin cooled by water. From this it is evident that the
less volatile bodies are condensed in the basins and run back
into b and from there into a, while the more volatile vapors
350
MANUFACTURE OF VINEGAR.
pass through the swan-neck and are condensed in d. Much,
of course, depends on the quantity (and temperature) of the
water running into the rectifying vessel.
With a rectifying vessel consisting of seven basins, each
1.64 feet in diameter, and with a correctly conducted inflow
of water, a product of 0.816 specific gravity is obtained by one
operation from crude wood spirit of 0.965 specific gravity.
This product can be used for many purposes, for instance
in the preparation of varnishes. It is, however, not entirely
FIG. 87.
pure, being rendered turbid by water which is due to a content
of the previously mentioned hydrocarbons; it further contains
some acetone, methyl acetate, aldehyde, ammonia, methyl-
amine, and is not lit for use in the production of aniline
colors.
For further purification, this rectified wood-spirit is diluted
with water until it shows a specific gravity of 0.934, and is
then allowed to rest a few days, when the greater portion of
the hydrocarbons lias separated as an oily layer on the top.
The clear fluid is now again rectified with an addition of 2 to
PREPARATION OF PURE WOOD SPIRIT. 351
3 per cent, of lime whereby a distillate is obtained which does
not become turbid with water, but in time turns yellow.
For the preparation of wood spirit suitable for denaturing
purposes, the crude wood spirit is diluted with water to from
30 to 40 per cent., compounded with milk of lime — 20.30
liters to every 1000 liters of spirit — and carefully and slowly
rectified from large columnar stills for several days, whereby
the following fractions are obtained :
1. First runnings containing acetone, with 60 to 80 per
cent, acetone. 2. High per cent, intermediate runnings, giv-
ing bright mixtures with water, and containing 7 to 10 per
cent, of acetone. 3. High per cent, intermediate running,
not giving bright mixtures with water. 4. Allyl alcohol-like
after runnings below 90 percent. 5. After runnings contain-
ing oil.
If the first of these fractions be diluted with water — 100
liters of water to 200 kilogrammes of distillate — and acidu-
lated with somewhat more sulphuric acid than required for
fixing the bases and again distilled from an iron or copper
still lined inside with lead, a product suitable for denaturing
purposes is obtained. For this purpose all the fractions are
used which are miscible with water without becoming turbid
and are so rich in acetone that the mixture finally contains at
least 30 per cent, of it and has a specific gravity of 90° Tralles.
For the further treatment of fraction 2, water in the pro-
portion of 1:2 is also added and then 1 to 3 per cent, of soda
lye. The object of the addition of soda lye is to fix the phenol-
like body, to saponify the esters and resinify the aldehyde.
During rectification the fractions that possess less than 0.1 per
cent, acetone are caught by themselves and designated " pure
methyl."
The third fraction is treated in the same manner but in
place of soda lye, sulphuric acid is added. The fourth frac-
tion is so far diluted with water that the dissolved oils are
separated. The latter are removed and the residue, after add-
ing sulphuric acid, is again rectified, products which may also
352 MANUFACTURE OF VINEGAR.
partially serve as wood spirit for denaturing purposes being
thus obtained.
Preparation of Acetone. — Acetone is a clear, mobile, ethereal-
smelling liquid, boiling at 134° F., and of specific gravity
0.797 at 59° F. It is prepared by heating calcium acetate in
retorts which are connected with a cooling apparatus. The
calcium acetate used for the purpose must be pure and should
be brought into the retorts in a perfectly dry and pulverized
state. It is then slowly heated until no more fluid runs off
from the cooler. The residue in the retorts consists of calcium
carbonate, and is again used for the preparation of calcium
acetate. Since acetone boils at a very low temperature, pro-
vision must be made for abundant cooling and it is best to
use ice water for feeding the cooling apparatus.
The decomposition of the calcium acetate to acetone and
calcium carbonate proceeds according to the following equation:
(CH3.COO)2Ca = CaCO3 -f 2CH3.CO.CH3.
This decomposition commences already in a slight degree
at 302° F., but takes place completely only at 752° F., and
hence the use of uniform and very high temperatures is indis-
pensable for the production of acetone. The theoretical yield
from 200 Ibs. of calcium acetate (gray acetate) amounts in
round numbers to 66 Ibs. of acetone. Since the gray acetate
contains besides calcium acetate other combinations, for in-
stance, calcium butyrate and propionate, the yield may be
materially less, and may in round numbers be given as about
44 Ibs. of acetone (dimethylketone). The homologues men-
tioned are of course also decomposed in a manner similar to
the calcium acetate, but higher ketones are then formed which
in the purification of the crude acetone, yield the so-called
acetone oils.
The decomposition of the calcium acetate is as a rule effected
in a cast-iron pan, Fig. 88, furnished with a powerful stirrer
and a man-hole for charging the calcium acetate. The tem-
perature for decomposition should not exceed 752° F., and is
PREPARATION OF PURE WOOD SPIRIT.
353
controlled by a pyrometer. The vapors evolved pass first
through a dust-separator and then through a pipe into a con-
denser, where they liquefy.
The crude distillate is rectified. This first distillate is
diluted to one-half with J volume of water and again recti-
fied, whereby a product with 90 per cent, acetone is obtained.
The last distillation is effected with the addition of potassium
permanganate. The first two or three liters of distillate are
FIG.
caught by themselves, and then all that boils between 122°
and 136.4° F.
Fig. 89 shows the arrangement of a plant for the production
of acetone. It contains several decomposing apparatuses for
the production of crude acetone. The pipes conducting the
vapors enter first a common collecting pipe, and from there
are conducted to the condenser which terminates in the col-
lecting vessel F, the quantity of fluid in it being indicated by
23
354
MANUFACTURE OF VINEGAR.
the float H. The decomposing apparatuses are separated by a
wall from the condenser and rectifier ; the fireplaces are out-
side the working room. The decomposing apparatus is
equipped with a dust collector T, above which is a broad
T-pipe for conducting the vapors. This pipe also serves for
the purpose of cleaning the dust collector.
From the collecting vessel the crude acetone is pumped into
the rectifier M, the latter being similar in arrangement to an
FIG. 89.
apparatus for rectifying alcohol. The pure acetone is caught
by itself in the vessel G.
The use of acetate of barium, strontium or magnesium in
place of calcium acetate is more advantageous. The draw-
back with the use of calcium acetate consists in that man)
tarry substances pass over and clog the pipes, and, besides, the
distillate is contaminated with empyreumatic substances.
The preparation of pure acetone is not very easy, notwith-
standing its apparent simplicity, and requires the use of per-
fectly separating columnar stills and experience, for the rea-
son that the admixtures of the acetone have nearly the same
boiling points. The acetone vapors are inflammable and when
mixed with air explosive.
PREPARATION OF PURE WOOD SPIRIT. 355
According to F. H. Meyer's system, German patent 134,978,
pure acetone is manufactured by spreading the gray acetate
in layers 2 to 4 centimeters deep upon sheets or sieves, which
rest upon trucks and are pushed into the distilling muffles.
These muffles are capable of working up 4400 Ibs. of calcium
acetate in 24 hours. They are heated by a direct fire, a uni-
form distribution of the heat and the same heating at all points
of the charge being secured by proper regulation of the fire.
When the acetone has been distilled off and the last remnants
blown out with steam, the truck is removed from the muffle
and is replaced by another previously charged with calcium
acetate.
The acetone oils which, as previously mentioned, are ob-
tained in the purification of crude acetone are decomposed to
two groups, namely to white acetone oil which comprises the
fractions boiling at from 167° to 466° F.. and to yellow ace-
tone oil boiling between 466'° and 502° F. These oils are
used in the celluloid industry and as additions to wood alco-
hol intended for denaturing purposes.
Working the wood tar. — Wood tar contains a large quantity
of combinations of which, however, only the mixture found
in commerce under the name of creosote can be separated to
advantage. By itself wood tar may be utilized as a preserva-
tive coating for wood, as well as for obtaining soot, and event-
ually as fuel in the destructive distillation of wood.
While beech tar, for instance, contains without doubt con-
siderable paraffin, it cannot be produced on a large scale at a
price to compete with that of the product obtained from crude
petroleum. The tar obtained from resinous woods contains
oil of turpentine and can be worked to greater advantage than
that from hard wood.
Preparation of creosote and tar oils. The wood tar is subjected
to distillation, this being best effected in a horizontal still of
the shape of a steam boiler and so bricked-in as to be slightly
inclined towards one side. On the lowest part of the still is a
larger aperture which can be closed by a cover and clamp.
356 MANUFACTURE OF VINEGAR.
The object of this arrangement is to facilitate the quick removal
of the pitch-like or asphalt-like mass which remains behind in
the still after the volatile products have been distilled off, and
which, if allowed to become cold, adheres so firmly to the
sides of the still that it can be detached only with great diffi-
culty.
All the tarry substances, which separate in distilling wood-
spirit from wood vinegar, and in neutralizing with lime or
soda, are combined with the tar taken from the condensing
vessels, and the mass thus obtained is subjected to distillation.
The latter might be conducted so that the distillates resulting
at certain temperatures are caught by themselves and the
distillate fractionated ; but, as a rule, the distillates are only
separated in such a manner that only the light oleaginous
products up to specific gravity 0.980 are caught by themselves
and worked further, separately from the heavy oils of upward
of 1.010 specific gravity.
At the commencement of distillation crude wood-spirit first
passes over, which is followed by quite a quantity of acetic acid
(distilled wood-vinegar). Next the light, and later on the
heavy, oils pass over, a pitch-like residue remaining in the still.
By mixing this residue, while still in a liquid state, with dry
hot sand, blocks may be shaped from the mass thus obtained,
which may be used for paving, like asphalt blocks. Mixed
with culm it yields a dough-like mass which may be utilized
for the manufacture of briquettes. If the residue cannot be
utilized in any other manner, it may be allowed to run upon
iron plates, and when cold, is broken up into small pieces and
used as fuel together with coal.
The quantities of the separate products of distillation depend
on the nature of the wood from which the tar has been ob-
tained and on the manner in which destructive distillation has
been conducted. Hard woods give on an average a tar which
by distillation yields, according to Vincent :
PREPARATION OF PURE WOOD SPIRIT. 357
Watery distillate (wood spirit, acetic acid) . . . 10 to 20 per cent.
Oleaginous light distillate, sp. gr. 0.966 to 0.977 . 10 to 15 "
" heavy " " 1.014 to 1.021 . 15 "
Pitch 50 to 62 "
The distillates, according to their specific gravities, are caught
separately in vats, a sample, for instance, 1 quart of the fresh
distillate, being immediately taken for the purpose of accurately
determining the quantity of soda required for neutralizing the
total quantity of fluid. The quantity of concentrated soda
solution necessary for neutralization is then added to the dis-
tillate, the whole thoroughly mixed, and the fluid allowed to
repose until two sharply separated layers are formed, the upper
one of which is of an oleaginous nature. The watery fluid is
then allowed to run off and is brought into one of the vats in
which crude wood-vinegar is caught. The oleaginous layer is
worked further by distillation.
The oils remaining after neutralizing the light and heavy
distillates are combined and subjected to careful rectification.
The receiver is changed as soon as it is ascertained by the
thermometer that the temperature has risen above 302° F.,
and is again changed when the temperature rises above 482°
F. The hydrocarbons distilling over at below 302° and above
482° F. might be used as solvents and for illuminating pur-
poses, but their preparation is not remunerative.
The distillate which has passed over between 302° F. and
482° F. contains phenol, cresol and phlorol, which together
form wood-creosote. The distillate is intimately mixed with
the assistance of a stirring apparatus with highly concentrated
soda lye (36° Be.), and the watery fluid is drawn off from the
supernatant layer of oil, which is combined with, the other
hydrocarbons. The watery fluid is for some time boiled in an
open pan to expel any hydrocarbons still present, and is then
saturated with sulphuric acid and allowed to repose. The
fluid of a penetrating odor separated thereby is creosote, which
is used for medicinal purposes. As a disinfecting agent it has,
however, been superseded by the cheaper coal-tar creosote
(carbolic acid).
358 MANUFACTURE OF VINEGAR.
To obtain the creosote prepared according to this process
permanently colorless, it is mixed with J to J per cent, of
potassium dichromate and £ to 1 per cent, of sulphuric acid,
allowed to repose for 24 hours and again distilled. The small
yield of creosote and its limited use make its profitable manu-
facture rather doubtful, except where sulphuric acid and soda
can be procured at cheap rates.
The heavy oils are worked up in the same manner. The
solution formed after treatment with soda solution is not added
to the crude wood-vinegar, but treated by itself, as it contains
scarcely any sodium acetate, but the sodium salts of the fatty
acids with higher boiling points, such as propionic, butyric,
valeric and caproic acids. This lye is used either for the
preparation of these acids, or the solution is evaporated to
dryness and ignited with the admittance of air to regain the
soda.
If the acids are to be prepared, the solution is evaporated
to the consistency of syrup, slightly oversaturated with sul-
phuric acid, and the resulting fluid diluted with water. The
oleaginous layer collecting upon the surface consists of a mix-
ture of the above-mentioned acids which are soluble with diffi-
culty in water. By rectifying the mixture at the temperatures
corresponding to the boiling points of the various acids, the
latter are obtained in an almost pure state.
It is still more suitable to distil the mass previously evapo-
rated to the consistency of syrup with alcohol and sulphuric
acid, whereby the odoriferous ethers of the various acids are
formed, which can then be separated by fractional distillation.
Since the heavy tar oils are entirely free from acid, and do
not gurn in the air, they may be used as lubricants for ma-
chinery, and were formerly much sought after for that pur-
pose ; but at present they have been largely superseded by
petroleum products, and in consequence of this are of less
value.
In the northern parts of Sweden and Finland considerable
quantities of birch-tar oil are prepared, and below are given
PREPARATION OF PURE WOOD SPIRIT. 359
*
the results of a series of experiments regarding the products
which were obtained in the distillation of a sample of Finland
birch-tar oil.
No. of the distillate. Limits of boiling points. Specific gravity.
1 212° to 226° F. 0.887
2. . . .... 4,... . - . . 356° to 437° F. 1.020
3 . . , 588° to 644° F.
No. 1 formed a red-yellow, very mobile oil of a not dis-
agreeable odor of birch tar. No. 2 was of a darker color and
of a less agreeable odor, while No. 3 represented a dark brown,
very viscous mass. By heating the residue in the still to
above 644° F., it is suddenly decomposed, heavy vapors being
evolved and a lustrous, very porous coal remaining behind.
By distilling the tar oil with caustic soda quite a series of
oleaginous distillates are obtained.:
No. of the distillate. Limits of boiling points. Specific gravity.
1 212° to 284° F. 1.046
2 ;..-.-. . . . 284° to 392° F. 1.114
3 i. . ........ . 392°to437°F. 1.171
4 -'. ' , ' , . 437° to 482° F. 1.058
5 ':..:'. . . ., . . 482° to 734° F. 1.039
Nos. 1 to 3 were pale, red-yellow oils ; Nos. 4 and 5 darker
and more viscous. The residue remaining in the still at above
734° F. was a dark black mass, soft and flexible at the or-
dinary temperature, and becoming hard only at a lower tem-
perature.
PART II.
MANUFACTURE OF CIDERS, FRUIT-WINES, ETC.
CHAPTER XXVII.
INTRODUCTION.
THE term wine in general is applied to alcoholic fluids
which are formed by the fermentation of fruit juices, and
serve as beverages. According to this definition, there may
actually be as many kinds of wine as there are fruits whose
juices, in consequence of their content of sugar, are capable
of vinous fermentation ; and, in fact, besides the apple and
pear, there are many other fruits which are likewise applicable
to wine-making. Among these may be named, currants,
gooseberries, mulberries, elderberries, cherries, oranges, dates,
pine-apples, raspberries, strawberries, etc. But, in order to
make the product from such fruits resemble the standard wine
made from grapes, various ingredients have to be added, as,
for instance, an acid, spices, coloring, and an astringent, to
replace the extractive matter. Tartaric acid is, as a rule,
used as an acid addition, and elderberry or whortleberry juice
as coloring matter. The "water employed in the manufacture
should be pure and soft.
Ripening of fruits, — In order to form a clear idea of the
process which takes place during the growth, ripening, and
final decomposition of a fruit, it is necessary to refer to the
constituents which are found in an unripe fruit at its first
appearance.
(360)
INTRODUCTION. - 361
Besides water, the quantity of which varies between 90 and
45 per cent., fruits contain partly soluble and partly insoluble
substances. The juice obtained by pressure contains the sol-
uble constituents, such as sugar, gum, tannin, acids, salts, etc.,
while the remaining insoluble portion consists chiefly of cellu-
lose, starch, a gum-like body, a few inorganic substances, and
further, the characteristic constituent of unripe fruits, to which
the term pectose has been applied. It forms the initial point
for the phenomena observed during the growth and ripen-
ing of fruits, and, therefore, requires a somewhat closer ex-
amination.
In regard to its behavior, pectose approaches cellulose and
starch. It is chiefly found in the pulp of unripe fruits, but
also in certain roots, especially in carrots, beets, and others.
It is insoluble in water, spirits of wine, and ether, but during
the ripening of the fruit it undergoes a change, induced by the
acids and heat, and is converted into pectine, which is readily
soluble in water. To pectose are due the hardness of unripe
fruits and also the property of many fruits and roots of boil-
ing hard in water containing lime, the pectose combining with
the lime.
The formation of pectine commences as soon as the fruits
are exposed to the action of heat, and then depends on the in-
fluence of the vegetable acid present upon the pectose. This
can be shown by expressing the pulp of an unripe apple. The
juice thus obtained contains scarcely a trace of pectine, but,
by boiling it for a few minutes with the pulp of the fruit, the
fluid, in consequence of the formation of pectine, acquires a
viscous quality, like the juice obtained from ripe fruits.
Pectine, nearly pure, is white, soluble in water, non-crystal-
lizable, and without effect upon vegetable colors. From its
dilute solution it is by alcohol separated as a jelly, and from
its more concentrated solution, in long threads. Brought into
contact with alkalies or alkaline earths, pectine is transformed
into pectic acid. Under the influence of a peculiar ferment
called pectase, which will be described later on, pectine is
362 MANUFACTURE OF VINEGAR.
transformed into pectosic acid, and by dilute acids into meta-
pectic acid.
By boiling a solution of pectine in water for a few hours, it
partially loses its viscous condition and separates a substance
called parapectine, which shows the same behavior as pectine,
except that it is not precipitated by neutral lead acetate.
When treated with dilute acids the parapectine is transformed
into metapectine, which might be called metapectous acid, as
it shows a decidedly acid reaction and colors litmus paper
strongly red.
Metapectine is soluble in water, non-crystallizable, and, like
pectine and parapectine, insoluble in alcohol, which precipi-
tates it from its solutions in the form of a jelly. On being
brought into contact with bases it is also transformed into
pectic acid. It differs from pectine and parapectine in that
the solution is precipitated by barium chloride.
Pectase, the peculiar ferment previously referred to, is sim-
ilar in its mode of action to diastase and emulsion. It can be
obtained by precipitating the juice of young carrots with alco-
hol, whereby the pectose, which was at first soluble in water,
becomes insoluble, without, however, losing its effect upon the
pectous substances.
By adding pectase to a solution of pectine, the latter is im-
mediately converted into a jelly-like body, insoluble in water.
This phenomenon is the pectous fermentation, which may be
compared with lactic acid fermentation. It is not accom-
panied by an evolution of gas, and may take place with the
air excluded, a temperature of 86° F. being most favorable for
its progress.
Pectase is an amorphous substance. By allowing it to stand
in contact with water tor a few days, it decomposes, becomes
covered with mold-formations, and loses its action as a fer-
ment, this action being also destroyed by continued boiling.
In the vegetable organism it occurs in a soluble as well as in-
soluble state.
Roots such as carrots, beets, etc., contain soluble pectase
INTRODUCTION. 363
and their juice added to a fluid containing pectine in solution
immediately induces pectous fermentation, while the juice of
apples and other acid fruits produces no effect upon pectine,
the latter being present in them in a modified insoluble form
and accompanying the insoluble portion of the pulp. On
adding the pulp of unripe apples to a pectine solution it gel-
atinizes in a short time, in consequence of the formation of
pectosic and pectic acids. It is therefore due to the presence
of these acids that many ripe fruits are so easily converted
into jellies.
Pectosic acid is the result of the first effect of the pectase
upon pectine ; it being, however, also formed by bringing
dilute solutions of potash, soda, ammonia or alkaline carbon-
ates in contact with pectine. In all these cases salts are formed
which, when treated with acids, yield pectosic acid. The lat-
ter is gelatinous, and with difficulty dissolves in water. In
the presence of acids it is entirely insoluble. It is quickly
transformed into pectic acid by long boiling in water, by pec-
tase, or by an excess of alcohol.
By allowing pectase to act for some time upon pectine, pec-
tic acid is formed ; the same conversion taking place almost
instantaneously by dilute solution of potash, soda, ammonia,
alkaline carbonates, as well as by barium, lime and strontium
water. Its formation in the above-described manner is pre-
ceded by that of pectosic acid, which, as previously men-
tioned, is converted by the same agents into pectic acid.
Pectic acid is insoluble in cold, and scarcely soluble in hot,
water. By boiling it, however, for a certain time in water, and
constantly replacing the water lost by evaporation, it disappears
entirely, and is converted into a new acid, soluble in water.
Alkalies decompose it very rapidly, the final result being met-
apectic acid, which is soluble in water, but non-crystallizable.
On boiling in hot water, the solution forms, after cooling, a
Pectic acid further possesses the special property of dissolv-
ing in a large number of alkaline salts and forming with them
364 MANUFACTURE OF VINEGAR.
true double salts, which always show a decidedly acid reaction,
dissolve in water, and on cooling form consistent jellies.
By boiling for a few hours a solution of a pectous salt, the
latter is transformed into a parapectous salt which, when de-
composed by a dilute acid, yields parapectic acid. It is non-
crystallizable, shows a strong acid reaction, and forms with
alkalies soluble salts. It is precipitated by barium water in
excess,
Metapectic acid is formed in various ways, among others
by leaving an aqueous solution of parapectic acid to itself for
some time, but also by the action of the lime contained in the
cell-tissues of roots and fruits upon pectose. It is insoluble in
water, does not crystallize, and gives soluble salts with all
bases. With an excess of bases the salts acquire a yellow
coloration. They are precipitated by basic lead acetate.
What has been said in the preceding may be briefly con-
densed as follows : —
1. By the influence of heat upon pectose pectine is formed.
2. Pectine is transformed into parapectine by boiling its
aqueous solution for several hours.
3. Parapectine, when treated at a boiling heat with dilute
acids, is converted into metapectine.
4. Pectase converts pectine into pectic acid.
5. By long-continued action of pectase upon pectine, pectic
acid is formed.
6. Pectic acid is by boiling water transformed into para-
pectic acid.
7. An aqueous solution of parapectic acid is rapidly con-
verted into metapectic acid.
All these bodies are derived from pectose, which through all
these transformations has not even suffered a change in the
proportion of weight of its constituents (carbon, hydrogen, and
oxygen); and hence all have the same qualitative and quanti-
tative compositions. This may, perhaps, sound odd, but
chemistry presents numerous analogies for such cases, and
hence the term isomeric has been applied to bodies which, with
INTRODUCTION. 365
the same quantitative composition, exhibit very different
chemical properties.
The changes pectose undergoes by the influence of heat, by
the action a peculiar ferment, acid and alkalies, and the re-
sulting combinations mentioned above, have of course been
artificially effected by chemical means. They resemble, how-
ever, so closely the state of fruits in the course of their growth
and ripening, and the influences and conditions to which fruits
are exposed in nature are sufficiently similar to those artifi-
cially induced, that their action may be reasonably supposed to
be the same. We know from daily experience that heat pro-
motes the development and ripening of fruit. Fruits contain
pectose and acids, and alkalies and bases are conducted to
them from the soil ; and hence in fruit in a normal state of
development none of the chemical agents are wanting which
the chemist uses for the production of derivatives of pectose.
If the transformation of substances under the influence of
other substances be considered as dependent on chemical
processes, the development of a fruit from its first formation
to complete ripeness, and even to its decomposition, rotting,
and putrefaction, is a chemical process in the widest sense of
the word. This is evident, not only from what has been said
in the preceding, but has also been plainly shown by special
chemical researches into the changes fruits undergo during
their development and perfection. The results of these
researches are briefly as follows : —
1. The quantity of water contained in the pulp of a fruit
is considerable ; it varying between 45 and 90 per cent. In
many fruits the content of water remains unchanged during
the different periods of ripening, but, as a rule, it is somewhat
greater in the commencement.
2. Fruits of the same kind examined at the same season of
the year always contain the same quantity of water ; the same
holding good as regards the various parts of the pulp of a fruit.
3. The solid constituents in the pulp of fruits amount to
between 10 and 25 per cent. They consist of soluble substances
366 MANUFACTURE OF VINEGAR.
which dissolved in the water from the juice of the fruits ; and
of insoluble bodies which compose the membranes of the cells.
4. The quantity of soluble substances always increases with
increasing ripeness, while the weight of the insoluble decreases ;
and hence it may be said that the soluble substances contained
in the juice of a fruit are formed at the expense of the insolu-
ble portion of the pulp. The bodies which become soluble
are starch, pectose, and a gum-like substance capable of being
converted into gum.
On this modification of the solid portion of the pulp of a
fruit depend also the changes a fruit undergoes in regard to
hardness and transparency during ripening.
According to the mode of action of the pectase and acids
upon the pectose, all ripe fruits contain pectine.
5. Various acid fruits, such as plums, cherries, etc., are fre-
quently observed to secrete a neutral juice which, in conse-
quence of the evaporation of the water, leaves a gum-like
substance upon the exterior of the fruit. This phenomenon
throws some light upon the separation of gum as it appears in
many trees, and which, when it occurs very abundantly, is
actually a disease.
In fruits becoming thus covered with a gum, a transparent,
neutral substance insoluble in water occurs stored in the cells
of the pulp. Under the influence of nitrogenous substances,
which act as a ferment, and perhaps also of acids, this gum-like
substance is modified and transformed into actual gum, which
is then converted into sugar in the interior of the pulp of the
fruit ; an excess of this gum-like substance being secreted and
forming a firm coating upon the exterior of the fruit.
6. The sugar occurring in ripe fruits is evidently derived
from various sources. The occurrence of a large quantity of
starch in many unripe fruits, especially in apples, and its com-
plete disappearance at the time of ripeness, allow of no other
explanation than that the sugar occurring in fruits is formed
by the conversion of the starch under the influence of the acids
present ; other indifferent substances, such as gum, vegetable
INTRODUCTION. 367
mucus, etc., undergoing similar transformations and yielding
in this manner a certain portion of sugar. Even tannin, which
occurs in all unripe, but not in ripe, fruits, can be changed by
acids and ferments so as to form sugar.
Thus far nothing justifies the supposition that the acids in
fruits, such as tartaric, citric, malic acids, are converted into
fruit sugar. To entertain such an opinion it would have to
be supposed that the molecules of these acids, which are far
more simple than those of fruit-sugar, become more complex
and are converted into sugar. In such natural transforma-
tions the reverse is, however, generally the case, the molecules
always endeavoring to become the more simple the farther they
withdraw from organized structures.
7. It has been attempted to explain in various ways the very
remarkable phenomenon of the gradual disappearance of the
acid in ripening fruits. It might not be impossible that the
acid of a fruit, is neutralized by the bases conducted to it
through the juice ; or that it is covered by the sugar or the
mucous substances formed in the juice ; or, finally, that it dis-
appears at the moment of ripeness by suffering actual combus-
tion. An examination of these various theories leads to the
conclusion that the acid is neither neutralized nor covered by
the sugar or the mucous substances, but that it actually under-
goes slow combustion.
During the stages of development and ripening, a fruit
passes through two different stages sharply separated from
each other by definite chemical phenomena. In the first
stage, which may be designated as that of growth, whilst the
fruit remains green, its relation to the atmosphere appears the
same as that of leaves, for it absorbs carbonic acid and evolves
oxygen. During this epoch it increases rapidly in size, and
receives through the stem the inorganic substances, indispens-
able for its development, and the water. If, at this stage, it
is taken from the tree, it soon commences to wither and decay.
But in the second period, when it fairly begins to ripen, its
green color is, as a rule, replaced by a yellow, brown-red, or
368 MANUFACTURE OF VINEGAR.
red. Oxygen is now absorbed from the air and carbonic acid
is evolved, whilst the starch and cellulose are converted into
sugar under the influence of the vegetable acids, and the fruit
becomes sweet. When the sugar has reached the maximum
the ripening is completed, and if the fruit be kept longer, the
oxidation takes the form of ordinary decay.
CHAPTER XXVIII.
FRUITS AND THEIR COMPOSITION.
FOR the preparation of fruit-wines, not only the fruits culti-
vated in our gardens and orchards on account of their fine
flavor are used, but sometimes also others which do not by any
means possess an agreeable taste, and whose juices, after fer-
mentation, yield a product which has at least only a very
doubtful claim to the name of " wine." The utilization of such
material for wine-making can only be explained by special
fancy, and hence here only such fruits will be considered
as, on account of the nature of their juices, will yield with
rational treatment a beverage of a sufficiently agreeable taste
to be liked.
For making fruit-wine, sugar not only by itself but also
in its proportion to the free acid present, is undoubtedly the
most important constituent of the fruit. The following table
from Fresenius gives the average percentage of sugar in
different varieties of fruit :
I,
Peaches 1.57 p. c.
Apricots. . .' 1.80
Plums 2.12
Keine Claudes 3.12
Greengages ...... 3.58
Raspberries 4.00
Blackberries 4.44
Strawberries .5.73
Whortleberries. . .5.78
Currants 6. 10 p. c.
German prunes 6.25 "
Gooseberries 7.15 "
Pears 7.45 "
Apples 8.37 "
Sour cherries ...... 8.77 "
Mulberries 9.19 "
Sweet cherries 10.79 '*
Grapes 14.93 "
FRUITS AND THEIR COMPOSITION.
369
II. Table according to average percentage of free acid
expressed in malic acid :
Pears 0.07 p. c.
Greengages 0.58 u
Sweet cherries 0.62 "
Peaches 0.67 "
Grapes 0.74 "
Apples 0.75 "
German prunes 0.89 "
Keine Claudes 0.91 "
Apricots 1.09 "
Blackberries 1.19 p. c.
Sour cherries 1.28 "
Plums 1.30 "
Whortleberries 1.34 "
Strawberries 1.37 "
Gooseberries 1.45 "
Kaspberries ....... 1.48 "
Mulberries 1.86 "
Currants. . 2.04 "
III. Table according to the proportion between acid, sugar,
pectine, gum, etc.
Plums
Apricots ....
Peaches ....
Easpberries . .
Currants. . . .
Keine Claudes .
Blackberries . .
Whortleberries .
Strawberries . .
Gooseberries . .
Mulberries . . .
Greengages . .
Sour cherries . .
German prunes .
Sweet cherries .
Grapes ....
Pears .
Acid.
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Sugar.
1.63
1.65
2.34
2.70
3.00
3.43
3.73
4.31
4.37
4.93
4.94
6.20
6.85
7.03
11.16
20.18
94.60
Pectine, gum, etc.
3.14
6.35
11.94
0.96
0.07
11.83
1.21
0.41
0.08
0.76
1.10
9.92
1.43
4.35
5.60
2.03
44.40
IV. Table according to the proportion between water, solu-
ble and insoluble substances.
24
370
MANUFACTURE OF VINEGAR.
Composition of the juice in
100 parts, without the in-
soluble substances;
Water.
Soluble
substances,
Insoluble
substances. Water.
Soluble
substances.
Raspberries ....
100
9.12
6.88
91.64
8.3C
Blackberries ....
100
9.26
6.46
91.53
8.47
Strawberries ....
Plums
100
100
100
3.39
9.94
11.00
5.15
0.87
6.62
91.42
91.13
90.09
8.58
8.87
9.91
Currants . . . . •
Whortleberries. . .
100
12.05
16.91
89.25
10.75
Gooseberries ....
100
12.18
3.57
89.14
10.86
Greengages ....
Auricots
100
100
100
13.04
13.31
14.25
1.53
2.07
5.54
88.46
88.25
87.52
11.54
11.75
12.48
Pears
Peaches
100
14.64
2.10
87.23
12.77
German prunes. . .
100
15.32
3.15
86.71
13.29
Sour cherries . . .
100
16.48
• 1.31
85.85
14.15
Mulberries ....
100
16.57
1.47
85.79
14.21
Apples
100
16.89
3.61
85.46
14.54
Reine Claudes . .
100
18.52
1.22
84.37
15.63
Sweet cherries . . .
Graoes . . .
100
100
18.61
2281
1.53
5.81
84.30
81.42
15.70
18.58
V. Composition
sugar, pectine, etc.
of the juice according
in 100 parts :
to the content of
Peaches
Pectine,
Sugar, etc.,
p. c. p. c.
. 1.99 10.05
2 04 6 98
German prunes ....
Pectine,
Sugar, etc.,
p. c. p. c.
7.56 4.70
8.00 1.24
8.12 0.77
8.43 4.02
9.14 4.59
10.00 2.22
10.44 2.17
15.30 2.43
16.15 2.07
. . 1.42 n. r
Apricots .
Plums
. 2.13 8.19
2.80 5.40
. 4.18 6.45
. 4.84 1.73
. 5.32 1.72
. 6.89 0.13
. 7.30 0.16
free acid in 1
. . . 0.09 p. c.
. . . 0.59 "
. . . 0.67 "
. . . 0.80 u
. 0 82 "
Whortleberries . . . .
Pears
Apples
^Mulberries
Raspberries
Blackberries
Strawberries
Currants
VI. Content of
Pears
Reine Claudes ....
Greengages
Grapes
Apples
Sour cherries . . .
Sweet cherries. ....
Grapes
.00 parts of juice :
Blackberries . ...
Sour cherries . .
52 "
57 "
Gooseberries ....
1.63 u
Plums
.72 "
Pparhptj
0 85 u
80 tk
Sweet cherries ....
German prunes. . . .
Apricots.
. . 0.88 "
. . . 1.08 "
. 1.29 "
.88 "
2.02 "
2.43 "
Mulberries
Currants
FRUITS AND THEIR COMPOSITION. 371
Tables V. and VI. represent the proportion in which the
soluble constituents of the fruit are found in the juice or must
obtained from them. In the practical execution of the pre-
paration of fruit wines we will have occasion to refer to these
tables.
For the preparation of wine, only the soluble substances,
which pass into the must, and from which the wine is formed,
are chiefly of interest, and it will be necessary to consider
them somewhat more closely.
Grape-sugar or Glucose. — This sugar is widely diffused
throughout the vegetable kingdom, it occurring in most kinds
of sweet fruits, -in honey, etc. Artificially it can be readily
obtained by heating a solution of cane-sugar with a dilute acid.
It is also formed by dissolving cane-sugar in wine. On a large
scale it is prepared by boiling starch with very dilute sulphuric
acid for several hours, neutralizing the liquid with chalk and
evaporating the solution.
Grape-sugar is much less sweet than cane-sugar. In alco-
hol of 90 per Tr. it is sparingly soluble ; in hot water it dissolves
in every proportion ; of cold water it requires, however, about
1J- parts for solution. It crystallizes from aqueous solution
with one molecule of water, in cauliflower-like masses and from
hot alcohol in warty, anhydrous needles. A solution of crys-
tallized grape sugar turns the plane of polarization to the
right, but one of anhydrous grape-sugar to the left.
Acids. — The acid reaction of fruit juices is partly due to
malic acid and partly to citric acid, and also as in the case of
grapes to tartaric acid. As a rule all these acids are present ;
in currants citric acid predominates; in apples, etc., malic
acid.
The presence of potassium in grape-must gives rise to the
formation of potassium bitartrate of crude tartar. Tartar
requires for its solution 240 parts of cold water ; in alcoholic
fluids it is less soluble, and hence it is found as a crystalline
deposit in wine casks. Fruit-musts contain no tartaric acid,
and, consequently, the wines prepared from them cannot de-
372 MANUFACTURE OF VINEGAR.
posit tartar. The salts formed by malic and citric acids with
potassium being readily soluble and even deliquescent form
no deposit in the wine.
Albuminous substances. — By this general term are designated
several nitrogenous vegetable substances which have the same
composition ; they being vegetable albumen, fibrin, and glue.
The quantities of these substances in the different musts are,
on the one hand, so small, and the difficulty of accurately dis-
tinguishing them from each other is, on the other, so great,
that it is scarcely possible to definitely determine the kind
actually present in the fruit juice. Most likely all are present
at the same time.
For the preparation of wine these bodies are of importance ;
they furnishing the material for the development of the yeast-
fungus during fermentation.
Pectous substances. — Under the heading " Ripening of fruits,"
the pectous substances have been sufficiently discussed. They
are scarcely ever wanting in a fruit juice, but being insoluble
in alcoholic fluids they are entirely separated with the yeast,
and hence are not present in fruit-wines.
'' Gum and Vegetable Mucilage. — Our knowledge as regards
gum is still limited. Gum-arabic, which may be studied as a
representative of this class, is an exudation from certain species
of acacia and consists essentially of arabin. It is generally
supposed to be soluble in water, but on endeavoring to filter a
somewhat concentrated solution not a drop will be found to
run off, and the little which possibly may pass through the
filter is by no means clear.
Closely related to gum-arabic is bassorine, the gum which
exudes from the cherry, plum, almond, and apricot trees. It
does not give a slime with water, but merely swells up to a
gelatinous mass.
Wine brought in contact with the smallest quantity of gum-
arabic remains permanently turbid and cannot be clarified by
filtering or long standing. From this behavior of gum it may
be concluded that, though it may occur dissolved in the must,
it is not present in the wine.
FRUITS AND THEIR COMPOSITION. 373
The various kinds of vegetable mucilage have also not yet
been accurately examined ; it only being known that there are
quite a number of them. It is, however, likely that only a
few of them are actually soluble in water. Though the muci-
lage of certain seeds, such as linseed and quince-seed, may be
considered to be as soluble in water as gum-arabic, and per-
haps more so, because it is a perfectly clear fluid drawing
threads, yet on filtering it will be found that what passes
through contains scarcely a trace of mucilaginous substance.
Hence, it is doubtful whether mucilages exist which are
actually soluble in water, and whether they occur in wine.
Artificial dextrin is, however, an exception, as it forms with
water a perfectly clear fluid, which can be filtered. Attention
may here be called to an easy method of distinguishing be-
tween solution of gum-arabic and of dextrin. The first can-
not be heated, even for a minute, over an open fire without
scorching, while the latter can be completely boiled down
without fear of burning.
Tannin. — Several kinds of tannin occur in plants, which can,
however, be finally reduced to two modifications, viz.: patho-
logical and physiological tannin. The first occurs in large
quantity in nut-galls, especially in the Chinese variety, also in
sumach (the twigs of Rhus coriaria) and in many other plants.
Pathological tannin is characterized by splitting under the
influence of dilute acids as well as by fermentation into gallic
acid and grape-sugar. Furthermore, it completely precipitates
glue from its solutions, but it is not suitable for the conversion
of the animal skin into technically serviceable leather which
will withstand putrefaction. Besides, only the gallic acid
obtained from pathological tannin yields pyrogallic acid by
destructive distillation.
Physiological tannin is chiefly found in materials used for
tanning. It cannot be split by dilute acids or fermentation,
does not yield gallic acid, and the product of destructive dis-
tillation is not pyrogallic acid, but pyrocatechin or oxyphenic
acid. It converts the animal skin into perfect leather.
374 MANUFACTURE OF VI^GAR.
There can be but little doubt that physiological tannin is
the variety found in fruits and fruit-juices. Generally speak-
ing, a content of tannin in wine is not exactly a- desirable
feature, as it is readily decomposed. It can only have an ad-
vantageous effect when the wine contains an excess of albumin"
ous substances which the tannin removes by entering
into insoluble combinations with them. This may be the
reason why wine containing tannin is considered more dura-
ble, because if it contained albuminous substances in large
quantity it would be still more readily subjected to changes.
Under such circumstances a small addition of tannin to the
wine may be of advantage, though instead of tannin it is
advisable to use an alcoholic extract of grape-stones, they being
uncommonly rich in tannin.
Inorganic constituents. — The inorganic constituents of the
different varieties of fruit are very likely the same, namely,
potash, lime, magnesia, and sulphuric and phosphoric acids,
they varying only in the proportions towards one another and
in the total quantity of all the substances. Moreover, their
quantity is too small to exert an influence upon the quality of
the wine to be produced, being of interest only in regard to
the exhaustion of the soil. Though lime and sulphuric acid in
sufficient quantity occur almost everywhere in the soil, this
cannot be said of potash and phosphoric acid. Unfortunately
there are no accurate statements regarding the amount of these
substances which is withdrawn from the soil by the crop of one
year, but there can be no doubt that it is very large, and that
consequently fruit trees from time to time require a certain
amount of manure in order to return to the soil what has been
taken from it.
Fermentation. — Fermentation is a chemical process which is
always caused by the presence of a ferment or a substance in a
peculiar state of decomposition. Although to induce fermen-
tation the presence of a ferment is necessary, it does not take
part in the decomposition of the fermenting substance. The
products of fermentation vary according to the nature of the
FRUITS AND THEIR COMPOSITION. 375
fermenting body, as well as according to the nature of the fer-
ment itself. Each peculiar kind of fermentation requires a
certain temperature, and it is nearly always accompanied by
the development of certain living bodies (bacteria or fungi).
.When yeast is added to a dilute solution of dextrose or
another glucose, vinous fermentation speedily sets in ; whilst a
solution of cane-sugar undergoes fermentation but slowly, the
cause being that this sugar must first be converted into inverted
sugar before fermentation can commence. Vinous fermenta-
tion proceeds most rapidly at 77° to 86° F., and does not take
place below 32° or above 95° F. The presence of a large
quantity of acids or alkalies prevents fermentation, while if the
liquid has a faint acid reaction, fermentation proceeds best.
The yeast which is formed in the fermentation of the juice
of grape and other kinds of fruit is produced from soluble albu-
minous bodies contained in fruit. It consists of one of the
lowest members of the vegetable kingdom (Torula cerewsise)^
and under the microscope is seen to be made up of little oval
transparent globules, having a diameter of not more than 0.1
millimeter and often adhering in clusters and strings. They
are propagated by budding, and die as soon as they have
reached their highest state of development. In contact with
air and water yeast soon undergoes putrefaction.
The chief products of vinous fermentation are alcohol and
carbon dioxide ; a small quantity of the sugar being at the
same time converted into other products, about 2.5 per cent,
being transformed into glycerin and 0.6 to 0.7 per cent, into
succinic acid. A further portion of the sugar, about one per
cent., is assimilated in the form of cellulose by the yeast and
separated. By the simultaneous formation of these different
secondary products about 5.5 to 6.5 per cent, of sugar is lost
in the formation of alcohol. As they are not always formed
in equally large quantities, no conclusion can be arrived at
from the content of sugar in the must as to the quantity of
alcohol corresponding to theory in the finished wine. It is,
as a rule, supposed that the sugar yields one-half its weight
376 MANUFACTURE OP VINEGAR.
of alcohol, which is sufficiently correct for all practical pur-
poses.
Absolute alcohol, i. e., alcohol entirely free from water, is a
very mobile fluid, clear as water and almost odorless. It boils
at 173° F., and when it is cooled down to 148° F. it becomes
viscid, but does not solidify. Its specific gravity at 32° F. is
0.80625, and at 59° F. 0.79367. It is very inflammable, and
burns with a blue, non-luminous flame. It absorbs moisture
with great avidity, and is miscible with water in all propor-
tions, the mixture evolving heat and undergoing contraction.
The methods for determining the content of alcohol in a
fluid have already been previously given.
Sucdnic add. — No accurate researches have as yet been
made in regard to the quantity of this acid in wine, its influ-
ence upon the quality of the wine, and the conditions under
which more or less of it is formed during fermentation. Ac-
cording to Pasteur, the more succinic acid is formed the slower
fermentation progresses; the weaker the development of yeast
and the less nourishment offered to the latter. In acid fluid
more succinic acid is formed than in neutral.
Succinic acid is quite readily soluble in a mixture of alcohol
and water, and consequently also in wine. Its taste is not
very sour, but disagreeable, and adheres for some time to the
tongue ; hence its presence can scarcely be expected to give
an agreeable taste to the wine.
Glycerin. — Glycerin being found in grape-wines, in which
it is formed from the sugar by fermentation, there can scarcely
be any doubt of its formation under the same conditions in
fruit wines. According to Pasteur, the quantity of glycerin
in wine is in a definite proportion to the succinic acid formed,
and, hence, more glycerin would be produced with slow fer-
mentation and in an acid fluid. In red wines Pasteur found
4 to 7 per cent, of glycerin.
Pure glycerin is a colorless, very viscid liquid having a spe-
cific gravity of 1.27. It can be mixed with water and alco-
hol in all proportions and possesses a very sweet taste. It is
FRUITS AND THEIR COMPOSITION. 377
very likely that the mild sweet taste of many ripe wines is due
to a certain content of glycerin.
A solution of 7 parts of glycerin in 1000 of water (the pro-
portion in which Pasteur found glycerin in wine) does not
possess a sweet taste and differs from water only in being more
insipid. By adding to such a solution 100 parts of alcohol,
the mixture shows a taste different from that of alcohol alone,
diluted in the same proportion, the predominant taste of the
latter being decreased by the glycerin and that of the mixture
becoming milder. Hence a certain importance has to be as-
cribed to the glycerin.
Carbonic acid. — The greater portion of the carbonic acid
formed by fermentation escapes as a gaseous body during the
process, but a certain portion remains dissolved in the wine as
long as the temperature of the latter is not raised. The tem-
perature of cellars generally increases, however, towards the
end of spring, which causes anew a slight development of car-
bonic acid in consequence of which the wine again becomes
turbid. The presence of carbonic acid is of advantage only in
young wine, as its protects it from the direct action of the air
by forming a layer upon the surface. In old wines it conceals,
however, the fine aroma and taste, making them appear
younger than they actually are.
Though it cannot be said that carbonic acid plays an essen-
tial part in the preparation of wine, it deserves attention on
account of its deleterious influence upon the workmen. To
avoid all injurious consequences, provision should be made
for a thorough ventilation of the cellar by means of windows
and doors. If fermentation is carried on in barrels, the car-
bonic acid developed in a number of them should be conducted
by means of tubes secured air-tight in the bungs to a zinc pipe
which passes through a suitable aperture into the open air.
Alkaloid in wine. — It has frequently been asserted that an
alkaloid exists in young wine, which not being contained in
the must or the yeast must have been formed from the nitro-
genous constituents of the yeast or of the fluid during fermen-
378 MANUFACTURE OF VINEGAR.
tation. It has not been found in old wine, and it is therefore
concluded that it in time decomposes. Should this observation
be confirmed, it would explain the difference in the effects of
the very intoxicating young wines and of old wines.
CHAPTER XXIX.
MANUFACTURE OF CIDER.
THE first step in the preparation of fruit-wines is to obtain
the juice or must from the fruit. Stamping or grinding and
subsequent expressing of the paste thus formed by means
of strong pressure suffice in most cases for berries and other
small fruits. With apples, etc., this manner of reduction is
not only difficult, but also connected with considerable loss
caused by larger and smaller pieces jumping from the trough.
The earliest appliance known was simply a trough in which
the apples were reduced to an imperfect pomace by rolling
them with a heavy cylindrical stone or by pounding them as
in a mortar. An improvement was the production of the
English cider-mill. This consisted of a pair of coarsely cor-
rugated iron cylinders from which the apples fell to a second
pair close together and finer in their surfaces, and passed
through finely mashed to the pomace vessel underneath. In
1852, Mr. W. 0. Hickock, of Harrisburg, Pa., invented a
portable cider-mill which consisted of a pair of small horizon-
tal cylinders armed with small spirally arranged teeth or spikes
revolving close together, one at a higher velocity than the
other. The apples were first broken by the action of a
coarsely-fluted roller which revolved against a table under
the hopper, and after passing between the cylinders, the apples
were not only bruised but also grated into the required pomace.
This machine was capable of grinding 100 bushels of apples
per day. Numerous modifications have been made in the
MANUFACTURE OF CIDER. 379
plan of Mr. Hickock's mill, some being simply spiked cylinders
against which the apples were carried and held till grated by
reciprocating plungers.
The limits of this work will not permit of a notice of all
the various styles of portable mills before the public or the
multitude of graters or apple grinders, many of which possess
excellent points and are worthy of commendation. An excel-
lent apparatus for crushing apples is the crushing-mill shown
in Figs. 90 and 91, B C (Fig. 91) representing the cylinders
provided with teeth. A hopper, A, receives the apples, which
pass between the cylinders, where they are crushed and fall
FIG 90. FIG. 91. •
into the receiver F placed underneath. Two men operate
this mill by means of cranks. Larger and stronger mills are
used when the quantity of apples seems to require them, and
in that case horse-power is applied.
Fig. 92 shows Davis's star apple-grinder. The grinder
shown in the illustration is a heavy machine weighing 340
Ibs. The cylinder is 12 inches in diameter and 12 inches long,
is turned and carefully balanced, has grooves planed in to
receive the knives, six in number, which are finely made and
tempered. Each knife furnished is made of steel-plated iron,
the steel being very thin and having a back of iron ; there
380 MANUFACTURE OF VINEGAR.
is no danger of breaking, although made very hard. The
end of the cylinder is banded with wrought-iron bands
and the knives are set with set- screws. The shaft is of steel
and runs in anti-friction metal. The concaves are hung at
top, so they can swing back at the bottom to allow stone, pieces
of iron, etc. to pass through without injuring the knives. The
concaves are held to their places by a bolt which allows the
concave to be set as close as desired to the cylinder, and is
held to its place by coil-springs which will give enough to
allow stones to pass and yet hold rigid in grinding even fro-
zen apples. The frame is one casting, and as the concaves
are fast to the frame they cannot get out of line or be dis-
placed, as in the case when the concave is fast to the hopper.
The hopper can be readily removed to adjust knives, and all
parts are adjustable and easy to get at. This machine can be
gauged to grind from 200 to 400 bushels per hour. Power
required to grind six bushels per minute, about six horse-power,
say about as many horse-power as desired to grind bushels per
minute.
Presses. — For obtaining the juice from berries, etc., a press
is generally not required, or at least only a slight pressure ;
the greater portion of it running out from the must by placing
MANUFACTURE OF CIDER.
381
the latter upon a cloth spread over a perforated bottom in a
vat. The juice retained by the lees, which, as a rule, is very
sour and has to be diluted with water, can be extracted with
the latter more completely than is possible with the strongest
press.
For obtaining the juice from apple pomace, etc. a good press
is, however, an important auxiliary. Before the introduction
of screws the method of extracting the juice of the apple was
by the use of heavy weights, wedges, and leverage. Until
within a late period a large wooden screw was used and is even
now employed in some sections of the country. Of these
screws two and frequently three and four, set in a strong frame-
work of double timbers, were found no more than sufficient to
separate the cider from the pomace. In order to operate these
screws a long heavy wooden lever became necessary, which
required the united services of four or five men to handle, and
not unfrequently the strength of a yoke of oxen was called
into requisition before the work
could be accomplished. An im-
provement upon the wooden screw
was made by the substitution of
the iron screw and iron nut. But
the objectionable feature of hav-
ing to handle heavy and cumber-
some levers still remained, mak-
ing labor irksome and expensive.
In modern presses this difficulty
has been entirely overcome, and
the juice is extracted from the
pomace with great ease and com-
pleteness.
Of the many presses before the
public, a hand-press a-nd a power-
press are here illustrated ; presses of all sizes between these
two are found in the market. Fig. 93 shows the " Farmer's
cider-press." It is 7 feet 1 inch high, with a width between
Fig. 93.
MANUFACTURE OP VINEGAR.
the rods of 3 feet If inches. It will hold 15 to 16 bushels of
apples at a pressing and is especially designed for individual
use. It is also admirably adapted for squeezing the juice from
small fruits, berries, etc.
Fig. 94 shows the " Extra power cider-press," with revolv-
ing platform. It is 13 feet 4 inches high, 6 feet 4 inches wide
FIG. 94.
between the rods, and has a platform 13 feet 3 inches long.
It gives a pressure of 250 tons. The press is always loaded
in one place, and consequently the grater can be located
immediately over the middle of the cheese, avoiding the
necessity of conveying the pomace from one end of the press
MANUFACTURE OF CIDER.
383
to the other. This press can easily make a pressing of 12
barrels of cider each hour.
Fig. 95 shows the revolving platform belonging to the
above press, for which the following advantages are claimed :
1. Both ends of the platform are loaded and unloaded in the
same place. 2. It is so geared that one man can easily and
quickly revolve it. 3. The grinder can be directly over the
centre of the cheese, thus avoiding all the labor of shoveling
the pomace. 4. The pomace being dropped in the centre of
the cheese, it is an easy matter, to spread it with equal density
over the entire surface, thus building a cheese that is not
liable to tilt or slide. The cider runs into a copper basin in
the centre of the platform between the two cheeses. The basin
is so arranged that it receives the cider while the platform is
being revolved as well as while the press is working.
A is the copper basin- to receive the cider from platforms,
and has an outlet through the bottom, about 6 inches in diam-
eter, for the cider to pass off into the tank below. B is a cop-
per tube encasing the rods. C, (7, C, C are four posts fastened
to the platform to hold guide-pieces for racks. D, D are rack
guides.
Improved Racks. — The single racks are made of some light
and tough wood — bass-wood or spruce seems best — cut into
strips about JXJ inch and placed about J inch apart, with
384 MANUFACTURE OF VINEGAR.
four, five, or more elm strips, 2 inches wide about f inch thick,
placed across and nailed to the narrow slats. The 2-inch slats
extend beyond the narrow ones on each side about 4 inches.
This is to support the wings, which are fastened to the rack
by 3 or more bronze hinges. These wings, with the aid of 2
retaining bars, make the box to form the pomace in. The slats
are rounded on the edges, so as not to injure the press-cloth.
Steel wire nails or wire staples are used of sufficient length to
clinch.
Double racks are made by using slats -ft- Xf inch. The slats
on one side are laid directly across the slats on the other side.
Four wide slats are put at the outer edges, then these are all
fastened together by steel wire nails or staples. These racks
have the advantage of having an even surface on each side.
The press-cloth will last much longer than when used on single
racks, where it is strained over 4 to 9 elm slats.
To lay up a cheese with the improved rack, commence on
the platform of the press and lay a rack ; then turn up the
wings on each side of the rack and place the retaining bars on
each end, with the hooks on the outside of the wings, so as to
hold them up. Over this box spread the cloth, fill the box
evenly full of pomace, then turn in the sides and ends of the
cloth over the pomace, the cloth being of sufficient size to
cover it. The retaining bars are then removed, allowing the
wings to fall in place. Another rack is placed on the cheese
just made, the retaining bars placed in position to hold up the
wings, another cloth placed on the box, etc., and this opera-
tion is continued until there is the right number of layers in
the press. A rack should be placed on the top of the last layer.
A guide should be used in laying up the cheese, so as to bring
each rack directly above the other.
Plain racks.- — These are made, either single or double, of
slats of the same description and dimensions as are used in the
improved racks, but in the place of wings and retaining bars,
a form square in size and 4 inches deep is used to form the
sides of a box for the pomace. In laying up a cheese com-
MANUFACTURE OF CIDER. 385
mence by placing a rack on the platform, and upon this place
the form, spread a cloth over the form and fill even up with
pomace ; then fold the ends and sides of the cloth over onto
the pomace, as described with the other style of rack, and
remove the form. Place another rack on the layer just formed,
and put the form on that and proceed as before until the
cheese is complete. It will require one cloth less than the
number of racks used for a cheese. Care must be exercised in
laying a cheese to have the racks come evenly, as they are
liable to tilt if they overhang. The best way to avoid the
FIG. 96.
liability to slide or tilt is to lay the racks alternately the length
and breadth of the press.
In the equipment of a first-class modern cider mill nothing
gives better satisfaction for the money expended than an
apple elevator. The expense is a small matter compared with
the convenience of having the mill so arranged that apples
may be brought from any part by a perfect working elevator
and carrier. Fig. 96 shows a section of an elevator. The
chain runs over and is operated by a sprocket gear at the
head with fast and loose pulleys. The scrapers are of wood,
25
386
MANUFACTURE OF VINEGAR.
3 inches wide and 11 J inches long, bolted to lugs or projections
on the chain. When run at from 50 to 70 revolutions per
minute it will elevate from 5 to 10 bushels per minute. It
works at an inclination or carries on the level.
Fig. 97 shows the arrangement of a plant for making cider
on a large scale, as described by Paul Hassack.* The apples
are shoveled direct from the vehicle in which they are brought
to the plant into the shed A, which is divided into not too
large compartments. It is not advisable to pile the apples
more than 3 to 4J feet high, as otherwise, when the weather is
FIG. 97.
unfavorable, the entire pile may become heated, and rotting,
browning or the formation of acetic acid set in. Alongside
the shed runs up to, underneath the roof of the press-room
the elevator B, which conveys the apples to the grinder 0,
the finely ground pulp falling into the receptacle D. The
latter is furnished with a wooden tube E which can be closed,
and leads to the press-room. By opening a slide a quantity
of pulp just sufficient for one layer is allowed to run from the
* ' ' Garungs-Essig."
MANUFACTURE OF CIDER. 387
tube. F is a press-platform equipped with wheels and run-
ning on a track. Upon this the pulp is uniformly spread,
layer upon layer, each layer enclosed in a press cloth and a
rack between each layer. According to the size of the press
eight to twelve such layers are made into a cheese. The plat-
form is then pushed under the press G, which is put in action
by the motor M. In the commencement of the operation
pressing has to be done carefully and not too suddenly to
avoid bursting the press cloths, a more powerful pressure
being applied only towards the end of the process when the
juice runs off more slowly. In the meanwhile the next
cheese is prepared.
Testing the Must as to its Content of Acid and Sugar. — With
the exception of the grape but few varieties of fruit contain
acid and sugar in such proportions and in such quantity (gen-
erally too much acid and too little sugar) in that the must ob-
tained from them will yield, when subjected to fermentation,
a drinkable and durable wine. Wine whose content of acid
exceeds 1 per cent, is too sour to the taste, and one containing
less than 5 per cent, of alcohol cannot be kept for any length
of time. Now as all fruit wines may be called artificial
wines, and a natural product has consequently to be improved
in order to make it more agreeable and wholesome, it is nec-
essary to find ways and means by which the object can be
accomplished in a manner most conformable to nature. For
this purpose a knowledge of the content of acid and sugar in
the fruit-must is required.
To find the quantity of acid, compound a determined quan-
tity, about 50 cubic centimetres, of must with about 5 grammes
of purified animal charcoal,* boil the mixture about five
minutes, and after cooling replace the exact quantity of water
lost by evaporation. After shaking bring the whole upon a
*Bone-black which is first boiled with solution of sodium carbonate for some
time, and then after washing and extracting with hydrochloric acid is again
washed and dried.
388 MANUFACTURE OF VINEGAR.
coarse paper-filter in a glass funnel , and let it run off. Of the
clear and generally colorless filtrate bring 6.7 cubic centimeters
into a small beaker, add sufficient distilled water to form a
layer of fluid 2 to 3 centimeters deep, and color red with 5 to
10 drops of litmus tincture. While holding the beaker in the
left hand and constantly moving it slowly in a horizontal
direction, allow to run or drop in from a pipette, graduated in
TV cubic centimeters and filled to the 0-mark, decinormal
liquid ammonia until the last drop no longer changes the
color of the fluid, and the place where the drop falls appears
as if made clear by a drop of water. Now prevent a further
flow of the ammonia by closing the pipette with the index
finger of the right hand, and read off the quantity of ammonia
consumed. The must examined contains as many thousandths
of malic acid as cubic centimeters of liquid ammonia were
required to color the fluid blue.
Now if the examination shows that a must contains more
than 8 parts, of acid per thousand, it is evidently too sour for
the preparation of a palatable and wholesome fruit wine, and
hence must be diluted to such a degree as to reduce the con-
tent of acid to 6 or at the utmost to 8 parts per thousand. The
calculation for this dilution is very simple, and consists in
multiplying the acid per thousand parts present by 100 and
dividing with the content of acid the wine is to have, the entire
volume containing the desired acid per thousand being thus
obtained. If, for instance, 18 parts per thousand of acid have
been found in currant-must and the wine is only to show 6J
parts per thousand, then 1QO X 18 .= 276.923, in round num-
6J
bers — 277, i. e., 277 parts by measure of water have to be
added to every 100 parts by measure of must.
The content of acid in the must thus forms the initial point
for the dilution in order to obtain, after fermentation, wine
with a determined quantity of acid. To be sure the content
of acid is sometimes increased by fermentation, some succinic
acid, as previously mentioned, being formed and perhaps also
MANUFACTURE OF CIDER. 389
some acetic acid. Sometimes, however, the content of acid
decreases, which is very likely partially due to the water used
for the dilution of the must containing earthy carbonates
(lime, magnesia). It is, therefore, best not to have too much
acid in the must, since, if the finished wine should be lacking
in acid, it can readily be remedied by a suitable addition of
tartaric acid, which is, however, not the case when it contains
too much free acid.
The determination of the sugar in must presents less diffi-
culty and has already been fully described, hence there re-
mains only the question how much sugar has to be added
to the must in order to obtain a durable wine.
Numerous analyses have shown that there is scarcely any
grape wine which contains less than 7 per cent, by weight of
alcohol, while in more generous wines the content rises to 12
per cent, and more. Fruit-wines in order to possess good
keeping properties should never show less than 7 per cent, by
weight of alcohol, but there is no reason why they should not
contain as much as 10 per cent. The advantage of the latter
content is evident, the wines being thereby almost absolutely
protected from spoiling, while they improve in aroma and
taste, the various kinds of ether being only formed in wine
rich in alcohol.
The manner of calculating the quantity of sugar which has
to be added to the must to give the wine the desired content
of alcohol, wrill be best shown by the following example : Sup-
pose 135 liters of must which contains 4 per cent, of sugar are
to be changed into must with 15 per cent, of sugar.
For this purpose deduct from the weight of the must (which
for the sake of simplicity we will consider equal to its volume)
the weight of the sugar contained therein, multiply by the
difference the per cent, of sugar the must is to contain, divide
the product by 100 less the per cent, of sugar, and deduct
from the quotient the per cent, of sugar already present in the
must. For instance : 135 liters of must with 4 per cent, of
sugar are to be changed into must with 15 per cent, of sugar.
390 MANUFACTURE OF VINEGAR.
In 135 liters are contained 6.4 kilogrammes of sugar; 135 —
5.4 = 129.6, which multiplied by 15=1944; this number
divided by 100 — 15 = 85 gives 22.87. Deduct from this 5.4,
and there remain 17.47 kilogrammes of sugar which have to
be added to the must to give it 15 per cent, of sugar.
For 325 liters of must with 3J per cent, of sugar to be
changed into must with 20 per cent, of sugar the calculation
would be as follows :
(325 — 11.375)20 = 313.625 X 20 =
100 — 20 ~8QT
01 q ftOK
^pD = 78.406 — 11.375 = 67.03 kilogrammes of sugar to
be added.
600 liters of must with 6 per cent, of sugar are to be changed
..
into must with 22 per cent, of sugar : _l — 36 = 117.4
39
kilogrammes of sugar.
The above examples will suffice to enable any one to exe-
cute the calculations as required.
The above calculations are based upon pure, anhydrous
grape sugar, an article which does not exist in commerce, and
hence has to be replaced either by commercial grape-sugar
(glucose) or cane-sugar. Glucose, however, containing as a
rule only 67 per cent, of anhydrous grape-sugar, 1 J times the
quantity calculated above must be used, thus in the last ex-
ample 176 kilogrammes instead of 117.4. With cane-sugar
the proportion is the reverse, 171 parts by weight of cane-sugar
being equal to 180 parts by weight of anhydrous grape-sugar;
hence the per cent, of anhydrous grape-sugar calculated accor-
ding to the above method must be multiplied by the fraction
TyT or the factor 0.95. According to this, instead of the 117.4
kilogrammes of grape-sugar in the last example, 111.73 kilo-
grammes of cane-sugar will have to be used.
Glucose. — Pure glucose being identical with the sugar in
sweet fruits, its use for sweetening fruit-juices intended for the
MANUFACTURE OF CIDER. 391
preparation of wine is perfectly justifiable. With the dispute
still carried on with honest weapons, whether it is permissible
to assist nature with glucose when it fails to succeed in its labor
of forming sugar in abundance, we have here nothing to do,
since we know that the principal product — alcohol or spirits of
wine — and almost the only one which passes into the wine by
the fermentation of sugar, possesses the same properties whether
it be formed from fruit-sugar or from glucose, and that neither
one or the other can be injurious to health in the state of dilu-
tion in which it presents itself in the wine, provided the latter
be used in moderation. The must might be sweetened, as is
frequently done, with cane-sugar which occurs in sugar-cane,
in beet root, in sugar-maple, etc. But with the use of glucose
we are one step in advance, since cane-sugar before fermenting
is first resolved into a mixture of dextrose (glucose) and levulose.
Commercial glucose is never pure, as it contains, besides
about 15 percent, of water, of which about 6 per cent, is water
of crystallization, about 18 per cent, of dextrin or similar sub-
stances, and some gypsum. It has a white color, and is found
in commerce packed in boxes into which it is poured while in
a fluid state and gradually congeals to a hard mass. It is odor-
less and has a faint sweet taste. On heating it becomes smeary
and, finally melts to a yellowish syrup. Its content of anhy-
drous fruit-sugar varies between 62 and 67 per cent. Inferior
qualities contain either less sugar, or have a more or less dark
color, and a disagreeable odor and taste. Independently of the
content of sugar, glucose to be suitable for the preparation of
wine, should show no odor or by-taste.
The accurate determination of the content of pure sugar in
glucose is connected with some difficulty. But few manufac-
turers are provided with the necessary materials for making
the analysis with Fehling's solution, and besides a certain
amount of skill is required for obtaining accurate results by
chemical tests. In consideration of this, Anthon of Prague
has devised tables which are based upon the varying specific
gravity of different saturated solutions of glucose, or rather
392
MANUFACTURE OF VINEGAR.
upon its solubility in water. While 1 part of anhydrous grape-
sugar requires for its solution 1.224 parts of water at 53.6 F.,
the foreign admixtures accompanying it dissolve in every pro-
portion in water. Hence a saturated solution of glucose will
show a greater specific gravity the more foreign substances
it contains. In Anthon's tables is found the specific gravity
and from this the content of anhydrous grape-sugar or glucose
in the solution. In preparing a solution of starch-sugar for
examination care must be had that it is completely saturated.
Heat must not be used for effecting the solution, but a certain
quantity of the glucose to be examined is rubbed in a mortar
with one-half its weight of water at 53.6° F., and after pouring
the thickish, turbid fluid into a tall beaker it is allowed to
stand until clear. Anthon's table is as follows : —
Specific gravity
Specific gravity
of the solution
of the solution
saturated at
Contains of foreign
saturated at
Contains of foreign
53.6° F. i j
substances.
53.6° F.
substances.
1.2066
0 per cent.
1.2522
25 per cent.
1.2115
2.5 "
1.2555
27.5 "
1.2169
5.0 "
1.2587
30.0 "
1.2218
7.5
1.2631
32.5 "
1.2267
10.0
1.2665
35.0 "
1.2309
12.5
1.2703
37.5 "
1.2350
15.0
1.2740
40.0 "
1.2395
17.5
1.2778
42.5 "
1.2439
20.0
1.2815
45.0 "
1.2481
22.5
Cider from Apples. — The expressed juice from well-selected
apples, properly prepared, forms a lively, sparkling liquor far
superior to many wines. It is quite a favorite article of home
production, nearly every farmer in regions where apples are
grown, making his barrel of cider for use through the winter,
but a large amount finds its way into the city markets. -A
considerable quantity is also consumed in the shape of bottled
cider, " champagne cider," "sparkling cider," and similar
substitutes for, or imitations of, champagne wines.
MANUFACTURE OF CIDER. 393
In England and France considerable quantities of cider find
their way into the markets, though it is there, as here, largely
an article of home consumption. Certain parts of those coun-
tries are famous for the quality of their ciders, notably Nor-
mandy, in France, and Herefordshire and Devonshire, in
England.
The Municipal Laboratory of Paris deduces from analyses
of pure ciders from different parts of France the following as
a type of composition for pure ciders :
Alcohol, per cent, by volume 5.66
Extract, per liter, at 212° F. . . 30.00
Ash 2.80
Other analyses of pure ciders, from different parts of France,
published by M. G. Lechtartier, have shown great variations
from this type, and show the necessity for the examination of
large numbers of samples from various parts of the country
for the establishment of a proper standard of analysis.
Analyses of Ciders by the United States Agricultural Depart-
ment.— The samples for the investigation were purchased in
the city in the same manner as samples of wine and beer : —
394
MANUFACTURE OF VINEGAR.
Designation.
Serial No.
^,
"s
"8
6
Specific gravity.
'o
Alcohol by volume.
Total solids.
-S
a
a
£
X
1
1
Albuminoids.
Carbonic acid.
'§!
Well-fermented ciders.
Draft cider (" extra dry ") ...
Bottled cider, known to be
4830
483?
1
?
1.0132
1.0003
p. ct.
4.18
8.09
p.ct.
5.23
10.05
3.31
1.88
p.ct.
.602
.456
p.ct.
p. ct.
.396
.279
p.ct.
.038
063
p.ct.
trace
0
-19.5
— 7.0
Bottled cider
1SSS
8
1 0007
628
7 83
180
376
340
044
6 1
Bottled " extra dry russet "
cider
4
1.0264
4.48
5.61
5.52
.339
393
051
—352
" Champagne cider," bottled.
"Champagne cider," bottled.
4 'Sparkling cider," bottled. .
4835
4836
4927
5
6
7
1.0223
1.5143
1.0306
4.08
5.45
3.63
5.10
6.79
4.54
5.02
3.69
5.92
.567
.361
.113
-
.310
.415
.506
.050
.038
.161
.120
-23.4
—20.4
-338
Average
1 0154
5 17
• 6 45
3 88
402
377
044
"Sweet" or incompletely
fermented ciders.
Draft cider
1
1.0537
0.65
0.81
9.34
.565
.315
.069
—41.6
4831
0
1 0516
061
077
9 59
302
270
063
— 34 2
" Sweet " cider (draft)
Do ..
4837
3
4
1.0567
1 0203
0.20
3 46
0.25
4 33
9.53
3 84
.575
302
-
.283
374
.075
044
-
—48.4
—24 2
Do
48S9
g
1 0552
0.55
0.67
9.75
.409
336
031
—48 5
Do
4841
r,
1 0355
2.96
3.71
698
478
348
069
—391
1 0455
1 40
1 76
8 17
405
321
059
1 A circumstance arising after the samples had been thrown away seemed to throw con-
siderable doubt upon the determinations of sugar, which were made by an assistant, and
the entire set had to be thrown out.
2 Determinations of the carbonic acid in three different bottles gave the following results:
.728, .654, .482.
The choice of the varieties of apples is of great importance
in the manufacture of cider. All apple juice will not make
equally good cider, even if it is equally well handled. It is not
always the best flavored apple or the best tasting juice that will
make the best cider. Indeed, as a rule, the best cider is made
from apples which are inferior for table use, such as the crab-
apple and the russet. But it is a pretty general rule that the
most astringent apple will make the best cider. This astrin-
MANUFACTURE OF CIDER. 395
gency is due to an excess of tannin. While a portion of this
tannin is changed to sweetness, a considerable portion remains,
which serves to render the cider more easily and thoroughly
clarified and to make it keep better. The tongue alone being,
however, not sufficient to detect the tannin in apples, the fol-
lowing will serve as a reliable test: Express the juice of a
few apples and add a few drops of isinglass, which combines
with the tannin and forms a precipitate. From the greater
or smaller quantity of this precipitate a conclusion can be
drawn as to the quantity of tannin present. The specific
gravity of the juice, which may vary between 1.05 and 1.08
should be determined. The greater the specific gravity of
the juice the better the respective variety of apple is for
making cider. According to these directions, the raw mate-
rial should be selected, though in most cases it will be
necessary to use a mixture of different varieties. In France,
for a quality of cider which will keep well, the apples are
mixed in the following proportions : f bitter-sweet and J-
sweet apples. If a sweet cider is wanted not intended to be
kept for a long while, J bitter-sweet and f sweet apples are
used.
The apple, like every other fruit, consists of solid and fluid
constituents. The solid constituents are the skin, core, seeds,
as well as the pulp in the cells of which the fluid constituents
— the juice — are enclosed. The solid insoluble constituents
consist chiefly of cellulose, albuminous substances, pectose,
mucilage and other less insoluble substances. The average
proportion between solid and insoluble substances and juice is
of course subject to wide fluctuations, according to the nature
of the soil, season of the year and degree of ripeness.
Generally speaking, the composition of the apple may on an
average be given as follows :
Solid substance (pulp) . . 3 to 7 per cent.
Juice . . . . 93 to 97 per cent.
396 MANUFACTURE OF VINEGAR.
The juice constituents contain about :
Water 80 to 88 per cent.
Sugar . . . 9 to 18, even up to 24 per cent.
Acid 0.6 to 1.8 percent.
Extractive substance . . 1.3 to 3 per cent.
The juice pressed from apples is called must or cider. The
sugar in the must is a mixture of different kinds of sugar
varying greatly in proportion, and consists of dextrose, laevu-
lose and sucrose. The acid of the apple, as well as that of the
pear, consists of malic acid, and frequently also of small frac-
tions of citric acid ; tartaric acid, however, is never present.
Must with less than 5 per cent, of acid has an insipid taste, and
consequently an addition of artificial malic or citric acid has
to be made to musts augmented with water in order to
improve the taste. On the other hand, when the must con-
tains too much acid, the latter cannot be fixed with calcium
or potassium carbonate, but should be reduced by the addition
of water and sweetening with sugar. The extractive substances
of apple-must consist of tannin 0.2 to 0.6 per cent., pectin
bodies 4 to 4.5 per cent., albuminous substances and mucil-
age, various soluble mineral substances and a series of gums
thus far undetermined.
The apples intended for the preparation of cider should be
allowed to attain complete maturity, which is recognized by
their color, the dark hue of the pips, little specks covering the
skin, and by the sharp and agreeable ethereal odor emanating
from them. In fact they should be allowed to remain on the
trees as long as vegetation is active or until frosts are appre-
hended, for thus the conversion of the starch into sugar is best
effected and their keeping better secured than by storing.
They should be gathered by the hand to prevent bruising and
coming in contact with dirt. They are then placed in piles and
allowed to sweat. This sweating process has a tendency to ripen
the fruit and make it uniform, thereby improving the flavor
as well as the quality and strength of the cider in consequence
MANUFACTURE OF CIDER. 397
of the apples having parted with six or eight per cent, of water.
The strongest cider is made from apples containing the smallest"
percentage of juice, and, in its aqueous solution, the largest
proportion of saccharine matter. If the weather be fine, the
piles may be exposed in the open air upon clean sod or where
this is wanting upon boards or linen cloths, but under no cir-
cumstances should the apples be placed upon the bare ground
or upon straw, as they contract an earthy or musty taste which
is afterwards found in the cider.
After sweating and before being ground the apples should be
wiped with a cloth to free them from exudation and adhering
particles of dirt, and if any are found bruised or rotten they
should be thrown out. Ripe, sound fruit is the only basis for a
good article of cider, and the practice of mixing rotten apples
with the sound, as is frequently done and even advocated by
some, cannot be too strongly condemned. Mellow or decay-
ing apples have lost almost all their perfume, a certain quan-
tity of water by evaporation, and a large portion of their sugar.
Rotten apples yield a watery liquid of an abominable taste,
which prevents the cider from clarifying and accelerates its
acetification.
The apples being wiped, sorted, and, if necessary, mixed in
the desired proportions, are now brought into the grinder and
reduced to an impalpable pulp. By this operation the numer-
ous infinitesimal cells of the apple should be thoroughly broken
up so as to permit the free escape of the juice when under
pressure, and the machine which accomplishes this most
effectually is the best for the purpose. If the cells are not
thoroughly torn asunder, their tendency is to restrain and
hold, as it were, in a sack much that otherwise would escape.
As regards the crushing of the seeds there is a diversity of
opinion, some holding that they communicate to the cider a
disagreeable bitterness and acidity, while others consider them
as rendering the cider more alcoholic and making it keep
better.
According to M. Bergot, for cider of superior quality it is
398 MANUFACTURE OF VINEGAR.
preferable not to crush the seeds, because the diffused odor of
the essential oil would undoubtedly injure the fine taste of cer-
tain notable products. For ordinary cider the crushing of the
seeds will, on the other hand, be of advantage, because their
essential oil helps to give to the cider the bouquet which it
otherwise lacks. For cider intended to be converted into
brandy the seeds must, however, be crushed. The grinder
should be cleansed with hot water every evening, or at least
every third' day.
The treatment to which the pulp obtained by grinding is
subjected varies according to the color the cider is to have.
Where the consumer prefers a pale-yellow color the pulp must
at once be pressed, while for a darker color it is allowed to
stand 12 to 18 hours.
The next step in the operation is pressing. The various kinds
of presses, racks, and manner of laying up the cheese have
already been described. The primitive custom of laying the
cheese was to lay upon the platform of -the press a quantity of
straw, upon which a quantity of pomace was placed, and the
edges secured by laps of straw, thus alternating straw and
pomace until the pile was complete. The object of using the
straw was to hold the mass together while it was being sub-
mitted to pressure, and also to serve as a means of exit for the
cider. An improvement was in the substitution of hair-cloths,
and within the past few years the adoption of the cotton press-
cloth and racks to hold the pomace in laying up the cheese
for the press. The racks have already been described. The
press-cloth is woven from yarn made expressly for the purpose
and is of equal strength in warp and filling. The use of straw
in laying up the cheese should be entirely discarded, as the
slightest mustiness imparts an unpleasant odor^to the cider.
The pressure applied to the cheese should be slow at starting
and then gradually increased until finally the full force is
applied. The juice as it comes from the press runs through a
fine hair-sieve into a receiver. With a good press about 65 to
75 per cent, of juice will be obtained.
MANUFACTURE OF CIDER. 399
After the cider has been extracted and the cheese removed
from the press the pomace may be utilized for the manufacture
of vinegar, as previously described. In France it is, however,
used for the manufacture of the small cider. The method is as
follows: — After the extraction of the pure cider by the first
pressing, the pomace is taken from the press, and after adding
12 litres of water for every hectoliter of apples used, the mass
is allowed to macerate 15 to 20 hours, care being had to stir
every two or three hours. Then this pulp is put a second time
under pressure and a quantity of juice extracted equivalent to
the amount of water added.
Extraction of the juice by diffusion. — Diffusion, which gives
such excellent results in the extraction of sugar-beets, has also
been applied to extract the soluble constituents of the apple.
In practice this method might be suitable for persons having
no cider press and only a small quantity of apples to handle.
The quality of cider is nearly equal to that obtained by three
pressures, and the juice obtained is almost as rich as that
yielded by the press.
Successful experiments in expressing the juice of the grape
by means of the centrifugal would indicate that the same
method might also be applied to apples.
. The freshly-expressed apple-juice is either sold as sweet
cider or subjected to fermentation. Fermentation in sweet
cider is retarded by pasteurizing, carbonating, or the addition
of preservatives. The objections urged against pasteurizing
or sterilizing fresh apple-juice are that a "cooked " taste is
added to the juice, and that it is impracticable to hold the
juice sterile for more than a limited period. Experiments to
develop a method for sterilizing apple-juice in wooden, tin and
glass containers have been made by H. C. Gore,* and his
investigations demonstrate that only a slight cooked taste is
produced by the heat treatment required, and that it is a sim-
* U. S. Department of Agriculture, Bureau of Chemistry, Bulletin No. 118.
" Unfermented Apple-juice."
400 MANUFACTURE OF VINEGAR.
pie matter to protect the juice from inoculation after steriliz-
ing. A summary of these investigations is here given : —
(1) " The experiments show conclusively that it is possible
to sterilize apple-juice in wooden containers, the product re-
maining sound for at least six months under actual observa-
tion. The precautions which must be taken to insure this are
as follows : First paraffin the containers on the outside, then
sterilize, and fill with juices heated to between 149° and 158°
F. (65° to 70° C.) ; seal, taking measures to relieve the vacuum
produced by the contraction of the juice on cooling by filter-
ing the air through cotton. Twenty-four 10-gallon kegs suc-
cessfully stood a severe shipping test, showing no loss due to
fermentation of the juice. The juice so prepared was found
to be palatable, and acceptable as a summer drink.
(2) " It is demonstrated that apple-juice can be successfully
sterilized in tin containers, using the type of tin can sealed by
the mechanical process, excluding all metals from contact
with the juice except the tin of the can. Where lacquered
cans are used the contamination with tin was reduced about
one-half. Apple juices were canned and sterilized by heating
in a hot water-bath, up to the temperature of 149° F. (65° C.)
for a half hour, and then allowed to cool. These juices pos-
sessed only a slight cooked taste due to the heating and re-
tained much of their distinctive apple flavor. It was found
that from finely flavored apple-juice a first-class sterile product
could be made, while a poorly flavored apple-juice yielded an
inferior product. The process conditions mentioned were not
quite thorough enough to sterilize all of the varieties canned.
A slight increase in the temperature or time of processing, or
both, should be made, the temperature not to exceed 70° C.
(158° F.) in any case.
(3) " The best treatment for sterilizing in glass was found
to consist in heating for one hour at 149° F., or for one-half
hour at 158° F. Heating for one hour at 158° did not pro-
duce marked deterioration in flavor, a half hour being allowed
in all cases for the juice to obtain the temperature of the
water-bath.
MANUFACTURE OF CIDER. 401
(4) " It was shown that the great bulk of the insoluble
material naturally contained in apple-juice can be removed
by means of a milk separator."
These investigations extended also to carbonating fresh
apple-juice and the conclusions arrived at are as follows:
" It is possible to carbonate the juice slightly before canning
or bottling, thus adding a sparkle to the product. A flavor
foreign to fresh apple-juice is also added, however, and un-
carbonated sterile juice will resemble fresh apple-juice more
closely. Carbonating by the addition of water charged with
carbon dioxid was considered by some to injure the flavor,
lessening the characteristic fruit flavor by dilution. In the
opinion of others a heavy, rich juice was improved both by
the charge of carbon dioxid and by the consequent dilution.
Experiments indicated that the danger of contamination by
mold growths was lessened by maintaining an atmosphere of
carbon dioxid above the surface of the juice after opening."
When apple-juice is sold in bulk a small amount of benzo-
ate of soda is, as a rule, added to retard fermentation, one-
tenth of 1 per cent, being tolerated by regulation in the United
States. H. C. Gore's investigations demonstrated that benzo-
ate of soda in quantities varying from 0.03 to 0.15 per cent.,
while it checks the alcoholic fermentation, allows other organ-
isms to develop — notably the acetic acid ferment — whereby
the palatability of the product as a beverage is destroyed.
H. C. Gore has also investigated the cold storage of apple
cider,* and the summary of the results of these investigations
is here given :
(1) " Ciders prepared from apples free from decay chilled
rapidly to the freezing-point immediately after pressing, and
then held in cold storage at 0° C. (32° F.) remained without
noticeable fermentation for a period of from thirty-six to fifty-
seven days, an average of fifty days for the Tolrnan, Winesap,
* U. S. Department of Agriculture, Bureau of Chemistry, Circular No. 48,
"The Cold-Storage Apple Cider."
26
402 MANUFACTURE OF VINEGAR.
Yellow Newtown, Rails, Gilpin, and Baldwin varieties, and of
eighty-three days in the case of the Golden Russet, Roxbury
Russet, and Kentucky Red.
(2) " These ciders were held for a period of from ninety to
one hundred and nineteen days, an average of ninety-nine
days for the first six varieties and of one hundred and twenty-
five days for the last three, before they fermented sufficiently
to be considered as becoming " hard " or " sour."
(3) " The ciders were found to have suffered no deteriora-
tion (with the exception of the Tolman), but rather had be-
come more palatable during storage."
The apple-juice to be fermented should be tested with a
must-spindle or densimeter as to its content of sugar. A good
quality of juice will generally range from 10 to 14 per cent.
If less than 10 per cent, the juice will not make a cider that
will keep, though, if the flavor in other respects is all right, a
beverage for immediate use may be produced from it.
When the juice has been tested and, if found wanting in
saccharine strength, corrected by the method previously given,
the next step in the operation is fermentation. For this pur-
pose the juice is brought into casks. Regarding the size of
the latter it may be said that, as a rule, the juice ferments
more uniformly and more steadily, and retains the carbonic
acid better with the use of larger casks, though it develops
somewhat more slowly than in smaller containers. For the
production on a large scale of cider of first-rate quality the
use of large casks can, therefore, be recommended. However,
if the cider is to be used for daily consumption, and perhaps
be directly drawn from the yeast, smaller containers are pre-
ferable, there being less danger of the cider becoming mouldy
or sour. The casks should be scrupulously clean, and new
ones must be freed by steaming or washing with hot water
from all extractive substances, otherwise the cider will acquire
a disagreeable taste and dark color.
In many places the fermentation-casks are filled by means
of a power pump which delivers the juice to the receptacles
MANUFACTURE OF CIDER. 403
placed in adjacent rooms or in another building. When the
press-room is over the fermentation room, filling is accom-
plished by gravity. Hose-pipes are largely used for this work,
but brass or copper must be used for all metal fittings. The
less the juice comes in contact with the air after it leaves the
press the less liable it is to be contaminated with various un-
desirable organisms. The pumps and pipes must be kept
scrupulously clean.
In Fig. 97 p. 386 the juice running off from the press
through the pipe H is freed from the principal particles of
pulp in the box J, which is fitted with two or three wire-
sieves of different fineness. This box is located above the
collecting vat K.
The fresh juice having been brought into the casks, fermen-
tation is still left in many places to the organisms normally
present on the fruit and those which may at the time of grind-
ing and pressing enter the juice from contact with the air, the
machinery and the vessels. Fermentation in this case does
not always progress as norn^lly and favorably as required
for the production of a sound, palatable and durable cider.
The various races of yeast present on the apple possess but
little fermenting power and the elliptic wine yeast (sacchar-
omyces ellipsoidus) which has to be taken chiefly into account,
being generally represented only in very small quantities, is
stifled and readily suppressed. It is a well-known fact that,
generally speaking, apple juice ferments completely only with
difficulty. This appears to be due to the fact that the nat-
ural cane sugar, which is frequently present in considerable
quantities in apple and pear juices, is fermented with great
difficulty by the organism normally present on the fruit, and
to assure the ascendancy of the true yeasts and thus give them
the control of the entire process of fermentation, the practice
of sowing the juices with pure cultures of yeast has been intro-
duced. In Germany all the important factories employ these
cultures, which are obtained in small flasks from the Royal
Pomological School at Geisenheim. With the use of pure
404 MANUFACTURE OF VINEGAR.
, culture of yeast it is best to add it to a smaller quantity of
sterile juice previously heated to 140° F. and then cooled to
68° F. When fermentation in the sterile fluid is most vig-
orously developed i't is added to the juice to be fermented.
Another cause of the difficult fermentation of apple juice is
the frequent want of nitrogenous combinations required for
the nutriment and propagation of the yeast. This may be
remedied by the addition of 20 grammes of ammonium tar-
trate or ammonium chloride per hectoliter of juice ; in place
of it the same quantity by weight of ammonium phosphate or
ammonium carbonate may also be used. Such an addition
should also be made with the use of pure culture of yeast.
The first or tumultuous fermentation of the apple juice is in
some places effected in open vats, this method being generally
preferred with juice not previously strained, so as to be able
to remove during fermentation the insoluble constituents of
the must which are forced to the surface.
When, however, the must has been purified by straining or
filtering over thoroughly washed sand, fermenting in casks is
preferable. The casks are fillea about three-quarters full and
equipped with a ventilating bung to prevent the entrance of
germ-laden air. There are various constructions of ventilating
bungs but the principle is in all cases the same, namely, to
allow the escape of the excess of carbonic acid and prevent the
entrance of air. The best protection of the must is the car-
bonic acid developed during fermentation, because, on the one
hand, neither mould or acetic acid formation can appear for
want of oxygen, and, on the other, the exciters of these decom-
positions cannot develop in an atmosphere of carbonic acid.
Care should, therefore, be taken that until fermentation is fin-
ished and the cask has been entirely filled and bunged, an
atmosphere of carbonic acid always lies over the cider in the
empty space of the cask.
The fermentation funnel or ventilating funnel, Fig. 98 which
is largely used in Germany, is a simple device for controlling
the air. It is generally made of pottery or porcelain, though
MANUFACTURE OF CIDER. 405
it can also be constructed of metal, for instance, aluminium.
It consists of two parts, the actual funnel c with the tapering
pipe d, which is secured air-tight in the bung-hole and is filled
half-full with water, and a cup-like vessel b, which is placed
over the elongated portion of the pipe of the funnel. The
carbonic acid escaping from the cask passes through the pipe
into the cup b, forces back the water at o and escapes at e from
the open portion of the funnel, the entrance of air being on
the other hand prevented by the water.
The first or tumultuous fermentation runs its course, accor-
ing to temperature and other conditions, in two to four weeks,
the temperature being under otherwise, normal conditions, the
most important factor. The higher it is , the more energetic-
ally fermentation sets in and the more rapidly it runs its
course. While formerly a not too tumultuous course of the
first fermentation was not desired by many manufacturers and
the temperature was kept relatively low, most of them have
now arrived at the conclusion that as energetic a course as
possible of the first fermentation is the best guarantee for a
good product, and the temperature for the first stage of fer-
mentation should be at least between 59° and 68° F. When
the first fermentation has run its course, which is recognized
by the cessation of the hissing sound made by the carbonic
406 MANUFACTURE OF VINEGAR.
acid gas, the cider is drawn off from the sediment into clean,
unsulphured casks, furnished with a ventilating bung. The
casks are placed in a cellar or a cool room having a tempera-
ture of 40° to 50° F., and the cider is left to the second or after
fermentation. The casks should be constantly kept full, and
abrupt variations in the temperature carefully avoided and
provided against. Generally speaking, the more energetically
the first fermentation has run its course, the more quietly the
second fermentation will progress, and vice versa. By the
second fermentation, the remainder of the sugar is decomposed,
there is but a slight evolution of carbonic acid, the yeast as
as well as the albuminous substances in the must settle on
the bottom, and the cider becomes more or less clear.
When the second fermentation has progressed to the desired
degree, the cider is drawn off into other casks and fined. Ac-
cording to one method this is done with isinglass, 1J ozs. of it
being allowed for each cask. This quantity is dissolved in 1
pint of cider over a moderate fire, and the solution when
cold, poured with constant agitation into the cask. Drawing
off may be commenced after eight days.
A better method of clarification, which at the same time in-
creases the purity of taste of the cider, is as follows : For each
barrel of 30 gallons, take 4 Ibs. of fresh wheat bran, and, after
washing it twice in hot water to remove all soluble substances,
press out thoroughly. Now dissolve about 2 drachms of alum
in a bucketful of hot water and. pour the solution upon the
bran. After 6 to 8 hours take the latter from the alum water
and press as before. The bran is best used before the cider is
racked off for the third and last time. Stir it into the cider,
and then draw off the latter through a fine strainer into the
actual storage barrel. The cider first passing through the
strainer is generally somewhat turbid, and must be poured
back until it runs off clear.
In France, the cider is generally clarified by dissolving 2 ozs.
of catechu in 1 quart of cider and adding the solution to 100
quarts of cider, with constant stirring. The tannin thus added
MANUFACTURE OF CIDER. 407
precipitates the albuminous matters, the result being a clear
cider which will not blacken in the air.
It is always advisable before fining large quantities of cider
to make a clarifying experiment on a small scale, the content
of tannin in the fluid being frequently so small that the clari-
fying agent added is ineffectual. In such cases a small addi-
tion of tannin in the form of an alcoholic-aqueous solution
previous to the addition of the clarifying agent can be recom-
mended. However, as a perfectly bright product is not always
obtained by fining, filtering will ha^ to be resorted to. Fil-
ters of various types, such as bag filters, cellulose filters and
asbestos filters are in use for this purpose. Filtering cider
appears to be a process much more difficult than filtering wine
made from grapes and should be avoided if possible. The
reason for this is the presence of mucilaginous substances in
the liquor.
Pared apples, if used for the production of cider, yield a
product poor in aroma. Washing the apples in washing
machines of special construction previous to grinding and
pressing is of great advantage for the production of fine must
and cider. Fairly good products can be obtained from dried
American apples, the cheapest brands (waste, parings, cores)
of which can be used for the purpose.
Cider intended for export must be made somewhat richer
in alcohol, which is generally done by adding sufficient
French brandy to increase its content of alcohol 2 per cent.
Sometimes, also, J Ib. of sugar for every 2 quarts of juice is
added during fermentation. For shipping to tropical countries
experiments might be made with salicylic acid, adding it in
the same proportion as to beer, which is for beer sent in
barrels f oz. for 100 quarts, and for bottled beer, J oz.
There are several methods of improving the taste of cider,
but they are rather questionable, because tastes differ, and
what might be considered an improvement by one would be
declared a defect by another. A favorite method of improve-
ment is as follows : For 45 gallons of cider measure off 3 quarts
408 MANUFACTURE OF VINEGAR.
of French brandy and mix it with the following substances?
all finely powdered : 0.7 drachm of bitter almonds, 0.7 drachm
of mace, and 7J drachms of mustard-seed, and finally 3J
drachms of catechu, previously dissolved in water. Pour this
mixture into the cider and shake the barrel frequently during
the next 14 days. Then allow it to rest three or four months,
and should it then not run off clear when tapped, clarify it
with 1 J oz. of isinglass or the whites of a dozen eggs. If the
color of the cider is to remain pale yellow, catechu cannot be
used, and instead of isinglass or white of egg, skimmed milk
is to be used for clarification. For a reddish color, which is
sometimes desired, use If drachms of powdered cochineal in
place of the catechu.
Sometimes cider is prepared in the same manner as other
fruit-wines. In this case J Ib. of sugar is added to every quart
of juice, and the latter is allowed to completely ferment in the
same manner as grape wine. According to another direction,
add to every 2 quarts of juice, 2 Ibs. of white sugar, and boil
as long as scum is formed ; then strain through a fine hair-
sieve and allow to cool. Now add a small quantity of yeast,
stir thoroughly, let the whole ferment three weeks, and after
clarifying rack off into bottles.
Red apple wine, or, as it is frequently called, red wine from
cider, is prepared as follows : Boil for 2 hours 50 quarts of
apple juice, 27 Ibs. of honey, 1 oz. of tartar, 6 Ibs. of comminuted
red beets, and 3, Ibs. of brown sugar. Let the fluid completely
ferment, and if no apple juice is on hand to fill up the barrel
during this process, use solution of sugar. When fermentation
is finished, pour a mixture of 1 quart of French brandy and
about 1 drachm each of pulverized cinnamon and ginger into
the barrel. After three months clarify the wine and rack off.
In his treatise on " Cider," Dr. Denis-Dumont gives the fol-
lowing directions for bottling cider : The cider is to be bottled
at three distinct periods. It should never be bottled before
the tumultuous stage of fermentation is entirely completed and
the liquid clarified.
MANUFACTURE OF CIDER. 409
First period. At the termination of the tumultuous fermen-
tation, the cider still contains considerable sugar. Fermen-
tation continues in the bottle and produces in a few weeks a
large quantity of carbonic acid. In order to prevent the bottles
from being broken by the pressure, champagne bottles should
be selected, and care taken to have them stand upright until
the development is considerably reduced. The bottles are
then laid on their side, as otherwise the cider would cease to
be sparkling. This cider has to be kept for a number of years,
it being good to drink only when old.
Second period, when fermentation is more advanced, about
six weeks or two months after the first period. Mineral water
bottles are strong enough to hold this cider, it liberating less
carbonic acid than the preceding. The bottles are left in an
upright position for a few weeks only. This cider has a good
flavor and is fit to drink much sooner than the preceding. It
keeps for a long time.
Third period, when fermentation is complete or almost so,
any quality of bottles may be used, a great deal less of car-
bonic acid being developed than in the preceding cases. The
bottles should be laid down immediately after filling, in order
to retain the carbonic acid which will still be developed. This
cider is not sparkling ; it is, however, lively, strong, and has a
fine flavor.
The bottles should, in every instance, be well corked, and
the corks, for the sake of safety, tied. The cider is very good
when kept in small bottles, better in quart bottles, and best in
jars holding two quarts. A few moments before opening a
bottle of sparkling cider, it is advisable to provide a minute
opening for the escape of the gas by piercing the cork with a
fine punch. As soon as the tension of the gas has become
sufficiently weak, the cork is allowed to blow out in the same
manner as with champagne. Without this precaution, most
of the cider might be thrown up to the ceiling.
In the island of Jersey, where the manufacture of cider is
carried on in a very rational manner, the juice as it comes from
410 MANUFACTURE OF VINEGAR.
the press is allowed to ferment in large open vats placed in a
cellar having a uniform temperature of from 53° to 59° F. On
account of the large surface presented to the air, tumultuous
fermentation soon sets in, and in about four or five days, or at
the utmost a week, fermentation is over. The liquid is then
drawn off in barrels, thoroughly cleansed and sulphured, in
which fermentation continues slowly. These barrels are not
entirely filled, and when the development of carbonic gas has
proceeded so far that the flame of a lighted candle introduced
by the bung-hole is extinguished, the liquid is drawn off into
other barrels sulphured like the first. This transfer from one
set of barrels to another is continued until no escape of gas is
perceptible, i. e., until fermentation is quite complete.
Prepared in this manner the cider will keep perfectly good
for several years, and stand transportation by sea without any
difficulty.
Devonshire cider is made from a mixture of one-third of
bitter-sweet apples with a mild sour. These being gathered
when thoroughly ripe are allowed to undergo the sweating pro-
cess before grinding. The cider is then pressed in the usual
manner and strained through a hair-sieve into hogsheads,
where it remains for two or three days previous to fermenting.
It is then drawn off into clean casks to stop the fermentation,
but if this is very strong only two or three gallons are first put
in, and after burning cotton or linen rags saturated with sul-
phur in the cask, thoroughly agitated. This completely stops
fermentation in that quantity and usually checks it in the other
portion with which the cask is then filled up. In a few weeks
the cider becomes very fine. If this be not satisfactorily ac-
complished by the first operation, it is repeated until fermen-
tation is completely checked and the cider is in a quiet state
and in a proper condition for drinking and bottling.
Champagne-cider. — The manufacture of this beverage has
become quite important — it resembling the ordinary but more
expensive champagne-wine, and being frequently sold as such.
Since the devastation of the vineyards by the phylloxera, a
MANUFACTURE OF CIDER. 411
large trade in the spurious champagne-wine is carried on in
France. This champagne-cider if sold under its right name
is an excellent beverage. It is prepared as follows : To 50
gallons of apple-juice add 12 quarts of brandy and 14 Ibs. of
sugar or honey. Mix the whole thoroughly, and allow it to
ferment for one month in a cool place. Then add about 4
drachms of orange-blossom water, and clarify with 2 quarts
of skimmed milk. The champagne is now ready and is racked
off into bottles, into each of which a small piece of white sugar
is thrown, and the corks of which are wired. The duration
of fermentation has been stated as one month. It may, how-
ever, last a few days more or less, it being entirely a matter of
observation when the most suitable time for racking off has
arrived. No more rising of bubbles of gas should be observed,
but fermentation must not be completely finished.
According to another process, 40 quarts of fermented apple-
juice are mixed with 2 quarts of solution of sugar, J quart of
rectified alcohol and 2 ozs. and 4 drachms of pulverized tar-
tar. The mixture is allowed to stand 24 hours and then
racked off into bottles, each bottle receiving a drachm of bicar-
bonate of soda. Cork and wire.
Another process consists in bringing into a vat 40 quarts of
apple-juice, 5 Ibs. of white sugar, J Ib. of tartar, 1 pint of rec-
tified alcohol, j- pint of yeast and 1 oz. and 2J drachms of
acetic ether. Shortly before fermentation is finished the mix-
ture is drawn off into bottles, each of which has previously
been provided with a small piece of sugar. Clarification with
isinglass, white of egg or skimmed milk must, of course, pre-
cede the drawing off into bottles. The bottles must be thor-
oughly corked and wired in the same manner as genuine
champagne, and laid in a cool cellar.
Cider serves frequently as a basis for artificial wines, genuine
Burgundy, sherry or port-wine, prepared from cider mixed
with suitable substances, being frequently served even in first-
class hotels. Nothing could be said against these beverages if
they were sold under their proper names, because they consist
412 MANUFACTURE OF VINEGAR.
of harmless substances, which cannot always be said of the
genuine wines, they being only too frequently adulterated with
substances injurious to health.
Burgundy. — Bring into a barrel 40 quarts of apple juice, 5
Ibs. of bruised raisins, £ Ib. of tartar, 1 quart of bilberry juice
and 3 Ibs. of sugar. Allow the whole to ferment, filling con-
stantly up with cider. Then clarify with isinglass, add about
1 oz. of essence of bitter almonds, and after a few weeks draw
off into bottles.
Malaga Wine. — Apple juice, 40 quarts ; crushed raisins, 10
Ibs.; rectified alcohol, 2 quarts; sugar solution, 2 quarts;
elderberry flowers, 1 quart; acetic ether, 1 oz. and 2 drachms.
The desired coloration is effected by the addition of bilberry
or elderberry juice ; otherwise the process is the same as given
for Burgundy.
Sherry Wine. — Apple juice, 50 quarts; orange-flower water,
about 2 drachms ; tartar 2 ozs. and 4 drachms ; rectified alco-
hol, 3 quarts; crushed raisins, 10 pounds; acetic ether, 1 oz.
and 2 drachms. The process is the same as for Burgundy.
Claret Wine. — Apple juice, 50 quarts ; rectified alcohol, 4
quarts ; black currant juice, 2 quarts ; tartar, 2 ounces and 4
drachms. Color with bilberry juice. The further process is
the same as for Burgundy.
Diseases of Cider. — Ciders are subject to diseases which may
be due to the bad quality of the apples used, a faulty method
of manufacture, or bad management in the cellar.
Badly fermented cider, especially such as has merely passed
through the stage of tumultuous fermentation, or has been
acidified by contact with the air, is liable to produce serious
disorders. The first, says Dr. E. Decaisne, being heavy and
indigestible, inflates the intestines and produces diarrhoea ; the
second, though of a sweet taste and a piquant and agreeable
flavor, does not quench the thirst, but excites the nervous
system and produces flatulency ; the third, which is really
spoiled cider, causes inflammation of the intestines by the
large amount of malic and acetic acid it contains. When in
MANUFACTURE OF CIDER. 413
the production of cider, water containing organic matter has
been used, putrid fermentation is produced in the mass, the
products of which impart some very deleterious properties to
the cider.
Acidity in cider may be due either to an excess of malic acid
or of acetic acid.
Some ciders contain too much malic acid when manufac-
tured from apples not sufficiently ripe, or when, in mixing the
apples, too large a proportion of sour apples has been taken.
In both these cases the acidity may be neutralized by adding
to the apple-juice 3 ounces and 8 drachms of potassium tartrate
per 22 gallons. Sometimes there is an excess of acetic acid,
due to the oxidation of the alcohol by long contact with the air.
This defect is difficult to remedy. It might have been pre-
vented by means of a thin coat of olive oil, as previously men-
tioned, or by hermetically closing the bungs. The acidity will,
however, disappear by putting in the bottles a pinch of bicar-
bonate of soda. It must, however, be done immediately on
detecting the defect.
Viscosity or greasy appearance of cider is recognized by the
cider becoming stringy, viscous and greasy, and is due to too
great an abundance of gummy substances in the fruit, a lack
of tannin, and finally to defective fermentation. In order to
check this malady from its first appearance, add to every 228
quarts of the cider 1 pint of alcohol or 2 grammes of catechu
dissolved in 3 quarts of water. Cider may be prevented from
turning viscous by the addition of sugar to the juice when it
comes from the press, fermentation being thereby promoted.
The cause of cider turning black is an excess of oxide of iron,
which, on coming in contact with air, becomes a peroxide and
gives the beverage a brown color. The oxide of iron may
have been introduced into the cider either by the water used
in making it, or by fruit grown on ferruginous soil. By mix-
ing such cider with 12 drachms of powdered oak bark per 22
gallons, a quantity of tannin is introduced which combines
with the iron to an insoluble product that settles on the bot-
tom of the barrel. Tartaric acid may also be used.
414 MANUFACTURE OF VINEGAR.
Turbidity or lack of clarification of cider is caused by too
small a quantity of sugar in the juice, or by imperfect
fermentation.
In rainy seasons the apples ripen imperfectly and contain
but little sugar. Cider prepared from such fruit generally re-
mains turbid. During seasons in which abrupt changes of
temperature take place, and also when cold weather sets in
very early, fermentation does not progress well, and clarifica-
tion is imperfect. When the cider remains turbid after the
first racking off, add a solution of 2 Ibs. of sugar in 1 gallon
of water to every 132 gallons of the liquid. This sugar be-
comes converted into alcohol and renders the cider limpid.
The use of lead salt, formerly much in vogue in Normandy,
is very dangerous. Persons drinking cider thus treated fre-
quently feel sharp pains in the abdominal region, which pre-
sent all the symptoms of lead colic and may even prove fatal.
An admixture of lead salt is readily recognized. Add to
the suspected cider solution of potassium iodide ; if lead salt
be present, a yellow precipitate of iodide of lead will be
formed.
Adulteration of Cider. — According to most of the authorities
on food, cider is but little subject to adulteration. Even Has-
sall, who generally enumerates under each article of food a
list of every conceivable adulteration that has ever been found
or supposed to have been used in such food, only speaks of
the addition of water, of burnt sugar as a coloring matter, and
of the use of antacids for the correction of the acidity of spoiled
cider. On the other hand, in France where, as previously
mentioned, the consumption of cider is quite large, its adulter-
ation is by no means uncommon. The following is considered
in the Paris Municipal Laboratory as a minimum for the com-
position of pure cider :
Alcohol, per cent, by volume 3.00
Extracts, in grammes per liter 18 00
Ash . 1.7
MANUFACTURE OF CIDER. 415
This is for a completely fermented cider. In sweet ciders
the content of sugar should exceed the limit sufficiently to
make up for the deficiency of alcohol, to which it should be
calculated.
In the samples of American ciders investigated by the
United States Agricultural Department (see pp. 393-4), it was
fully expected to find a number preserved with antiseptics.
This supposition failed to be confirmed, however, for no sali-
cylic acid was found, and in but one case was any test ob-
tained for sulphites. None of the samples fell below the
standard proposed by the French chemists, given above, and
no metallic or other adulteration was discovered.
There was, however, a single exception, No. 4927 in the
table of analyses, p. 394, which was an embodiment in itself
of nearly all the adulterations which have been enumerated
as possible in cider. It was handsomely put up in neatly-
capped bottles, and was of a clear, bright color. Its tremendous
" head " of gas when uncorked gave rise at once to the sus-
picion that it had received some addition to produce an
artificial pressure of gas. The low content of free acid,
together with the large amount of ash and a variable content
of carbonic acid in different bottles, established the fact that
bicarbonate of soda had been added, probably a varying
quantity to each bottle, while the dose of sulphites added was
so large that a bottle stood open in the laboratory all through
the summer without souring.
Manufacture of brandy from cider. — Brandy is a mixture of
water and alcohol produced by the distillation of a fermented
liquor. It owes its aroma to the essential oil peculiar to the
substance subjected to distillation.
In Normandy the heavy ciders only are distilled, i. e., those
containing the most alcohol.
In years when there is an abundant crop of apples, it will
generally be found of advantage to distil the cider made from
fallen fruit and also from early apples. The cider yielded by
them does not keep well, and brings a very low price, espe-
cially when there is a large product from late apples.
416 MANUFACTURE OF VINEGAR.
Sour ciders should not be distilled, they being better utilized
for the manufacture of vinegar. Spoiled cider, as a rule,
makes bad brandy.
Different qualities of cider should be distilled separately.
A skilled distiller can classify them by the taste, and separates
them in order to obtain brandy of first and second qualities.
The cider is distilled when it is completely fermented, i. e.,
when the largest possible quantity of sugar has been converted
into alcohol. Cider from early apples generally ferments
faster than that from late apples and can be distilled towards
the end of December, i. e., from six weeks to two months after
it has been made. Cider made from late apples, during
December and January, is ready for distillation three or four
months later, i. e., in March or April.
Preparation of the juice for distillation. — When there is an
abundant crop of apples and barrels are scarce, the juice as it
comes from the press is brought into large open vats in which
fermentation progresses rapidly, but in this case some beer
yeast previously mixed with a small quantity of cider is added
to each vat and the temperature must be maintained between
59° and 68° F. Under these conditions the juice ferments
very promptly and may be distilled eight or ten days later.
Sometimes the whole of the pulpy mass obtained by grind-
ing the apples is submitted to distillation. In order to accel-
erate fermentation a small quantity of hot water containing
some sugar in solution is added to the mass, also one or two
thousandths of sulphuric acid, the latter regulating the progress
of fermentation.
Fermentation being finished, the mass is subjected to distil-
lation. In order to prevent this mass from adhering to the
still and scorching, distillation must be conducted as slowly
as possible and a small quantity of straw placed upon the
bottom of the still, or, better, a piece of cloth to prevent direct
contact of the mass with the heating surface.
Plums, damsons, etc., are also subjected to distillation and
produce good brandy. They ferment more slowly than wild
MANUFACTURE OF CIDER. 417
cherries which produce the well-known cherry-bounce. Atten-
tion may here be called to the distillation of wild plums, which
should be gathered in the fall when the leaves begin to drop.
Some connoisseurs consider brandy made from plums equal to
that from cherries. On a farm, no fruit containing sugar should
go to waste, as it can be converted either into brandy or vinegar.
Distillation. — For distilling cider on a small scale no ex-
pensive apparatus is necessary, an ordinary still answering all
requirements. Cider is distilled like wine. The still is filled
about { full and after placing the head in position the joints
are carefully luted by pasting strips of cloth or even paper over
them. The tub holding the worm is tilled with cold water and
the fire started. The vapors escaping from the boiling liquid
condense in the worm and run into the receiver. Heating
should be done slowly, in order to vaporize as little water as
possible, and especially to avoid sudden ebullition, as the boil-
ing liquid, getting into the head, would pass through the worm
and become mixed with the liquor already distilled. In such
an event it would be necessary to begin distillation anew. The
operation is continued until the liquid produced contains
hardly any alcohol, which can be ascertained by the use of the
alcoholometer or by the taste. It is unnecessary to say that
care must be had to constantly renew and keep cold the water
in the tub holding the worm.
Distillation being finished, the boiler is emptied, and after
thorough cleansing is refilled for a second operation.
The liquid produced by successive distillations is mixed
together and brought into the still a second time, whereby a
liquor richer in alcohol and of a better taste is produced. It
would be desirable if this second distillation or rectification
could be effected by means of steam. This would prevent the
empyreumatic taste which is often noticed in apple-brandy.
The first arid last runs of the still being of inferior quality are
collected separately and poured back into the still when re-
filling for the next operation.
Calculations have been made to establish by means of figures
27
418 MANUFACTURE OF VINEGAR.
the immense advantage offered in a financial point of view by
the distillation of cider. These theoretical calculations, how-
ever, are frequently very deceptive. If, on the one hand, the
producer knows the content of alcohol of his cider and, on the
other, the market value of the alcohol and of the cider, it will
be easy for him to decide which product will pay him best.
Pear-cider. — The manufacture of pear-cider is very limited,
and no great future can be promised for it, as even when most
carefully prepared it is far inferior to apple-cider and other
fruit-wines. Its preparation is best understood in England,
and how little it is appreciated there is shown by the fact that
three-fourths of the quantity manufactured is consumed by the
farm-laborers. But any one who has large pear crops at his
disposal and washes to use a portion of them for the manufac-
ture of a beverage should add to the pear-must one-quarter its
quantity of must of bitter-sweet apples or a few quarts of black
currant juice, which will improve the taste of the cider and
its keeping qualities. The mode of preparation is the same
as for apple-cider, though still greater care must be exercised
in the choice of the raw material. The pears must have a
sufficient content of sugar, as otherwise the cider would not be
sufficiently rich in alcohol and at the same time they must
contain a bitter substance to prevent the cider from turning
sour as soon as the conversion of the sugar is effected. Hence
the use of fine table pears for the preparation of cider would
be simply a waste of material. The only varieties suitable
for the purpose are those which when eaten from the tree pro-
duce a long-continued sharp heat in the throat and lie half a
day undigested in the stomach, which, however, become sweet
by long storing and lose enough of their acerbity to be no
longer disagreeable to the palate. In England, the wild pear
grown in hedges is generally used for the purpose. They
must be ripe, but not soft or mellow.
In the northern part of France pear-must is sometimes used
for the preparation of " port wine," the taste of which is very
much praised. The process consists in heating 50 Ibs. of must
PREPARATION OF FRUIT WINES. 419
to between 176° and 185° F. and adding 5 pounds of raisins.
At this degree of heat must and raisins are brought into a
barrel which is tightly bunged and placed in a cool place.
When in the course of a day the must is cooled to 59° or 68°
F., the raisins, which are generally put in a bag, are taken
from the barrel and after bruising returned (but not inclosed
in the bag) to the must, which is then allowed to ferment for
14 days. The wine is then drawn off into stone jugs which
are well corked and sealed.
Quince Wine. — A very spicy wine can be prepared from
quinces in the following simple manner : Place the quinces
for a few moments in hot water and then rub them with a
cloth to remove the down. Next remove the cores by means
of a knife or in any suitable manner. Now pour hot water
over the quinces thus prepared and boil them slowly over a
moderate fire until soft. Then press out the juice and add
white sugar in the proportion of 1J Ibs. to every 20 Ibs. of
fruits. Allow the whole to ferment in a cool room and from
time to time add some sugar-water during the process. Clari-
fication and racking off is effected in the same manner as with
cider.
CHAPTER XXX.
PREPARATION OF FRUIT WINES.
THE manner of obtaining the juice and appliances for that
purpose have already been described in the previous chapter.
a. From small fruits. — One of the principal objections to
wines from small fruits is that they easily turn. This can,
however, be overcome by adding, after fermentation is finished,
5.64 drachms of salicylic acid to every 100 quarts. By in-
creasing the dose to 8.46 drachms less sugar can be added to
the must, which, of course, makes the beverage poorer in alco-
hol. A saving of sugar can be further effected without injury
420 MANUFACTURE OF VINEGAR.
to the keeping quality of the wine by a suitable mixing of
juices. By working, for instance, the juices of currant, or of
raspberries by themselves, a considerable addition of sugar,
about 1 pound per quart, has to be made, which can, however,
be reduced one-half by mixing with a juice containing some
bitter principle, and later on treating the wine with salicylic
acid. Thus a large field for experimenting is opened to all,
and only a few hints will here be given. Raspberry -juice
should be mixed with one-quarter its volume of blackberry-
juice ; and in the preparation of currant-wine it is especially
recommended to use four-fifths of red to one-fifth of black cur-
ants, the wine obtained being far more spicy and possessing
better keeping qualities. Moreover, black currants used
within limits are an excellent material for improving the
flavor of almost all fruit-wines. The flavor and keeping qual-
ities of fruit-wine are also improved by throwing a couple of
handfuls of crushed hazel-nuts or walnuts into the barrel, and
also by the addition of 2 ounces and 8 drachms of bitter al-
monds, the peels of 10 lemons, 3 ounces and 5 drachms of
cassia, and a few handfuls of bruised wild plums. By these
means wine with a moderate content of alcohol acquires a
strong taste, while its keeping quality is at the same time im-
proved. The latter can also be effected by bringing 2 ounces
and 3 drachms of tartar into the barrel during fermentation.
A few other mixtures of juices may be mentioned. Blackberry-
juice is better adapted to ferment by itself than any other juice
from small fruits, but by the addition of J to J its weight or
its volume of strawberry-juice the aroma of the wine is greatly
improved. Strawberry -juice is least suitable for fermentation
by itself, and should be mixed with must containing a bitter
principle. The addition of J of the volume of the juice of the
Siberian crab-apple (Pyrus baccata) can be highly recommen-
ded for the purpose, it being especially suitable for improv-
ing the keeping quality of fruit-wine. The juice of rhubarb
•stems may be added to that of elderberries, while the juice of
gooseberries is suitable for mixing with that of mulberries.
PREPARATION OF FRUIT WINES. 421
Moreover, a combination of several juices may also be used; an
excellent wine being, for instance, prepared from equal parts of
blackberry, raspberry, currant, and strawberry -juice, with an
addition of walnuts as given above. In the receipts for the
different varieties given below, the customary addition of sugar
for unmixed fermentation and the omission of salicylic acid is
retained, but it may be repeated that with the assistance of these
means the cost may be reduced one-half. In order to avoid
repetition, the following general rules are here given, which
hold good not only for the preparation of wine from small
fruits, but also from stone-fruits.
The fruit to be used should be sound and ripe, though not
over-ripe, and must be freed from adhering dirt by washing in
warm water. Large quantities are best expressed by means of
a press, while for small quantities a bag of coarse linen is suffi-
cient, which is kneaded and squeezed until no more juice runs
out. Over the residue pour as much hot water as juice is ob-
tained, and after allowing it to stand for two hours press again
and mix the juice obtained with the first. Now add sugar in
the proportion of one pound to a quart of juice, and bring the
whole into a thoroughly cleansed barrel previously rinsed out
with salicylated water. Fermentation should take place in a
room having a uniform temperature of from 59° to 64° F.
During this process lay a piece of gauze upon the open bung-
hole and secure it by means of a stone, piece of iron, etc., which
prevents the access of foreign substances to the must. Every
other day the barrel is filled up to the bung-hole with sugar-
water prepared in the proportion of J Ib. of sugar to 1 quart
of water. As soon as the "hissing" in the barrel ceases, bung
the barrel tightly and after 14 days draw off the contents into
another barrel placed in the same room. After 6 months the
wine can be drawn off into bottles, being, however, 8 days pre-
viously clarified with the whites of a dozen eggs or 1 oz. of
isinglass slowly dissolved over a moderate fire in 1 pint of wine.
Whatever fining is used, add it to the wine with constant stir-
ring. If salicylic acid is to be used, it is best done in the man-
422 MANUFACTURE OF VINEGAR.
ner described for cider when the wine has acquired the desired
degree of ripeness. The bottles should be rinsed with salicyl-
ated water and closed with corks previously soaked for a few
hours in hot salicylated water. Sealing the bottles is not nec-
essary, but in order to be sure that the corks fit closely, shake
each bottle, with the neck downwards, with the right hand
holding the left under the cork. If the slightest moisture is
observed, the bottles must be recorked, as carelessness in this
respect may cause a portion of the supply of wine to spoil.
The corked bottles are laid in the cellar.
This general method, according to which all kinds of wine
from small fruits can be prepared, may be supplemented by
the following receipts :
Currant Wine. — Among all varieties of berries the currant
contains the largest quantity of free acid, about 2 per cent.,
and comparatively little sugar, about 6 per cent. The propor-
tion between these two principal constituents is very unfavor-
able for the manufacture of wine. The currant juice fer-
mented by itself would yield a product which does not deserve
that name.
Free the thoroughly ripe currants from the stems and after
crushing press out the juice. To the residue add twice or three
times as much water as juice obtained and after again pressing
add the juice obtained to the first. Now examine the juice
as to its content of acid and if necessary dilute further with
water. Then calculate the sugar in the manner previously
given. Sugar and acid having been brought to the right
proportion, the juice is allowed to ferment.
Currant wine is frequently prepared as a sweet liqueur-wine,
the following directions being much used for the purpose :
Juice 100 parts, water 200, sugar 100. According to an an-
alysis by Fresenius, the wine thus prepared showed after two
years the following composition : —
PREPARATION OF FRUIT WINES. 423
Alcohol 10.01
Free acid • . 0.79
Sugar 11.94
Water 77.26
100.00
According to another receipt, 17 J Ibs. of thoroughly ripe
currants freed from the stems are bruised in a wooden vessel
with the addition of 3J quarts of water. The paste thus ob-
tained is gradually brought into a bag of coarse linen, which
is laid upon an oblique board, and pressed out by means of a
rolling-pin. The press-residues are returned to the wooden
vessel and, after adding 7 quarts of water, thoroughly worked
with a pestle, and then again pressed in the above manner.
The juice thus obtained is brought into a barrel having a
capacity of 34f quarts, a solution of 12 Ibs. of sugar in 14
quarts of water is then added, and finally sufficient water to
fill up the barrel to within 3 inches of the bung. After cover-
ing the bung-hole with a piece of gauze, the whole is allowed
to ferment in a room having a temperature of from 59° to
64° F. When the principal fermentation is over, the barrel
is entirely filled with water and closed with a cotton bung.
The wine is then allowed to further ferment for six months in
a cellar having a temperature of from 54° to 59° F., when it
is drawn off into another barrel or into bottles. By adding to
the fermenting juice J Ib. of comminuted raisin stems a pro-
duct closely resembling Tokay-wine is obtained.
A very strong beverage is obtained by adding to the expressed
juice of currants twice the quantity of water and stirring in 2
tablespoonfuls of yeast. Allow the juice to ferment for 2 days ;
then strain it through a hair-sieve and after adding 1 Ib. of
sugar for every quart, allow it to ferment. When fermenta-
tion is nearly finished, add French brandy in the proportion
of 1 quart to 40 quarts of the juice, and bung up the barrel
two days later. The wine is ripe in four months.
According to another receipt the currants separated from
424 MANUFACTURE OF VINEGAR.
the stems, are pressed and the juice mixed with an equal quan-
tity of water. Then add to each gallon of liquid 2J Ibs. of
sugar, 2 ozs. of cream of tartar, and 1 oz. of pulverized nutmegs,
with 1 quart of alcohol. Allow the whole to ferment, then
fine with isinglass, draw off and bottle.
Another method is to express all the juice possible, then take
an equal amount of boiling water, and pour it on the expressed
fruit. Let it stand for 2 hours, squeeze out as much as there
is of juice and mix; then add 4 Ibs. of brown sugar to each
gallon of Ihe mixture ; let it stand for 3 or 4 weeks, until fairly
worked, with the bung out, and when it is done working, bung
it up, then place it in a cool cellar.
Strawberry-wine. — For the preparation of wine very fragrant
strawberries should be selected. The aroma of the strawberry
is so delicate that it readily undergoes a change and soon dis-
appears entirely. Hence to secure it and transfer it into the
juice the strawberry requires special treatment, whereby neither
the content of acid nor that of sugar is taken into considera-
tion. This treatment consists in mixing the sound, ripe berries,
without previous crushing or bruising, with the same weight of
pulverized sugar and allowing the mixture to stand in a glass
or stoneware vessel in a cool place until all the sugar is dis-
solved to a clear syrup in which the shrunk and tasteless
berries float. To separate the latter, strain the juice through
a woolen cloth previously rinsed with some lemon-juice or
tartaric acid, dilute with the same quantity of water, bring
the acid to 0.5 per cent., and subject the whole to fermenta-
tion in the usual manner at a temperature of from 50° to
59° F.
Some allow the berries to ferment with the juice, but the
wine obtained is somewhat harsh and not as delicate.
By finally adding to the finished wine from 4 to 5 per cent,
of rock-candy, a liqueur-wine is obtained which, as regards
aroma, cannot be surpassed, and is especially liked by ladies.
Excellent strawberry wine is also obtained according to the
following directions : Press out 10 Ibs. of different varieties of
PREPARATION OF FRUIT WINES. 425
small and large cultivated strawberries, which give about 2J
quarts of juice. Pour water over the residue and press again,
so as to obtain about 3 quarts more of juice or a total of 5J
quarts. Next dissolve 4 pounds of rock candy in 5 quarts of
cold water, bring the solution, together with the 5J quarts of
juice, into a small cask, and allow the whole to ferment in a
cellar having a temperature of 61° F. In four weeks the wine
is ready for drawing off into bottles. It is of a beautiful pale
yellow color and possesses an excellent bouquet, and if made
sparkling furnishes an excellent beverage.
According to a receipt in the " Weinzeitung," 40 quarts of
strawberries and 41 quarts of water, with an addition of 12 Ibs.
of sugar, 3J ozs. of tartar, and a gallon of whiskey free from
fusel .oil are allowed to ferment and the resulting wine i&
treated in the usual manner.
Another method is to pour 1 quart of hot water upon 1
quart of crushed strawberries and pressing out after allowing
the mass to stand for 2 days. Then add to every quart of
juice 1 Ib. of sugar, and to every 40 quarts of juice the grated
peel and juice of 2 lemons and 2 oranges and 4 quarts of
French brandy. Allow the whole to ferment, and treat the
resulting wine in the usual manner.
Gooseberry-wine. — The proportion between sugar and acid
is somewhat more favorable in the gooseberry than in the-
currant, but not sufficiently so as that the pure juice would
yield a good wine by fermentation. Hence the juice must be
converted into suitable must, as regards sugar and acid, in
accordance with the rules previously given. The yellow varie-
ties are preferable, they alone having a distinctly vinous taste ;
the wine obtained from the red and green varieties being
somewhat insipid. The juice is obtained in the same manner
as from currants, the berries being bruised, the juice allowed
to run off and the residue washed several times with water, so
that each volume of juice receives an addition of 1 volume of
water, though as the mixed juice has to be tested as to its-
content of acid, the direction in regard to the addition of
426 MANUFACTURE OF VINEGAR.
ivater need not be accurately followed. The must may contain
-as much as 30 per cent., because the fermentation of goose-
berry-must is generally carried on in the warmer season of
the year, so that all or the greater portion of the sugar fer-
ments and the wine, on account of the quantity of alcohol
formed, will keep for an almost indefinite time. Gooseberry-
wine made from must rich in sugar generall}7 acquires by age
an odor of Madeira-wine, which frequently deceives even con-
noisseurs.
Gooseberry-wine, like currant-wine being liked sweet, a
larger quantity of sugar may be added to the must from the
^tart, though for a quicker process of fermentation it is better
io add the desired quantity of sugar to the fermented wine.
If the must has been made quite sweet, so that a wine rich in
alcohol is formed, no fear need be had of the wine fermenting
anew on account of the addition of sugar.
There are a number of receipts for the preparation of goose-
berry-wine, but when more closely examined the products pre-
pared according to them will be found either more or less rich
in alcohol, or to contain more or less free acid, and to be either
sweet or not sweet, so that- the proportion can evidently be
-changed in any manner desired. It is further evident that
nothing is gained thereby as regards quality, because the type
for all artificial wines is grape wine obtained in a good season.
In such wines the proportions between alcohol and free acid
are well known and within such narrow limits that they cannot
be essentially exceeded on either side, and they alone can serve
as a basis for the rational preparation of gooseberry wine as
well as of all artificial wines. With the aroma or bouquet which
is to be imparted to such wine it is, of course, different ; but no
special directions are required, as every one manages it accord-
ing to his own taste or according to that of those who buy and
drink the wine. Thus it is also with the addition of sugar ; one
likes a sweet wine, the other one less sweet, and the third one
without any sugar. The principal aim is to prepare a wine
which contains the necessary quantity of alcohol to insure its
PREPARATION OF FRUIT WINES. 427
keeping properly, and the power of resistance against decom-
posing influences, and from which the greater portion of the
fermentable substances is removed by fermentation. In most
oases the natural conditions are of great use in this respect,
for in order to decrease the content of free acid it becomes
necessary to dilute the fruit juices, whereby the quantity of fer-
mentable substances is also relatively decreased, and sometimes
even to such an extent that they do not suffice for the complete
fermentation of the sugar. Such wine, if not wanting in alco-
hol, will keep for an almost indefinite time and may be ex-
posed to the access of air and a high temperature without the
appearance of the formation of acetic acid.
Gooseberry Champagne. — The taste of this beverage closely re-
sembles that of genuine champagne. There are several modes
of its production. In France a light wine which does not con-
tain too many fermentable substances is used. Somewhat less
than 2 per cent, of sugar, or about 15 grammes to a bottle of
800 cubic centimeters' capacity, is dissolved in the wine and the
latter drawn off into strong champagne bottles, which are then
hermetically corked and tied with twine. The wine is then
allowed to ferment in a room having a temperature of from
77° to 99° F. When fermentation is finished, the bottles are
brought into a cool cellar and placed first horizontally and
then gradually bottom uppermost so that the yeast may collect
on the cork and the wine become clear. When all the yeast
is precipitated to the neck of the bottle, the sediment is care-
fully removed — degorgie as it is termed — by first raising the
string securing the cork and then the latter, the bottle being
held in a horizontal position. The cork being no longer held
by the string is forced out together with the deposit of yeast,
while the clear wine impregnated with carbonic acid remains
behind. To prevent the unavoidable loss of wine, the cork,
together with the yeast and wine forced out, is collected in an
upright barrel with a large aperture, towards which the mouth
of the bottle is held during the operation.
The wine thus impregnated with carbonic acid, however, is
428 MANUFACTURE OF VINEGAR.
not yet champagne ; it only becoming so after the addition of
a solution of fine rock-candy in brandy with which the bottle
is filled up. Each bottle after receiving the necessary quantity
of the solution, or liqueur as it is termed, is at once closed with
a cork which is secured with twine or wire. Removing the
deposit of yeast is the most difficult portion of this operation,
long experience being required before the workman possesses
the necessary skill.
According to another method, which is also called the im-
pregnating method, the sugar required for sweetening is dis-
solved in the wine, and after clarifying the solution by filtering
through paper pulp in a bag, or, if necessary, with some isin-
glass, it is taken to the impregnating apparatus, one similar to
that used for mineral water answering the purpose. The wine
is then saturated under a pressure of 4J to 5 atmospheres with
the desired quantity of carbonic acid and at once drawn off
into bottles, which are corked and wired as above.
The advantage of this last named method consists in the
rapidity with which champagne can be made, 30 to 36 months
being required for the first method before the champagne is
ready for transportation.
The following method is the most simple of all, but does
not yield as fine a product. Each bottle is finished by itself
and no special apparatus is required. The wine is sweetened
and clarified in the same manner as in the impregnating
method and then drawn off into bottles. In case the wine is
not rich enough in alcohol, the content of the latter may be
increased by 10 per cent.
After having filled the bottles about 1.52 cubic inches less
than generally, add first to each bottle 11 drachms of pure
crystallized bicarbonate of potash and immediately afterwards
1 oz. of pure crystallized tartaric acid in pieces. Then close
the bottle with the cork and secure the latter by tying or wir-
ing it crosswise. The potash and acid are now brought to
solution by gently swinging the bottle to and fro, the contents
becoming at the same time turbid by the separation of bitar-
PREPARATION OF FRUIT WINES. 429
trate of potash. By placing the bottle bottom upwards, the
separated tartar is collected as much as possible upon the
lower surface of the cork, and after the wine is clear, removed
in the same manner as described in the first method. It is
not absolutely necessary to remove all the tartar, as it settles
on the bottom and the champagne will pour out clear.
According to any of these methods all fruit wines can be
converted into champagne or sparkling wines.
Semler gives the following directions for the preparation of
gooseberry champagne. Pour 20 quarts of warm water over
20 quarts of crushed gooseberries and add 6 Ibs. of sugar, 4|
Ibs. of honey, 1 oz. of pulverized tartar, J oz. of dried lemon
peel, and f oz. of dried orange peel. After standing for two
days strain the mixture through a hair-sieve into a barrel and
add 2 quarts of French brandy. When the " hissing " in the
barrel ceases, clarify the wine and after a few days draw it off
into bottles, securing the corks with wire. Before filling the
bottles throw a piece of sugar and J drachm of bicarbonate of
soda into each.
Raspberry Wine. — Raspberries have such an agreeable and
refreshing taste and odor that, while they are not very sweet
and the proportion of acid to sugar is not very favorable, they
are great favorites. Their aroma passes into the wine and
would be even too predominant if for the preparation of wine
the juice had not to be strongly diluted with water in order to
decrease the acid.
As in all other fruit, the quality of the raspberry depends on
the weather, and when this is favorable during the time of the
development and maturing of the fruit, the latter is sweet and
palatable, but in cold and wet seasons, sour and harsh. No
other fruit suffers as much from such conditions as the rasp-
berry.
We have the wild and -cultivated raspberry. The wild rasp-
berry is smaller than the cultivated but possesses a stronger
aroma, but unfortunately is too frequently infested with the
larva of many insects to render it always palatable. The cul-
430 MANUFACTURE OF VINEGAR.
tivated raspberry is considerably larger, and is less attacked
by worms, but possesses less aroma and is frequently even
watery.
To obtain the juice for the preparation of wine the thoroughly
ripe raspberries are crushed to a paste in a wooden tub by
means of a wooden pestle. To separate the grains, the paste is
forced through a fine wire sieve, which, in order to protect it
from the acid is best provided with a coat of asphalt or shellac
varnish. It is, however, no disadvantage to allow the grains
to ferment with the pulp, some tannin being thereby intro-
duced into the wine, which under certain circumstances may
be even desirable.
The content of acid in the raspberry varying considerably in
different years, a test of the juice in this respect becomes abso-
lutely necessary in order to enable one to dilute it in. the cor-
rect proportion with water. For this purpose press out a small
quantity of the crushed raspberries and determine the acid in
the manner previously given. The sugar contained in the rasp-
berry need not be taken into consideration, since by dilution it
is reduced to 1 per cent, and still less. The must is simply
brought up to 25 per cent, of fruit-sugar and allowed to fer-
ment in the usual manner. The treatment of the wine after
fermentation is the same as for other fruit wanes.
Blackberry wine is prepared in the same manner as raspberry
wine. Of the numerous directions for its preparation we give
the following : Gather the berries on a dry day, crush them
with the hand into a kettle, and add just enough hot water to
cover the mass. Then add a handful of bruised raisins and a
handful of strawberry leaves, from the heart of the mother
plant, or, still better, from the suckers, and allow the mass to
stand for four days, when a crust of yeast will have formed on
the surface. The mass is now pressed out and sugar in the
proportion of 1 pound to every 4 quarts added. Fermentation
is allowed to go on for two weeks, when the barrel is bunged
up and* the wine drawn off after six months. During fermen-
tation, and especially in the beginning of it, care must be had
to fill up the barrel.
PREPARATION OF FRUIT WINES. 431
To make from blackberries a beverage resembling port-wine
the following method is recommended : Press out the juice and
allow it to stand for 36 hours. While fermenting during this
time remove all scum from the surface. Now add of water,
one-fourth the quantity of juice, and 3 pounds of brown sugar
to every 4 quarts of fluid and filter after 32 hours. Fermen-
tation, which requires but a few days, being finished, bung up
the barrel tightly and after six months draw off the wine.
The latter improves by age.
Mulberry Wine. — Press the juice from the fruit, dilute with
the same quantity of water, add 1 pound of sugar for every
quart of liquid, and boil the whole j- hour. Then add for
every 100 quarts, 3 quarts of alcohol, 6J ounces of tartar, 1
ounce of cassia, and J ounce of bruised bitter almonds, and
allow the whole to ferment. The further treatment of the
wine is the same as for other fruit-wines.
Elderberry Wine. — Boil equal quantities of berries and water
one-half hour, pour the whole into a hair-sieve, press the pulpy
portion of the berries gently through with the hand and re-
move the residue. Compound the strained juice with sugar
in the proportion of { pound to 1 quart, and boil 20 minutes.
As soon as cool bring it into a barrel to ferment. Fermenta-
tion being finished, paste stiff brown paper over the bung-
hole, and after eight weeks draw off the wine in bottles.
Another method is to boil 50 quarts of water, 10 quarts of
elderberries, 40 pounds of sugar, 5 ounces of pulverized ginger^
and 2J ounces of cloves for 1 hour, with constant skimming.
Then bring the liquid together with 4 pounds of crushed rai-
sins into a barrel and allow it to ferment. At the termination
of the fermentation it will yield a wine similar to the Cyprus^
or Greek-wine.
Juniperberry Wine. — 70 quarts of water, 35 pounds of crushed
raisins, 10 quarts of juniperberries, 4 ounces of tartar, 1 quart
of French brandy, and a handful of fresh marjoram leaves
are brought into a barrel and the mixture is allowed to fer-
ment for 12 hours.
432 MANUFACTURE OF VINEGAR.
Rhubarb Wine. — Add to every 5 pounds of the thinly-sliced
stalks 2 \ quarts of soft water and bring the whole into a clean
wooden vessel. Cover the latter and stir the contents with a
wooden stick three times daily for one week. Then pass the
fluid through a wide-meshed sieve and add to every 3 quarts,
4 pounds of white sugar, the juice of 2 lemons, and the peel
of 1 lemon rubbed upon sugar. Allow the mixture to ferment
in a barrel, and after clarifying, draw the wine off into bottles
in March.
The variety of rhubarb known as Victoria is best adapted
for the preparation of wine, which can also be effected accor-
ding to the following directions : Cut up the stalks and express
the juice. To every gallon of juice add 1 gallon of soft water
and 7 pounds of brown sugar. Bring the mixture into a bar-
rel and allow it to ferment until clear, with the bung out, keep-
ing the barrel filled with sweetened water as it works over ;
then bung the barrel tightly or draw the wine off into bottles.
It makes an agreeable and healthful wine affording a good
profit, as nearly 1800 gallons of wine may be obtained from
each acre of well-cultivated plants. The stalks will furnish
about three-fourths their weight in juice.
Tomato Wine. — Press out the juice from ripe tomatoes, add
to each quart of it 1 pound of brown sugar, and allow the
whole to ferment. After three months the wine can be drawn
off into bottles.
Parsnip Wine. — Cut 12 pounds of parsnips into thin pieces,
add 15 quarts of water and boil until soft. Then press out
the juice and after straining through a hair-sieve sweeten with
j pound of sugar per quart. After again boiling for j hour it
is brought, when cold, into a barrel and a tablespoonful of
yeast is added. Stir the juice daily for 10 days, then bung up
the barrel tightly and after six months draw off the wine into
bottles.
In the same manner wine may be prepared from carrots,
clover heads, corn stalks, etc. It is, however, recommended
to add to the juice some aromatic substance such as a handful
PREPARATION OF FRUIT WINES. 433
of marjoram, almonds, plum kernels, currants, walnuts, ginger,
or still better a few quarts of black currant juice.
b. From Stone Fruits. Cherry Wine. — Stone sweet cherries
and after crushing the pulp to a paste allow it to ferment in
stoneware pots for 12 hours. Then press out the juice, which
is returned to the pots and allowed to stand until yeast fungi
rise to the surface. Now add 1 pound of sugar to every 3
quarts of must, bring the latter into a barrel and allow it to
ferment 8 days. Then rack the wine into bottles and keep in
a cool place. The preceding is the method followed in Eng-
land where pure cherry wine is made. It may, however, be
remarked that it is somewhat insipid. A mixture of the juice
of cherries with that of the raspberry or currant can, however,
be highly recommended, it yielding a beverage similar to port
wine. It is an American receipt and much preferable to the
English. Press the freshly gathered cherries, black or red,
but selecting those with the softest pulp, without crushing the
stones. To the juice obtained add one-eighth of its quantity
each of raspberry and black currant juice, and sweeten with
lump sugar in the proportion of 1 pound to 2J quarts of juice.
The whole is then brought into a barrel to ferment. When
fermentation is finished close the barrel tight and allow it to
rest for three months. Then clarify the wine and draw it off
into bottles. It is fit to drink in six weeks.
Morello Wine. — Press 60 pounds of morellos so as to crush
the stones, mix the juice obtained with 20 quarts of sherry
wine and the same quantity of warm water, and bring the
whole into a barrel to ferment. Suspend in the barrel a bag
containing 1J ounces each of cinnamon, powdered nutmeg
and mace, allowing it to remain until drawing off the wine.
The latter is very palatable in two months after fermentation
is finished.
Plum Wine. — Not all varieties of plums are suitable for the
preparation of wine, but the Heine Claude and Mirabelle can
be highly recommended, the latter especially making as spicy
and agreeable wine as any variety of fruit. With the almost
28
434 MANUFACTURE OF VINEGAR.
innumerable varieties of plums it is not possible to say which
are suitable for the preparation of wine and which are not. It
can only be determined by experiment, though right sweet
varieties only should be chosen. In this country the small
sweet variety known as the wheat plum, etc., is frequently
used for the purpose. The process is as follows : Stone the
plums, then bruise the pulp, and add to every 8 pounds of the
latter 3 quarts of hot water. After 2 days press out the juice
and add to every two quarts of it one pound of sugar. Now
bring the juice into a barrel in a cool room and add the
crushed kernels of -f- of the stones. Allow the whole to fer-
ment completely. After 12 months the wine is clarified and
drawn off into bottles, each of which receives a small piece of
sugar, which improves the keeping qualities of .the wine.
Apricot and Peach Wines. — Both these varieties of fruit are
used when nearly ripe. Remove the stones and crush the pulp
to a paste. For every 8 pounds of the latter add 1 quart of
fresh soft water, and let the mass stand 24 hours. Then
press out the juice, add for every 2 quarts of it 1 pound of
sugar, and allow it to ferment. During fermentation it is rec-
ommended to throw a handful of the crushed stones into the
barrel, which gives to the product a more spicy flavor.
Sloe or Wild Plum Wine. — This beverage is not to be de-
spised if prepared in the manner given for plum wine. The
sloes must, however, remain on the bushes until after the first
frost, which sweetens them.
PART III.
CANNING AND EVAPORATING OF FRUIT.
MANUFACTURE OF CATSUPS, FRUIT-
BUTTERS, MARMALADES, JELLIES,
PICKLES, AND MUSTARD. PRES-
ERVATION OF MEAT, FISH,
AND EGGS.
CHAPTER XXXI.
PRESERVATION OF FRUIT.
THE use of hermetically closed tin cans for preserving fruit
has become of great commercial importance. Before discuss-
ing it, the various ways which have proved more or less satis-
factory for household purposes will be briefly mentioned.
The following rules apply, however, to all methods : —
1. The fruit must be gathered in dry weather and when free
from dew. It is to be kept as free from dust as possible.
2. Absolutely sound fruit, not over-ripe, should only be se-
lected.
3. The fruit should be preserved immediately after gather-
ing.
4. The utensils used must be kept scrupulously clean.
5. The preserving vessels should not be placed directly
upon the fire.
6. A good quality of white sugar only should be used ;
brown sugar injuring the taste and color of the fruit.
7. Copper or enameled pans alone should be used for boil-
"(435)
436 MANUFACTURE OF VINEGAR.
ing, if the latter is not effected in glass. The spoons should
be of wood or of bone.
8. The jars or cans should be thoroughly rinsed, best with
salicylated water, and if corks are to be used they should be
perfectly sound and scalded in hot water to which some sali-
cylic acid has been added.
9. Small jars or cans are preferable to large ones, and they
should be kept in a dark, cool, dry place.
Bottled fruits should always be sterilized for 10 minutes,
from the time the boiling-point is reached, in the case of
J-bottles, 12 minutes for J-bottles, and 15 minutes for full-
sized bottles. Only in the case of halved apricots and peaches
and similar fruits that lie closely together, should a few
minutes extra be allowed. Fruits that change color when
heated, for instance, white .pears, peaches and gooseberries
should be separated after sterilizing in order to accelerate
cooling.
First may be mentioned the old French method, known as
au Baine-Marie, which on account of its simplicity, is still
much used. Berries require no preparation, but peaches,
apricots and plums must be stoned and halved, and cherries
and small plums stoned. Apples arid pears are peeled and
quartered and immediately thrown into boiling water for 4
minutes to bleach, They are then laid a few minutes upon a
sieve to dry, and brought, like other fruit, by means of a spoon
into wide-necked glass jars which are rilled to within 2 inches
of the edge. In placing the fruit in the jar press it well to-
gether. The empty space is then filled up with hot syrup
composed of 2 parts of sugar and 1 part of water, and the jars,
after heating them somewhat upon a stove, are placed in boil-
ing water for 8 minutes for kernel fruit and for 10 minutes for
stone-fruit or berries. The jars are then immediately corked
and sealed.
According to another French method, the flesh of the fruit
is preserved without boiling. Stone-fruits and berries only
can be used. The fruit is pressed through a, hair-sieve and
PRESERVATION OF FRUIT. 437
the pulp mixed with an equal weight of pulverized sugar.
The mixture is then brought into glass bottles, which are
corked and sealed. This fruit-pulp keeps, however, only
through the winter, or if kept in a cold place or in a refrig-
erator.
The following method gives better satisfaction : The fruit,
such as cherries, berries, plums, peaches, apricots, etc., is,
without the addition of water, brought into wide-necked glass
jars in such a manner that a layer of fruit alternates with
a layer of sugar, the top layer being sugar. The jars are then
tied up with salicylated parchment paper, placed in a water-
bath, and the water kept boiling for 15 to 30 minutes, accord-
ing to the variety of fruit, small fruit requiring less time than
large, and berries only about 1G minutes. The jars are then
stored in a cool, dark place. For closing jars with narrow
mouths corks are preferable. They are soaked in hot salicy-
lated water and sealed.
Fruit thus preserved retains its fresh, natural appearance
and keeps for a considerable time. If appearance is, however,
of secondary consideration, it is better to boil the fruit, as is
done with kernel fruit, melons, and all large varieties. The
preparation for this method varies according to the nature of
the fruit. Apples and pears must be peeled, and, if not too
large, only cored, otherwise they have to be halved or quar-
tered. Melons are peeled and cut into strips. Quinces are
steamed until soft, then peeled as clean as possible, quartered,
and the cores removed. After this preparation the fruit is
brought into the preserving kettle and as much water as is
necessary for boiling added. Boiling should be done very
slowly and continued until the fruit commences to get soft.
It should not be boiled too soft, but only sufficiently so to
enable it to absorb the sugar-liquor. When this is the case
the fruit is taken from the fire and strained, and with the liquor
a syrup of the following composition is prepared : For each
pound of fruit take one pound of sugar and soak it in J pint
of the liquor. It is then placed upon the fire and the resulting
438 MANUFACTURE OF VINEGAR.
syrup skimmed. When it boils the fruit is introduced and
slowly boiled, or rather simmered, because it must not fall to
pieces, for five to ten minutes, according to its softer or harder
nature. The fruit while still warm is then brought into the
jars, in which no vacuum must remain. Hence they must be
filled up to the cork, or if bladder or parchment paper is used,
for closing them up to the rim. In the latter case it is advis-
able to place upon the surface a close-fitting piece of paper,
previously saturated with a concentrated solution of salicylic
acid in rum. Currants, blackberries and grapes are sometimes
preserved in their natural clusters. They are first washed in
fresh water, then slowly boiled soft, and strained. With the
liquor a syrup of the previously mentioned composition is
prepared, which is boiled and skimmed and poured upon the
fruit in the jars.
Fine table pears are sometimes preserved in the following
manner : Eight large pears are placed in a syrup prepared
from 6 ounces of sugar, 3 ounces each of cloves and allspice,
J pint of water, and J pint of port wine or other sweet red
wine. In this syrup they are boiled very slowly — as much as
3 hours — until soft, and, while still warm, are brought to-
gether with the syrup into jars, which are treated in the
manner previously described. By taking equal parts of pears
and of fine plums a very beautiful product is obtained.
The boiling down of fruit in large stoneware pots is fre-
quently accompanied by mishaps, and is more and more super-
seded by other methods. It consists in dissolving J to f pound
of sugar in water and boiling the resulting syrup together with
the fruit until the whole forms a jelly-like mass. While still
warm the pots, which must be full, are tied up with bladder.
A piece of salicylated paper should be placed upon the surface
of the fruit before tying up the pots.
Preserving in Air-Tight Cans. — This method, as previously
mentioned, has become of great commercial importance. The
number of factories, briefly termed canneries, has largely in-
creased, and not a few of them employ 1,000 hands during the
PRESERVATION OF FRUIT. 439
fall. Of course these factories do not limit themselves to the
canning of fruit, as otherwise they would have to cease opera-
tions during the winter months, but that branch of the busi-
ness preponderates over all others. The search after other
suitable material is constantly more extended, and the trade-
list of a large English factory now contains 200 different
articles ; including all Southern fruits, a portion of which
is, singularly enough, returned in this state to the tropics.
The American trade-lists embrace, as a rule, three groups, viz :
1. Apples, pears, peaches, apricots, plums, strawberries,
raspberries, blackberries, currants, cranberries, whortleberries,
nectarines, grapes, cherries, quinces, cocoanuts, pineapples,
marmalade, jelly, green walnuts.
2. Peas, beans, beans with pork, corn, tomatoes, asparagus,
carrots, onions, pickles, cauliflower, horseradish, mushrooms,
catchups, succotash, plum-pudding, sweet potatoes.
3. All kinds of poultry, venison, salmon, lobster, crawfish,
oysters, crabs, beef, mutton, pork, eels, salt-water fish, ham,
pig's feet, beef tongue, lamb's tongue, frog legs, mussels, etc.
All the varieties of fruit named in the first group being not
-equally well adapted for canning, the less suitable kinds are
only used in small quantities. Plums and cherries are pre-
ferably stoned, as well as peaches and apricots. Heart-cherries,
black raspberries and whortleberries are the best suitable
varieties of fruit for canning, as they loose their agreeable
taste by steaming. Strawberries also become somewhat insip-
id, but red raspberries are excellent provided they are canned
as soon as possible after being gathered. Blackberries are not
quite so good though if, brought into the can immediately
when plucked, they furnish an agreeable dish. Currants
have too many seeds, and are better used for jelly. Black
•currants are well suited for canning, and in this state are
much used by bakers for tarts. Gooseberries canned before
entirely ripe are very good. Among the smaller stone fruit
the Mazard cherry has few superiors, as if carefully canned it
retains its shape, color, and aroma as on the tree. Most plums
440 MANUFACTURE OF VINEGAR.
are suitable for canning, provided they are stoned. Among
the kernel fruits the quince occupies the first rank, as it is the
only variety of fruit which gains by steaming. Pears are very
suitable for canning, and even the inferior qualities can be
used for the purpose. Apples, however, must be carefully
selected, and only sweet varieties with firm flesh should be
used. The Siberian crabapple can be highly recommended
for the purpose. •
As a general rule fruit for canning should have a firm flesh
and fine aroma, these conditions being found in all the vari-
eties preferred by the packers in the United States, whose
canned goods can be found in every large city of the world.
Next to the variety of fruit, the cans are of the greatest im-
portance. Much has been said and written in regard to them,
and the discussion pro and con will very likely be continued.
Glass jars have some advantages. They are comparatively
cheap, allow of an inspection of their contents and the ready
recognition of a leak, and are not attacked by the vegetable
acid. But, nevertheless, they have not been introduced into
general use because they are liable to break, and, being heavy,
increase the cost of transportation, and, finally, it is difficult to
close them air-tight. The sealing of a bottle with a narrow
mouth is quite a different thing from sealing one with an aper-
ture three inches in diameter. It may do for pickles, marmalade
or jelly, but for preserved fruits which are to be transported
long distances it cannot be depended on. The same objections
may be made to stoneware jars, which possess the further dis-
advantage .that their contents cannot be inspected and a leak is
difficult to discover. Nevertheless, they are used by some large
English factories for the reason, it is claimed, of keeping their
products free from influences deleterious to health. To facili-
tate sealing, the jars are generally small — of about one pound
capacity. Tin cans have many defects, but their use is very
extensive, and in the United States they are almost exclusively
employed. Complaint has been frequently made that the use of
tin cans is deleterious to health because the tin contains lead,
PRESERVATION OF FRUIT. 441
which is dissolved by the vegetable acid and transferred to the
fruit-s}Trup. In reply it has been said that only the inferior
qualities of tin contain lead, and that only in an infinitesimal
quantity ; but it cannot be denied that the solder may readily
become injurious to health and in cases of poison investigated
in the United States and England it could in every case be
shown that the respective cans were soldered on the inside.
The time is very likely not very distant when such soldering
will be entirely done away with. To completely overcome all
complaints against solder, as well as against a content of lead
in the tin, cans are manufactured which are provided inside
with a thin coating whereby the contents are protected from
contact with the metal. The insoluble constituent of this
coating consists of silicate of lirne or glass-powder previously
treated with hydrofluoric acid, while the soluble constituent is
silicate of soda or of potash. Any silicate of earthy bases or
metals may be used, or a precipitated gelatinous silicate. The
alkali is fixed or removed by means of a bath containing a
dilute solution of hydrofluosilicic acid, or a dilute solution with
any other suitable acid. For preparing the composition mix
the soluble with the insoluble silicate. The tin plates are
coated with this mixture by means of a brush, or dipped in a
bath of it and then dried by heat. The plates thus acquire a
glass-like coating, which remains fixed no matter how the
plates may be handled and worked.*
In the canneries in the United States the cans are manufac-
tured in a special department, and the division of labor is
carried so far that every can passes through eight hands before
it is finished ; and only with such a system is it possible to turn
out large quantities in an incredibly short time. This far-
reaching division of labor is, however, not limited to this
department alone, but is the supreme law in the entire estab-
lishment. In the same department the solder is cut by a
* In this country some packers of lobsters, shrimps, etc., line the cans with
parchment paper.
442 MANUFACTURE OF VINEGAR.
machine into small three-cornered pieces. Each workman
receives a certain quantity by weight of solder and of char-
coal, with which he is expected to solder a certain number of
-cans. The workmen are paid by the piece, and each solderer
has a number which is stamped in every can he solders, so
that those which prove leaky may be returned to him for re-
pair. By this system there is no waste of material, and the
leaky cans do not exceed 5 in 1,000.
In another department the fruit is carefully inspected on long
tables ; the unsound being thrown out, and the sound turned
•over to the peelers and stoners, who of course work with the
most improved machines. There are carriers bringing un-
interruptedly fresh fruit, and off-bearers removing and sorting
the waste. Nothing is thrown away, the waste being used
partially in the manufacture of jelly and partially in distilling,
-and even the stones are utilized, as they are sold either to
nurserymen or to chemical factories. Other workmen are
occupied in placing the peeled and stoned fruit in the cans,
which are handed over to boys, who place them upon small
trucks running upon rails and transport them to the depart-
ment where the filling in takes place. In the same department
the syrup of sugar and water is prepared, but if the propor-
tion of composition were asked a different answer would be
received in every cannery. In regard to this point every
manufacturer has his own ideas, which also extend to modifi-
cations for the different varieties of fruit. All manufacturers
agree, however, that the best quality of white sugar should be
used for light-colored fruits, and light-brown sugar for dark-
colored, and that the syrup must be perfectly clear, and hence
very carefully skimmed in boiling. In most factories the
syrup used consists of 1 Ib. of sugar dissolved in 1 pint of
water. The filling of the cans with the fruit and syrup, the
latter being generally kept warm, is effected with the assist-
ance of scales, so that each can has exactly the weight upon
which the selling price is. based. The caps, previously pro-
vided with a hole the size of a small pea, are then soldered
PRESERVATION OF FRUIT. 443
upon the cans. The hole in the cap serves for the escape of
the air during, the succeeding process.
Different kinds of apparatus are used for the expulsion of
the air by heating the cans. In large factories a steam retort
is used which resembles in shape a ship's steam boiler. It is
provided with a door closing air-tight, and is divided in the
•center so that it can be filled either half or entirely with steam,
as may be required. The cans to the number of from 400 to
600 are placed upon trucks which run upon rails leading into
the retort. Eight such trucks can be introduced at one time,
so that is is possible to steam from 30,000 to 40,000 cans per
day. The retort being filled, the door is closed and the pipe
•communicating with the steam boiler opened. The cans re-
main in the retort from 15 to 30 minutes, according to the
variety of the fruit : Berries 15 minutes, stone-fruits 20, apples
and pears 25, quinces and tomatoes 30. The door is then
opened, and after the steam has somewhat dispersed the trucks
are quickly pushed to the tin-shop, where the cap holes are
soldered up. To cleanse the cans and make them shiny they
are next put, in a bath of soda water and then rinsed off with
cold fresh water. They are then transferred to the store room,
where they remain standing quietly for one week, when they
are tested by striking the cap of each a short sharp blow with
a wooden hammer. If everything is in order, the cap sinks
slowly down, but if it is elastic and jumps back the can is
what is called a "swellhead," and is returned to the tin-shop
for repairs and is then again steamed. The perfect cans are
labeled and packed and are now ready for market.
Another apparatus which can be highly recommended for
small factories consists of a round iron plate resting upon a
brick base about one foot high. Two round iron rods run up
opposite to each other from the edge of this plate and serve
as a support for a movable iron cylinder open at the bottom
and closed on top. Upon the iron plate the cans are placed in
the form of a pyramid, and the cylinder is then drawn down
and screwed air-tight to the plate. A pipe communicating
444 MANUFACTURE OF VINEGAR.
with the steam-boiler enters the cylinder, and as soon as the
latter is connected with the plate steam is admitted. After a
certain time, which corresponds with that previously given,
the steam is shut off, the cylinder pushed up, and the cans re-
moved, the further treatment of which is the same as given
above.
In some factories the cans are still heated, according to the
old method, in boiling water. For this purpose the cans —
100 at a time — are placed upon an iron plate attached to a
steam-crane and submerged for 15 to 20 minutes in boiling
water in a large shallow kettle. In this case the caps, are not
perforated, but soldered down air-tight. A workman watches
the cans while they remain in the water and by means of a
tool removes those from which small bubbles arise. Such cans
being not air-tight are returned to the tin-shop for repairs.
The rest after being heated are also brought to the tin-shop,
where the caps are perforated with a hole the size of a small
pea, which is again soldered up after the escape of the heated
air.
The canning of tomatoes, asparagus and other vegetables
is effected in a similar manner except that no syrup is used.
The Appert process for canning meat described later on under
"Preservation of Meat, Fish and Eggs" is frequently used for
the more expensive kinds of vegetables, such as asparagus,
green peas, etc., glass vessels being generally used. The vege-
tables are first cleaned and trimmed, and are then covered
with water in the vessels, with or without a little salt. Sticks
of asparagus, or whole beans, are stood on end. The vessels
are now lightly corked and boiled in a bath of concentrated
brine, in which they are stood upright as fully immersed as
possible. The bath is heated very slowly to avoid cracking
the glass. It should take about two hours to bring the tem-
perature to 212° F. The brine is then brought to the boil,
whereupon the contents of the glasses will also boil. After
they have been boiled for about ten minutes, the bath is al-
lowed to cool to about 140° F., and the corks are driven in
PRESERVATION OF FRUIT. 445
tightly. Fused paraffin is then poured over them, and when
the bath is quite cold, the glasses are taken out. The vege-
tables will then keep for as long as the vessels are unopened,
for all ferments in them have been destroyed, and the para-
fined cork prevents any more from getting access to them.
The paraffin should come flush with the edge of the jar, and
should be tied over with vegetable parchment to prevent it
from cracking and flaking off. The top of the cork should be
rough so that it may adhere better to the paraffin.
As the canning of tomatoes may serve as a type for all other
vegetables a description of the process, for which we are in-
debted to Mr. Richard T. Starr, of Salem, N. J. is here given.
The tomato was for many years found only in hot-houses
and conservatories of the rich. It was known as the love-
apple and considered a curiosity. Our ancestors had no idea
that this small red berry, for such was about its size, would
ever, even under careful cultivation, become of mammoth
size and form one of our most important articles of food. But
such is actually the case to-day. The exact time when the
now great industry of canning this vegetable commenced can-
not be established with any certainty. The taste for the
tomato seems to be an acquired one, and for years the industry
struggled in its infancy until the breaking-out of the War of
the Rebellion caused a demand that rapidly grew into gigantic
proportions, and to-day finds the tomato-canning industry
employing an army of men, women and children, while
millions of dollars are invested in the payment of labor and
the erection of plants.
In order that our readers may have a clear idea of the busi-
ness we will commence with the beginning. Having made up
his mind to engage in it on an average scale, the packer will
first find a suitable plot of ground, on a navigable stream,
if possible. Having secured this, the next thing is the erec-
tion of the buildings ; these are generally one story in height
and as large and roomy as the capital will warrant. The
next step is to secure the requisite supply of fruit, and for
446 MANUFACTURE OF VINEGAR.
this purpose the farmers are drawn on and contracts entered
into with them in which the packer agrees to take the entire
marketable product of a certain number of acres, or else to take
so many tons. These contracts are generally made about the
first of the year, and as soon as the sun drives the frost from
the ground the farmer prepares his beds and sows his seed.
While the latter is growing, the land which is to be planted is
heavily manured and plowed and carefully worked until it be-
comes mellow, and then hills about four feet apart are made,
and into each one is put a small quantity of compost of phos-
phates. The tomato plants, having by this time grown to the
height of 6 or 8 inches, are taken from the beds, and on a
cloudy day, or the latter part of a bright day, transplanted
and tended about as other growing crops. With a favorable
season the farmer should commence delivering to the factory
about the middle of August.
The arrangement of a canning factory is, of course, a matter
of taste, but the most complete, in our opinion, is one where
everything moves in a straight line, and in which none of the
help are obliged to interfere with one another. The first thing
to be done with a load of tomatoes is, of course, to weigh
them, and for this purpose platform scales are built at an end
door and the wagons driven on them. After being weighed
the tomatoes are handed over to the scalder. Tomatoes arriv-
ing in all kinds of weather and conditions must, of course, not
•only be washed but scalded, so as to thoroughly loosen the skin
from the pulp; and to do this quickly and properly, a heavy
box of white pine is fitted with both steam and water pipes, and
attached to it is an iron cradle swinging on hinges and raised
and lowered by a wheel and pulley suspended above. On the
back of this is placed a box, and as the farmer hands off his
baskets they are emptied into this box, and at the command
of the man at the rope, who is called the " scalder," they are
dumped into the boiling water beneath. A few seconds suffice
to clean and scald them ; the cradle is then raised and the
tomatoes are poured into kettles set in front of the scalder to
receive them.
PRESERVATION OF FRUIT. 447"
While this has been going on a group of women and girls
have been filing into the factory and seating themselves along
the trays that are to receive the tomatoes from the scalder.
These trays are of different construction, but are similar as re-
gards length, breadth and depth, the only difference being in,
the various ways of getting rid of the water and juice. This-
is generally done by making a slat frame fit in the bottom and>
over a trough fastened under the tray. This leads to a drain,
which carries it to the creek or wherever else it is to go. At
each tray are from ten to twelve women, each of them furnished
by the packer with a bowl and knife, and provided at their own
expense with a neat water-proof apron. The tomatoes are-
dumped from the kettles in front of them, and they remove
rapidly the already loosened skins and cores and deposit the
prepared fruit in a bucket sitting beside them. They become
so efficient that a smart, active woman will frequently skin from,
40 to 60 buckets a day, and as they receive 4 cents per bucket
it will be seen they make fair wages. Standing just beyond1
the women are the machines which fill the cans. To describe-
them would be impossible, there being so many shapes and
many makes. Some are very good, some very poor, every
man thinks his the best, and so it goes ; but in one respect they
all agree : they have a hopper into which the fruit is poured*
from the buckets, and all have the plunger which forces the
fruit into the cans ; the treadles of some of them are moved by
hand and some by steam. The machines rapidly fill can after
can, which are then set on the " filling table "and receive
" top them off," or in other words the fruit is cleared away
from the top of the can so that the solder used in capping:
them will not become chilled. They are then placed in trays-
each holding either 10 or 12 cans and removed to the " wiping
table," where everything is cleared from the top, wiped dry
with sponges, and the cap placed over the opening. The
" cappers " stand directly in front of the wiping table, and
each one has his own fire-pot, irons, files, and everything he
uses before him. Taking the tray, he rapidly applies by
448 MANUFACTURE OP VINEGAJR.
means of a small brush the acid or flux necessary to make the
solder flow freely around the cap, and then with the iron melts
the solder and puts it in the groove. The can is then vented
and is ready for the "bath." The baths, except in size, are
-constructed similarly to the scalder, and a thin cedar cover
fits over each one. The cans are placed in wire or iron crates,
lowered into the boiling water, and allowed to remain as long
as necessary to cook them. The time of working varies in
the different factories, but all the way from 30 to 50 minutes
is required. They are then taken from the bath and placed
on a slat-floor, where the air can pass through them, and when
they are cold are " tested," generally by striking them with
an awl. The testers become so expert that they can instantly
•detect by the sound an imperfect or leaking can ; these are
thrown out, mended, re-pressed, and put back in the pile.
The cans are now ready for the next thing, which is labeling.
Labeling is done in different ways, and some canners with
an idea of saving labor employ devices which are not only
hard on the young girls who do the work, but which often re-
sult in much confusion and poor work. The best method is
to divide the help into parties of five, one girl sitting on one
side of the table with paste-pan, brush, and labels and the
other four opposite her. The one girl, if quick and active,
will paste the ends of the labels as fast as the other four can
put them on the cans. The table is of course alongside the
pile of cans, and two smart boys will place the cans on the
table. As a girl labels a can she pushes it from her, when it
is taken by the boxer, put in the box, and nailed up. This
mode is simple and effective, and as the gang will label from
700 to 900 cases in a day the work progresses rapidly.
In many of the larger factories patent processing kettles,
capping irons, and improved machinery are used, but as the
result is, of course, the same, and they do not affect the mode
of packing, it is not thought necessary to enter into any de-
scription of them.
In the foregoing an outline of the packing process has been
PRESERVATION OF FRUIT. 449
given, but nothing has been said of the many trials and vexa-
tions of a canner's life. If everything went always smoothly,
it would be as pleasant as any other business, but it does not.
The canner will early in the season employ his hands and com-
mence in a small way. He may start and run only two or
three hours, and for that length of time boilers will have to be
fired up, help got together, and at the close the factory cleaned
the same as if he had run the day out. Then, as the crop
rapidly matures, work becomes heavier, and at last the inev-
itable "glut" commences, and he finds the products of 400 or
500 acres of perishable fruit at his doors, maybe 50 wagons,
each owned by an impatient farmer standing in the street wait-
ing his turn to unload. That is the time he has need of nerve ;
help must be secured, everything and everybody pushed to
their utmost endurance, and from early morning until way
into the night, day after day, the week goes on ; help succumbs,
and machinery breaks, but the factory must move in storm
and in sunshine. The work must go on, and at last the agony
is over, and the crop coming in again gradually gives a little
relief to the overworked people.
It would be an impossibility to correctly state the amount
of capital invested or the number of persons employed in the
industry. The States of New Jersey, Maryland and Delaware
pack a large proportion of the goods, the late falls and the
nature of the soil being particularly well adapted for raising
tomatoes.
In connection with the canning of tomatoes it may be of
interest to our readers to give the preparation of
Catchups. — Under the name of catchup or catsup a thickly-
fluid sauce comes into commerce, which is used as a condiment
with meat, and the preparation of which has become of some
importance. Everywhere where Anglo-Saxons reside catchup
is found, though it has also been introduced on the continent
of Europe and in the tropics. The varieties most liked are
tomato and walnut catchups, and immense quantities of them
are manufactured in the American canning establishments.
29
450 MANUFACTURE OF VINEGAR.
The mode of preparation is so simple that it can be introduced
into every kitchen.
Tomato Catchup. — The receipts for making this favorite
catchup are innumerable, and should those of every packer
and housewife in the land be taken and put together they
would make a good-sized volume.
In some factories where the tomatoes are peeled and either
canned or made into some whole tomato product, such as
chili sauce, the trimmings are made into catchup, all decayed
portions being rejected. The trimmings are sometimes run
to a chopper before going to the pulping machine. In some
plants the stock is cooked before running it into the pulping
machine, while in others the pulp is made from raw tomatoes.
It makes little difference which method is used, so there is no
material delay between the time of pulping and the using of
the pulp. At some places the pulp is run as fast as made
into a single vat and drawn out from the same during the
day as needed. In this way the pulp is run with some that
may have been in the vat for several hours, and there is a
possibility of spoilage to begin with and consequently of some
injury to the product. If the pulp is to be stored at all, a set
of smaller vats is preferable, so that each vat as it is emptied
can be cleaned out before a new lot is run in, thus checking
any fermentation that might result due to the storing of the
pulp in the same vat throughout the day's run.
The pulp obtained from the fruit, in making catchup is
generally concentrated to about 50 or 25 per cent, of the orig-
inal volume by boiling or the gravity method, the latter being
employed by the majority of the plants making trimming
pulp. At some plants it is customary to process the catchup
after bottling while others find it unnecessary.
No receipt can be given that will suit all in regard to the
amount of the different condiments to be used as each person
has ideas of his own, but all catchup should be made hotter
than desired, as it will undoubtedly lose some of its strength
when it becomes cold. The best of spices and vinegar should
PRESERVATION OF FRUIT. 451
be used and every vessel into which it is put should be scrup-
ulously clean and free from any mold or dust. Seal the
bottles carefully, and if you have them thoroughly air-tight,
the catchup will improve with age.
Below a few receipts for making catchup on a small scale
are given.
I. Take 15 quarts of thoroughly ripe tomatoes, 4 tablespoon-
fuls each of black pepper, salt, and allspice, 8 red peppers, and
3 teaspoonfuls of mustard. The pepper and allspice must be
ground fine and the whole boiled slowly 3 to 4 hours; then
pass all through a fine sieve and when cold put it in bottles,
which must be immediately sealed.
II. Boil 4 quarts of tomatoes together with 2 quarts of vine-
gar, 2 tablespoonfuls of red pepper, 4 tablespoonfuls of black
pepper, 1 tablespoonful of cloves, 1 teaspoonful of salt, and 1
ground nutmeg, to a thick paste. Strain through a coarse-
meshed sieve and sweeten the sauce obtained with J Ib. of
sugar. Fill in bottles and shake once every day for a week.
III. Cut up perfectly ripe tomatoes and place them upon
the fire until they commence to bubble. Then take them
from the fire, and when cool rub them with the hand through
a hair-sieve and season according to the following propor-
tions : For each quart of sauce add 1 teaspoonful of ground
allspice, 1 teaspoonful of ground cloves, 1 tablespoonful of salt,
and 1 quart of wine-vinegar. Stir the whole thoroughly to-
gether, replace it upon the fire, and boil for one hour, with
constant stirring. When cool put the catchup in bottles and
seal immediately.
Walnut Catchup. — I. In June, when the walnuts are still-
soft, take 10 dozen of them, and after crushing pour over
them 2 quarts of 'wine-vinegar, add the following spices, all
ground : 2 tablespoonfuls of black pepper, 1 J oz. of nutmeg,
40 cloves, J oz. of ginger, J oz. of mace, and boil the whole
i hour, stirring constantly. When cold strain through a
hair-sieve and put the catchup in bottles.
II. Crush about 10 dozen of young, soft walnuts, sprinkle
452 MANUFACTURE OF VINEGAR.
{ lb. of sugar over them, and then add 1 quart of vinegar.
Let the whole stand six weeks, stirring frequently. Then
strain through a bag, with constant pressing with the hand.
Pour 1 pint of vinegar over the residue, let it stand over night,
and strain again through the bag. Combine the fluid with
that previously obtained and season with the following spices,
all ground : 1} oz. of black pepper, \ oz. of nutmeg, J oz. of
ginger, \ oz. of mace, and 40 cloves. Then boil J hour, strain
through a hair-sieve and bottle.
Cucumber Catchup. — Thoroughly ripe cucumbers, before turn-
ing yellow are peeled and grated upon a coarse grater. This
paste is brought into a colander to allow the juice to run off,
then pressed through a coarse hair-sieve to remove the seeds,
and finally brought into small, wide-mouthed bottles, which
are rilled j full. The remaining space is filled up with good
wine-vinegar. This catchup has the taste and odor of fresh
cucumbers, and is used as a condiment with meat. Before
bringing it to the table it is seasoned to taste with salt and
pepper.
Horseradish Catchup. — The mode of preparation is the same
as for the preceding, putting the grated mass in a colander and
straining through a hair-sieve being, however, not necessary.
Both varieties of catchup must be immediately corked, sealed,
and kept in a cool place. Within the last few years both have
been prepared on a large scale in the United States and Eng-
land, and have become an article of export. They are packed
in small, wide-mouthed bottles, sealed, and provided with
gaily-colored labels. Some English factories use small earth-
enware pots of a cream color, closed with corks over which is
tied strong colored paper. The pots are very good, but the
manner of closing them is not ; the corks should be sealed.
Currant Catchup. — Heat nearly to the boiling point, with
constant stirring, 4 Ibs. of thoroughly ripe currants together
with 1J Ibs. of sugar. Then add 1 tablespoonful each of cin-
namon, salt, cloves, and pepper — all finely pulverized — and 1
quart of vinegar. Boil the mixture one hour and then treat
in the same manner as tomato catchup.
PRESERVATION OF FRUIT. 453
Gooseberry CatcJiup. — This product also comes into commerce
under the name of " spiced gooseberries." It is an excellent
condiment with roast fowl. Take 6 quarts of gooseberries,
ripe or unripe as may be desired, and carefully remove the
steins and pistils. Then bring them into a kettle, and after
pouring some water and scattering 5 Ibs. of pulverized sugar
'over them, boil for 1J hours. After boiling 1J hours add 4
Ibs. more of sugar and 1 tablespoonful each of allspice, cloves
and cinnamon. The catchup is not strained, but brought at
once and while warm into wide-mouthed bottles or pots, which
are immediately corked and sealed. It is advisable before
closing the bottles to lay a closely-fitting piece of salicylated
paper upon the surface of the catchup. The bottles should be
kept in a cool place.
It need scarcely be remarked that catchup can be prepared
not only from the above, but from all varieties of fruit, and it
is only necessary to take one of the above receipts as a type.
But, with few exceptions, those given are the only catchups
prepared on a large scale and brought into commerce.
Another subject which may be referred to in connection
with the preservation of fruit is the preparation of
Fruit-butter, Marmalade and Jelly — Fruit-butter. — The manu-
facture of apple-butter, which may serve as a type of that of
all other fruit-butters, is effected as follows : Fill the boiler
two-thirds full with the juice of sweet and bitter-sweet apples
in about the same proportion as given for the manufacture of
cider. The other third of the boiler is filled up with slices of
ripe, juicy apples, and the mixture boiled, with frequent stir-
ring. When the slices of apples are so soft that they com-
mence to fall to pieces, they are carefully removed from the
boiler by means of a skimmer, care being had to allow the
juice to run off. The same quantity of fresh slices of apples
is then brought into the juice and boiled in the same manner
as the preceding. When these have acquired the necessary
degree of softness, the entire contents of the kettle, together
with the slices of apples previously boiled, are brought into a
454 MANUFACTURE OF VINEGAR.
stoneware pot and allowed to stand covered for 12 hours.
The mass is then replaced upon the fire and boiled, with
constant stirring, until it has acquired the consistency of soft
soap. If desired, it can at the same time be seasoned with
cinnamon, nutmeg, etc. To prevent scorching, the second
boiling is effected in vessels standing in boiling water.
In the same manner fruit-butter can be prepared from all
varieties of fruit, pear or apple juice forming, however, always
the boiling liquor. Apple and peach butters are commercially
of the greatest importance, though butter of quinces, pears,
blackberries, cherries, plums and cranberries is also manu-
factured on a large scale. Whortleberries, which grow in
enormous quantities in some parts of the country, might also
form an excellent material for this product. In the foregoing
only the varieties are mentioned which are manufactured on a
large scale by American and English factories that chiefly con-
trol the trade in fruit-butters, but these do not by any means
exhaust the list. Green gages can, for instance, be highly
recommended for the purpose.
The excellent product brought from France into commerce
under the name of raisine is prepared in the above manner by
slowly boiling sliced apples and pears in unfermented grape-
juice.
Fruit-butter is packed in wooden buckets of 5 or 10 Ibs.
capacity and in stoneware jars. Tin cans holding 2 Ibs. are
also sometimes used, but they are not liked. The buckets
are slightly conical towards the top and are provided with a
wire handle. Resinous wood should not be used in their
construction, as it would impart an odor to the fruit-butter.
The buckets are filled up to the edge, and a closely fitting
round piece of paper previously saturated with concentrated
solution of salicylic acid in whiskey is laid on top of the butter.
The tight-fitting lid is placed upon the bucket without being
sealed or otherwise closed. A large lable occupying the space
between the lower and upper hoops finishes the packing.
Marmalade. — The same product is sometimes called mar-
PRESERVATION OF FRUIT. 455
malade and sometimes jam. The French prepare only mar-
malade, while the Englishman brings the same product into
commerce as jam or as marmalade, just as it may suit him
best, and the German is not much better. The term marma-
lade was originally applied to a jam prepared from quinces,
it deing derived from marmelo, the Portuguese word for quince.
The term was gradually given to all jams in order to give
them a more distinguished character, and this has led to a
confusion of terms which sometimes extends even to jelly.
There is, however, a wide distinction : Marmalade or jam is
prepared from the pulp of fruit and jelly from the juice, while
fruit-butter, as above indicated, is a blending of both with the
omission of sugar.
For the manufacture of marmalade on a large scale all the
rules and receipts can be condensed as follows : The fruit must
be of excellent quality, entirely free from blemishes and
washed perfectly clean. Kernel fruit is peeled, quartered and
freed from the cores ; peaches are also peeled, halved, and
stoned ; other stone-fruit is only stoned and halved, while
berries are carefully freed from the stems. Melons and pump-
kins are peeled and cut into small pieces. Rhubarb should
not be washed but rubbed with a moist cloth and be then cut
into small pieces. Tomatoes are to be peeled which is facili-
tated by previously placing them for one minute in hot water.
Being thus prepared the fruit is brought into a copper kettle
and as much water as is required for boiling- added. While
the fruit is boiling, weigh off as many pounds of white sugar
as there is fruit, soak it in water, boil and skim carefully.
The fruit should be boiled quickly, and when perfectly soft is
allowed to cool off somewhat and then rubbed through a wide-
meshed hair-sieve. The mass passing through the sieve is
combined with the sugar and replaced upon the fire. The
whole is then boiled with constant stirring, to the required
consistency. The latter is tested by taking a small sample
with a wooden or bone spoon — nothing else should be used —
and if it draws threads between the fingers the boiler is removed
456 MANUFACTURE OF VINEGAR.
from the fire. The marmalade is then brought into straight
jars, and after laying a piece of salicylated paper on top, the
jars are iied up with white parchment paper or sometimes
covered with a glass cover and labeled. It may be remarked
that in the last stage of boiling the marmalade is sometimes
flavored, which is generally effected by stirring in lemon juice,
cinnamon, and nutmeg according to taste. The liquor ob-
tained by boiling crushed kernels of plums or peaches is also
often at the same time added as flavoring. Frequently the
sugar is not treated as stated above, but added in the form of
powder.
The quantity of sugar has above been given in the propor-
tion of 1 Ib. to 1 Ib. of fruit. Though this is the customary
rule, many manufacturers use only j Ib. of sugar, a method
which can be highly recommended. In fact there is frequently
a perfect waste as regards the addition of sugar, some adding
even 1J Ibs. of it to the pound, whereby the taste of fruit is
entirely lost and the product, on account of its sweetness, to
many becomes repugnant. It may be laid down as a rule that
in all fruit boiling no more sugar than is absolutely necessary
should be used. The secret of the great reputation the prod-
ucts of the principal American factories enjoy in all portions of
the world is simply due to the fact that they use as little sugar
as possible, whereby the products are rendered not only
cheaper, but they retain their natural fruit taste, and that is
what the consumer desires, and not a sugary paste having only
the color of the preserved fruit. The durability of the product
need not necessarily suffer if due care is exercised in its prep-
aration. Marmalade should not be made, as it is only too fre-
quently done, from fruit which has been gathered for several
days and shows signs of decay. Fruit not over-ripe and freshly
gathered should be used and the boiling finished as quickly as
possible. By then rinsing the jars with salicylated water and
covering the marmalade with a piece of paper saturated with
concentrated solution of salicylic acid or with alcohol, } Ib. of
sugar to 1 Ib. of fruit will be ample, and even J Ib. with sweet
PRESERVATION OF FRUIT. 457
fruits such as pears, raspberries, etc. Independently of the
saving of sugar, such marmalade will give better satisfaction
than an article twice as sweet, and will keep well in a dark,
cool place.
Some manufacturers use glucose in large quantities in mak-
ing jams and marmalades. Some think it cheapens the bulk
and causes it to congeal, while others claim that it causes the
preserve to be heavy, syrupy and stringy.
In some factories apple pulp is used as foundation for cheap
jams, the proportion of it employed varying according to what
fruit is available. It is made by filling the steam-pan full of
good cooking apples and, after turning on the steam, boiling
them for 20 to 30 minutes. It is advisable to put some heavy
weight on the cover of the steam-pan before turning on the
steam to prevent it from being blown off. When boiling is
finished take off the cover, and with a long paddle crush any
apple that may have remained whole against the sides of the-
steam-pan. Then replace the cover and steam for about ten
minutes more. The pulp is then ready for immediate use or
storage.
All berry fruit-pulp will keep best when poured boiling hot
into glass jars that have been rinsed out with boiling water.
Fill the jars to the top and close at once. Sterilizing in tins
alters the color of berry fruit-pulp. Lower grade fruit-pulp,
of which large quantities are made for stock, may be stored in
tins holding up to 50 Ibs. as follows : The tins, which are sol-
dered top and bottom, have a two-inch hole in the lid and are
stood in a vessel of boiling water. When the fruit-pulp is
boiling hot the tins are taken out in succession and filled up
to the top, the lids being soldered on at once. The tins are
then stood on their heads, so that the small amount of im-
prisoned air is compelled to rise through the boiling hot pulp,
and is thus rendered innocuous. This method is perfectly
reliable, and large quantities of pulp can thus be prepared for
storage in a short time.
From France a very fine perfumed apple marmalade is-
458 MANUFACTURE OF VINEGAR.
brought into commerce. It is prepared from equal parts of
Calvilles and Pippins, and after boiling is sprinkled with rose-
water or violet essence.
The term tutti-frutti is applied to marmalade prepared from
a mixture of different kinds of fruit. As the name implies, it is
of Italian origin. The composition is made according to taste
and the fruits at disposal.
English orange marmalade is made from bitter oranges. Cut
the fruit into halves without injuring the core, throw into
boiling water, a few at a time, boil for several minutes and
then cool them quickly. The flesh can be easily squeezed
away from the rind. Heat the flesh to boiling with a suffi-
cient quantity of water and pulp it in a mill, quarter the rind
and cut it into thin slices, a special machine being used for
this purpose. Blanch the slices until soft and lay them aside
in a sieve. Next weigh out 30 parts of the pulp and 10 of
the slices and mix thoroughly. In the meantime dissolve 54
parts of refined sugar and 6 of syrup and heat till they ball.
Then add the pulp and rind and boil the whole to a finish.
The marmalade should have a golden-yellow color and be
perfectly clear. It is filled hot into the pots and fastened
down when cold. The orange pulp is sometimes mixed with
half its weight of apple pulp.
Jelly. — This product is, unfortunately, often made expensive
and at the same time spoiled by too large an addition of sugar.
Many housekeepers do not like to prepare jellies under the im-
pression that they require too much sugar ; but this is an error,
because in France, in factories as well as in households, they
use only f pound, or at the utmost f pound, of sugar to the
pound of fruit, instead of 1 pound or even 1J pounds, as is
customary in England, Germany, and parts of the United
States. Moreover, the apple-jelly which is made in the United
States and sent to all parts of the world is made without any
addition of sugar. Instead of apples, as the raw material,
apple-juice is used, which must be perfectly sweet and treated
immediately after it comes from the press. A moderate tern-
PRESERVATION OF FRUIT. 459
perature is absolutely necessary for success, for, if the juice
commences to ferment — and it does very rapidly in warm
weather — the keeping quality of the jelly is injured, except it
be mixed with a considerable quantity of sugar. A tempera-
ture of 41° F. is considered the most suitable, and if it rises to
above 66° F. the manufacture is at once stopped. The juice
runs directly from the press into the boiler, under which a
strong fire is kept because the starchy matters contained in
the juice are only converted into sugar if the boiling down is
quickly effected. For this reason shallow pans offering a large
surface to the fire are used. When the juice commences to
boil it is clarified, and the acid it contains neutralized by the
addition of one teaspoonful of elutriated chalk to each quart of
juice. The chalk weighed off in this proportion is mixed with
the juice, and appears in a few minutes as a thick scum upon
the surface, from which it is carefully removed with a skimmer.
By this operation the jelly is clarified, and all the albuminous
substances contained in it being removed by the chalk, filter-
ing is not required. The process is similar to the defecation
of the juice of sugar-cane and beets by lime. The juice is now
boiled to the consistency of 30° or 32° B., which is found on
cooling to be the proper point for perfect jelly. It is then filled
direct from the pan into tumblers, which are treated in the
same manner as marmalade jars.
Successful jelly boiling on a large scale is impossible with-
out the use of the saccharometer. It is the only reliable guide
for the addition of sugar, for if the product is to be protected
from spoiling it must show from 30° to 32°. If this result can
be reached without the addition of sugar, it is so much the
better.
Pear and mulberry jellies are prepared in exactly the same
manner as above. Other fruits containing more acid require
an addition of sugar, especially currants, which next to apples
and pears are most used for jelly, but in no case is the same
weight of juice and sugar required.
To prepare jelly from berries and other small fruits, pour hot
460 MANUFACTURE OF VINEGAR.
water over the fruit in order to free it from adhering dirt and
to facilitate the separation of the juice. When the water is
cool take the berries out, express the juice, and bring the latter
immediately into a copper or brass kettle over a lively fire.
Then stir in pulverized sugar, the quantity of which varies
according to the variety of fruit. For raspberries, strawberries,
and blackberries J pound of sugar to the pound of juice will
be sufficient, and f pound or at the utmost f pound for cur-
rants, barberries, elderberries and whortleberries. The sugar
being added, stir in the chalk in the proportion previously
given, and after allowing the juice to boil not longer than 15
minutes, take it from the fire and strain it at once into the
glasses. In this manner a clear, beautiful jelly of an agreeable
taste will be obtained. If, on the other hand, the juice is
boiled slowly over a weak fire, the result will be a turbid
product which has lost its fruity taste.
Stone-fruit is boiled, and after boiling it with a small quan-
tity of water until soft, the juice is pressed out and f pound
of sugar added for every pound. It should be boiled quickly,
and not, as some receipts have it, for f hour. Quinces are
peeled and then treated like stone-fruit. Rhubarb is cut into
small pieces and then treated in the same manner. A quite
good jelly can also be prepared from the medlar, provided it is
allowed to become completely ripe, and is then slowly steamed
with a very small quanity of water. When thoroughly soft
the juice is pressed out and f pound of sugar added to each
quart. The mass is sharply boiled for 20 minutes, when the
result will be a clear jelly.
In France, as previously mentioned, perfumed marmalade is
prepared from equal parts of Calvilles and Pippins. From the
same material, which is considered best for the purpose, a per-
fumed jelly is also prepared. The apples are not peeled, but
cut into slices, and boiled with a small quantity of water until
soft enough to be pressed in a filter-bag. To every pound of
juice } pound of sugar is added, and five minutes before the
saccharometer indicates 30° B., J or J pound of violet bios-
PRESERVATION OF FRUIT. 461
soms is stirred into the juice, a few drops of cochineal being
generally added to improve the color. The jelly, when
finished, is strained through a hair-sieve into wide-mouthed
bottles, which are corked and sealed.
A jelly is made from raspberries, and sometimes also from
strawberries and blackberries, in which the berries remain in-
tact. The process consists in dissolving 2 pounds of white
sugar in water and boiling until thickly fluid. Two pounds of
berries are then brought into the kettle and carefully mixed
with the sugar so as to avoid crushing. The kettle is then
taken from the fire and allowed to stand covered for 15
minutes, when it is replaced on the fire and the sugar boiled
up once more. The product is kept in jars well corked and
sealed.
A description of the process of manufacturing apple jelly
in one of the largest plants for that purpose may here be
given.
The factory is located on a creek which affords the neces-
sary power. A portion of the main floor, first story, is occu-
pied as a saw-mill, the slabs furnishing fuel for the boiler
furnace connected with the evaporating department. Just
above the mill, along the bank of the pond and with one end
projecting over the water, are arranged eight large bins hold-
ing from 500 to 1000 bushels each, .into which the apples are
delivered from the teams. The floor in each of these bins has
a sharp pitch or inclination towards the water, and at the
lower end is a gate through which the fruit is discharged,
when wanted, into a large trough half submerged in the pond.
Upon hoisting a gate in the lower end of this trough con-
siderable current is caused, and the water carries the fruit a
distance of from 30 to 100 feet, and passes into the basement
of the mill, where, tumbling down a four-foot perpendicular
fall into a tank, tight in its lower half and slatted, so as to
permit the escape of water and impurities, while in the upper
half, the apples are thoroughly cleansed from all earthy or
extraneous matter. Such is the friction caused by the concus-
462 MANUFACTURE OF VINEGAR.
sion of the fall, the rolling and rubbing of the apples together,
and the pouring of the water, that decayed sections of the fruit
are ground off and the rotten pulp passes away with otHer im-
purities. From this tank the apples are hoisted upon an end-
less chain elevator, with buckets in the form of a rake-head
with iron teeth, permitting drainage and escape of water, to
an upper story of the mill, whence by gravity they descend to
the grater. The press is wholly of iron ; all its motion, even
to the turning of the screws, being actuated by the water-
power.
The cheese is built up with layers inclosed in strong cotton
cloth, which displaces the straw used in olden times and serves
also to strain the juice. As it is expressed from the press tank
the juice passes to a storage tank and thence to the defecator.
This defecator is a copper pan 11 feet long and about 3 feet
wide. At each end of this pan is placed a copper tube 3 feet
inches in diameter and closed at both ends. Lying between
and connecting these two are twelve tubes also of copper, 1 J
inch in diameter, penetrating the larger tubes at equal distances
from their upper and under surfaces, the smaller being paral-
lel with each other and 1J inch apart. When placed in posi-
tion the larger tubes, which act as manifolds, supplying the
smaller with steam, rest upon the bottom of the pan, and thus
the smaller pipes have a space of } inch underneath their
outer surfaces.
The apple-juice comes from the storage tank in a continu-
ous stream about f inch in diameter. Steam is introduced to
the large or manifold tubes, and from them distributed through
the smaller ones at a pressure of from 25 to 30 Ibs. per inch.
Trap-valves are provided for the escape of water formed by
condensation within the pipes.
The primary object of the defecator is to remove all im-
purities and perfectly clarify the liquid passing through it.
All portions of pomace and other minute particles of foreign
matter, when heated, expand and float in the form of scum
upon the surface of the juice. An ingeniously contrived float-
PRESERVATION OF FRUIT. 463
ing rake drags off this scum and delivers it over the side of the
pan. To facilitate this removal, one side of the pan, com-
mencing at a point just below the surface of the juice, is curved
gently outward and upward, terminating in a slightly inclined
plane, over the edge of which the scum is pushed by the rake
into a trough and carried away.
A secondary purpose served by the defecator is that of
reducing the juice by evaporation to a partial syrup of the
specific gravity of about 20° B. When of this consistency the
liquid is drawn from the bottom and the less agitated portion
of the defecator by a syphon and thence carried to the evap-
orator, which is located upon the same framework and just
below the defecator.
The evaporator consists of a separate system of six copper
tubes, each 12 feet long and 3 inches in diameter. These are
jacketed, or inclosed in an iron pipe of 4 inches internal diam-
eter, fitted with steam-tight collars so as to leave half an inch
space surrounding the copper tubes. The latter are open at
both ends, permitting the admission and egress of the syrup
and the escape of the steam caused by evaporation therefrom,
and are arranged upon the frame so as to have a very slight
inclination downward in the direction of the current, and
each nearly underneath its predecessor in regular succession.
Each is connected by an iron supply-pipe, having a steam-
gauge or indicator attached, with a large manifold, and that
by other pipes with a steam boiler of 30 horse-power capacity.
Steam being let on at from 25 to 30 Ibs. pressure, the stream
of syrup is received from the defecator through a strainer,
which removes any impurity possibly remaining, into the
upper evaporator tube; passing in a gentle flow through that,
it is delivered into a funnel connected with the next tube be-
low, and so back and forth through the whole system. The
syrup enters the evaporator at a consistency of from 20° to
23° B., and emerges from the last tube, some three minutes
later, at a consistency of from 30° to 32° B., which is found
on cooling to be the proper point for perfect jelly. This
464 MANUFACTURE OF VINEGAR.
point is found to vary one or two degrees, according to the
fermentation consequent upon bruises in handling the fruit,
decay of the same, or any little delay in expressing the juice
from the cheese. The least fermentation occasions the neces-
sity for a lower reduction. To guard against this, no cheese
is allowed to stand over night, no pomace left in the grater
-or vat, no juice in the tank ; and further to provide against
fermentation, a large water tank is located upon the roof and
filled by a force-pump, and by means of hose connected
with this, each grater, press, vat, tank, pipe, trough, or
other article of machinery used can be thoroughly washed
-and cleansed. Hot water instead of juice is sometimes sent
through the defecator, evaporator, etc., until all are thoroughly
scalded and purified.
If the saccharometer shows too great or two little reduction,
:the matter is easily regulated by varying the steam pressure
in the evaporator by means of a valve in the supply pipe.
If boiled cider instead of jelly is wanted for making pies,
sauces, etc., it is drawn off from one of the upper evaporator
tubes, according to the consistency desired ; or it can be pro-
cured at the end of the process by simply reducing the steam
pressure.
As the jelly emerges from the evaporator it is transferred to
.a tub holding some 50 gallons, and by mixing a little therein
•any slight variations in reduction or in the sweetness or sour-
ness of the fruit used are equalized. From this it is drawn
through faucets, while hot, into the various packages in which
it is shipped to market.
A favorite form of package for family use is a nicely turned
little wooden bucket with cover and bail, of two sizes, holding
5 and 10 pounds respectively. The smaller packages are
shipped in cases for convenience in handling.
Each bushel of fruit will produce from 4 to 5 pounds of
jelly, fruit ripening late in the season being more productive
than other varieties. Crab-apples produce the finest jelly, sour
•crabbed natural fruit makes the best-looking article, and a
EVAPORATION OF FRUIT. 465
mixture of all varieties gives most satisfactory results as to
flavor and general quality.
Saving of the Apple Seeds. — As the pomace is shoveled from
the finished cheese it is again ground under a toothed cylinder,
and thence drops into large troughs through a succession of
which a considerable stream of water is flowing. Here it is
occasionally agitated by raking from the lower to the upper
end of the trough, as the current carries it downward, and the
apple seeds becoming disengaged drop to the bottom into still
water while the pulp floats away upon the stream. A succes-
sion of troughs serves to remove nearly all the seeds.
CHAPTER XXXII.
EVAPORATION OF FRUIT.
EVAPORATION is one of the most important methods em
ployed for preserving fruit for any length of time. The rea-
son for this can be readily given : The process does not require
great technical skill ; it excels in cheapness because neither
vessels, sugar nor other auxiliaries are required ; the product
possesses excellent keeping qualities, retains its natural flavor,
and by many is considered healthier and more agreeable than
fruit preserved by any other method. While much fruit is
still dried in the sun, and large quantities of it are marketed,
the superiority of evaporated fruit has caused a large demand
for it, and aside from the consumption in this country, large
amounts are shipped abroad.
The Alden patent for evaporating fruit was granted about
40 years ago. Like all other new inventions, some years
were required before its merits became thoroughly under-
stood, though at the Paris Exposition of 1878 the first prize
was unanimously awarded to the fruit dried by that process.
Since then it has spread from California, where it was first
30
4G6 MANUFACTURE OF VINEGAR.
introduced, throughout the entire country, and though many
types of evaporators are now in use, they are all based upon
the same principle. At first only kernel and stone-fruits were
evaporated, but at present the list includes almost every
known fruit and vegetable.
Before entering upon a description of the apparatus and its
use, an explanation of the principle upon which it is based
and the theory of evaporating fruit will be given.
The object to be attained is not only to make the fruit keep,
but also to retain the properties for which it is valued. This
can only be reached by withdrawing the content of water, and
at the same time converting a portion of the starch into sugar
in as short a time as possible without boiling the fruit. The
latter would injure the taste of the fruit, and slow drying gives
a flavor calling to mind decay. The more quickly the watery
portions are removed from thoroughly ripe fruit, the richer
and more durable its taste will be ; and the more completely
the oxygen of the air is excluded during this process, the more
perfectly will it retain its color. Rapidity of the drying pro-
cess sometimes increases the content of sugar by 25 per cent.,
and this increase is in an exact proportion to the quicker or
slower evaporation of the content of water, always provided,
however, the fruit does not suffer injury from the heat.
Any one who has boiled down the juice of the maple,
sorghum, sugar-cane, or sugar beet knows that with slow
evaporation sugar is not formed, the content of sugar being
then converted into acid. Now, the change of substance must
be constantly kept in view : Starch is converted into sugar (in
this case very largely already in the plant), sugar into al-
cohol, and alcohol into acetic acid. This experience must also
hold good in drying fruit. The chemical process by which
the content of starch of the fruit, when brought into a high
temperature, is converted into sugar, is similar to that during
the ripening process on the tree, only it takes place more
rapidly.
A few days of warm sunshine produce sufficient sugar in
EVAPORATION OF FRUIT. * 467
gooseberries and grapes to change the sour unpalatable fruits
to a refreshing article of food. A few hours in an evaporating
apparatus, in which the proper degree of heat is maintained,
can produce a still greater change, provided the fruit be not
placed in it before it has reached perfection in a natural man-
ner. It must be remembered that 212° F. is the boiling point,
and that subsequent treatment, no matter how careful, cannot
restore the taste lost in such a temperature. Of no less im-
portance is another point : The surface of the fruit to be dried
must be kept moist and soft, so that the internal moisture may
find a way by which it can readily and quickly escape, and a
strong hot current of air must uninterruptedly pass over the
fruit to carry off the escaping moisture. Hence, cold air must
under no circumstances have access to drying fruit, and above
the latter an aperture must be provided for the escape of the
air saturated with moisture.
The apprehension that fruit cannot be dried in a hot moist
apparatus is refuted by the well-known scientific fact, that air
of the temperature of the freezing point absorbs I-J-Q part of its
weight of moisture, and that its capacity for absorption doubles
with every 15° C.. (27° F.) of higher temperature. Thus, if
the temperature is 59° F. it absorbs ^V parts of its weight of
water, 81° F. ^ part, 113° F. ^ part, 140° F. ^ part, 167° F.
i part, 194° F. i part, and 221° F. its own weight which is
nearly equal to one pound of water to every \ cubic foot of
air.
The fruit would evidently never become dry if the air loaded
with such moisture remained stationary, but set it in motion
with a velocity of 880 feet per minute, which is equal to 20
miles per hour, and the cause of the rapid drying, or, in other
words, of the withdrawal of water, becomes apparent. Now if
we figure to ourselves an apparatus of 225 cubic feet content,
the air heated in it to 212° F. contains, according to the above
statement, 60 pounds of water, 50 pounds of which have been
withdrawn from the fruit, while the remaining 10 pounds were
contained in the air prior to its entrance into the apparatus,
468 MANUFACTURE OF VINEGAR.
because its temperature is supposed to be 62.5° F. With
sufficient circulation to empty the apparatus every 20 minutes
150 pounds of water will each hour be carried away from a
quantity of fruit supposed to amount to 800 pounds. Hence,
in 5 hours, the time generally required for apples, 750 pounds
of moisture could be removed if present.
Moreover, reference to a drying apparatus is not required to
prove that heat alone does not suffice for drying. Is it not
the wind which dries up the puddles after a rain more quickly
than the hottest rays of the sun? The sun alone would effect
nothing else but envelop the moist earth in a dense mantle of
vapor destructive to both men and animals. Thus in the dry-
ing apparatus also it is rather the current of air which dries
than the heat, but, of course, both must work in conjunction.
The rapidity of the process prevents decay, and causes the
color and aroma of the fresh fruit to be retained. The greater
advantage of this rapidity consists, however, in the conversion
of a considerable quantity of starch into sugar, which in sweet
fruits, such as peaches, is sometimes formed in such abund-
ance as to appear in small congealed drops upon the surface.
From the preceding it will also be readily understood why
drying in the sun or in the oven must yield unsatisfactory re-
sults. Even with favorable weather the process lasts about 14
days. During this long time a fermentation sets in which par-
tially destroys the content of sugar, and essentially changes the
color and taste in an unfavorable direction. Such fruit when
boiled tastes as if it had been preserved after the appearance
of decay. Besides, during this process, the fruit is frequently
selected as a breeding place by insects, in consequence of which
it soon spoils, and when shipped to a distance resembles on
arrival at its place of destination a heap of maggots. Such
cases are not rare, especially if the dried fruit is shipped to
tropical countries.
Drying in the oven has the disadvantage that the dry heat
immediately closes the pores of the fruit, thereby rendering the
escape of the internal moisture very difficult. If the heat is
EVAPORATION OF FRUIT. 469
not very strong the fruit remains moist in the interior, which
causes it to spoil, and with a strong heat the surface carbon-
izes more or less. A portion of the sweetness is lost by being
converted into caramel, the appearance of the fruit suffers by
the tough shriveling of the surface, and the taste is injured
by carbonization.
All these disadvantages are avoided by the modern evapo-
rating process, which may be called a preservation of the fruit
in its own juice with the assistance of steam.
A chemical analysis of a parcel of Baldwin apples shows
best the changes effected in the composition of fruit by dry-
ing in the oven and by evaporation, and how the results with
these two methods compare with each other. The first col-
umn gives the composition of 500 parts of fresh Baldwin
apples. The second column gives the composition of the same
parcel of apples after being reduced to 100 parts (loss of 400
parts of water) by drying in the oven, and a third column the
result of 100 parts of the same parcel reduced by evaporation.
Dried in Evapo-
Fresh. the oven. rated.
Water (free and fixed). . ... . 411.15 12.42 16.62
Cellulose 9.60 10.54 10.22
Starch 32.95 30.95 29.75
Protein 0.75 0.80 0.76
Pectine *...'. . . . 12.35 11.35 10.88
Gum ."'. ., . 6.75 7.22 4.33
Fruit acids '. . .. . 6.70 4.88 3.43
Mineral constituents . . .' . . . . 0.85 0.87 0.78
Chlorophyl > i ; 0.15 0.12 0.15
Dextrin ...,. 2.10
Grape sugar • 18.75 18.75 23.08
Volatile oils, traces —
500.00 100.00 100.00
Attention must especially be drawn to the fact that dextrin,
the formation of which is due to dry heat, is only found in the
second column, and must be considered as an essential dis-
advantage of drying in the oven. The absence of this sub-
stance in evaporated fruit, as well as the presence of a larger
470
MANUFACTURE OF VINEGAR.
FlG> "'
quantity of water (chemically fixed), is to be ascribed to the
influence of moisture during evaporation.
As previously mentioned, many types of evaporators are
now in use, some of them being small box-like structures of
such a size that they can be placed on top of an ordinary
cook-stove, while others* have a sufficient capacity for hand-
ling fruit on a very large scale.
Fig. 99 shows an improved Aid en evaporator which, like
the Williams evaporator to be described later on, belongs to
the type known as tower evaporators. A is the air-furnace
which is formed by the fire-box D,
the ash-box Dlt and the doubled hori-
zontal pipes G, of which, according to
the size of the apparatus, there are
from 3 to 6, each 4 inches in diameter,
and running parallel to each other.
The products of combustion pass
through them in the direction of the
arrows, and escape through the smoke-
pipe 0 at the back of the apparatus.
The fire-box is surrounded by an air-
space provided at M with apertures.
Similar apertures to permit the en-
trance of cold air are provided on the
side near the foot of the brick casing.
The cold air comes first in contact
with the lower, only moderately heated
pipe, then rises to the second, and
finally to the third and hottest series
of pipes. It is thus gradually heated,
and the pipes lying close together, each
atom of air comes in contact with them,
which is considered a better mode of heating than by radia-
tion, formerly used. The pipes are of cast-iron, and an escape
of smoke into the drying-tower is impossible. By always
keeping the pipes clean, which can be conveniently done, the
EVAPORATION OF FRUIT. 471
heat passes rapidly through their walls, and ascends im-
mediately into the drying-tower without the possibility of
super-heating.
The draught-pipe d connects the exit of the drying-tower
with the fire-box of the furnace. The importance of this ven-
tilation is sufficiently shown by the statement that for com-
bustion 25,000 cubic feet of air per hour are required, which
are introduced from the neighborhood of the opening of the
tower through the pipe d into the fire-box. The removal of
such a considerable quantity of air produces a vacuum in the
upper portion of the tower, and consequently a very quick cur-
rent of air over the trays of fruit in the tower— an absolute
requirement for attaining great perfection in the art of drying
fruit by evaporation. Besides, a saving of fuel is effected by
the introduction of air, already heated, into the fire-box. The
smoke-pipe 0 is surrounded by a wooden jacket, leaving a small
intermediate space in which the heat radiating from the pipe
collects, and is forced to enter the tower below the discharge-
door. This also accelerates the current of air in the tower and
prevents the condensation of the moisture, so that the fruit
completely dries off in a short time. The branch-pipe/con-
nects the opening of the tower with the smoke-pipe, which by
its power of absorption also increases the current of air. The
draught-pipe c is provided, as will be readily seen, for the
purpose of uniformly distributing the heat in the tower.
The bulb of the thermometer, with which the apparatus is
provided, is placed in the interior of the tower and the scale
on the outside, so that the temperature can be read off without
opening a door, whereby cold air would enter, which must be
avoided. The air-furnace is constructed of brick, and the
tower, as well as the draught-pipes d and c and the jacket of
the smoke-pipe 0, of double boards.
The hurdles or trays for the fruit consist of wooden frames
with galvanized iron-wire bottoms. They hold from 20 to 60
Ibs. of fruit each, and when charged are pushed through the
door over the air-furnace into the tower, where they rest upon
472 MANUFACTURE OF VINEGAR.
pins of an endless chain set in motion by a wheel, as seen in
the illustration. The trays sit close to the walls on two sides
of the tower, while in the other direction there is an inter-
space of two inches. The first tray is pushed tight against
the back wall, the mentioned, interspace thus remaining in
front of the door.
After six to ten minutes, according to the variety of fruit,
the tray is raised five inches by means of the endless chain ;
the second tray is then placed in position, but so that the
above-mentioned intermediate space is at the back wall. At
regular intervals the trays, when placed in position, are raised
by the endless chain and the fresh trays pushed in, so that
they touch alternately the front and back wall, the current of
air being thus forced to ascend in a zigzag. When the tower
is filled with trays it contains — taking apples as an example
—from 1200 to 3000 Ibs. of fruit. Every 50 Ibs. of each yield
from 40 to 45 Ibs. of water, which ascends as vapor, which by
surrounding the fruit with a moist mantle prevents its burn-
ing and keeps the pores open. When the tray first placed in
position arrives at the discharge-door it has been in the tower
for about five hours, and its contents have been converted
into evaporated fruit which will keep for many years. Thus
fruit can be gathered, evaporated and sold all in one day.
By considering the construction of the tower it will be seen
that the fruit during its ascent remains in a uniform moisture
and heat, so that up to the moment it is taken from the appa-
ratus, its content of water can escape through the opened
pores and, on the other hand, the heat can act to its very
center. A uniform, perfect product can be obtained only by
these means. When the fruit arrives at the discharge-door it
is cool and as soft as fresh fruit.
Fig. 100 shows the Williams evaporator. It is heated by
steam radiators located at the base of the vertical tower and
has vertical radiating pipes up the center of the vertical tower,
around which the trays of fruit revolve, with deflectors at in-
tervals of two feet projecting from each side of said pipes to
EVAPORATION OF FRUIT.
FIG. 100.
474 MANUFACTURE OF VINEGAR.
direct the heat under the trays of fruit as they revolve around
the pipes. (The trays and hanger are left out in the illustra-
tion to show the interior arrangement of the pipes.) These
pipes or radiators extending up the tower from bottom to top
produce a uniform heat the entire length of the tower, and
increase the draught by increasing the heat at the top, which
produces a more rapid circulation than when the heat is all
at the bottom, as with the hot-air furnace ; and the capacity
of the apparatus is also increased in proportion to the increase
of the heat and the draught through the tower. The trays
of fruit in passing up the tower are exposed from one side to
the pipes, and on descending are exposed from the other,
which causes the fruit to dry uniformly. The tower being
vertical the heat is utilized until it reaches the top. In this
apparatus a very strong heat can be had throughout the en-
tire length of the tower, without incurring any risk of fire
from siftings from the trays, when drying cores and skins,
falling on the hot-air furnace, which is always placed directly
under the tower. Several sizes of this evaporator are manu-
factured.
The manner of operating the Alden apparatus is as follows :
The maintenance of a uniform temperature in the tower
being essential, the thermometer should indicate 194° to 212°
F. Berries and stone fruit are to be kept somewhat cooler.
The introduction of too much cold air into the air furnace
must be avoided. As a rule an aperture two feet square
suffices.
The upward motion of the trays must be effected at regular
intervals. How long these intervals are to be, cannot be
•definitely stated, it depending on the content of water in the
fruit and on the temperature of the tower. The following
table may, however, serve as a guide :
EVAPORATION OF FRUIT. 475
Apples interval 6 to 10 minutes.
" 12 ;
20
K 15 <•
20
(C
« 8 '
15
tt
" 10 '
20
t|
'4 1Q '
90
<4
" fi '
0
«
" 5 c
7
it
t <
<i on u
9JS
It is supposed that the temperature directly above the air-
furnace is 212° F., and it is best to keep it at that degree ex-
cept for berries and stoned fruit, for which it may be from 41°
to 50° less. As previously stated, it is an essential condition
that the fruit should not boil. This will, however, not be the
case at the temperature mentioned, because the fruit remains
too short a time in it, and in rising upwards meets a some-
what more moderate heat. As a rule, it may be said that as
high a temperature as possible is most advantageous, provided
boiling be avoided.
The evaporated fruit, when taken from the tower, is spread
out in an airy room, where it remains for a few hours to dry
off previous to packing. Care must be had that during this
time it does not come in contact with insects, and to prevent
this the windows and air-holes should be provided with screens,
or the fruit covered with mosquito netting. The fruit when
ready for packing is put in boxes as follows : Line the box
with colored paper with the ends projecting above the edge.
Then fill the box with fruit. Kernel fruit is piled up about
one inch above the edge of the box, while stone fruit is not
piled so high, it being subsequently not subjected to pressure.
To press down the contents even with the edge of the box a
weight, or, still better, a press is used. After pressing, fold
the ends of the paper over the fruit, nail down the lid, and put
on the label.
Sliced evaporated apples are packed as follows : Line the
476 MANUFACTURE OF VINEGAR.
box with white paper, one piece on the bottom and four pie -
on the sides long enough to fold over. Then nail down the
lid. take off the bottom, and commence packing by placing
one layer of slices in the manner of roof-tiles. Sufficient fruit
to make up the required weight is then piled in, and after
pressing down the box is nailed up and labeled. A general
rule as regards weight has not been introduced, though in
California all varieties of evaporated fruit are packed in boxes
holding 50 pounds net.
In recent years tower evaporators have been largely super-
seded, especially for evaporating apples, by the kiln evaporator.
This type is described by H. T. Gould* as follows : " While the
principles of construction of the different evaporators of this
type are similar in all cases, the details of the arrangement of
the appliances are endlessly varied.
" In constructing kilns the same general principles are fol-
lowed, whether the evaporator is a small one with only a sin-
gle kiln or an extensive establishment having several of them.
The most satisfactory size of a kiln, all things considered, is
about 20 feet square. This is a convenient size to fill, so far
as the preparation of the fruit is concerned ; the heat can be
well regulated, made sufficiently intense for the purpose de-
sired, and evenly distributed, so that the fruit will dry uni-
formly, and for various minor reasons a kiln of this size
is a desirable 'unit ' in the construction of evaporators of this
type.
"A kiln consists essentially of a floor made of slats and
placed over a furnace room or over a system of steam pipes.
The floor is usually built from 10 to 12 feet above the floor of
the furnace room. Provision should be made for regulating
the heat by means of small openings in the base of the walls
communicating with the outside which can be opened or
closed as desired. The inflow of cold air can thus be regu-
lated. Such control is specially desirable in windy weather.
*U. S. Department of Agriculture. Farmer's Bulletin 291. Washington, 1907.
EVAPORATION OF FRUIT. 477
While many evaporators are constructed without special pro-
vision of this kind, it is an important point to have such
openings, particularly if the walls are brick or otherwise made
very tight, so that there is but little circulation of air.
" If the evaporator is a frame building, the walls of the
furnace room may be well plastered or covered with asbestos
paper to lessen the danger from fire, which may otherwise be
great, because of the intense heat generated within them.
"If the walls, at least the portion below the kiln floor, are
double, with an air-space between the two sides, the insula-
tion will be more perfect than if they are solid or of only a
single thickness, thus best conserving the heat and increasing
the efficiency of the plant The height of the walls of the
kiln above the drying floor should be sufficient to permit an
attendant to work on the floor conveniently and with comfort.
" Some means for the escape of the air laden with moisture
from the fruit is necessary. This may be provided for by
means of an opening in the roof, or a cupola-like ventilator
may be built, the sides of which should consist of slats placed
so that they overlap one another, as in an ordinary window-
blind. Another form of ventilator is in the form of a tower
about 3 feet square and extending 8 or 10 feet above the
roof, which is sufficiently bigh to cause more or less draft, and
hence augments the circulation of hot air through the fruit,
•• The kiln floor is constructed of strips especially designed
for the purpose. Such floors are generally made of poplar or
basswood strips, seven-eighths of an inch thick, one inch wide
on the top surface and one-half inch wide on the under side.
In laying the floor these strips are placed one-eighth to one-
fourth inch apart on the upper surface. This makes the
space between them wider on the under side than on the
upper, thus allowing the small particles of fruit which work
down between them to drop through without clogging the
intervening spaces,
"Satisfactory results are so dependent upon the heating
apparatus that this becomes one of the most important features
478 MANUFACTURE OF VINEGAR.
of an evaporator. In the larger kiln evaporators, ordinary
cast-iron stoves were formerly used considerably, two or more
of them being frequently required to heat a single kiln, but
these have largely gone out of use. -In their stead large fur-
naces are now most commonly used. These are specially de-
signed for the purpose and are provided with relatively large
fire-pots, correspondingly large ash-pits, and large radiating
surfaces. As it is necessary to burn a relatively large quantity
of fuel in a given time, the size of the grate is made with this
end in view. For a kiln floor 20 feet square, or 400 square
feet of surface, the grate surface is usually about 3 feet in
diameter, containing from 5 to 7 square feet.
" As to the most satisfactory length of pipe connecting the
furnace and chimney, opinions differ. Perhaps the most
common method of piping is as follows : The furnace, with
two flanges for attaching the pipe, is placed in the center ; the
pipe from each flange is then extended to the side of the room
opposite the chimney, and from this point the two sections,
extending in opposite directions, follow the wall, at a distance
of 2 or 3 feet from it, to the chimney. In a kiln 20 feet
square, some 65 or 70 feet are thus required. Ten-inch pipe
is a common size to use for this purpose. It is placed about
3 feet below the kiln floor.
" Some operators think that a better distribution of heat is
obtained if the pipes extend back and forth, 2 or 3 feet apart,
under the entire floor of the kiln, thus requiring 200 feet or
more instead of the shorter length above suggested. The
greater length, however, is less frequently used than the
smaller.
" In some cases the heat is so intense directly over the fur-
nace that the fruit dries more rapidly in the center of the
floor than about the sides. To regulate this and make the
drying as uniform as possible, a ' deflector,' consisting of a
piece of sheet iron or tin several feet square, is attached to the
floor directly above the furnace.
" Open grates, which in effect are furnaces with all parts
EVAPORATION OF FRUIT. 479'
above the grates removed, are used occasionally and are recom-
mended by some because they require less fuel, less attention,
to firing, and will dry the fruit in a shorter space of time.
On the other hand so much dust rises from them that they are
not used in making the best grade of fruit.
" In some respects a steam system is the most satisfactory
method of heating, but it is comparatively little used, possi-
bly due to the larger cost of installing such a system. In.
kiln evaporators the pipes are generally placed in as close
proximity to the floor of the drying room as is convenient
within a foot or even closer. That every steam pipe nearest
the floor may supply the greatest amount of heat it should,
have its own return to the main return of the system. One
inch pipe is generally used for such systems. No very defin-
ite data are available in regard to the amount necessary to
supply the requisite heat. Several kilns, however, which are
said to work admirably have about 600 running feet of pipe
for every 100 square feet of floor space. One half of this is
" riser," the other half " return".
"A convenient arrangement for an evaporator having four
or five kilps is as follows : The kilns are built of brick and
the apples are pared in an adjacent building. A bin built of
slats for containing the apples in bulk extends the entire length
of the building, except a small space in the center where a 5-
horsepower gasoline engine is located, which furnishes power
for running the parers, slicers and other machinery. The
paring table is on the opposite side of the building, from which
the fruit is taken by a carrier and elevated to a platform which
is on the same level as the two bleachers between the evapor-
ator and the paring shed. This carrier discharges the fruit
into trays which are then placed by hand into one of the
bleachers ; from this they are taken to the slicer, located in a
compartment just within the brick portion of the structure and
with which all the kilns communicate, thus making it con-
venient after the fruit has been sliced.
" Other large establishments have the kilns arranged in a
480 MANUFACTURE OF VINEGAR.
series situated end to end. The fruit is pared on the first
floor of an adjoining structure centrally located ; then elevated
to the second floor which is on the same level as the kiln
floors, where it is bleached and sliced. Communication is
had with the kilns not adjacent to the floor on which the fruit
is sliced, by means of a platform extending from this floor
along the sides of the kilns and on the same level as the kiln
floors."
For commercial purposes the selection of the varieties of
fruit to be evaporated must be carefully made. This ap-
plies especially to apples and pears. As a rule, a product of
high grade can be made from any sort which has a firm tex-
ture and bleaches to a satisfactory degree of whiteness. Many
evaporating plants have, like the canning establishments,
•certain favorites, for instance, of apples, the Baldwin, Bell-
flower, Pippin, Northern Spy, of pears, the Bartlett, Clapp's
Favorite.
Apples are pared with a machine. So many different styles
of apple parers for operating either by hand or power are in
the market that it is difficult to say which is the best. The
more recent patterns have two or even three forks for holding
the apples while they are being pared. The attendant puts
an apple on one of the forks while one on another fork is being
peeled. The apples are cored in the same operation by an
Attachment applied to the paring .machine for this purpose.
The fruit is automatically forced from the fork and drops to
the table where it is next taken in hand by the trimmers, who
•cut out with a straight-back sharp-pointed knife, worm-holes,
decayed parts and other blemishes.
To make the fruit as white as possible it is usually bleached
by subjecting it to the fumes of burning sulphur by means of
a contrivance called a bleacher. The simplest form of con-
struction consists of a box sufficiently long to meet the require-
ments, placed horizontally, and large enough in cross section
to admit the boxes or crates in which the fruit is handled.
Rollers are placed in the bottom, on which the crates rest,
EVAPORATION OF FRUIT. 481
which permit them to be moved along with but little friction.
The crates are entered at one end of the bleacher, those pre-
viously put in being pushed along to make room for the
following ones. The sulphur is usually burned immediately
below the point where the fruit is put into the bleacher. A
short piece of stovepipe is placed at the opposite end for the
escape of the fumes after they have passed through the bleacher.
Another simple bleacher in which the fruit is handled in
bulk (not in crates) consists essentially of a large square box,
the interior of which is fitted with a series of inclined planes
sloping in opposite directions to prevent the fruit from dropping
to the bottom in a compact mass. The fruit is usually admit-
ted at the top directly from the paring table. It then rolls
from one inclined plane to another to the bottom, where there
is the necessary opening, with means for closing it tightly to
to prevent the escape of the sulphur fumes, for removing the
fruit when it is bleached. The sulphur is burned beneath
the lowest inclined plane.
After bleaching, the fruit is sliced in a machine called a
slicer, of which there are various styles. In general, a slicer
consists of a table in which a series of knives is so arranged
that when the apples are carried over them by a revolving
arm they are cut -into slices about J inch in thickness. In
the kiln-evaporator the sliced fruit is evenly spread on the
floor to the depth of from 4 to 6 inches. It is a common
practice to treat the floor of the kilns occasionally with tallow
to prevent the fruit from sticking to it. Sometimes a mixture
of equal parts of tallow and boiled linseed oil is used for this
purpose.
No definite rules can be given regarding the temperature
to be maintained in the kiln, this being largely a matter of
experience. Some operators consider 150° F. a suitable tem-
perature when the fruit is first put into the drying compart-
ment, dropping to about 125° F. as the drying process nears
completion.
The fruit while drying in the kiln has to be occasionally
31
482 MANUFACTURE OF VINEGAR.
turned to prevent it from burning and from sticking to the
floor. For the first five or six hours it is generally turned
every two hours or so, and more frequently as it becomes
drier, until perhaps it may require turning every half-hour
when nearly dry.
When drying in the tower evaporator the trays or racks
must not be too heavily loaded with fruit. Stone-fruit not
freed from the stones is placed close together with the stem
ends upwards, but only in one layer. Plums after evaporat-
ing are generally brought into a bath of sugar-water to give
them a lustrous and uniformly dark appearance. For this
purpose brown sugar is dissolved in an equal quantity of hot
water, and the prunes in a wire basket are submerged in the
bath for half an hour. They are then spread out upon
hurdles and packed when perfectly dry. Quartered or halved
stoned-fruit, as well as sliced apples, are placed close together,
edge upward, until the bottom of the tray is covered. Sliced
pears are arranged in a similar manner. Of berries, several
layers an inch deep may be made, but they must be covered
with tissue paper. Grapes are but seldom converted into
raisins in the evaporating apparatus, because the process
would require 40 hours, it being impossible to use a tempera-
ture exceeding 167° F. Hence it is considered more advan-
tageous to dry grapes in the sun. .The well-known Malaga
raisins are obtained by allowing the bunches of grapes to dry
in the air. They are dipped for an instant in boiling water
to sterilize them and then dried on straw in the sun. When
the grapes have shrunk to a third or half of their original
volume, the best are packed in the original bunches, but the
inferior raisins are picked from the stalks before packing.
The richer the grapes are in sugar, the less drying they need.
In Spain the bunches are dipped into a boiling lye of wood
ashes on which a little oil is floating. They are dipped and
removed as quickly as possible, and the trace of oil that ad-
heres to them gives a characteristic luster.
Tomatoes to be evaporated in the tower evaporator are
EVAPORATION OP FRUIT. 483
peeled but not sliced, and placed close together in one layer
in the trays. Pumpkins are peeled and cut in pieces two or
three inches thick. For several years a flour has been made
from the dried pieces, which serves as a substitute for rice
flour. Sweet potatoes are treated in a similar manner, their
flour serving as a substitute for chicory.
Green corn is first steamed on the ear for not more than five
minutes. The grains are then picked off, placed in two-inch-
deep layers in the trays and thoroughly evaporated, but not
at too high a temperature, 185° to 194° F. being sufficient.
When dry they are rubbed and passed through a fanning-mill
to remove the hulls loosened by rubbing. The corn is packed
in boxes holding 10, 20 and 50 Ibs. each.
The following must also be steamed before evaporating :
Green peas and beans, asparagus, beets, carrots, lettuce, cab-
bage and parsnips. Vegetables are cut up with a cabbage-
cutter, and roots in slices like apples.
Onions are first freed from their external red or yellow peel
and then cut into slices one-fourth inch thick with a cabbage-
cutter. The slices are steamed for five minutes with a suitable
steaming apparatus, which is best effected by spreading the
slices in a two-inch-deep layer in the trays, placing the latter
in the steaming apparatus, and immediately after the above-
mentioned time in the evaporator. They are packed in tin
boxes holding 50 Ibs. each, which are placed in a wooden box.
By evaporation, 100 Ibs. of onions are reduced to 12 Ibs.
Potatoes must be thoroughly washed. This is best effected
in a cradle, the bottom of which is provided with wide perfor-
ations so that the water, constantly pouring in, can run off
quickly. The potatoes are then placed in trays, and from
four to six of the latter, according to the size of the steaming
apparatus, brought into the boiler. Steam is then admitted,
and after 35 minutes the potatoes are taken out, care being
had, however, not to steam them too much, as otherwise they
become of no value for the evaporating process. The loosened
peels are then rubbed off with the hand, and the peeled pota-
484 MANUFACTURE OF VINEGAR.
toes brought into a press, the bottom of which consists of
a perforated wooden plate or of woven wires. The lid must
fit tight into the interior walls of the press, so that the entire
mass of potatoes falls coarsely crushed through the bottom.
The crushed potatoes are placed in layers two or three inches
deep in the trays and leveled with an instrument made by
driving small nails into a board so that their points project
one-half inch. They are then evaporated at not too high a
temperature — 185° F. is sufficient — to prevent scorching;
taking care, however, to dry them through. The evaporated
mass is coarsely ground in a suitable mill, and the resulting
flour packed in zinc canisters, holding 28 and 56 Ibs. each.
Two such canisters are placed in a wooden box and are then
ready for shipment.
It is of the utmost importance to select only perfectly sound
potatoes and remove all which sour or are injured in any other
way during the process. Success depends on the rapidity and
regularity from the commencement to the end of the process.
All potatoes which become cold before being brought into the
evaporating apparatus are worthless, and the same may be
said of those which have been steamed too long ; they are con-
verted into paste.
Attention may be drawn to a sun-drying apparatus shown
in Fig. 101, which may be recommended to those who do not
wish to employ artificial heat, and are forced to give the
preference to as cheap an apparatus as possible. The appar-
atus is constructed of boards and window-glass. The board
walls, which are somewhat inclined outwardly, project above
the panes of glass and serve, as is readily seen, for catching
the rays of the sun. They are lined inside with tin, thus be-
coming reflectors. The side door serves as an entrance to the
apparatus when the panes of glass are to be cleansed or repairs
are to be made in the interior. The trays containing the fruit
are pushed in from the back, the entrance of each tray being
covered by a wooden flap. According to the size of the ap-
paratus two or three rows, each consisting of twelve trays, are
EVAPORATION OF FRUIT.
485
placed alongside each other. Above the uppermost entrances
for the trays are slides, which can be opened or closed accord-
ing to whether the heat in the interior is to be increased or
moderated.
The apparatus stands upon a turn-table, so that the front
can from morning to evening be exposed to the full rays of
the sun. When the latter no longer reach the apparatus the
reflectors, which are hinged, are laid over the panes of glass,
which prevents the radiation of heat, and protects the fruit
from dew.
The time required for drying fruit in this apparatus cannot
FIG. 101.
be definitely stated, but on an unclouded, hot summer day,
apples pared by a machine can be dried in eight hours. The
product obtained is not of as good a quality as evaporated
fruit, but it is incomparably superior to that produced by the
primitive method of drying in the open air or in the oven.
In conclusion it remains to say a few words about drying
fruit in the oven, and we describe the French method, which
is decidedly the best, as proved by the prunes brought into
market from that country. The prunes having been sorted
by a machine into three qualities are placed upon trays and
exposed to the sun until the skin commences to shrivel. They
486 MANUFACTURE OF VINEGAR.
are then placed in a bake-oven previously used for baking
bread. If no bread is to be baked, the oven is very moderately
heated to prevent the rapid closing of the pores and the forma-
tion of a crust upon the surface. They are allowed to remain
in the oven for 12 hours, when they are taken out, and when
perfectly cold, moistened with alum water and replaced in the
oven, which must now be somewhat hotter. After 12 hours
they are again taken out, moistened with alum water, and re-
placed for the third and last time, together with a dish full of
water, in the oven, which must now be still hotter than before.
The prunes when taken from the oven are submerged for a
short time in a bath of sugar-water, and are then packed in
boxes. It will be seen that this process is quite tedious, and
the product is not so good as that obtained by evaporation.
Besides prunes, the French bring into the market dried
pears, which have also become celebrated. The process is as
follows : Fine table-pears are pared, quartered, and boiled in
sugar syrup for five minutes. They are then placed in a
moderately warm oven, where they remain for 12 hours ; they
are then taken out, allowed to cool off, and replaced in the
oven, which must now be hotter than the first time, until
sufficiently dried.
The French method can be recommended, but it would be
still better if it wer£ executed in the improved manner prac-
ticed here and there in central England and in the New Eng-
land States. This improvement consists in the previous boil-
ing of the fruit, which must, however, not be continued
longer than five minutes. The fruit is not gradually heated,
but submerged in boiling water for five minutes, and, with-
out being allowed to cool, brought at once into a moderately
hot oven. Steaming instead of boiling the fruit is still bet-
ter. It should.be exposed to the steam for not longer than
five minutes, and must then as quickly as possible be brought
into a moderately hot oven.
PREPARATION OF PICKLES AND MUSTARDS. 487
CHAPTER XXXIII.
PREPARATION OF PICKLES AND MUSTARDS.
Pickles. — Enormous quantities of pickles are brought into
commerce, especially by American and English factories.
The most remarkable varieties are piccalilli or Indian pickles,
mixed pickles and walnut pickles. The packing is always the
same, some of the oldest and largest English factories still ad-
hering to stoneware pots, which have the advantage of entirely
excluding the light from the product, thus contributing to its
keeping quality. Both the French and Americans use glass
bottles, the chief difference being in the diameter of the mouth,
which is smaller in the American bottles. The latter style is
to be preferred, because in the former the pickles, when fre-
quently opened, are more exposed to the air than is good for
them. Stone pots, which are no doubt best for family use, are
too expensive for commercial purposes, not only as regards
the first cost, but also on account of their weight, which in-
creases the cost of transportation. The bottles are always
provided with neat lables, and the corks generally covered
with tin-foil.
The following general rules apply to the preparation of
pickles : The best quality of fruit must be gathered at the right
time, washed in fresh cold well-water, and placed for some
time in strong brine. They are then laid upon fruit hurdles
to completely dry in the air, and finally brought into the bottles,
which must be nearly filled. The interspaces are then filled
up with hot-spiced vinegar, and the bottles immediately corked,
and, when cold, sealed. Strong vinegar must be used, the
manufacturers generally employing wine-vinegar, known in
commerce as No. 24. Fruit-vinegar, clarified and spiced and
evaporated to three-fourths its volume, also answers very well.
Pickles for immediate use are soaked in hot brine, but as a
commercial article they must be treated with cold brine only.
488 MANUFACTURE OF VINEGAR.
Moreover, hot brine must not be used for vegetables of a soft
and juicy nature such as cabbage and cauliflower ; and besides,
cold or only slightly heated vinegar should be poured over
such articles. Soft and delicate fruits must, as a rule, not re-
main as long in the brine as hard and coarse-fibred ones ; and
the softest are most advantageously pickled by pouring cold
spiced vinegar over them. The same may be said of red beets
and other roots which are cut into strips. Sometimes the spice
is put whole into the bottle, but it is better and more econom-
ical to bring it powdered into the vinegar while heating the
latter, or if the vinegar is to be used cold, to previously boil
the powdered spice in a small portion of the vinegar, and
when cold add it to the rest. The spiced vinegar is prepared
as follows : —
To 1 quart of vinegar add 2J ounces of salt, J ounce of
black pepper, and 2J ounces of ginger. Let the mixture boil
up once or twice in an enameled iron pot, filter through a
flannel cloth, and pour the liquid, hot or cold, over the fruit.
For a more strongly spiced vinegar reduce in a mortar 2
ounces of black pepper, 1 ounce of ginger, and J drachm of
cayenne pepper, and for walnuts, 1 ounce of eschalots, and add
to the mixture in a stoneware pot, 1 pint of vinegar, and tie
up the pot with a bladder. Place the pot for three days near
the fire, shaking it several times, and then pour the contents
upon the fruits by allowing it to run through a filtering cloth.
In the preparation of pickles the use of metallic vessels must
be avoided, the vinegar as well as the brine dissolving copper,
brass, and zinc, and becoming thereby poisonous. Ordinary
earthen pots should also be mistrusted. Stoneware pots, which
can be heated in a water-bath or upon a stove, are best for the
purpose. Moreover, air and light must be kept away from the
pickles as much as possible, and they should be touched only
with wooden or bone spoons. An essential condition for suc-
cess is to treat the fruits immediately after being gathered.
The method of some manufacturers, who add verdigris to the
pickles or boil the vinegar in a copper boiler until it is suffi-
PREPARATION OP PICKLES AND MUSTARDS. 4891
ciently "greenish" to communicate its color to the product,
cannot be too strongly condemned. That this crime against
the health of the consumer is unfortunately committed to a
considerable extent is conclusively proved by numerous chem-
ical examinations made in the large cities of Europe and the
United States, and undertaken with the laudable purpose of
bringing the adulterators of food to justice. Many of the
pickles in the market and most of the imported canned peas
contain copper, and this notwithstanding the fact that there
are very innocent means for coloring pickles green, it being
only necessary to put a handful of spinach or grape leaves in
the boiling vinegar, which acquires thereby a green coloration
and communicates it later on to the pickles.
The following list comprises the fruits and vegetables which
are chiefly used for the preparation of pickles in factories :
Barberries. — The berries are gathered before they are ripe
and washed with salt water. The vinegar is added cold.
Beans. — Cold vinegar is poured over the young pods, pre-
viously soaked in cold water.
Cabbage, Red and White. — The heads are cut up into fine
strips, which are placed in a strong brine for two days, then
dried upon hurdles for twelve hours, next brought into bottles,
and after pouring cold vinegar upon them, at once sealed up.
Cauliflower. — The heads are broken up into small pieces,
which are placed in brine, and finally treated with hot
vinegar.
Cucumbers. — Young cucumbers are placed in salt water for
one week. The brine is then poured off, and after being made
boiling hot is poured back over the cucumbers. The next
day the cucumbers are dried upon a sieve, slightly rubbed
off with a cloth, and then boiling vinegar is poured over them.
Elderberry Flowers. — The umbels are gathered just before
the flowers open, and treated in the same manner as cauli-
flower. These pickles are much liked in England.
English Bamboo. — Young elder shoots are freed from the
bark, placed in a brine for 12 hours, and after drying brought
490 MANUFACTURE OF VINEGAR.
into bottles and hot vinegar is poured over them. They are
highly esteemed as an addition to boiled mutton.
Gooseberries. — The unripe fruits are treated like cauliflower.
Mixed pickles are a mixture of young, tender vegetables,
preserved separately, each at the proper season, and stored for
mixing later on. Small gherkins, young corn cobs, pickling
onions, green and red capsicums, cauliflower, young beans,
French beans and French carrots form the chief ingredients
•of this mixture, large capers and salted olives being also used
by some makers. All the vegetables are highly blanched
and left to stand for several days in strong brine in order to
ensure their keeping. They are then put in jars with good
vinegar, warmed up in the water-bath and closed up. The
vegetables may, however, be stored separately in brine in case
•of very large quantities.
For packing in bottles and other containers, good 4 per
•cent, wine-vinegar is used, this being spiced with an extract
prepared as follows : To 5 gallons of vinegar add 36 ozs. of
black pepper, 18 ozs. of ginger, 18 ozs. of salt, 10 ozs. of
pimento, 6 ozs. of white pepper, a few laurel leaves and a lit-
tle tarragon, allowing the mixture to stand for 14 days in a
warm place and then filtering. The filled bottles should be
^carefully heated on the water-bath before they are closed.
Picalilti. — These mixed pickles are packed with the follow-
ing preparation instead of vinegar: Stir 2J pounds of best
English mustard powder together with 1 pint of best olive oil,
and to this add 2J Ibs. of sugar, £ Ib. of salt, and 3 to 4 pints
•of good vinegar, with J pint of curry vinegar. The curry
vinegar is prepared from turmeric 3J ozs., coriander 4 ozs.,
black pepper 1 oz., ginger 1 oz., cardamoms J oz.. carraway
-seeds 1 oz., cayenne pepper J oz., all powdered, with 2J gal-
lons of wine vinegar. When all has been thoroughly mixed
together, the sauce is strained through a hair sieve.
Pickled Gherkins. — Cut off the stalks and sort the gherkins
into three sizes. Then wash them carefully and pack them
into suitable clean barrels. Dill may be used as spice but
PREPARATION OF PICKLES AND MUSTARDS. 491
nothing else. Pour over them a pickle consisting of 12 per
cent, brine containing 25 per cent, of good wine vinegar.
Place the barrels in the sun or a warm place, with the bung-
holes open, so as to quickly start a slight fermentation. When
this has run its course, clean up the barrels, fill them to the
top with the same liquor, if necessary, and bung them down.
For use the gherkins are taken out of the barrels and packed
with fresh wine vinegar spiced with tarragon. If these small
gherkins are to be kept stored in the barrels for a long time;
the fermented pickle should be drawn off and replaced by
fresh 12 per cent, brine.
Gherkins in Mustard. — Skin and cut in halves large, ripe
gherkins, remove the cores, and then cut them into long
strips. Place the latter in tubs, sprinkle well with salt and
allow to stand for several days. Then wash the gherkins,
pack them into barrels with yellow mustard seed, a few laurel
leaves and white pepper-corns, small onions, sliced horse-
radish and shredded ginger. Pour in sufficient boiling wine
vinegar to cover the whole. After a few days draw off the
vinegar, boil it up and return it to the barrels and heavily
weight the latter. The vinegar should not be allowed to fall
below 4 per cent., otherwise it will have to be supplemented.
In 3 to 4 weeks the gherkins should be clear and translucent.
Pickled Mushrooms. — Clean and trim off at the bottom young
small mushrooms and free them from the brown skin. Then
wash them in cold water and carefully dry them. Then pack
them in bottles and pour boiling wine vinegar over them.
Pickled Onions. — Small onions are peeled and hot vinegar
is poured over them. Sometimes the onions are placed in
brine for one day.
Pickled Peaches. — The fruits, not entirely ripe, are treated
like cucumbers.*.
Pickled Peas — The peas are treated like beans and cauliflower.
Pickled Tomatoes — must not be entirely ripe ; they may be
even green and half grown. They are pickled in the same
manner as cucumbers.
492 MANUFACTURE OF VINEGAR.
Pickled Walnuts. — Place the young, soft nuts in strong brine
for one week, then dry upon a sieve and pour hot vinegar
over them. A better method is to expose the walnuts after
they have been in the brine for nine days, upon a cloth, to the
sun until they are black, and then put them into bottles, which
are filled up with hot vinegar. These pickles are much liked
with fish, and when well sealed and stored in a dark place
keep for ten years. If they are to be used in the first three
months after being made, the brine must be heated for one
hour.
Mustard. — Mustard of commerce is the seed, whole or ground,
of several species of the genus Brassica, cruciferous plants,
which grow wild and are cultivated under various conditions.
The two common varieties are the black or brown mustard,
which has a very small seed, and furnishes the most aroma,
and the white, which is two or three times as large, often used
in the whole condition in pickles and ground, either by itself
or oftener in mixture with the brown seed, for the purpose of
obtaining the desirable qualities of both.
The most rational manner of preparing mustard for table
use has been introduced into the English factories. The seed
is freed from the husk, ground to flour, and the fat oil, which
can be used as an illuminating oil, pressed out. Generally
speaking, the preparation of mustard consists in several times
grinding in a mill a mixture of white and brown mustard
with an addition of wine-must, either fresh or strongly boiled
down, or of wine vinegar, until it forms a moderately fine or
very fine pasty mass, and adding different substances as a
seasoning. In the Diisseldorf mustard the seasoning consists
of cinnamon, cloves, and sugar ; in the Frankfort mustard of
cloves, allspice, and sugar ; in the English mustard, of wheat
flour, common salt and pepper: and in French mustard, of
tarragon, ginger, cinnamon, thyme, marjoram, onions, garlic,
cloves, etc. An addition of flour is most generally made, as
it modifies the sharpness of the mustard and holds the mass
better together. The quantity of the constituents varies, the
PREPARATION OF PICKLES AND MUSTARDS. 493
usual proportions being from 20 to 30 per cent, of white,
and 5 to 10 per cent, of brown, mustard, 1 to 2 per cent, of
common salt, £ to J per cent, of pulverized spices, and 40 to
50 per cent, of must or vinegar. According to the English
method the use of mustard-seed freed from oil is recommended.
In the following a few special receipts are given :
Gumpoldskirchner Must-mustard. — -Evaporate 30 quarts of
freshly pressed wine-must to one-half its volume over a mod-
erate fire, dissolve in it 5 Ibs. of sugar, and strain the whole
over 2 or 3 roots of horseradish cut in thin slices. Then add
in the form of fine powder, cardamoms 0.35 oz., nutmeg 0.35
oz., cloves 0.63 oz., cinnamon 1 oz., ginger 1 oz., mustard-
seed, grourtd and freed from oil, brown 6 Ibs. and white 11
Ibs. Grind the whole several times in a mill and strain.
Moutard des Jesuites. — Make a paste of 12 sardines and 280
capers and stir it into 53 ozs. of boiling vinegar, and mix with
it ground mustard-seed freed from oil, brown 5J ozs. and
white 14J ounces.
French Mustard. — Ground mustard 2 Ibs., and J oz. each of
fresh parsley and tarragon, both cut up fine, are thoroughly
mixed together; further 1 clove of garlic, also add, cut up very
fine, 12 salted anchovies. Grind the mixture very fine, add the
required must and 1 oz. of pulverized common salt, and for
further grinding dilute with water. To evaporate the water
after grinding the mustard, heat an iron red-hot and cool it
off in the mixture, and then add wine-vinegar of the best
quality.
Ordinary Mustard. — I. Stir gradually 1 pint of good white
wine into 8 ozs. of ground mustard-seed, add a pinch of pul-
verized cloves, and let the whole boil over a moderate fire.
Then add a small lump of white sugar, and let the mixture
boil up at once.
II. Pour \ pint of boiling wine-vinegar over 8 ozs. of ground
mustard-seed in an earthen pot, stir the mixture thoroughly,
then add some cold vinegar, and let the pot stand over night
in a warm place. The next morning add \ Ib. of sugar, j
494 MANUFACTURE OF VINEGAR.
drachm of pulverized cinnamon, J drachm of pulverized
cloves, 1J drachms of pepper, some cardamom and nutmeg,
half the rind of a lemon and the necessary quantity of vine-
gar. The mustard is now ready, and is kept in pots tied up
with bladder.
III. Pound to a paste in a mortar the flesh of a salt herring,
and 2 ozs. of capers, and mix this with 2 ozs. of pulverized
white sugar and 13 ozs. of ground mustard-seed ; then pour
If pints of boiling wine vinegar over it, stir, and let the
whole stand near a fire for several hours. Finally add £ pint
of boiling vinegar, stir thoroughly and pour the mustard into
glass bottles.
Frankfort Mustard. — Mix 1 Ib. of white mustard-seed, ground,
a like quantity of brown mustard-seed, 8 ozs. of pulverized
sugar, 1 oz. of pulverized cloves, 2 ozs. of allspice, and com-
pound the mixture with white-wine or wine-vinegar.
Wine Mustard. — Ground mustard-seed, white, 23 ozs., brown
12 ozs., common salt 2| ozs., wine vinegar 8J ozs., a like
quantity of white wine, and water 16 ozs.
Aromatic or Hygienic Mustard. — Ground mustard-seed, white,
23 ozs., brown 12 ozs., wine vinegar 17J ozs. Extract all-
spice 0.35 oz., cassia, white pepper, and ginger, of each 0.17
oz., with alcohol 1} ozs., and water 8J ozs., add 3J ozs. of
common salt and a like quantity of sugar, filter the whole
and add it to the mustard.
Dusseldorf Mustard. — Ground mustard-seed freed from oil,
brown 3 ozs., white SJ ozs., boiling water 26J ozs., wine
vinegar 18 ozs., cinnamon 0.17 oz., cloves 0.1 oz., sugar 11
ozs., white wine 18 ozs.
Sour Dusseldorf Mustard. — Fill 2 casks with vinegar, steep
in one of the casks 2 Ibs. of origan leaves, and in the other
an ordinary bucket full of onions cut up, and let them digest
for 2 days. Then bruise 44 Ibs. of white mustard-seed
and 66 Ibs. of brown ; put this in a vat and add 1 Ib. of pul-
verized cloves, 1J Ibs. of pulverized coriander seed, and 4J
gallons of each of the prepared vinegars. Stir the whole thor-
PREPARATION OF PICKLES AND MUSTARDS. 495
oughly and grind it twice in a mill. To every gallon of this
add and mix thoroughly with it, 1 Ib. of salt dissolved in 1
quart of the onion vinegar.
Sweet Kremser Must-mustard. — Ground mustard-seed, brown
10 Ibs., white 5 Ibs., is intimately mixed with 3 Ibs. of fresh-
ly-pressed must, and boiled down to the desired consistency.
Sour Kremser Must-mustard. — Boil to a stiff paste 15 Ibs. of
brown mustard ground, and 5 Ibs. of white mustard ground,
together with 4 Ibs. of must, and after cooling stir in 4 Ibs. of
vinegar.
Moutarde de maille. — Cut up 8 ozs. of fresh tarragon leaves
without the stems, 2^ ozs. of basil, 2 ozs. of bay leaves and 4
ozs. of rocambole (a spice of garlic). Place these ingredients-
in a glass alembic, pour 2 J quarts of strong wine-vinegar over
them, and, to allow the vapors to escape, tie up the mouth of
the alembic with a piece of perforated moist bladder. Place
the alembic upon hot sand for 4 days, then filter the fluid
first through linen arid then through blotting paper. Add to
this aromatic vinegar, 1 oz. of common salt, then stir it into a
thick paste with ground brown mustard-seed, and keep the
the mustard in earthenware jars tied up with bladder.
Moutarde aux epices is prepared by extracting 18 ozs. of
tarragon leaves, 7 ozs. of basil, If ozs. of bay leaves, 3J ozs.
of white pepper, If ozs. of cloves, and 0.35 oz. of mace with
vinegar and mixing the extract with mustard prepared in the
ordinary manner from ground mustard-seed, brown 44 Ibs.,
white 11 Ibs., and vinegar 8J Ibs.
Moutarde Aromatisee. — Boil ground mustard-seed, brown 22
Ibs., white 44 Ibs, with 9 Ibs. of vinegar, and add oil of tarra-
gon 1 oz., oil of thyme J oz., oil of mace 0.35 oz., and oil of
cloves 0.17 oz., all previously dissolved in very strong vinegar.
English Mustard. — Ground mustard-seed 9 Ibs., wheat flour
9 ozs., common salt 1} Ib., cayenne pepper 2| ozs., and as
much vinegar and water as required.
496 MANUFACTURE OF VINEGAR.
CHAPTER XXXIV.
PRESERVATION OF MEAT, FISH AND EGGS.
Appert's Method of Canning Meats. — This method consists in
soldering up the food in tin cans with great care, and then
heating the cans for considerable time in water. The cans
used are either cylinders or four-sided cases. Although the
latter do not waste so much space as the former when packed
with others, the cylinders are generally preferred, they being
•easier to make by machinery and much easier to solder up.
The duration of the heating depends on the size of the can,
for every part of its contents must be kept at the temperature
of boiling water for a sufficient time. Meat is a bad conduc-
tor of heat and it takes "considerable time before the contents
of larger cans are heated through and through to 212° F.
The time required for the purpose can only be learned by
experience. Insert in one of the cans a thermometer so that
the bulb is exactly in the centre of the can, and observe re-
peatedly the time which elapses between when the water com-
mences to boil and the moment at which the mercury rises to
212° F.
In placing the prepared meats in the cans, the pieces should
be so arranged as to leave but few interspaces between them,
&nd the cans should be filled as full as possible, so that but
little air remains in them. Immediately after the cans are
filled, the lids are soldered on. When a sufficient number of
•cans have been soldered, they are at once heated to the tem-
perature of boiling water. Heating by steam is more suitable
•and less troublesome than by water. For this purpose the
•cans are so arranged in a chamber that the steam can circu-
late freely round each one, the bottom layer of cans resting
•on a lattice bottom. The steam enters the chamber below
this lattice bottom and escapes through an aperture on the
tipper side of the chamber. Below the lattice bottom is a
trap for drawing off the condensed water. At first the steam
PRESERVATION OF MEAT, FISH AND EGGS. 497
is admitted at a pressure of two to three atmospheres. The
steam condenses on the cold cans and, when condensation has
ceased, the blow-off cock is shut, and the passage of steam is
continued until the contents of the cans have been heated to
212° F. The time required for this purpose depends on the
size of the chamber, the number of cans in it, the quantity
and temperature of the steam introduced, etc. Iii all cases,
whether heating is done by water or by steam, care must be
had to only gradually increase the heat to give the heated
oxygen time to be absorbed by the meat. By heating too
rapidly it may happen that, in consequence of the great pres-
sure exerted by the strongly heated air upon the sides of the
cans, the soldered places may become defective, and the cans
be spoiled.
When heating has been successfully finished, i. e., when all
the oxygen has been absorbed and the cans remain perfectly
tight, it will frequently be observed that, after cooling, the
bottoms of the cans bulge inward, though they were perfectly
flat previous to heating. This is a favorable indication of
successful preservation of the contents, because the oxygen
contained in the box being completely fixed to the meat, the
tension of the other enclosed gas (nitrogen) is considerably
decreased in cooling, which causes the slight bulging inward
of the bottoms. When, on the other hand, it is observed that
the bottoms of cans which have been stored for some time
bulge outward, it is an indication that the contents are in a
state of decomposition produced by the ferments contained in
them not having been destroyed. In consequence of decom-
position gases are evolved which accumulate more and more,
and by their pressure force the bottoms to bulge outward and
finally burst the cans.
The object to be attained in operating according to Appert's
method, is to leave as little air as possible in the cans. This
object may be reached in various ways. With meat, which is
to be canned together with the broth, the smaller cans are
closed in the usual manner by soldering, and a small hole is
32
498 MANUFACTURE OF VINEGAR.
punched in the lids. When the cans have been sufficiently
heated and the steam escapes from the small holes, the latter
are closed by a drop of solder. For larger cans sufficient
water is added. to the broth to fill the cans nearly to the rims.
They are then closed in the usual manner, a small hole is
punched in the lids and the cans are heated as long as a cur-
rent of steam escapes from the holes, when the latter are
closed by a drop of solder. In consequence of heating, the
expanded air escapes first from the cans, the last portions being
displaced by the steam. After closing the small holes and
cooling, the free spaces in the cans are almost free from air.
When a hole is punched in a can a peculiar hissing sound is
heard, which is produced by the air rushing into the can.
Appert's method is adapted for all kinds of meat, whether
stewed or roasted, with or without broth. To save space the
bones of larger animals are removed and the cans are packed
with pieces of meat. Smaller animals, for instance, poultry,
are cut up and then canned.
Corned beef is prepared by Appert's method. The meat is
freed from fat and cut into slices. The latter are then packed
closely interstratified with a little salt into cans of a truncated
pyramidal shape. The cooking is done with high-pressure
steam, and causes the slices to cohere into a solid mass.
Meat Biscuit according to Gallamond. — The preparation of
this product embraces three operations : Preparation of the
bouillon, preparation of the dough, and baking of the biscuit.
1. Preparation of the bouillon. Bring 56 Ibs. of beef and 24
quarts of water in a boiler, add, tied in a linen bag, thyme,
bay leaves, two nutmegs, cloves, pepper, cinnamon or ginger,
and 22 Ibs. of vegetables (carrots, turnips, leek). After boil-
ing for four hours, remove the bones from the meat, divide
the latter into small pieces, return them to the bouillon and
continue boiling for 1J hours longer. The contents of the
boiler are then of the consistency of a very thin paste. Dissolve
in this paste about \ Ib. of rock candy, which is claimed to in-
crease the keeping qualities of the biscuit. In the manner
PRESERVATION OF MEAT, FISH AND EGGS. 499
above described about 11 quarts of very concentrated broth
are obtained, which contains all the soluble parts and the fibrin
of 48 Ibs. of meat (8 Ibs. being lost in the form of bones, sin-
ews, etc.).
2. Preparation of the dough. 110 Ibs. of wheat flour are in-
corporated by kneading with the 11 quarts of bouillon. The
dough is very solid and is cut up into biscuits, generally 237.
3. Baking the Biscuit. The biscuits remain in the oven for
1J hours. The composition of 100 parts of this biscuit is
about as follows : Dry flour, 76.45 ; dry meat, 5.79 : fat, 6.27 ;
dry vegetables, 2.77 ; spices and sugar, 0.92 ; water, 7.80.
Soup Tablets. For the preparation of soup tablets it is first
of all necessary to extract the soluble matters from the meat.
The proper plan to do this is to keep the meat in cold water
and then to heat it gradually and not to a temperature so
high as to coagulate the albumen. If the meat is plunged
from the start in boiling water, the outside of it is made im-
pervious by the coagulation of the albumen and the soluble
constituents are only imperfectly extracted even by long boil-
ing. The meat should be scrupulously cleaned from fat. It is
then minced in a mincing machine or cut up small with a
chopper, and steeped in water which should not be too hard
and is gradually brought to a temperature not exceeding 140 °F.
Heating is kept up, whilst constantly stirring, for several
hours. When working on a large scale a mechanical stirrer
should be used. The proportion of water to meat should be
two parts to one by weight. After heating for three hours
nothing will be left undissolved but worthless fibrin. The
temperature is then raised to about 194° F. The liquid,
previously clear, then becomes thick, and a scum rises to the
surface, both these appearances being due to the coagulation
of the albumen. The liquid thus prepared may be stored by
bringing it, while still hot, into vessels, filling them quite full
and closing them air-tight. The liquid will keep for many
months.
For the preparation of soup tablets, the liquid is mixed with
500 MANUFACTURE OP VINEGAR.
about 1 lb. of salt for every 100 Ibs. of meat used and filtered
through several folds of linen. The filtrate is evaporated in
very shallow thvplate pans, without, however, allowing it to
boil, till a sample becomes hard when cold. The entire mass
is then cast into molds. When properly made soup tablets
are usually of a pale brown color and give a perfectly clear
solution in water, having the taste of fresh beef tea.
Beef extract. — This product is made at Fray Bentos in
Uruguay, by the following method. The meat from the cattle
of the grass plains of the pampas is freed from bones and fat,
and minced. The paste is mixed with water and subjected
to great hydraulic pressure. The concentrated solution of the
soluble constituents of the meat thus obtained is at once
boiled to coagulate the albumen. The clear liquid is then
evaporated in vacuum pans till the mass on cooling is of a
semi-solid consistency. When prepared in this manner the
extract contains no gelatine and forms a perfectly clear solution
with water. The absence of gelatine and fat makes the extract
so unalterable that a pot of it can be left for as long as desired
in a damp mouldy room without undergoing change.
Quick Salting of Meat by liquid pressure. — This process is
especially applicable to the preservation of large masses. A
reservoir of concentrated brine is placed on a high level, at
least 30 feet above the room where the process is worked. A
pipe brought down from the reservoir is connected by a length
of rubber tube with an iron-pointed pipe. This pipe is about
8 inches long, is provided with a tap and has numerous holes
bored in it towards the point. If this point is inserted into the
middle of a piece of»meat and the tap is opened, the hydrostatic
pressure causes the brine to penetrate the meat completely in
a very few minutes. The pieces impregnated in this manner
are placed for about 24 hours in concentrated brine, and the
meat loses no nutritive matter as it is already thoroughly
penetrated with brine. The pieces are then simply dried or
slightly smoked.
Quick Process of Smoking Meat. — This process is based upon
PRESERVATION OF MEAT, FISH AND EGGS. 501
the fact that crude wood vinegar (pyrol igneous acid) as ob-
tained iu the destructive distillation of wood contains creosote
as well as acetic acid and water. It has a strong smoky
smell and is a powerful antiseptic. The meat is for a few
seconds dipped in the fluid, allowed to drain off and then
hung up to dry. The room in which the work is done should
be warm enough for the fat of the meat to become soft, the
absorption of the wood vinegar being thereby facilitated.
When the meat has absorbed the acid it is again dipped two
or three times in the wood vinegar, and then left to itself for
48 to 60 hours when it may be considered as thoroughly
cured. To give the cured meat the aromatic taste of juniper,
a small quantity of oil of juniper is dissolved in the wood
vinegar diluted with water. A fluid of the following com-
position yields excellent results :
Crude wood vinegar 50 gallons.
Water ...*..... ... . . 100 "
Oil of juniper . I . . . V . . . . . 2£ "
Although the acetic acid contained in the wood vinegar
acts as a preservative, the greater portion of it is lost by evap-
oration, and hence a fluid may suitably be used which con-
tains only a small quantity of wood vinegar, but a larger
quantity of the actually effective creosote. Such a fluid may
be prepared as follows :
Water 500 parts by weight.
Creosote 5 " "
Crude wood vinegar 50 "
Oil of juniper 5 " c<
Dissolve the creosote in the wood vinegar, dissolve in this
solution the oil of juniper, and pour the fluid in a thin jet,
with constant stirring, into the water.
Curing may also be very rapidly effected by bringing the
meat into a smoke-house connected with a well-drawing chim-
ney, and placing on the floor of the smoke-house shallow
dishes containing a mixture of
502 MANUFACTURE OF VINEGAR.
Wood vinegar 50 parts.
Creosote 10 "
Water 50 <k
Place a large bath sponge in each dish, and conduct a cur-
rent of warm air over the dishes.
By the current of warm air the fluid absorbed by the
sponges is evaporated, and curing rapidly effected.
Preparation of Powdered Meat. — An excellent product — a
kind of pemmican — is obtained by a process patented by
Hassal. The meat used for the purpose should be as free as
possible from fat, veins and sinews, fat being particularly sub-
ject to decomposition. The meat is cut up in a mincing
machine to a paste, and the latter is spread out in thin layers
on tin plate and dried in a drying room, a very convenient
way being to force hot air over the layers by means of a fan.
The temperature should never exceed 140° F., otherwise the
albuminous constituents of the meat coagulate and become
insoluble. Drying is continued at between 122° and 140° F.
till the meat is considerably reduced in volume and forms a
crusty mass. The latter is next reduced to powder in a mill,
dried again, and then brought into metal cans or paper cylin-
ders lined with tin-foil. A soup of excellent taste and quality
is obtained from this meat powder by simmering for some
time in water at between 122° and 140° F.
Preservation of Fish. — In order to obtain a good product, fish
which are to be preserved in oil should be treated a few hours
after having been caught. The fish should be carefully cleaned,
the entrails taken out, the tails cut off, and eventually the heads
also, as they impart a bitter taste to the fish. Finally the fish
are for a short time laid in brine. They are then taken out,
thoroughly rinsed in clean water, laid upon grates to drain, and
finally dried in the air, or, when this is impossible on account
of unfavorable weather, in ovens of special construction, in
which they remain until they feel perfectly dry and solid.
They are then laid upon shallow wire sieves, and boiled in
olive oil until done. The boiler is generally heated by steam.
PRESERVATION OF MEAT, FISH AND EGGS. 503
The oil should have a temperature of 310° to 338° F., and,
according to the size of the fish, 45 to 80 seconds are required
for boiling. When boiling is finished, the sieves with the fish
are taken from the oil, and after draining off and drying, the
fish are packed, according to sizes, in tin cans. The latter are
then filled with oil, closed by soldering on the lids, and,
according to Appert's method, again boiled. Separate pieces
of larger fish are treated in the same manner.
According to Appert's method, all kinds of fish, lobster,
crabs, oysters, etc., can be preserved by preparing them in the
same manner as for immediate consumption, then putting
them in tin cans, closing the latter by soldering, and heating
them in hot water or by steam, so that the contents are
exposed to a temperature of at least 212° F.
Preservation of Eggs. — Eggs are frequently preserved by
means of lime water, which, to be sure, is one of the most
convenient, but at the same time one of the worst methods,
the eggs acquiring the disagreeable taste of lime.
To prevent eggs preserved in lime water from acquiring a
disagreeable taste of lime, Kubel recommends lime water of
1.0029 specific gravity, and to dissolve in it 6 per cent, of con-
mon salt, so that the fluid shows a specific gravity of 1.042.
Perhaps a 6 per cent, common salt solution without lime water
would answer as well.
A good preserving fluid is commercial glycerin diluted with
half its volume of well water. Salicylic acid is also very use-
ful for the purpose. Prepare a mixture of 2 quarts of water
and 1 quart strong alcohol, add 7 ozs. of glycerin, and dissolve
in this fluid as much crystallized salicylic acid as will dissolve
in it. Bring the eggs to be preserved into the fluid, allow them
to remain for one hour, and then let them dry, placing them
for this purpose in a frame of boards or sheet zinc provided
with holes, one egg being placed in each hole. In drying,
the water and alcohol rapidly evaporate, and the salicylic acid
dissolved in them would separate in crystals upon the surface
of the eggs. However, the glycerin does not evaporate, as it
504 MANUFACTURE OF VINEGAR.
possesses the property of vigorously absorbing water from the
air, and, besides, dissolves salicylic acid. Hence a fluid is
formed which consists of a saturated solution of salicylic acid
in glycerin and fills the pores of the eggs.
The expense of preserving eggs by this method is very small,
since a fluid containing 2 Ibs. of salicylic acid in solution
suffices for many thousands of eggs. In order not to waste
any of the preserving fluid, the drippings from the eggs al-
ready treated may be collected in a vessel and again used.
Eggs preserved in this manner may be kept for many
months at the ordinary temperature of living-rooms without
the slightest alteration.
The result of the competition for prizes offered by the Asso-
ciation of Poultry Breeders of the Province of Saxony, Prussia,
has shown that water-glass (silicate of soda) is an excellent
preservative for eggs. The first prize was awarded to a com-
petitor who had used the following process: The eggs, which
should be perfectly clean, were placed in a can filled with a 10
per cent, solution of silicate of soda and the can was closed
air-tight. The solution was once renewed during the preserv-
ing time of six months. The temperature of the storage room
on the hottest day was 77° F. In appearance the eggs could
not be distinguished from fresh eggs. The yolk and white
were perfect, and the taste excellent.
A simple method of preserving eggs by means of silicate of
soda is as follows : Immerse the eggs in a solution of silicate of
soda for about 10 minutes by floating a board on top of them.
Then remove them and stand them up with their small ends
in little holes in a shelf for two days, when they can be packed
for storage or transit. The silica of the silicate of soda is set
free by the carbon dioxide of the air and thenfforms with the
lime of the egg-shell a glassy sheet of calcium silicate which
closes all the pores.
The competition previously referred to has further shown
that the breed of chickens is without influence upon the pre-
serving capacity of the eggs, which, however, appears some-
PRESERVATION OF MEAT, FISH AND EGGS. 505-
what affected by the feed. As is well known, eggs of chickens
which run free and subsist chiefly on animal food — worms,
insects, etc. — have a reddish-yellow yolk, while chickens fed
chiefly with grain lay eggs with a pale yellow yolk. The
latter have a finer taste than the former. Exporters also
assert that eggs with a red-yellow yolk do not keep so well,
and in Russia, for instance, are for this reason excluded as-
much as possible from export. To recognize the color of the
yolk, hold the egg before the light.
APPENDIX.
TABLE I. — Hehner's Alcohol Table.
.s3
S3
J5,c
S3
s3
13
.s3
S3
rt
§1
al
rt
00 O
11
«
§1
11
rt
M o
1 8
|>
> rt
H
fr
•g-a
H
>,
<L> P-M
£ «
o«
>,
1-3
w
1
!l
K|
,£> 3
*j"0
1
*j
j'S
>>2
•51
'>
rt
a
fc,s
; ^3,3
1 *J O
4
*J9
'>
•
M
"1
rf
*-' 9
**
§3
u
it
8|
o w
§1
K
H
§1
lo^
«'!
u w
c S
8*«
P
»•*
S°
B
So
^
1-8
s^
S^
P
5°
53°
W
PH
PH
en
Pi
PH
ca
: P-
PH
W
PH
PH
I.CXX)O
0.00
0.00
0.9969
i-75
2.20
0.9938
3-53
442
0.9907
5-44
6.78
8
1.81
2.27
7
3-59
4-49
6
5-50
6.86
0.9999
0.05
0.07
7
1.87
2-35
6
3-65
4-56
5
5.56
6.94
8
O.I I
0.13
6
1.94
2.43
5
3-71
4-63
4
5.62
7.01
7
0.16
O.2O
5
2.00
2.51
4
3.76
4.71
3
5.69
7.09
6
0.21
O.26
4
2.06
2.58
3
3-82
4.78
2
5-75
7.17
5
0.26
0.32
3
2. 1 1
2.65
2
3-88
4.85
I
5.81
7-25
4
0.32
0.40
2
2.17
2.72
I
3-94
4-93
O
5.87
7-32
3
0.37
0.46
I
2.22
2.79
O
4.00
5.00
2
0.42
0-53
o
2.28
2.86
0.9899
5-94
7.40
I
0.47
O.6O
0.9929
4.06
5.08
8
6.00
7.48
0
0.53
0.66
0.9959
2-33
2-93
8
4.12
5.16
7
6.07
7-57
2-39
3.00
7
4.19
5-24
6
6.14.
7.66
0.9989
0.58
0-73
7
2-45
3-07
6
4-25
5-32
5
6.21
7-74
8
0.63
0.79
6
2.5I
3-14
5
4-31
5-39
4
6.28
7.83
7
0.68
0.86
5
2-57
3.21
4
4-37
5-47
3
6.36
7.92
6
0.74
0-93
4
2.61
3-28
3
4.44
5-55
2
6.43
8.01
5
0.79
0.99
3
2.65
3-35
2
4-5°
5-63
j
6.50
8.10
4
0.84
.06
2
2.71
3-42
I
4-56
5-71
0
6.57
8.18
3
0.89
•13
I
2.78
3-49
O
4.62
5.78
2
0-95
.19
0
2.84
3-55
0.9889
6.64
8.27
I
1. 00
.26
0.9919
4.69
5.86
8
6.71
8.36
0
i. 06
•34
0.9949
2.89
3-62
8
4-75
5-94
7
6.78
8-45
8
2.94
3-69
7
4.81
6.O2
6
6.86
8.54
0.9979
.12
.42
7
3.00
3.76
6
4.87
6.10
5
6-93
8.63
8
7
.I9
•25
•49
•57
6
5
3.06
3.12
3.83
3-90
5
4
4.94
5.00
6.17
6.24
4
- 3
7.00
7.06
8.72
8.80
6
•31
.65
4
3.18
3.98
3
5.06
6.32
2
7-!3
8.88
5
•37
•73
3
3-24
4-05
2
5.12
6.40
I
7.19
8.96
4
.44
.81
2
3-29
4.12
I
5-J9
6.48
O
7.27
9.04
3
•50
1.88
I
3.35
4.20
O
5-25
6.55
2
.56
1.96
O
3.41
4.27
0.9879
7-33
9-13
I
.62
2.04
0.9909
5-3i
6.63
8
7.40
9.21
0
.69
2.12
0.9939
3-47
4-34
8
5-37
6.71
7
7-47
9-29
1
(506)
APPENDIX.
TABLE I. — Continued.
507
rt
[Mg
11
rt
•il
|1
-j
3 O
rt
il
11
F— tJ
ITS
'3 Jj
•£ ™
£>
'!*«
f-S
'C J
f "3
V
5
n* 3
£ =
rt
.a Ja
^ "2
£ -03
J? "3
nj
jQ 3
^ "S
!*;
§1
§1
M
^"3
il
M
~j
jl
So
||
il
l&
5^
$°
i
5^
S^
S
5°
P
S^
£
£
Pu
C/3
PH
*
*
b
O>
0.9876
7-53
9-37
0.9836
10.38
12.87
0.9796
13.46
16.61
0.9756
16.77
20.61
5
9-45
5
10.46
12.96
5
13-54
16.70
5
16.85
20.71
4
7^67
9-54
4
10.54
13.05
4
13.62
1 6.80
4
16.92
20.80
3
7-73
9.62
3
10.62
13.15
3
13.69
16.89
3
17.00
20.89
2
7.80
9.70
2
10.69
13.24
2
13.77
16.98
2
17.08
20.99
I
7.87
9.78
I
10.77
13.34
I
13-85
17.08
I
17.17
21.09
O
7«93
9.86
0
10.85
13.43
0
13.92
17.17
0
17-25
21.19
0,9869
8.00
9-95
0.9829
IO.92 13.52
0.9789
14.00
17.26
0.9749
17.33
21 29
8
8.07
10.03
8
u.oo 13.62
8
14.09
17-37
8
17.42
21.39
7
8.14
10.12
7
11.08 13.71
7
14.18
17.48
7
17.50
21.49
6
8,21
10.21
6
11.15
13.81
6
14.27
17-59
6
17.58
21.59
5
8.29
10.30
5
11.23 J3-90
5
14.36
17.70
5
17.67
21.69
4
8.36
10.38
4
11.31
13.99
4
14.45
17.81
4
17.75
21.79
3
8.43
10.47
3
11.38
14.09
3
T4-55
17.92
3
17.83
21.89
2
8.50
10.56
2
11.46 14.18
2
14.64
18.03
2
17.92
21.99
I
0
8.57
8.64
10.65
10.73
I
O
11-54
11.62
14.27
14.37
0
M.73
14.82
18.14
18.25
I
0
1 8.00
1 8.08
22.O9
22.18
0.9859
8.71
10.82
0.9819
11.69
14.46
0.9779
14.91
18.36
0-9739
18.15
22.27
8
8.79
IO.9I
8
11.77
14.56
8
15.00
18.48
8
18.23
22.36
7
8.86
11.00
7
11.85
14.65
7
15.08
18.58
7
18.31
22.46
6
8-93
11.08
6
11.92 14.74
6
15.17
18.68
6
18.38
22.55
5
9.00
11.17
5
12.COJ 14.84
5
18.78
5
18.46
22.64
4
9.07
11.26
4
1 2.08 14.93
4
15-33
18.88
4
18.54
22-73
3
9.14
n-35
3
12.15 ^-o2
3
15.42
18.98
3
18.62
22.82
2
9.21
11.44
2
12.23 I5«12
2
15-50
19.08
2
18.69
22.92
I
9.29
11.52
I
12.31
15.21
I
15.58
19.18
I
18.77
23.01
0
9.36
11.61
O
12.38
15-30
0
J5-67
19.28
O
18.85
23.10
0.9849
9-43
11.70
0.9809
12.46
15.40
0.9769
15.75
19.39
0.9729
18.92
23.19
8
9.5°
11.79
8
12.54 15.49
8
15.83
19.49
8 19.00
23.28
7
9-57
11.87
7
12.62
15-58
7
15.92
«9-59
7( 19.08
23.38
6
9.64
11.96
6
12.69
15.68
6
16.00
19.68
6
19.17
23.48
5
9.71
12.05
5
12.77
15-77
5
1 6.08
19.78
5
19.25
23.58
4
3
9-79
9.86
12.13
12.22
4
3
12.85
12.92
15.86
15.96
4
3
16.15
16.23
19.87
19.96
4
3
19.33
19.42
23-68
23.78
2
9-93
12.31
2
13.00
16.05
2
16.31
20.06
2
19.5°
23.88
I
IO.OO
I2.4O
I
13.08
16.15
I
16.38
20.15
I
19.58
23.98
0
10.08
12.49
0
13.15
16.24
O
16.46
20.24
O
19.67
24.08
0.9839
10.15
12.58
0.9799
13.23
16.33
0-9759
16.54
20.33
0.9719
19.75
24.18
8
10.23
12.68
8
I3-3I
16.43
8
16.62
20.43
8
19-83
24.28
7
10.31
12.77
7
13.38 16.52
7
16.69
20.52
7
19.92
24.38
1
508
APPENDIX.
TABLE I. — Concluded.
rt
II
I*
8
||
J2 8
^
4-*O
II
CC
sj
§1
>*, i "^ *^5
83
bk,
^
'«~
"o *~*
>•>
"o *""
|£ ^
§
I""
> ^
•g
S «
> ^
C
^ 03
^ ^
1
.a «
b!
1
*|
.03
g
^3
^3
5
j£»{j
^3
M
*J 3
4-1 3
to
4-J "O
M
^j *o
«"s
M
• *o
5JJB^
U
§]
1C •
^u!
§-§
slj*
§•«
51
•- O
5 «
S-I
Is
*l
u «
£"8
n
i*
1*
£°
^°
P
CA)
I*
ff-
0.9716
20.00
2448
0.9699
21.38
26.13
0.9682
22.69
27.68
0.9666
23.92
29.13;
5
20.08| 24.58
8 21.46
26.22
I
22.77
27.77
5
24.00
29.22
4
20.17 24.68
7 21.54
26.31
o
22.85
27.86
4
24.08
29.31
3
20.25 24.78
6 21.62
26.40
3
24.I5
29.40
2
20.33, 24 88
5! 21.69
26.49
0.9679
22.92
27.95
2
24.23
29.49
I
20.42! 24.98
4
21.77
26.58
8
23.00
28.04
I
24.31
29.58
O
20.50
25.07
3| 21.85
26.67
7
23.08
28.13
0
24.38
29.67
2! 21.92
26.77
6
23.15
28.22
0.9709
8
20.58
20.67
25.27
i
o
22.00
22.08
26.86
26.95
5
4
23.23
23.31
28.31
28.41
0.9659
8
24.46
24.54
29.76
29.86
7
20.75
25-37
3
23-38
28.50
7
24.62
29-95
6
20.831 25.47
0.9689
22.15
27.04
2
23.46
28.59
6
24.69
30.04
5
20.92
25^7
8, 22.23 27.13
I
23.54
28.68
5
24.77
30.13
4
2I.OO
25.67
7 22.31 27.22
O
23.62
28.77
4
24.85 30.22
3
2 1. 08
25.76
6; 22.38 27.31
3
24.92
30.3!
2
21.15
25.86
5
22.46 27.40
0.9669
23.69
28.86
2
25.00
30.40
I
21.23
25-95
4
22.54
27.49
8
23-77
28.95
O
2I.3IJ 26.04
3! 22.62
27-59
7
23.85
29.04
APPENDIX.
509
TABLE II. — Which indicates the specific gravity of mixtures
of alcohol and water.
The figures in the column to the left show the per cent, by volume of alcohol; the
figures in the column to the right give the specific gravities which correspond to
the content of alcohol at 60° F.
1
Specific
1
Specific
1
Specific
1
Specific
fl
gravity at
0
gravity at
•L
gravity at
3
>"o
gravity at
,0 8
rCt <J
•& 8
•° 8
+z "c3
*- ^
.j'w
** "rt
g-s
60° F.
§°
60° F.
§o
60° F.
§0
60° F.
Jl
|
1
1
I
0.9985
26
0.9698
51
0.9323
76
0.8747
2
0.9970
27
0.9688
52
0.9303
77
0.8720
3
0.9956
28
0.9677
53
0.9283
78
0.8693
4
0.9942
29
0.9666
54
0.9263
79
0.8665
5
0.9928
30
0.9655
55
0.9242
80
0.8639
6
0.9915
31
0.9643
56
0.9221
81
0.86II
7
0.9902
32
0.9631
57
0.9200
82
0.8583
8
0.9880
33
0.9618
58
0.9178
83
0-8555
9
0.9878
34
0.9605
59
0.9156
84
0.8526
10
0.9866
35
0.9592
60
0.9134
85
0.8496
ii
0.9854
36
0-9579
61
0.9112
86
0.8466
12
0.9843
37
0.9565
62
0.9090
87
0.8436
13
0.9832
38
0.955°
63
.0.9067
88
0.8405
14
0.9821
39
0-9535
64
0.9044
89
0.8373
'5
0.9812
40
0.9519
65
0.9021
90
0.8339
16
0.9800
41
0.9503
66
0.8997
91
0.8306
17
0.9790
42
0.9487
67
0.8973
92
0.8272
18
0.9780
43
0.9470
68
0.8949
93
0.8237
19
0.9770
44
0.9452
69
0.8925
94
0.8201
20
0.9760
45
o-9435
70
0.8900
95
0.8164
21
0.9750
46
0.9417
0.8875
96
0.8125
22
0-9740
47
0-9399
72
0.8850
97
0.8084
23
09729
48
0.9381
73
0.8825
98
0.8041
24
0.9719
49
0.9362
74
0.8799
99
0-7995
25
0.9709
5°
0.9343
75
0-8773
100
0.7946
510
APPENDIX.
TABLE III. — Proportion between per cent, by weight and by vol-
ume of alcoholic fluids at 59° F.
(According to Stampfer.)
ioo liters of
|
In ioo
In
ioo liters of
1
In ioo
In
the alcoholic
rt
•g <S
kilgr.
i kl.
the alcoholic
2
IS
kilgi.
lid.
liquid
Efl
o
ul
liquid
o
t« C
contain —
10
Is
contain —
<C
j= £
L
°1
1
g-13
5|
V- ^
'*
o'l
*£ ^4
!^<U
Of the alcoholic
if
Of the alcoholic
Alco-
•5- "5
J'fl)
liquid
Alco-
° 7 "S
liquid
hol,
Water,
v^o
I
are contained
hol,
Water,
So
11
are contained
hers.
liters.
°
alcohol, kilogr.
liters.
liters.
Q
alcohol, kilogr.
IOO
0.00
o 7951
79-51
100.00
79-51
49
54-70
0.9366
93-66
41-59
38.96
99
1.28
0.8000
80.00
98.38
78.71
48
55-68
9385
93.85
40.66
38.16
98
2-54
8046
80.46
96-83
77.92
47
56.66
9403
94-03
39-74
37-37
97
3-77
8089
80.89
95-35
77.12
46
57-64
9421
94.21
38.82
36.57
96
95
4-97
6.16
8130
8169
81.30
81.69
93-89
92.45
76.33
75-53
45
44
58.61
59-58
9439
9456
94-39
94.56
37-9°
37-—
35-78
34-98
94
7-32
8206
82.06
91.08
74-74
43
60.54
9473
94-73
36.09
34-I9
93
8.48
8242
82.42
89.72
73-94
42
61.50
949°
94.90
35-iS.
33-39
92
9.62
8277
82.77
88.37
73-15
62.46
9506
95-o6
34-30
32.60
91
10.76
. 8311
83.11
87.04
72.35
40
63.42
0.9522
95-22
33-4°
31.80
90
1.88
0-8344
83.44
85.74
39
64-37
9538
95.38
32.52
31.01
88
3.01
4.12
8377
8409
83-77
84.09
84.74
83.22
70.76
69.97
38
37
65-32
66.26
9553
9568
Q5-53
95-68
31-63
30-75
30.21
29.42
87
5-23
8440
84.40
81.96
36
'67.20
9582
95-82
29.88
28.62
86
6.32
8470
84.70
80.72
68.38
35
68.12
9595
95-95
29.01
27.83
85
7.42
8500
85.00
79-51
67.58
34
69.04
9607
96.07
28.14
27.03
84
83
8.52
19.61
8530
8559
85-30
85.59
78.29
77.09
66.78
65.99
33
32
• 69.96
70.89
9620
9633
96.20
96.33
27.27
26.41
26.24
25-44
82
20.68
8588
85.88
75-91
65.10
3i
71.80
9645
96-45
25-56
24.65
Si
21.76
8616
86.16
74-75
64.40
30
72.72
0.9657
96.57
24.70
23-85
80
^2.83
0.8644
86.44
73-59
63.67
29
73.62
9668
23-85
23.06
79
23.90
8671
86 71
72.43
62.81
28
74-53
9679
96.79
23.—
22.26
78
77
24.96
26.03
8698
8725
86.98
87-25
70.16
62.02
61.22
:?
75-43
76.33
9690
9701
96.90
97.01
22.16
21.31
21.47
20.67
76
27.09
8752
87.52
69.04
60.43
25
77-23
9711
97.11
20.47
19.88
75
28.15
8778
87.78
67-93
59-63
24
78-13
9721
97-21
19-63
19.08
74
29.20
8804
88.04
66.82
58.84
23
79.02
973*
97-31
18.79
18.29
73
30.26
8830
88.30
65.72
58.04
22
79.92
9741
97.41
17.96
17.49
72
31-30
8855 88.55
64.64
57-25
21
.80.81
9751
97-5
17.12
16.70
71
32.35
8880 ! 88.80
63.68
56.45
20
81.71
0.9761
97-6
16.29
15.90
7°
33-39
0.8905 : 89.05
62.50
55-66
19
82.60
9771
97-7
I5-46
15.11
69
34-44
8930 i 89.30
61.43
54-86
18
83.50
9781
97-8
14.63
I4-3I
68
35-47
8954 ! 89.54
60.38
54-07
J7
84.39
9791
97-9
13.80
67
36.51
8978 | 89.78
59-33
53-27
16
85.29
9801
98.0
12.98
12 72
66
37-54
9002
90.02
58.29
52.48
15
86.19
9812
98.1
12.15
11 -93
65
38-58
9026
90.26
57-35
51.68
87-09
9822
98.22
"•33
11.13
64
39-6o
9°49
90.49
56-23
50.89
13
88.— 9833
98.33
10.51
10.34
63
40-63
9072 90.72
55-21
50.09
12
88.90 : 9844
98.44 9.69
9-54
62
41.65
9095 90.95
54-20
49-30
II
89.80 I 9855
98.55 8.78
8-75
61
42-67
9117 91.17
53-19
48.50
10
90.72 0.9867
98.67
8.06
7-95
60
43-68
0.9139 91.39
52.20
47-71
g
91.62 9878
98.78
7.24
7.16
59
58
44.70
45-72
9161 ; 91.61
9183 : 91.83
51.20
50.21
46.92
46.12
7
92.54
93-45
9890
9902
98.90
99.02
6.43
5.62
6.36
5-57
57
46.73
9205 92.05
49.24
45-32
6
94-38
99*5
4.81
4-77
56
55
47-73
48.74
9226 ] 92.26
9247 92.47
48.26
47.40
44-53
43-73
5
4
95-30
96.24
9928
9942
99-28
99.42
4-—
3.20
3-98
54
49-74 9267 ' 92-67
46.33
42.94
3
97-77
9956
99.56
2.40
2-39
53
50.74
9288 92.88
45-37
42.14
2
98.11
997°
99.70
i. 60
i-59
52
51-74
93°8 ! 93.08
44.41
I
99-05
9985
99.85
0.80
0.80
51
5273
9328 93.28
43-47
40-55
0
IOO.OO
1. 0000
100.00
0.00
0.00.
50
53.72 0.9348 j 93.48
42-53
39-76
APPENDIX.
511
TABLE IV. — The actual content of alcohol and water in mixtures
of both fluids, and the contraction which takes place in mixing.
ioo volumes contain
ioo volumes contain
volumes —
volumes —
Specific
Contrac-
Specific
Contrac-
gravity.
tion-
gravity.
tion.
Alcohol.
Water.
Alcohol.
Water.
1. 0000
0
100.000
O.OOO
0.9323
51
52.705
3.705
0.9985
I
99.055
°55
°3
52
711
70
2
98.111
in
0.9283
53
50.716
7l6
56
3
97.176
176
63
54
49.722
722
42
4
96.242
242
42
55
48.717
717
28
5
95-307
307
21
56
47.712
712
15
6
94.382
382
O.92OO
57
46.708
708
02
7
93458
458
0.9178
58
45.693
693
0.9890
8
92.543
543
56
59
44.678
678
78
9
91.629
629
34
60
43.664
664
66
10
90.7H
7H
12
61
42.649
649
54
ii
89.799
799
0.9090
62
41.635
635
43
12
88.895
895
67
63
40.610
610
32
13
87.990
990
44
64
39.586
586
21
II
M
15
87.086
86.191
1.086
191
21
0.8997
8
38.561
37.526
526
0.9800
16
85.286
286
73
67
36.492
492
0.9790
17
84.392 392
49
68
35-457
457
80
18
83.497
497
25
69
34423
423
70
19
82.603
603
0.8900
70
33.378
378
60
20
81.708
708
75
7i
32.333
333
50
21
80.813
813
5°
72
31.289
289
40
22
79.919 9I9
25
73
30.244
244
29
23
79.014
2.014
0.8799
74
29.190
190
19
24
78.119
119
73
75
28.135
135
09
25
77.225
225
47
76
27.080
080
0.9698
26
76.320 320
20
77
26.016
016
88
27
75-426
426
0.8693
78
24-951
2-951
77
66
28
29
74.521
73.617
I21
617
65
39
g
23.877
22.822
877
822
55
30
72.712
712
n
81
21.747
747
43
31
71.797
797
0.8583
82
20.673
673
32
70.883
883
55
83
19.598
598
18
33
69.958
958
26
84
18.514
5*4
05
34
69.034
3-034
0.8496
85
17.419
419
0.9592
79
if
68.109
67.184
109
184
66
36
86
87
16.324
15.23°
324
230
65
37
66.250
250
05
88
14.125
I25
50
38
65.305
. 305
0.8373
89
13.011
on
35
39
64.361
39
90
11.876
1.876
19
40 63.406
406
06
91
10.751
751
41
62.451
451
0.8272
92
9.617
617
0.9487
42
61.497
497
37
93
8.472
472
70
43
60.532
S32
01
94
7.3*8
52
44
59.558
558
0.8764
95
6.153
r53
35
46
58.593
57.618
593
618
25
0.8084
96
97
4.968
3.764
0.968
764
0-9399
47
56.644
644
41
98
2-539
539
81
48
55.669
669
0-7995
99
1.285
285
62
49
54.685
685
46
IOO
0.000
oco
43
5°
53.700
700
512
APPENDIX.
TABLE V. — For comparing the different aerometers with
Tralles's alcoholometer.
The statements of figures of the other aerometers corresponding to the per cent, by
volume according to Tralles's alcoholometer stand in the same horizontal line.
,11
>>
;
Veromete
r of-
Jl
^
J
Aerometer
of-
Per cent, t
volume ace
ing to TK
Per cent, b
weight.
Richter.
1
Beaume.
3
Per cent, b
volume ac
ing to Tn
Per cent, t
weight.
Richter.
jj
i
Beaume.
•I
I
0
O.
O.O
0.0
10
ii
51
43-47
12.3
I
0.80
—
—
—
—
52
44.42
—
12.7
—
—
2
1. 60
—
—
—
—
53
4536
—
13.1
21
—
3
2.40
—
—
—
—
54
46.32
—
13.5
—
21
4
3-20
—
.0
—
—
55
4729
41.00
13.9
—
—
5
4-IO
4-00
.2
II
12
56 -
48.26
14.3
22
—
6
4-8!
•4
—
57
49-23
—
—
22
7
5.62
—
.6
—
—
58
50.21
—
15-2
23
—
8
6-43
—
•9
—
—
59
5I.2O
—
15.6
—
—
9
7-24
—
2.1
—
—
60
52.2O
45-95
16.1
—
23
.10
8.05
7-50
2-3
12
—
61
53.2O
16.5
24
—
ii
8.87
2-5
—
—
62
54-21
17.0
—
—
12
9.69
—
2.7
—
13
63
55-21
—
17-5
25
24
'3
10.51
—
2.9
—
—
64
56.22
—
18.0
—
—
M
u-33
—
3-1
65
57.24
51.40
18.4
—
25
'5
12.15
10.58
3-3
—
—
66
58.27
18.9
26
—
16
12.98
—
3-5
13
—
67
59.32
19.4
—
—
17
13.80
—
3-6
68
60.38
—
2O.O
27
26
J 8
14.63
—
3-8
69
61.42
—
20-5
—
—
19
15.46
—
4.0
14
70
62.50
57-12
21.0
28
27
20
16.28
13-55
4-2
71
63-58
21-5
—
—
21
17.11
4.4
—
72
64.66
22.1
—
—
22
J7-95
—
4-6
—
73
65.74
—
22.6
29
28
23
18.78
—
4.8
14
—
74
66.83
—
23.2
—
—
24
19.62
—
4-9
—
75
67.93
62.97
23.8
30
29
25
20.46
1 6. 60
—
76
69.05
24-4
—
—
26
21.30
—
5-3
15
77
70.18
—
25-0
31
30
27
22.14
—
5-5
—
78
71.31
—
25-6
—
28
22.96
—
5-7
—
79
72.45
—
26.2
32
—
29
23.84
—
5-9
15
—
80
73-59
69.20
26.8
—
31
30
24.69
19.78
6.1
—
81
74.74
—
27-4
33
—
31
25-55
—
6.4
—
82
75-91
—
28.0
34
32
32
26.41
—
6.6
—
83
77.09
—
28.7
—
—
33
27-27
—
6.8
—
16
84
78.29
—
294
35
33
34
28.13
—
7.o
16
—
85
79.50
75-35
3O.I
—
35
28.99
23-56
7-2
—
—
80
80.71
30.8
36
34
36
29.86
—
7-5
. .
—
87
81.94
—
31-5
•37
35
37
38
30.74
31.62
25-50
1:1
~
17
88
89
83.19
84.46
—
32.2
33-o
38
36
39
32.50
—
8.3
17
90
85-75
81.86
33-8
—
—
40
33-39
27-95
8.6
—
91
87.05
—
34-7
39
37
_o
41
34.28
8.9
—
—
92
88.37
—
35-5
40
38
42
35-18
—
9.2
—
18
93
89.71
—
36.4
41
43
3608
. —
9.5
18
—
94
91.07
—
37-3
—
39
44
36.99
—
9.8
—
—
95
92.46
89-34
38.2
42
40
g
37-90
38.82
28.30
IO.2
19
19
96
97
93.89
95-34
___
39-2
40.3
43
44
41
47
39-74
—
10.9
98
96.84
—
41-5
45
42
48
40.61
—
II. 2
—
—
99
98.39
—
42.7
46
43
49
41-59
—
u.6
—
—
100
100.00
100.00
43-9
47
—
50
42.52
36.46
ii. 9
20
20
APPENDIX. 513
Determination of the True Strengths of Spirit for the Standard
Temperature of 59° F. — Whe,n for the determination of the
strength of a spirit of wine, the indications of the alcoholo-
meter and of the thermometer have been read off, we possess
two figures by means of which the true strength of spirit of
the spirits of wine to be examined, i. e., the number of liters
of absolute alcohol contained in 100 liters of the fluid to be
examined, when the latter possesses the standard temperature
of 59° F., is found as follows : If the observed temperature of
the fluid is = 59° F., which is indicated on the scale of the
thermometer with a red mark, the figure read off on the scale
of the alcoholometer indicates at once the " true " strength of
spirit. If, however, the thermometer shows a different tem-
perature, in which case the figure read off on the scale of the
alcoholometer is termed the " apparent " strength of spirit,
the true strength of spirit is found from the figure read off on
the scale of the alcoholometer and the temperature with the
assistance of the following table :
33
514
TABLE VI. — Determination of the true strength of spirits for the
Standard temperature 0/59° F. (15° C.).
Temperature,
degrees C.
Temperature,
degrees F.
3i
32
33
34
35
36
37
38
3D
4^
4i
True strength of spirit for the above apparent strengths.
—25
— '3
47-9
48.7
49-5
50.3
5LI
51-9
52.7
53-6 54-4
55-2
56.0-
—23-75
—10.75
47-4
48.2
49.0
49-8
50.6
5L5
52.3
53-i
53.9
54-7
55 5
—22.5
-8.5
46.9
47 7
48.5
49.3
50.1
51.0
51.8
52.6
53-4
54-3
55.i
— 21.25
— 6.25
46.4
47-2
48.0
48.8
49-6
50.5
51-3
52.1
53-o
53-8
546
20
—4
45-8
46.7
47-5
48.'3
49-2
50.0
50.8
51-7
52.5
53-3
54-2
— 18.75
— I-7S
45-3
46.1
47-0
47-8
48.7
49-5
50.3
Si-2
52.0
52-9
53-7
— !7-5
+0-5
44-8
45-6
46.5
47.3
48.2
49-0
49.9
5°-7
5L6
52-4
53 3
— 16.25
+2-75
44-2
45?i
46.0
46.8
47-7
.48.5
49-4
50.2
Si.i
5L9
52.g
— is
+5
43-7
44-6
45-4
46.3
47-2
48.0
48.9
49.8
50.6
5i-5
52-3
— '3-75
+7-25
43-2
44.1
44-9
45-8
46.7
47-5
48.4
49-3
50.1
51.0
5i-9
—12.5
+9-5
42.7
43-5
44-4
45-3
46.2
47.1
47-9
48.8
49-7
50.6
5M
—11.25
+ "•75
42.1
43-o
43-9
44-8
45.7
46.6
47-5
48.3
49.2
50.1
51.0
— 10
+ H
41.6
42.5
43-4
44.3
45-2
46.1
47.0
47-9
48.8
49-7
50.6
-8-75
+ 16.25
41. 1
42.0
42.9
43-8
44-7
45-6
46.5
47-4
48.3
49-2
50.1
—7-5
+ 18.5
40.6
4L5
42.4
43-3
44-2
45.1
46.0
46.9
47-9
48.8
49-7
—6
+20.75
40.1
41.0
41.9
42.8
43-7
44-6
45-6
46.5
47-4
48.3
49.2
—5
+ 23
39-5
40-5
41.4
42.3
43-2
44-2
45-1
46.0
46.9
47-8
48.8
—3-75
+25-25
39-0
39-9
40.9
41.8
42.7
43 7
44.6
45-5
46.4
47-4
48.3
-2-5
+27-5
38.4
39-4
40.3
4i-3
42.2
43-2
44.1
45-0
45.9
46.9
47-8
—1.25
+29-75
37-9
38.9
39-8
40.8
41.7
42.7
43-6
44-5
45-5
46.4
47-S
0
+32
37-4
38.3
39-3
40.3
41.2
42.2
43-i
44.o
45-0
45-9
46.9
+ 1-25
+34.25
36*8
37-8
38.8
39.7
40.7
41.7
42.6
43-5
44-5
45-4
46.4
+2.5
+36.5
36.3
37-3
38.2
39-2
40.2
41.1
42.1
43*0
44.0
45-°
45-9
+3-75
+38.75
35-7
36.7
37-7
38.7
39-7
40.6
41.6
42.5
43-5
44-5
45-4
+5
+41
352
36.2
37-2
38.2
39-1
40.1
41.1
42.0
43-0
44-0
44-9
4-6.25
+43
34-7
35 7
36.7
37-6
38.6
39.6
40.6
41.5
42.5
43-5
44-5
+7-5
+45-5
34.1
35- *
36.1
37-i
38.1
39 i
40.1
41.0
42.0
43-°
44-0
+8-75
+47-75
33-6
34-6
35-6
36.6
37.6
38.6
39-6
40.5
41.5
42.5
43-5
+ 10
+ 50
33-i
34-1
35-1
36.1
37-1
38.1
39-o
40.0
41.0
42.0
43-°-
+ 11-25
+52-25
32-5
33-6
34.6
35-6.
36.6
37-5
38.5
39-5
40.5
41.5
42.5
+ I2-5
+54.5
32.0
33-0
34-0
35-o
36.0
37-0
38.0
39-0
AO.O
41.0
42.0
+ !3-75
+56-75
3L5
32.5
33-5
34-5
35-5
36-5
37-5
38-5
39-5
40.5
4i-5
-HI
+59
31.0
32.0
33-o
34-0
35-o
36.0
37-0
38.0
39.0 40.0
41.0
+16.25
+61.25
3°-5
31-5
32.5
33-5
34-5
35-5
36.5
37-5
38-5
39-5
40.5
+17.5
+63-5
30.0
31.0
32.0
33.o
34-o
35-0
36.0
37-0
38.0
39-0
40.0
+18.75
+65.75
29-5
30.5
3L5
32.5
33-5
34-5
35-5
36-5
37-5
38.5
39-5
+ 20
+68
29.0
30.0
31.0
31-9
32.9
339
35-o
36.0
37-0
38.0
39-o
+ 21.25
+70.25
28.5
29.5
30.4
3L4
32.4
33-4
34-4
35-5
36.5
37-5
38.5
+ 22.5
+72.5
38.0
29.0
29.9
30.9
3i-9
32.9
33-9
34-9
36.0
37-o
38.0
+ 23-75
+74-75
27-5
28.5
29.4
30.4
3L4
32-4
33-4
34-5
35.5
36-5
37 5
+ 25
+77
27.0
28.0
28.9
29.9
30.9
31.9
32.9
33-9
34-9
36.0
37-o
+ 26.25
+ 79.25
29.5
27.5
28.4
29.4
3°-4
3L4
32.4
33-4
34-4
35-5
36.5
+ 27-5
+81-5
26.0
27.0
28.0
28.9
29-9
3°9
3L9
32.9
33-9
35-o
36 o
+ 28.75
+83-75
25.6
265
27.5
28.4
29-4
3°-4
31-4
32.4
33-4
34-4
35-5
+ 30
+ 86
25-1
26.0
27.0
27-9
28.9
29.9
3°-9
3L9
32.9
33-9
35-o
+ 31.25
4 88.25
24.6
25-5
26.5
27.4
28.4
294
30.4
3i-4
32-4
33-4
34-5
+ 32-5
+90-5
24.1
25.0
26.0
26.9
27.9
28.9
29.9
30-9
3*-9
32.9
34-o
+33-75
+92.75
23.6
24-5
25-5
26.4
27.4
28.4
29.4
30.4
3M
32-4
33-5
+35
+95
23.1
24.1
25.0
25-9
26.9
27.9
28.9
29.9
3°«9
3J-9
32.9
+36.25
+97-25
22.7
23-6
24-5
25.4
26.4
27.4
28.4
29.4
3°'4
31-4
32-4
+37-5
+99-5
22.2
23.1
24.0
24.9
25.9
26.9
27.9
28.9
29.9
30.9
31-9
APPENDIX.
TABLE VI. — Continued.
515
Temperature,
degrees C.
Temperature,
degrees F.
42
43
44
45
45
47
43
49
53
5i
C2
True strength oi spirit for the above apparent strengths.
— 25.
— 13
56.8
57-6
58-4
59-3
60. i
61.0
61.8
62.7
63.6
64.5
65-4
—23-75
— 10.75
56.3
57-2
58.0
58.8
59-7
60.6
61.4
62.3
63.2
641
65.0
—22.5
-8.5
55-9
56.7
57.6
58.4
59-3
60. i
61.0
61.9
62.8
63-7
64.6
—21.25
— 6.25
55-4
56.3
57-i
58.0
58.8
59-7
60.6
61.5
62.4
63-3
64.2
— 2O
—4
55-o
55-8
56-7
57-6
58.4
59-3
60.2
61.1
61.9
62.9
63.8
— 18.75
— 1-75
54-6
55-4
56.3
57-1
58.0
58.9
59-7
60.6
61.5
62.5
63-4
— 17-S
4-0.5
54-i
55-o
55-8
56.7
57-6
58.4
59-3
60.2
61.1
62.1
63.0
— 16.25
+2.25
53-7
54-5
55.4
56.3
57-1
58.0
58.9
59-8
60.7
61.7
62.6
—'5
+5
53-2
54-i
55.o
55-8
56.7
57.6
58.5
59-4
60.3
61.2
62.2
— !3-75
+ 7-25
52.8
53-6
54-5
55-4
56.3
57-2
58.1
59-o
59-9
60.8
61.8
—12.5
+9-5
52-3
53-2
54-1
55-o
55-9
56.8
57-7
58.6
59-5
60.4
61.4
—11.25
+ "•75
Sl-9
52.8
53-7
54-5
55-4
56.3
57-2
58.2
59-1
60.0
61.0
— 10
+ H
5i-4
52-3
53 2
54-i
55-0
55-9
56.8
57.8
58.7
596
60.6
-8.75
+ 16.25
51.0
51-9
52.8
53-7
54-6
55-5
56.4
57-3
58.3
59-2
60.2
—7-5
+ 18.5
50.6
5i.5
52-4; 53-3
54-2
55.i
56.0
56-9
57-9
58.8
59.8,
-6
+20.75
50.1
51.0
5i.9 52.9
53-8
54-7
55-6
56.5
57-5
58.4
59-3
—5
+23
49-7
5°.6
5i.5 52.4
53-3
54-3
55-2
56.1
57-0
58.0
58.9
—3-75
+25-25
49-2
50.1
51.1 52.0
52-9
53-8
54-8
55-7
56.6
57.6
58.5
—2-5
+27.5
48.8
49.7
50.61 51.6
52.5
53-4
54-3
55-3
56.2
57-2
58.1
— 1.25
+29-75
48.3
49.2
50.2 51.1
52.0
53-o
53-9
54-9
55.8
5,6.8
57-7
0
+32
47-8
48.8
49-7 50-7
51.6
52.5
53-5
54-4
55-4
'56-3
57-3
+ 1-25
+34.25
47-4
48.3
49-3
50.2
51-2
52.1
53-o
54.o
54-9
!55.9
;56.9-
+2.5
+36.5
46.9
47-8
48.8
49-8
50.7
51.6
52.6
53-5
154.5
;5-&5
56.4
+3-75
+38.75
46.4
47-4
48-3
49 3
50.2
51-2
52.1
53-i
54-1
55.0
56.0
+5
+4i
45-9
46.9
47-9
48.8
49-8
50.7
5L7
52.7
53-6
54.6
55-6
+6.25
+43
45-4
46.4
47-4
48.3
49-3
50.3
51.2
52.2
:53-2
54.2
55-i
+75
+45-5
44-9
45-9
46.9
47-9
48.8
49-8
50.8
51.8
52-7
53-7
54-7
+8.75
+47-75
44-5
45«4
46.4
47-4
48.4
49-4
50.3
51-3
52.3
53-3
54-2
+ 10
+ 50
44.0
44-9
45-9
46.9
47-9
48.9
49-9
50-9
51.8
52.8
53-8
+ 11.25
+52.25
43-5
44-5
45.5
46.4
47-4
48.4
49-4
5°-4
51-4
52-4
53-4
+ 12.5
+54.5
43-°
44.0
45-0
46.0
47-o
48.0
48.9
49-9
50.9
51-9
52-9'
+ 13-75
+56.75
42.5
43-5
44-5
45-5
46.5
47-5
48.5
49.5 5o.5
5L5
52-5
+ 15
+59
42.0
43-°
44.0
45-o
46.0
47-o
48.0
49-o
5o.o
51.0
52.0
+16.25
+61.25
41-5
42.5
43-5
44-5
45-5
46.4
47-5
48.5 49-5
50-5
5i.5
+ 175
+63.5
41.0
42.0
43-o
44-0
45-o
46.0
47.1
48.1 49.1
50.1
5i.i
+ 18.75
+65.75
40.5
41-5
42-5
43.5
44-5
45«6
46.6
47.6 48.6
49-6
50.6
4-20
+68
40.0
41.0
42.0
43-1
44-1
45- i
46.1
47-i 48.1
49-i
50.2
+ 21.25
+70.25
39-5
40-5
41.6
42.6
43-6
44-6
45-6
46.6
47-6
48.7
49-7
+ 22-5
+ 72.5
39-o
40.0
41.1
42.1
43«i
44.1
45-i
46.1
47-2
48.2
40.2-.
+ 23-75
+ 74-75
38-5
39-5
40.6
41.6
42.6
43-6
44-6
45-7j46.7
47*7
487
+ 25
+77
38.0
39-0
40.1
41. i
42.1
43.i
44-2
45.2 46.2
47-2
48.3
+ 26.25
+79.25
37-5
38.5
39-6
40.6
41.6
42.6
43-7
44-7 45-7
46.8
47-8
+ 27.5
+81.5
37-o
38.0
39-1
40.1
41.1
42.2
43-2
44.2 45.2
46.3
47-3
+ 28.75
+83.75
36-5
37-5
38.6
39-6
40.6
41.7
42.7
43-7 44-8
45-8
46.8
+ 30
+86
36.0
37-o
38.1
39-1
40.1
41.2
42.2
43-2 44-3
45 3
46.4
+ 3L25
+88.25
35-5
36.5
37-6
38.6
39-6
40.7
41.7
42.7
43-8
44.8
45-9
+ 32.5
+90.5
35-o
36.0
37-i
38.1
39-i
40.2
41.2
42.3
43-3
44.4
45-4-
+33-75
+92.75
34-5
35-5
36.6
37-6
38.6
39-7
40.7
41.8
42.8
43-9
44-9
+35
+95
34-o
35-0
36.1
37-1
38.1
39-2
40.2
41-3
42.3
43-4
44-4
+36.25
+97-25
33-5
34-5
35-6
36.6
37.6
38.7
39-7
40.8
,41-8
42.9
43-9
+37-5
+99.5
33-o
34.o
35-i
36.1
37-i
38.2
39-2
40.3
4L3
42-4
43-4
516
APPENDIX.
TABLE VI. — Continued.
Temperature,
degrees C.
Temperature,
degrees F.
53
£4
55
56
57
53
59
60
61
62
63
True strengths of spirit for the above apparent strengths.
—25
— 13
66.3
67.2
68.1
69.1
70 o
09
1.8
27
36
744
75 3
—23.75
— 10.75
65-9
66.8
67.7
687
69.6
°-5
14
23
32
74.1
75°
—22.5
-8-5
65-5
66.4
67-3
683
69 2
O I
I.O
i 9
2.8
73-7
746
—21.25
-6.25
65.I
66.0
67.0
679
688
97
06
1 5
24
733
74.2
20
—4
64.7
65-6
66.6
<>7-5
684
9 3
O 2
i i
2.O
29
739
-18-75
—1-75
64.3
652
66.2
67.1
680
89
698
08
1 7
2.6
735
-^7-5
+05
63.9
64.8
65.8
60.7
67.6
85
69 5
04
71-3
2 2
73i
16.25
+ 2-75
63.5
64-4
65.4
66.3
672
8.1
69 i
70 o
7o.9
1.8
727
-'5
+5
63.1
640
65.0
65-9
65.8
67.8
687
69.6
705
1 4
724
—13-75
+ 7-25
62.7
63.6
64.6
65-5
664
67.4
683
69 2
70 2
71 I
720
—125
+9.5
62.3
63.2
64.2
651
660
67.0
67-9
68 9
69.8
707
716
—11.25
+ "•75
61.9
62.8
638
64.7
657
656
67.6
6S5
69 4
7° 3
71.3
— 10
414
6l.5
62.4
63-4
64 3
653
66 2
67 .2
68 i
69 o
70.0
70.9
-8.75
+ 16.25
OI.I
62.0
63.0
639
6^9
65 9
668
67 7
63.7
69.6
70S
—7-5
+ 18.5
60.7
61.6
62.6
636
645
65 5
664
67 4
68.3
69.2
70 2
— 1>
+ 20.75
60.3
61.2
62.2
63 2
641
65 l
66 o
670
67.9
68.9
69.8
—5
^-23
59-9
60.8
61.8
628
637
647
656
666
67 5
68.5
69.4
-3-75
+25-25
59-5
60.4
61.4
624
633
643
65-3
66 2
67 2
68.1
69.I
-2.5
+27-5
59-1
Co.o
61.0
62.0
62.9
639
64.9
658
66.8
67.7
68.7
—1.25
+29-75
58.7
59-6
60.6
61.6
625
635
64.5
654
66.4
67-3
68.3
0
+32
58-3
592
CO. 2
61.2
62.1
63.1
64.1
650
66.0
67.0
67.9
41.25
+3425
57-8
588
59-8
607
617
627
637
646
65.6
666
675
+ 2-5
+3&-S
57-4
584
59-3
60.3
61.3
62.3
63-3
64.2
652
66.2
67.1
+3-75
+38.75
57-o
57-9
58.9
599
60.9
619
62.8
638
64-8
65.8
66.7
+5
+41
56.5
57-5
58.5
59-5
60.5
614
624
634
64.4
65.4
66 3
+6.25
+43
56.1
57-1
58.1
590
60.0
61.0
620
630
640
64.9
65 9
4-7-5
+45-5
557
56.6
57-6
586
596
60.6
61 6
626
635
645
655
4-8-75
+47-75
55-2
56.2
57-2
582
59.2
60.2
61.2
62 i
631
64.1
65.1
+ 10
+5°
548
55-8
56.8
57-8
587
59-7
607
61.7
627
637
64.7
4-11.25
+52-25
54-3
55-3
56-3
57-3
583
59-3
60 3
61.3
62 3
633
643
+ 12.5
+54-5
53-9
54-9
55-9
56.9
579
589
59-9
60.9
61.9
62.9
63-9
+ 13-75
+56.75
53-5
54-4
55-4
56-4
574
584
59-4
60 \
61.4
62 4
634
+*S
+59
53-o
54.0
55-°
560
57-°
580
590
600
6 i.o
62.0
63.0
4-16.25
+61.25
5^-5
53-5
54-6
55-6
56.6
576
586
59-6
60.6
61.6
62.6
+17-5
+63-5
52.1
53-1
54-i
55-1
56.1
57-i
58.1
59i
60. i
61.1
62.1
+ 18-75
+65.75
51.6
52.6
53-7
547
557
56.7
577
58.7
59-7
60.7
61.7
4-20
+68
51-2
52.2
53-2
542
SS2
562
57 2
583
59 3
60.:
61.3
+21.25
+70-25
50-7
5'-7
52.7
538
548
55.8
568
57-8
58.8
59-8
60.8
+22.5
+725
50.2
5*-3
52-3
533
54-3
553
56-3
57-4
58.4
59-4
60.5
+23.75
+74-75
49-8
50.8
51.8
528
539
549
559
569
57-9
58-9
60.0
+25
+77
49-3
5°-3
51.4
524
534
544
55 5
565
57-5
58,5
59-5
+26.25
+79.25
48.8
49-9
5°-9
5»-9
530
540
55°
56.0
57-o
58.1
59-1
o /•
+27-5
-i-81-5
48.4
49-4
50.4
5l-S
525
535
545
55-6
56 6
57-6
58.6
+28.75
+83-75
47-9
48.9
50.0
51.0
520
53
54i
55
56i
5l'2
582
+30
+86
47-4
48.4
49-5
5° 5
51-6
526
536
547
557
56.7
57-7
+3'-25
'+88.25
46.9
48.0
49.0
50.1
5r-i
521
532
542
552
56.2
57-3
+32-5
490.5
46.4
47-5
48-5
49.6
506
5'-7
527
537
54-8
55-8
56.8
+33-75
+92.75
46.0
47.0
48.1
49 i
50.2
51-2
522
53
543
55 3
564
+35
+95
45-5
46.5
47-6
48.6
497
5°7
51.8
52.
538
54-9
55-9
+36-25
+97 25
45.0
46.0
47.1
48.2
49-
5°-3
5i-3
524
534
54-4
55-4
+ 375
+995
44-5
45-6
46.6
47-7
48.7
49.8
50.8
51 529
539
55-°
APPENDIX.
517
TABLE VI. — Continued.
Temperature,
degrees C.
Temperature,
degrees F.
I !
64 65
66
67
68 69
70
71 72
73
74
True strength of spirit for the above apparent strengths.
—25
—13
76.2
77-1
78.0
79.0 79.9 80.8 81.7
82.6
83.5
84.4
85-3
—23.75
— 10-75
75 9
76.8
77.7
78.6; 79.5 80.4 81.3
82.2
83.2
84.1
—22.5
-8.5
75.5
75.4
77-3
78.2; 79.1
80. i
81.0
81.9
82.8
83.7
84^6
—21.25
-6.25
75-1
76.0
77-o
77.9 ! 78.8 79.7
80.6
81.6
82.5
83-4
84.3
— 20
—4
74-8 j 75-7
76.6
77.5^ 78.4 70-3
80.3
81.2
82.1
83.0
84.0
-18.75
-i-75
74-4 I 75-3
76.2
77.2 78.1
79-0
79.9
80.9
81.8
82.7
83.6
-17.5 +0.5
74-0
74.9
75-9
76.8 77-7
78.6
79.6
80.5
81.4
82.4
83-3
—16.25' +2.75
73-7 74-6
75-4
76.4 77-4 ' 78.3
79.2
80.2
81.1
82.0
82.9
-15 +5
73-3 74.2
75-1
76.1 77-0
77-9
78.9
79-8
80.7
81.7
82.6
—13-75
+ 7-25
72.9 73-9
74-8
75-7 76.7
77.6 78.5
79-5
80.4
8i.3J82.3
—12.5 +9-5
72.6
73.5
744
75-4 76.3
77.2 78.2
79.1
80. i
81.0,81.9
—11.25 +11-75
72.2 73-1
74.1
75-0 75.9
76.9
77.8
78.8
79-7
83.7 81.6
—10 1 + 14
71.8 72.8
73-7
74-6
75-6
76.5
77-5
78.4
79-4
80.3 81.3
—8.75+16.25
7L5 72-4
73.4 74-3
75-2
76.2 77.1
78.1
79-0
80.0 80.9
-7-5 +18.5
71.1
72.1
73.o
73-9
74.9 75.8 76.8
77-7
78.7
79.6180.6
-6
+ 20.75
70.7
7L7
72.6
73.6
74-5 75-5
76.4
77-4
78.4
79-3 80,3
—5
+ 23
70.4
71-3
72.3
73-2
74.2
75-1
76.1
77-0
78.0
79.0:79.9
—3-75 +25.25
-2.5 i + 27-5
70.0
69.6
71.0
70.6
71.9
71-5
72.9
72.5
73-8
73.5
74-8
74-4
75.7
75-4
76.7
76-3
77-7
77-3
78.6 79-6
78.3 1 79-2
—1.25 +29.75
69-3
70.2
71.2
72.1
73-1
74.0 i 75.0
76.0
77.0
77-9
78.9
o +32
68.9
69.8
70.8
7L8
72.7 73-7
74-7
75-6
76.7
77-6
78.5
+ 1.25
+ 34-25
68.5
69.5
70.4
71-4
72.3
73-3
74-3
75-3
76.2
77-2
78.2
+2.5
436.5
68.1
69.1
70.0
7i.o
72.0
72.9
73-9
74-9
75-9
76.8
77-8
67.7
68.7
69.6
70.6
71.6
72.6 73.5
74-5
75-5
76.5
77-4
+5'
+41
67-3
68.3
69-9
70.2
71.2
72.2
73-1
74-1
75-1
76.1
77.1
+6.25
+43
66.9
67.9
69-3
69.8
70.8
71.8
72.8
73-7
74-7
75-7
76.7
+7.5
+ 45-5
66.5
67.5
68.5
69-4
704 71.4
72.4
73-4
74-3
75-3
76.1
+8.75
+47-75
66.1
67.1
68.1
69.0
70.0 71.0
72.0
73-0
74-0
74-9 75-9
+ 10
+ 50
65.7
66.7
67.6
68.6
69.6 70.6
71.6
72.6 73.6
74-6 75.5
+ 11.25
+ 52.25
65.3 66.3
67.2
68.2
69.2 70.2
71.2
72.2
73-2
74-2 75.2
4-12.5
+54-5
648(65.8
66.8
67.8
68.8 69.8
70.8
71.8
72.8
73-8 74.8
+ 13-75
+ 56.75
64-4 ! 65.4
66.4
67.4
68.4
69.4
70.4
71.4
72.4
73-4 74-4
+ 15 +59
64.0 65.0
66.0
67.0
68.0
69.0 70.0
71.0
72.0
73-0 74.o
+ 16.25 +61.25
63.6 64.6
65.6
66.6
67.6
68.6 69.6
70.6
71.6
72.6
73.6
+ 17.5 1+63.5
63.2 64.2
65-2
66.2 67.2
68.2 69.2
70.2
71.2
72.2
73.2
+ i8.75'+65-75
62.7 63.7
64.7
65.8 66.8
67.8 68.8
69.8
70.8
71.8,72.8
+20 +68
62.3 63.3
64.3
65.3
66.3
67.4 68.4
69.4
70.4
7L4 72.4
+ 21.25+70.25
61.9 62.9
63.9
64.9
65.9
66.9 68.0
69.0 70.0
; 71.0172.0
+ P2.5 +72.5
61.4 62.4
63-5
64.5 65.6
66.5 67.5
68 6
09.6
70.6
7[-6
+23.75+74.75
61.0 62.0
63.0
64-1 65.1
66.1
67..i
68'. i
69.2
7O 2
71.2
+ 25
+ 77
60.5 61.6
62.6
63.6 64.6
65.7
66.7
67-7! 68.7
69.8
70.8
+26.25 +79.25
60. i 61.1
62.1
63.2 64.2
65.2
66.3
67-3 i 68.3
69.4
70.4
+27.5 1+81.5
59.6 60.7
61.7
62.7 63.8
64.8
65-8
66.9 { 67.9
68 9
T"
+28.75 483.75
59.2 60.2
61.3
62.3 63.3 64.4
65-4
66.4 ! 67.5
68.5
6^5
+30
+86
58.7:59.8
60.8
61.9 62.9 63.9
65.0
66.0 07.1
68.1
69. T
+31 25 +88.25
58.3 59-3
60.4
61.4 62.5
63.5
64.5
65.6 66.6
67.7 68.7
+32 5 1+90.5
57-8 58.9
59.9 61.0 62.0
63.1
64.1
65.1 66.2
67 2 1 68 ->
+33-75 +92.75
57-4 58.4
59.5 60.5 61.6
62.6
63.7
64.7 ! 65.8
66!8l67lo
+35
495
56 9 ' 58.0
59.0 60. i 61.1
62.2
63-2
64-3 65.3
66.4 167.4
+36.25
+97-25
56.5 ' 57-5
58.6 59.6 60.7
61.7
62.8
63.8164.3
65-9 67.0
+ 37-5
+ 99-5 56.0
57-1
58.1 59.2,60.2
61.3 62.3
63-4 1 64.4
65.5 66.5
-518
APPENDIX.
TABLE VI . — Concluded.
1
Temperature.,
degrees C.
1
Temperature,
degrees F.
75
76
77
78 79
1 1
i 1
80 81
1 1
82 83
84 85
86
True strength of spirit for the above apparent strengths.
i
i
i
|
—25
— 13
862
87.1
88.0
88.9 89.7 90.6 91.1
;92-3 93-1
93-9 94.7195.5
—23.75
-10.75
85*9
86.8
87.7
88.5189.4 90.3 91.4 92.0 92.8
93-6 94-4
95-3
-22.5
-8.5
85.5
86.4
87.3
88.2 89.1
90.0 90. £
5 91.7 02.5
93-3 94-2
|95.°
— 21.25
—6.25
85.2
86.1
87.0
87.9 88.8 89.6 90.5 91.4 92.2
93-0 93-9
94-7
20
—4
84-9
85.8
86.7
87.6,88.5
89.3 00,2 9X.I 91.9
92.8 93.6! 94. 4
— l8.75
— 1.75
84.5
85-4
86.3
87.2l88.i
89.0 89.9 90.8 91.6
92.5 93-3
94-1
— 17.5
+0.5
84.2
85.1
86.0
86.9 87.8 88.7 89.6 90.4 9i.3
92.2 93.0
— 16.25
+ 2.75
83-9
84.8
85.7
86.6 87.5
88.4 89.3 90.1 91.0
9i.9!92.7
93.'6
-15
+5
83.5
84-4
85-4
86.3187.2
88.1 88.9 89.8 90.7
91.6:92.4
93-3
—13-75
+7-25
83.2
84.1
85.0
85.9186.8
87.7 88.6 89.5 90.4
91.3 92.1
93.°
—12.5
+ 9-5
82.9
83.8
84-7
85.6 86.5
87.4 88.3 89.2 90.1
91.0 91.9
92.7
— 11.25
+ 11-75
82.5
83.5
84-4
85.3 86.2
87.1 88.0 88.9 89.8
90.7 91.6
92.5
— 10
-8.75
+ 14
+ 16.25
82.2,83.1
81.9 82.8
84.1
83.7
85.0 1 85.9
86.8 87.7 88.6 89.5
86.5 87.4 88.3 89.2
90.4 91.3 j 92. 2
90.1 91.0 91.9
-7-5
+ 18.5
81.5
82.5
83-4
84*385^
86.2 87.1
88.0 88.9
83.8 90.7 9I-6
—6
+ 20.75
81.2
82.1
83.1
84.0 '85.0
85.9 86.£
> 87.7 88.6
89.5 90.5
91.4
—5
+ 23
80.9
81.9
82.8
83.7 84.6 85.6 86.5 87.4 88.3
89.2 90.2
91.1
—3-75
+25.25
80.5
81.5
82.4
83.4 84.3
85.2 86.2 87.1 88.0
88.9 89.9
90.8
—2.5
+ 27-5
80.2
81.1
82.1
83.0 8l.o
84.9 85.9 86.8 87.7
88.6 80.6
90.5
— 1.25
-29.75
79-8
80.8
81.8
82.7,83.7
84.6 85.5 86.5 87.4 88.3 89.3
90.2
o
+32
79-5
80.4
81.4
82.4 '83.3
i i
84.3 85.2 86.2 87.1
88.0 89.0
89.9
|
j
+ 1.25
+34-25
79-1
80. i jSi.i
82.0 83.0
83.9 ! 84. 9 85.8 86.8
87.7:88.6
89.6
+2.5
+36.5
78.8
79-7 i
80.7
81.7:82.6
83.6 84.5 85.5 86.4
87.4 88.3
89.3
+3.75
+ 38.75
78.4
79.4
80.3
81.3 82.3
83.2 84.2 85.2 86 i
87.1 88.0
+ 5
+41
78.0
79 -O
80.0
81.0 81.9
82.9 83.9 84.8 85.8
86.7 87.7
88 6
+6.25
+ 43
77.7
78. 6 j
79-6
80.6 81.6
82.5 83.5 84.5 85.4
86.4 87.4
88.*3
4 7-5
+ 45-5
77-3
78-3|
79-3
80.2 Si. 2
82.2 83.2 84.1:8=5.1
86.1 87.0
88.0
+8.75
+47-75
76.9
77-9
78.9
79.9 80.8
8r.8 82.8
83.8 84.8
85.7 86.7
87.7
+ 10
+50
76.5
77-5
78-5
79-5 80.5
81.5 82.4
83-4 84.4
85.4 86.4
87.3
+ 11.25
+ 52.25
76.2
77.1
78.1
79.1 80. i
81.1 82.1
83.1184.1
85.0 86.0
87.0
+12.5
+54-5
75.8!
76.8
77-8
78.8 79-7
80.7 81.7
82.7,83.7
84.7.85.7
86.7
+13.75
75-4
76.4
77-4
78.4 79-4
80.4 81.4
82.4183.4
84-3 85.3
86.3
+ 15
+59'
75-0
76.0
77-0
78.0 79.0
80.0 81.0
82.0 '' 83.0
84.0 85.0
86.0
+ 16.25
+ 61.25
74-6 1
75.6
76.6
77-6 78-6
1 79. 6 80.6
8i.6!82.6
83.6 84.6
85-6
+ 17-5
+63-5
74-2
75-2
76.2
77.2 78.2
79.2 80.3
8r.3!82.3:
83-3 84.3
85.3
+ 18.7^
+65.75
73-8
74-8
75-8
76-8 77-9
78.7J79-9
80.9 81.9
82.9 83.9
84.9
+ 20
+68
73-4
74-4 75-1
76.5:77.5
78.5(79.5 80.5 81.5
82.6 83.6
84.6
+21.25
+70.25
73-0
74.0 74-7
76. i | 77. i
78.1 79.i
80. i 81.2
82.2 83.2
84.2
+ 22.5
+ 72.5
72.6
73-6 74.4
77.7,78.7
79.8 80.8
81.8 82.9
83.9
+ 23-75
+ 74-75
72.2
73-2 74-3
75.3 ;! 76. 3
77.3178.4
79.4 80.4
81.5 82.5
83.5
+25
+ 77
71.8
72.8 73.9
74-9 75-9
76.9178.0
79.0 80.0
81.1 82.1
83-2
+26.25
+ 79-25
71.4
72.4 73-5
74-5 75-5
76.5 77-6
78.6 79-6
80.7 81.7
82.8
+27-5
+ 81.5
71.0
72 o 73-0
74-1 75.i
76.1 77.2 78.2 79.3
80.3 81.4
8;.!.4
+28.75
483.75
70.6
71.6 72.6
73-7 74.7
75.7! 76.8
77-8 78.9
79.9 81.0
82.0
+30
+ 86
70.2
71.2 72.2,
73-3 74.3
75.3I76.4
77-4 78.5
79.5 80.6
81.7
+31.25
+ 88.25
69.7
70.8 71.8
72.9 73-9
74. 9 ! 76.0 77.0 78.1
79.1 80.2
81.3
+32.5
+90.5
69-3
70.4 71.4
72.4 73-5
74-5 175-6
76.6 77.7 78.7 79.8 80.9
+ 33-75
+ 92.75
68.9 69.9 71.0!
72.0 73.1
74- 1 i 75 -2
76.2 77-3
78.3 79.4 80.5
+ 35
+95
68.5 69.5 70.6:
71.6 72.7
73-7 74-8
75.8 76.9
77.9 79.0 80. i
+36.25
+ 97-25
68.1,
&9.l|70.I
71.2 72.2
73-3 74-3
75-4 76.5
77-5 78.6 79-7
+37-5
+99-5
67.6,
58.7,69.7
70.8 71.8
72,9 73.9
75.0 76.1 77.1 78.2 79.3
i i
i
i '
APPENDIX.
519
Table VI. has two entries : one in the uppermost horizontal
line for the observed statements of the alcoholmeter, hence
the apparent strengths from 31 to 44 per cent. ; the other in
the first vertical column for the statements of Fahrenheit's
thermometer from — 13° to +99.5°. On the place where a
vertical and horizontal column cross, the strength correspond-
ing to the normal temperature of 59° F., i. e. the true strength
of spirits, is found.
If, for instance, the alcoholometer immersed into a sample
of spirits of wine indicates an apparent strength of 77 per cent,
and the thermometer the temperature of the fluid as 25.5° F.,
the figure 77 has to be found in the uppermost horizontal col-
umn, and then the vertical column belonging to it is followed
downward until the horizontal line is reached in which stands
the figure 25.5 in the column containing the degrees of tem-
perature. Here the statement 82.4 will be found as the true
strength of spirit, and this figure indicates that at the normal
temperature of 59° F, 100 liters of the spirit of wine exam-
ined contain 82.4 liters of absolute alcohol.
When the apparent strength read off on the alcoholometer
consists of a whole number and a fraction, the true strength
-corresponding to the whole number is determined in the above
manner, and the surplus fraction added to the number found.
If, for instance, the temperature read off is 74.75°, and the
apparent strength 81} per cent., the true strength belonging
to 81 per cent, and 74.75°, which is — 78.4, is first found in
the table, and to this is added the fraction £ = 0.72, or suffi-
ciently accurate = 0.7. This gives 78.4-1-0.7 = 79.1 per cent,
as the nearest accurate true strength.
520
APPENDIX.
TABLE VII. — Determination of the true volume of alcoholic fluids
from the apparent volume at different temperatures.
(According to A. F. W. Brix. )
cJ
I
!
Degrees F.
55-57
58-60
61-64
65-69
70-74
75-79
80-84
85-89
90-94
Reducing factors for the above strengths of spirits of wine.
— 10
+ I4
I.OI98
1.0203
1.0207
1.0213
I.O22O
1.0227
1.0233
1.023811.0246
—8-75
+ 16.25
0189
0193
0197
0203
O2IO
0217
0222
0227; 0235
—7-5
+ I8-5
Ol8o
0183
0187
0193
O2OO
0206
02 1 I
02161 0223
—6
+20.75
0170
0173
0177
0183
0189
oi9>
0200
0205
02 1 1
— 5
+ 23
0161
0164
0168
0173
0179
0185
0190
0194
O2OO
—3-75
+ 25-25
0152
oi55
0158
0163
0169
0175
0179
0183
Ol89
—2.5
+27-5
oi43
0146
0148
oi53
0159
0164
0168
0172
0178
—1.25
+ 29-75
oi33
0136
0138
0143
0148
oi53
0157
0161
0166
— o
+ 32
0123
0126
0128
0132
0138
0142
0X46
0150
0154
+ 1-25
+34.25
0114
0117
0118
0122
0127
0131
0135
0139
0142
+2.5
+ 36.5
0105
0107
0108
0112
OIl6
0120
0124
0128
0130
4-3-75
+38.75
0095
0097
0098
0102
0105
0109
0113
0116
0118
+5
+ 41
0085
0087
0088
0091
0094
0098
OIOI
0104
0106
-1-6.25
+43-25
0075
0077
0078
0080
0083
0086
0089
OOQ2
0094
+ 7-5
+45-5
0066
0067
0068
0070
OO72
0075
0078
0080
0082
+8.75
+47-75
0056
0057
0058
0060
OO6I
0064
0066
0068
0070
+ 10
+50
0046
0047
0048
0050
OO5O
0053
0054
0056
0058
+ 11.25
+ 52-25
0036
0037
0038
0039
0039
OO4I
0042
0044
0045
+ 125
+545
0026
0027
0027
0028
0028
OO29
0030
0031
0032-
+ '3-75
+56.75
0015
0916
0016
OOI7
OOI7
OOI7
0018
0019
0019
+ 15
+ 59
1.0005
1.0005
1.0005
1.0005
i oco6
I. OOO6 I. OOO6
1. 0006
i 0006
+ 16.25
4-61.25
0.9995
09995
°9995
°-9995
o 9994
0.9994:0.9994
0.99940.9993
+ 17-5
+63.5
9985
9985
9984
9984
9983
9983 9982
9982! 9981
+ 18.75
+65-75
9975
997 S
9974
9973
9972
9971 9970
9969! 9968
+ 20
+68
9965
9965
9963
9962
9961
9960 9958
9957 9955
+ 21.25
+ 70.25
9955
9955
9952
995 i
9950
9949 9946
994SJ 9942
+ 22.5
+ 72-5
9945
9944
9941
9940
9939
9937) 9934
9932
9929
+ 23-75
+74-75
9934
9933
993°
9929
9927
9925
9922
9919
9916
+ 25
+77
9923
9922
9919
9917
9915
9912
9909
9906
9Q03
+ 26.25
+ 79-25
9912
99"
9908
9906
9903
9901 9897
9893
9890
+ 275
+81.5
990i
9900
9897
9894
9891
9889' 9885
9880 9877
+ 28.75
+83.75
9890
9889
9886! 9882
9879
9876 9872
9867 j 9864
+ 30
+ 86
9879
9877
9874) 9870
9866
9883! 9859
9854! 9851
+ 3I-25
+88.25
o 9868
0.9865
0.9862 0.9858
o 98540.98500.9846
0.98410.9837
Explanation of Table VII.
Alcohol, or alcohol and water, heated above or cooled below
the standard temperature, expands or contracts. Now, for in-
stance, what is the volume of 10,000 liters of a mixture of 82
per cent, by volume at + 5° C. (41° F.) at the standard tern-
APPENDIX. 521
perature.* In the horizontal column below 80-84 and in the
vertical column at + 5° C. (41° F.) is the reducing factor
1.0101; hence 10,000 liters are 10,000 X 1.0101 = 10,101
liters. 82 being exactly the mean of 80-84, the reduction is-
accurate. At 83° the factor would have to be increased by J- ;
at 84 by f, and consequently the factor for 83° would be 1.0101
+ (1.0104 — 1.0101) | = 1.01016. For the practice the above
factors suffice without change. The measuring of the temper-
ature and reading-off of the percentage of the spirit should b&
done in the storage-cellar, and not in a warmer room, for
instance, the office, as is frequently the custom to the disad-
vantage of the seller.
* This table is calculated for a standard temperature- of 15.5P-C. (60aF.),
522
APPENDIX.
>
:l
«<4
*
:s
•i.
I
^
i ?
!i
^ 'H
1 ^
*
R
. <^
1
!
9
t*
I 1
t^» ON HH
rn
rj- r>. N q q f^
6 TJ-ON'^-C\ri-sLr>w
M'-'OOaN ONOO OO 00
vr> M
'
fOt^-i-Hvo >-"^o c4
Mi-ii-iOO ON O
ONOO OO t^ t^.
1-1 ^J Q ^°°. °^rt'~' rot^f?1-1 rj-XJ ro I- O .N "3-oq
'
o\ ONOO oo oo r-- r^v
r-O'<
HH O O
ONON O\OO OO
( o
t-^O
ON ONOO 00 OO
1-1 q\ N q PO q N t^« vr>vq q t^\q t^«
N W TJ-vO 00*i-<' TJ-t^wu^O rfO\4-c5^-«I~-.fn ON^O
ONOO t^vO vrjiorj-^nrOM W 1-1 O O O ON ONOO 00 t^ r^
t» o\ M TJ- i>»
r^\O vOLOT*-
ON ONOO OO 00
N ^7-00 Tj->O 1-1 ti ^- 1-1 « TJ- ON t^«OO O v> "-" ON ON HH rh
C^O'NO" N •^•t^.d roi>.« Lri^'f^Lodvd « i>.TJ-d
ONOO OO 1>.O vr>vOTJ-fOrnNi-ii-iOOOON ONOO 00 OO
, ^OMD ON
v£)iOTffO
»-i rooo vq oo N ONOO q> fn qsvq >oo oq
\O i^-00 O f^^O ON N vO* O ^n ON rf- O\ vr> O ^O N OO TJ-
ONOO *-• t^vo iOTt-TfrnroN«i-ioOOON ONOO 00
o qoo rj q <?•-;
O°v O O N
O O ONOO
t--.^ q\oo oq
"
« HH Q O ON ON ONOO
-^ O
ON ON
O 10 O •<*• O 10 i- J- ro ON
rONi-ii-iwOOON ONOO
>d vd t^od d p5
HH O ONOO OO t^-
<o TJ- q\ q lo^q « q PJ oq t^ q\ to q ON >-<
d d d pJ PO ^od w
N 1-1 O ONOO t>»vO vO
APPENDIX.
523
TABLE IX. — For the reduction of specific gravities to
saccharometer per cent.
(According to Balling.) — Temperature 63.5° F.
JJ
o v
c
A*"
fl
c
rt""
^ g
C
05 ""
ll
!«
c
O V
« S
* S
,
rt fl
« S
8 E
S S
4)
>> v
• 1)
.-s
M «
.-
cfS
•r
c*2
'JT
bf>«
'> .si
.-
si
S
•3 "
CS
'-a *"
i
t"" ""
s
•5 °1 •
£ *3 - <••'
<a
•3 '. ^
M
u
tC
ill
M
1C
If «
1
Jj"fl'
J-
B
HI
M
o
|| §
o
IS 8
'£
Ms,
'i
sis.
'S
1 i ij
'o
G 1 fr
'S
E 1 si
'S
^ ° S.
ft
0 t, p.
a
s *« **
O, i
0 v. a.
&
a.
o •- p-
a
C/3 U
Cfl
u
en
U
CJ
ca
U
in
o
1. 0000
0.000
1 .0040
1. 000
1.0080
2.COO
I.OI2O
3.000
i. 0160
4.000
1.0200
5.000
i. ooo i i 0.025
41
025
81
025
121
025
16;
025
201
025
2! 050
42
050
82
050
122
050
162
050
2O 2
050
3 °75
43
075
83
°75
123
°75
163
075
2O3
075
4
IOO
44
IOO
84
IOO
124
IOO
164
IOO
204
IOO
5
125
45
125
85
125
125
125
125
205 j 125
6 150
46
150
86
I5°
126
15°
1 66
150
206
150
7
175
47J 175
87
175
127
175
167
'75
207
175
8 200
48 200
88
200
128
2CO
i 68 200
208
2OO
9 225
49
225
89
225
129
225
169 225
209
225
i.ooio; 250
1.0050
250
i .0090
250
I.OI3O
250
1.0170 256
I.02IO 250
ii1 275
51
275
91
275
131
275
171
275
211
275
12 300
52
300
92
300
I32
300
172
300
212 300
13
325
53
325
93
325
133 325
I73J 325
213, 325
I4
35°
54
35°
94
350
134 35°
174 35°
214 35°
375
55
375
95
375
135 375
175 375
215
375
1 6
400
56
400
96
400
136: 400
i 76 400
216
400
17
425
57
425
97 425
137
425
177
425
217
425
18
450
58
45°
98
45°
138
45°
178
45°
218
45°
19
475
59
475
99
475
139
475
179
475
219 475
i .0020
500
i. 0060
500
1. 0100
500
1.0140
500
1.0180
500
I.022C
500
21
525
61
525
IOI
525
141
525
181
52
221
525
22
55°
62
55C
IO2
55°
142
55°
182 550
222 550
23
575
63
575
103
575
M3
575
183 57
223 575
24
600
64
600
104
600
144
600
184! 600
224 600
25
26
625
650
65
66
625
650
105
106
625
650
»45
146
625
650
185! 62
186 65
225! 625
226 650
27
675
67
675
107
675
147
675
187 67
227: 675
28
700
68
700
1 08
700
148
700
1 88 70
228 r 700
29
725
69
725
109
725
149
725
189 72
229' 725
I.OO3O 750
1.0070
75°
I.OIIO
750
1.0150
75°
1.0190
75
1.0230 750
31 775
7f
775
III
775
151
775
191 77
231! 775
32 800
72
800
112
800
'52
800
1921 80
232 800
331 82^
73
825
"3
825
153
825
193 82
233 825
34
850
74
850
114
8^0
154
850
194 85
2341 850
35
875
75
875
"5
875
875
195 87
235 875
36
900
76) 900
116
900
ip
900
196 90
236 900
37
925
77
925
117
925
157
925
197 92
237 925
38
95°
78
95°
118
95°
i5s
95°
198 95
238, 95°
39
975
79
975
119
975
159
975
199 97
239 975
524
APPENDIX.
TABLE IX. — Continued.
i
ifl«
j £S«
o iJ *<
i{2 J
oij~
<j v ~
>,
*" w! u
>i | " « 0
>,
M" "
>,
"wo
£
bio""
>,
V S V
I
o
lit
'i i-isS.
* 111-!
>
o
IP
*>
£
bfi
o
IP
ri
So
if!
be
0
Is!
§|.s
o. c —
tfl
1
ill
1 'SI8
1
tj 5
1C
O.
811
o <-> 5
1
III
CJ
£ ,u
<ft"
U
to
U
Cfl
U
en
U
1 .0240
6.000
1.0290 7.219
1.0340
8.438
1.0390
9.657
1.0440
10.857
1.0490
12.047
241
024
291 244
341
463
39'
68 1
441
881
491
07I
242
048
292 268
342
488
392
706
442
9 CM
492
°95
243
°73
293; 292
343
512
393
73'
443
928
4-3
119
244
097
2941 3*6
344
536
394
756
444
952
494
142
245
122
295 i 34'
345
560
395
780
445
976
495
1 66
246
I46
296 36^
346
584
396
804
446
II.OOO
496
190
247
170
297! 389
347
609
397
828
447
023
497
214
248
'95
298, 4U
348
633
398
853
448
047
238
249
219
299 438
349
657
399
877
449
081
499
261
1.0250
244
1.0300 46^
r.o35o
681
i .0400
90,
1.04:0
°95
i .0500
285
251
268
301! 488
35i
706
401
925
451
119
50i
3°9
252
292
302 512
352
731
402
950
452
142
502
333
253
3i6
303 536
353
7^6
4°3
973
453
1 66
5°3
357
254
34i
304 560
354
780
404
IO.CCO
454
ICO
5°4
381
25 <
365
305 584
355
804
405
023
455
213
505
404
256
389
306 609
356
828
406
047
45 6
238
506
428
257
413
307' 633
357
853
407
071
457
261
5°7
452
258
438
308 667
358
877
408
095
458
285
508
476
259
463
309' 681
359
901
409
119
459
309
509
5co
1.0260
488
1.0310' 706
1.0360
925
1.0410
142
1.0460
333
1.0510
523
261
512
311! 731
361
95°
411
1 66
461
3^9
511
547
262
536
312 756
362
975
412
1 90
462
512
57i
263
56o
313 78o
363
9.000
4'3
214
463
404
595
264
584
314 804
364
024
414
238
464
428
514
619
265
609
315! 828
365
048
415
261
465
452
5'5
642
266
633
3i6! 85'
366
°73
416
285
466
476
666
267
657
317 877
367
097
4'7
309
467
500
5'7
690
268
681
318, 901
368
122
418
333
468
523
5i8
7H
269
706
319 925
369
I46
419
357
469
547
738
1.0270
73i
1.0320 95°
1.0370
170
1.0420
38'
1.047°
57*
1.0520
761
271
756
32i| 975
195
421
404
47i
5<55
521
785
272
780
322 8.0CO
372
219
422
428
472
619
522
809
273
804
323 024
373
244
423
452
473
642
523
833
274
828
324' 048
374
268
424
476
474
676
524
857
275
853
325' 073
375
292
425
500
475
690
525
88r
276
877
326 097
376
3l6
426
523
476
714
526
904
277
901
327 122
377
341
427
547
477
738
527
928
278
925
328 146
378
365
428
571
478
761
528
952
279
950
329 17°
379
389
429
595
479
785
529
976-
1.0280
975
1.0330 195
i .0380
4'3
1.0430
619
i .0480
809
1.0530
13.000
281
7.000
331, 219
38.
438
43 1
642
481
833
023
282
024
332, 244
382
463
432
666
482
857
532
047
283
048
333 268
383
48S
433
690
483
881
533
071
284
°73
334 292
384
512
434
484
504
534
095,
285
097
335 3'6
385
536
435
738
485
928
535
119
286
122
336 34i
386
560
436
761
486
952
536
142
287
288
I46
170
337, 365
338 389
387
388
584
609
438
•785
809
487
488
976
I2.COO
537
538
1 66
289
«9S
339' 413
389
633
439
833
489
023
539
214
APPENDIX.
525
TABLE IX.— Concluded.
i _ B
, c
a
, c
c
• .S
! j= ~
A
43 •£
"5 c
Is
i'-
• y §
0 V
8S
o £
to
1 " £
>,
S|
>,
!J
g,
If
£
w>~
£
Sjj
a
' c 2
1 ^3 ^
a
I*
1
|s
§
fl
rt
•l«
rt
IL
SB
|||
M
0
ill
a
1 « 8
|| g
0
II §
° £ §
i
CO
U
1
CO
u
1
Els
38'
'o
JSS.
'o
£
CJ
°0
a.
CO
J22L
1.0540
13-238
1.0577
14.119
10614
15.000
1.0651
15.860
1.0688
16.721
1.0730
17.681
541
542
261
285
578
579
142
1 66
' 615
616
024
046
652
653
883
907
689
1.0690
744
767
732
734
725
772
543
309
1.0580
190
617
o7o
654
930
691
790
736
818
544
333
581
214
618
093
655
953
692
814
738
863
545
357
582
238
619
iie
656
976
693
837
1.0740
909
546
381
583
261
1.0620
139
657
16.000
694
860
742
954
547
404
584
285
621
162
658
023
695
883
744
18.000
548
428
585
309
622
1 86
659
046
696
907
746
045
549
452
586
333
623
209
1. 0660
070
697
93°
748
090
1-0550
476
587
357
624
232
66 1
093
698
953
1.0750
500
588
38i
625
255
662
116
699
976
752
181
552
523
589
404
626
278
663
139
1.0700
1 7.000
754
227
553
547
1.0590
428
627
302
664
162
7OI
022
756
272
554
571
591
452
628
325
665
1 86
702
045
758
3*8
555
595
592
476
629
348
666
209
703
067
1.0760
363
556
619
593
500
1.0630
371
667
232
7°4
090
762
409
557
642
594
523
631
395
668
255
7°5
764
454
558
666
595
547
632
418
669
278
706
136
766
5 c°
559
690
596
571
633
44i
1.0670
302
707
158
768
545
1.0560
7*4
597
595
634
464
671
325
708
181
1.0770
590
561
736
598
6i(,
635
488
672
348
709
204
772
636
562
563
761
785
599
1.0600
665
636
637
5"
534
673
674
371
395
1.0710
711
227
250
774
776
68 1
727
564
, 809
601
690
638
557
675
418
712
272
778
772
565
833
602
7M
639
58,
676
441
295
1.0780
818
566
857
603
738
1.0640
604
677
464
7'4
3'8
782
863
567
881
604
761
641
627
678
480
7*5
340
784
909
568
904
605
785
642
650
679
511
716
363
786
954
569
928
606
643
674
i. 0680
534
717
386
788
19.000
1.0570
952
607
833
644
697
68 1
557
718
409
1.0790
045
976
608
857
645
721
682
581
719
43'
792
090
572
14.000
609
88 1
646
744
682
604
1.0720
454
794
136
573
023
1.0610
904
647
767
684
627
722
500
796
181
574
047
611
928
648
790
685
650
724
545
798
227
575
071
612
952
649
814
686
674
726
590
1.0800
19.272
576
095
6,3|
976
1.0650
837
687
697
728
636
526
APPENDIX.
TABLE X. — Comparative synopsis of the aerometers for
must generally used.
i
V
.
il
§
Sugar, i
>er cent.
c
M
ft
§
Sugar, p
er cent.
f
6|
i|-§
by w
°ight.
^
S.lb'S
by w<
:ight.
£
«-•«;=
£ *^
I
s!
ifN
1
S.^
K^^-
1
i.^
%£^
.
&
O!
Babo.
Pillitz.
Q
10
w
Babo.
Pillitz.
o
I.05I
12.5
10.5
8.2
7
1.091
21.8
I8.3
17-5
_
52
12.8
10.7
8.5
92
22.1
18.5
I7.8
—
53
13.0
10.9
8-7
—
93
22.3
1 8.6
1 8.0
—
54
13.2
II. I
8.9
—
94
22.5
1 8.8
18.2
—
55
'3-5
"•3
9.1
—
95
22.7
18.9
18.4
—
56
'3-7
9-4
—
96
22.9
19.0
18.6
—
57
14.0
11.7
9-7
—
97
23.1
19.2
18.8
—
58
14.2
12.0
9-9
8
98
23-3
19-3
19.0
—
59
14.4
12.2
IO.I
—
99
23-5
19-5
19.2
13
60
14.7
12.4
10.4
—
l.IOO
23-7
19.7
19.4
61
14.9
12.6
10.6
—
01
23-9
19.9
19.6
—
62
12.8
10.8
—
02
24.2
20.1
19.9
—
63
15.4
13.0
ii. i
—
°3
24.4
20.3
20. i
—
64
i5.6
13-3
"•3
—
04
24.6
2O.5
20.3
—
65
66
,5.8
16.1
'3-5
'3-7
11.5
11.8
9
°5
06
24.8
25.0
2O.8
21.0
20.5
20.7
67
16.3
13.9
12.0
—
07
25.2
21.2
20.9
14
68
16.5
14.1
12.2
—
c8
254
21.4
21. 1
—
69
1 6.8
M-3
I2-5
—
09
25-7
21.6
21.4
—
70
17.0
12.7
—
10
25-9
21.8
21.6
—
17.2
4.1
I2.9
—
ii
26.1
22.0
21.8
—
72
14.8
13-2
—
12
26.3
22.2
22.O
—
73
17.7
15.0
—
13
26.5
22.4
22.2
—
24
17.9
1C. 2
13*6
10
14
26.7
22.6
22.4,
—
]l
18.1
18.4
15-4
I5.6
13-8
I4.I
I
26.9
27.1
22.8
23.0
22.6
22.8
15
77
18.6
15-8
14.3
—
17
27.4
23.2
23.I
78
1 8.8
15-9
M.5
—
18
27.6
23-5
23.3
—
79
IO.O
16.1
'4-7
—
19
27.8
23.8
23-5
—
80
J9«3
16.3
15.0
—
20
28.0
24.1
23-7
—
81
!9-5
16.5
If. 2
—
21
28.2
24-3
23-9
—
82
19.7
16.7
15-4
ii
22
28.4
24.6
24.1
—
83
20. o
16.9
—
23
28.6
24.9
24-3
—
84
20.2
17.1
IS-9
—
24
28.9
25-2
24.6
—
85
2c.4
17-3
16.1
—
25
29.1
255
24.8
16
86
20.7
17.4
16.4
—
26
29-3
—
25.0
—
87
20.9
17.6
16.6
—
27
29-5
—
25.2
—
88
21. 1
17.8
16.8
—
28
29.7
—
254
—
89
21.4
1 8.0
17.1
—
29
29.9
—
25.6
—
90
21.6
18.2
17-3
12
3°
3O.I
25.8
APPENDIX.
527
TABLE XI. — Table to Oechsle's aerometer for must.
gravity.
u."S
^ *** o
°-«S
a»l
gravity.
^ £
ll*
gravity.
8|
rt g
O ~fj Ji
all
gravity.
83
41
111
I
III
Percentc
crystall
grape-s
1
CO
Ps
M£ *
C3 ~ «
o
!
Degrees
Oechsle
meter f<
Percenta
crystall
grape-s
1
11 pi
1041
41
8.0
1059
59
13.0
1076
76
17.2
1093
93
21.7
1042
42
8-3
1060
60
13.2
1077
77
I7'5
1094
94
21.9
1043
43
8.6
1061
61
13.4
1078
78
17.8
1095
95
22.2
1044
44
8.9
1062
62
13-6
1079
79
18.0
1096
96
22.5
1045
45
9.2
1063
63
13-9
io£o
80
18.3
1097
97
22.7
1046
46
9.4
1064
64
14.0
1081
81
18.5
1098
98
23.0
1047
47
9-7
1065
65
14.2
1082
82
18.8
1099
99
23.2
1048
48
9.9
1066
66
14.4
1083
83
19 i
IIOO
100
23.4
1049
49
10.2
1067
67
14-7
1084
84
19.4
IIOI
101
23.7
1050
1051
5°
51
10-5
10.8
1068
1069
68
69
15.0
1085
1086
85
86
19.7
20. o
I1O2
IIO3
IO2
I03
23.9
24.2
1052
52
II. I
1070
70
15.5
1087
87
20.2
IIO4
IO4
24.5
1053
53
ii. 4
1071
I5.8
1088
88
20.4
IIO5
'05
24.8
1054
54
11.7
1072
72
16.1
1089
89
2O.7
nob
106
25.0
i°55
55
ii 9
1073
73
16.3
1090
90
20.9
1107
107
25.2
1056
56
12.2
1074
74
16.5
1091
21.2
IIOS
1 08
25.4
I057
57
12.5
1075
75
16.9
1092
92
21.4
1109
109
25.7
1058
58
12.7
TABLE XII. — To Massonfours aerometer.
Degrees,
according to
Massonfour.
Weight of a
liter,
grammes.
Degrees,
according to
Massonfour.
Weight of a
liter,
grammes.
Degrees,
according to
Massonfour.
Weight of a
liter,
grammes.
I
1008
8
1059
15
1116
2
1015
9
1067
16
"25
3
IO22
10
1075
17
"34
4
IO29
ii
1083
18
"43
5
1036
12
109!
r9
1152
6
1043
13
1099
20
1161
7
1051
H
IIO;
'
TABLE XIII. — For comparing per cent, of sugar with per cent,
of extract and the specific gravity. By Pillitz.
C 'N*
jj8-J
IB
C/)
Extract,
per cent.
(Balling).
Specific
gravity.
Sugar,
per cent
(Pillitz).
«"5o
«§:§
IS5!
,3 SB
o rf<
(fi.tj
11
s-l
MfcpLH
£°<~
Extract,
per cent.
(Balling).
Specific
gravity.
O
4-3
.0172
9
13-3
.0543
18
22.3
.0930.
I
5-3
.O2I2
10
14.3
.05»S
19
23.3
.0975
2
6.3
.0253
ii
15-3
.0627
20
24-3
. 1017
3
7-3
.0294
12
16.3
.0670
21
25.3
. IO6O
4
8.3
•0335
13
17-3
.0713
22
26.3
. IIO3
5
9-3
.0376
H
18.3
.0757
23
27-3
. 1146
6
10.3
.0417
15
19-3
.0800
24
28.3
.1189
7
ii. 3
•0459
16
20.3
.0844
25
29.3
. I232
8
12.3
.0501
17
21.3
.0887
-528
APPENDIX.
TABLE XIV. — For determining the content of per cent, of acetic
acid contained in a vinegar of — specific gravity.
Temperature 15° C. ( 59° F. ) .
(According to A. C. Oudemans.)
Anhydrous
•acetic acid,
Specific gravity.
Anhydrous
acetic acid,
Specific gravity.
Anhydrous
acetic acid,
Specific gravity
per cent.
per cent.
per cent.
100
1-0553
66
1.0717
32
1.0436
99
1.0580
65
1.0712
31
1.0424
98
1 .0604
64
1.0707
30
I.O4I2
97
1.0625
63
1.0702
29
1 .0400
96
1.0644
62
1.0697
28
1.0388
•95
1. 0660
61
1.0691
27
1.0375
94
1.0674
60
1.0685
26
1.0363
93
1.0686
59
1.0679
25 1.0350
92
1.0696
58
1.0673
24 L0337
9i
1.0705
57
1.0666
23
1.0324
90
1.0713
56
1 .0660
22
I.03II
-89
1.0720
55
1-0653
21
1.0298
88
1.0726
54
1.0646
20
1.0284
«7
1.0731
53
1.0638
19
1.0270
86
1.0736
52
1.0631
18
1.0256
85
1.0739
51
1.0623
17
1.0242
84
1,0742
5°
1.0615
16
1.0228
83
1.0744
49
1.0607
15
I.O2I4
82
1.0746
48
1.0598
14
1.0200
8 1
1.0747
47
1.0589
13
I.OI85
So
1.0748
46
1.0580
12
I.OI7I
79
1.0748
45
1.0571
II
I.OI57
78
1.0748
44
1.0562
10
1.0142
77
1.0748
43
1.0552
9
I.OI27
76
1.0747
42
1.0543
8
I.OII3
75
1.0746
4i
1-0533
7
1.0098
74
1.0744
40
I-0523
6
1.0083
73
1.0742
39
L05I3
5
1.0067
72
1.0740
38
1.0502
4
1.0052
7i
1.0737
37
1,0492
3
1.0037
70
1.0733
36
1.0481
2
1 .0022
69
1.0729
35
1 .0470
I
I.OOO7
68
1.0725
34
1.0459
O
0.9992
67
1.0721
33
1.0447
APPENDIX.
529
TABLE XV. — For determining the content of per cent, of acetic
acid contained in a vinegar of — specific gravity.
(According to Mohr.)
Anhydrous
acetic acid.
Specific gravity.
Anhydrous
acetic acid,
Specific gravity.
Anhydrous
acetic acid,
Specific gravity.
per cent.
per cent.
per cent.
100
1.0635
66
1 .0690
33
1.0440
99
1-0655
65
1. 0680
32
1 .0420
98
1.0670
64
1. 0680
31
I.04IO
97
1 .0680
63
1. 0680
30
1.0400
96
1 .0690
62
1.0670
29
1.0390
95
1.0700
61
1 .0670
28
1.0380
94
1.0706
60
1.0670
*1
1.0360
93
1.0708
59
1. 0660
26
1.035°
92
1.0716
58
1. 0660
25
1.0340
9i
1.0721
57
1.0650
24
1.0330
1.0730
56
1 .0640
23
1.0320
1.0730
55
1 .0640
22
I.03IO
1.0730
54
1.0630
21
I.O29O
87
1.0730
53
1.0630
2O I.O27O
86
1.0730
52
I.C620
19 1.0260
85
1.0730
51
1.0610
18
1.0250
84
1.0730
5°
i. 0600
17
1 .0240
83
1.0730
49
1.0590
16
1.0230
82
1.0730
48
1.0580
'5
I.O22O
81
1.0732
47
1.0560
H
1.0200
80
'•°735
46
1.0550
13
1.0180
79
I-°735
45
1.0550
12
1.0170
78
T-°733
44
1.0540
II
1.0160
77
1.0732
43
1.0530
10
1.0150
76
1.0730
42
1.0520
9
1.0130
75
1.0720
4i
1.0510
8
I.OI20 '
74
1.0720
40
1.0510
7
I.OIOO
73
1.0720
39
1.0500
6
1.0080
72
1.0710
38
i .0490
5
1.0070
7i
1.0710
37
1.0480
4
1.0050
70
i .0700
36
1.0470
3
1 .0040
79
1.0700
35
1.0460
2
I.CO2O
68
1.0700
34
1.0450
I
I.COIO
67
i .0690
34
530
APPENDIX.
TABLE XVI. — Comparison of the scales of Reaumur s, Celsius 's,
and Fahrenheit' s thermometers.
Reaumur.
Celsius.
Fahrenheit.
Reaumur.
Celsius. Fahrenheit.
— ls
-18.75
_
33
41.25 106.25
14
17-50
0.50
34 42.50 108.50
13
16.25
2-75
35 43-75 1*0.75
12 15.00
5.00
36 45.0° 113.00
ii !3 75
7.25
37 46.25 115.25
10 12.50
9. co
38 47.50 117.50
9
11.25
11-75
39 48.75 H9.75
8
10.00
14.00
40 50.00
I 22.00
7
8.75
16.25
4i 51.25
124.25
6
7.50
18.50
42 52.5°
126.50
5
6.25
20.75
43 53-75
I28.75
4
5.00
23.00
44 55-00
131.00
3
3-75
25-25
45 56.25
133.25
2
2.50
27.50
46 57-5°
I35.50
I
1.25
29*75
47 58.75
137-75
0
o
32.00
48 60.00
I4O.OO
+ 1
+ 1-25
34.25
49 61.25
142.25
2
2.50
36-50
5°
62. so
144.50
3
3-75
38.75
5i
63.75
146.75
4 5-°°
41.00
52
65.00
149.00
5 6.25
43.25
53
66.25
ICI.25
6 7.50
45-50
54
67.5°
153.50
7 8.75
47-75
55
68.75
155-75
8 10.00
50.00
56
70.00
It;8.OO
9 11-25
52.25
57
7!-25
160.25
10 12.50
54-5°
58
72.50
162.50
ii
13.75
56-75
59
73-75
164.75
12
15.00
59.00
60
75.00
167.00
13 16.25
61.25
61
76.25
169.25
H 17-5°
63.50
62
77-5°
171.50
15 18-75
6575
63
78.75
173.75
1 6 2O.CO
68.00
64
80.00
176.00
17 21.25
70.25
65
81.25
178.25
1 8 22.50
72.50
66
82.50
180.50
J9 23.7^;
74-75
67
83.75
182.75
20
25.00
77.00
68
85.00
185.00
21
26.25
79.25
69 86.25
187.25
22
27.50
81.50
70 87.50
189.50
23
28.75
83.75
7i 88.75
I9L75
24
30.00
86.00
72 90.00
194.00
11
31-25
32.50
8825
90.50
73 9L25
74 92.50
196.25
198.50
27
33-75
92.75-
75 93-75
200.75
28
35-°o
95.00
76 95-0°
203.00
29
36.25
97.25
77 96-25 205.25
30
37-5°
99.50
78 97-5°
207.50
31
38.75
101.75
79 98.75
209.75
32
40.00
104.00
80
IOO.OO
2I2.OO
INDEX.
ACETAL, 25-27
Acetaldehyde, 24, 25, 249
Acetates and their preparation, 313-348
Acetic acid, 248
bacteria, 1
composition of, SO
determination of, by titration,
222-224
of the chemical constitu-
tion of, 3
of content of, in vinegar,
113, 528, 529
formation of, by chemical pro-
cesses, 9, 10
of, from alcohol, 6
glacial, 3
newly formed, disturbances due
to the quantity of, 12<)-131
occurrence of, 9
oxygen required for formation
of, 31
practical yield of, from alco-
hol, 109
processes of preparation of, 255
production of, from its ele-
ments, 6
pure, 27-29
production of, from wood
vinegar, 296-313
theoretical yield of, from alco-
hol, 108
yields of, 29-32
yields of, 34, 35, 112, 113
aldehyde, 24, 25
; anhydride in vinegar, determina-
tion of, 220-224
degeneration of wine, 189, 190
ether, preparation of, 184, 185
fermentation, products of, 23-35
Acetification, accelerated, 97-99
of shavings, quantity of vinegar re-
quired for, 96
Acetoraeter, 220
Acetometry, 220-224
Acetone, 243, 244
oils, 355
plant for production of, 353, 354
preparation of, 352-355
(531)
Acetone, properties of, 248, 249
Acid, testing must for, 387-390
Acids in fruits, 371, 372
detection of, in vinegar, 227-229
Aerometers, different, comparison of,
with Tralles' alcoholometer, 512
for must, comparative synopsis of,
526
After-wine, 190-192
Air, absorption of moisture by, 467
Albucases. discovery by, 2
Albuminous substances in fruit, 372
Alcohol, absolute, 376
and water, actual content in mix-
tures of, and contraction
in mixing, 511
mixtures of, 114. 115
specific gravity of mix-
tures of, 509
calculation for the reduction of,
with water, 109, 110
composition of, 30
content of, in spirits of wine, 112
determination of, 214-220
of chemical constitution of, 3
formation of acetic acid from, 6
practical yield of acetic acid from,
109, 112, 113
theoretical yield of acetic acid
from, 108
Alcoholic fermentation, 8, 9
liquid, addition of finished vinegar
to, 108
addition of phosphate to, 129
constitution of fundamental
materials used in the prepar-
ation of, 113-116
contraction of. 117
definition of, 104
determination of true volume
of, from apparent volume,
520
distribution of, in the gener-
ator, 46-52
examples of composition of,
110
gradual increase of alcohol in,
106. 107
532
INDEX.
Alcoholic liquid, strengthening of, 118,
119
heating apparatus for, 95, 96
low wine for, 111
preparation of, 104-116
proportion between per cent,
by weight and by volume of,
510
quantity of, to be worked in a
generator, 117, 118
receipts for, 110, 111
role of vinegar in, 105
Alcoholometer, determination of alcohol
by, 214, 215
Aldehyde, 7, 24, 25, 249
Alden evaporator, improved, 470-472
manner of operating, 474-
476
patent for evaporating fruit, 465
Ale, sour vinegar from, 168, 169
Alkalies, effect of, on wood, 236, 237
Alkaloid in wine, 377, 378
Allyl alcohol, 244
Aluminium acetate, 320-323
hydrate, 320
sulphate, decomposition of, 321 , 322
Ammonia test solution, 222
Ammonium acetate, 316, 317
Amyl alcohol, 115
Amyloid, 235, 236
Anchovy vinegar. 182
Anise vinegar, 181
Anthon's table for finding content of
anhydrous sugar in saturated solu-
tions of glucose 392
Antimony, use of, for determining tem-
perature, 286
Appert's method of canning meats, 496-
498
^pple, acid in, 396
butter, 453, 454
composition of, 395
crusher, 379
elevator, 385, 386
grinder, 379, 380
jelly, 458, 459
perfumed, 460, 461
plant for making, 461-165
juice, addition of benzoate of soda
to, 401
• constituents of, 396
experiments to develop a me-
thod of sterilizing 399-401
extraction of, by diffusion, 399
fermentation of, 403-406
fresh, carbonating of, 401
methods of obtaining, 378-385
to be fermented, testing of. 402,
marmalade, perfumed, 457, 458
Apple must, extractive substances in, 396
testing of, for acid and sugar,
387-390
pomace, utilization of, for making
vinegar, 174
pulp, preparation of. 457
seeds, saving of, 465
wine, red, 408
Apples, bleaching of, 480. 481
choice of, for cider, 394, 395
cider from, 392-415
crushing of, 397
dried, chemical analysis of, 469
evaporated, packing of, 475, 476
gathering and sweating of, 396, 397
paring of, 480
pressing of, 398
slicing of, 481
Apricot wine. l.'!4
Aromatic mustard, 494
vinegar, 180, 181
Artificial culture of vinegar ferment, in-
duction of the operation with. 99-104
Assmus, yield of products from wood
according to, 289
Automatic principle, arrangement of a
factory working according to, 90-
96
vinegar apparatus, 73-96
BACTERIA, 11, 12
Bacterium aceti, 1,11
Pasteurianum, 12
Bag-filter, 156-158
Baine-Marie, 436
Baldwin apples, dried, chemical analy-
sis of, 469
Bamboo, English, 489, 490
Barberries, 489
Barium acetate, 317-319
Basic aluminium acetates, 320
cupric acetates, 332-335
lead acetates, 344, 345
Basilius Valentinus, distillation of vin-
egar by, 2
Beans, 489
Beech shavings, accelerated acetification
of, 97-99
dimensions of, 53
drying of, 54, 55
for filling generators 53-55
number of, required to fill a
generator, 53
packing of, 55
steaming of, 54
vinegar required for acetifica-
tion of, 96
Beef, canned, 498
extract, 500
INDEX.
533
Beer, determination of vinegar from,
230, 231
for alcoholic fluid. 107. 108
sour, vinegar from, 168, 1<>9
wort, vinegar from, 161, 1(52
Bell siphon, 89
Benzoate of soda, addition of, to apple
juice, 401
Berries, jelly from, 459, 460
vinegar from, 169-173
vinous fluids from, 171, 172
Berry fruit pulp, 457
Bersch's method of making wine vine-
gar, 201-209
plate generator, 82-86
Bioletti, Frederic T., description of
Claudon's method of
making wine vinegar
by, 200, 201
on vinegar from grapes,
186, 187
vinegar tester described
by, 224-2:>6
Birch tar oil, 358, 359
yield of products from, 289
Bismuth acetate, 346
Blackberry jelly, 461
wine, 430, 431
Black mordant, 324-326'
Bleachers, 480, 481
Boerhave, method of making wine by,
3
Boiled tar, 247
Boiling of wine vinegar, 193
Bottled fruits, sterilizing of, 436
Bottling cider, 408, 409
wine vinegar, 209, 210
Bouquet bodies, o
Box cooler, 278, 279
Brandy, manufacture of, from cider,
415-418
Bricking in retorts, 264, 265
Brown acetate of lead, 341
Biihler, plant for decomposition of cal-
cium acetate by the sulphuric acid pro-
cess arranged by, 308-310
Burette, 221
Burgundy, 412
from pear must, 418, 419
Burnt sugar, preparation of, 159, 160
p ABB AGE, 489
' Cadet-Gassicourt's process of mak-
ing vinegar from sugar, ] 70
Calcium acetate, 317
decomposition of, by the
hydrochloric acid pro-
cess, 305-307
of. by the sulphuric acid
process, 307-310
of, in vacuum, 310, 311
to aceone and cal-
cium carbonate,
352
evaporating and drying of,
298
plant for decomposition of.
by the sulphuric acid pro-
cess, 308-310
preparation of, 296-299
of sodium acetate from,
303
Canning factory, arrangement of, 446
fruits suitable and unsuitable for,
439, 440
meats by Appert's method, 496-
498
syrup for, 442
tomatoes, 445-449
vegetables, 444, 445
Cans, 440
air-tight, preserving in, 438-449
coating for inside, 441
expulsion of air from, 443
filling of, 442
heating of, 443, 444
labeling of, 448
manufacture of, 441, 442
Caramel, preparation of, 159, 160
Carbo-oven, 262
Carbonating fresh apple juice, 401
Carbonic acid, 377
Catchups, 449-453
Cauliflower, 489
Celery vinegar, 183
Cellulose, changes in, 234
effect of alkalies on, 236, 237
of sulphuric acid on, 235, 236
Chamber generator, Lenze's, 80-82
Champagne cider, 410, 411
Charcoal, burning of, in heaps, 256
for filling generators, 52
quantity of vinegar required for
acetification of. 96
wood vinegar and tar, preparation
of. in closed vessels, 254-283
Cheese, laying up a, 384
Chemical examination of raw materials
and control of operations in a vinegar
factory, 213-226
Chillies in vinegar, 232
534
INDEX. '
Chromic acetate, 328
Chromium acetates, 328
Chromous acetate, 328
Cider, acidity in, 413
adulteration of, 414, 415
as basis for artificial wines, 411,412
bottling of, 408, 409
choice of apples for, 39-1, 395
clarification of, 406, 407
cold storage of, 401, 402
Devonshire, 410
diseases of, 412-414
fermentation of, 403-406
fermenting casks for, 402, 403
for export, 407
from apples. 392-415
greasy appearance of, 413
improving the taste of, 407, 408
manufacture of, 378-419
of brandy from, 415-418
in the island of Jersey.
409, 410
mill, Hickock's, 378
pasteurizing of, 399-401
plant, arrangement of a, 386, 387
preparation of, like other fruit
wines, 408
presses, 381-383
pure, minimum of composition, for
414
sweet, retarding fermentation in,
399-401
turbidity of, 414
vinegar, 173-178
home made, 174-178
viscosity of, 413
wine from, 408
Ciders, analyses of, by United States
Agricultural Department,
393, 394
fruit wines, etc., manufacture of,
360-434
pure, type of, 393
Claret wine, 41 2
Claudon's method of making wine vin-
egar, 200, 201
Cleopatra, anecdote of, 1
Clove vinegar, 183
Cobalt acetate, 328
Collecting boxes for liquid products of
distillation, 281, 282
Coloring vinegar, 159,160
Combustion, formation of vinegar a pro-
cess of, 32
Continuous acting apparatus, 75, 86
Coolers, 267, 275-279
Copper acetates, 329, 335
detection of, in vinegar, 229
Cork and cork waste for filling genera-
tors, 52
Corn cobs for filling generators, 52
Corned beef, 498
Cosmetic vinegar, 181
Counter-current pipe cooler. 275-278
Courtenvaux, experiments of, 2, 3
Creosote, 252, 253
preparation of, 355-359
Crusher for apples, H79
Crystallized verdigris, 329-332
Crystallizing pans for sugar of lead, 338,
339
Cucumber catchup, 452
Cucumbers, 489
Culture, pure, of vinegar ferment, 100-
104
disturbances in, 103, 104
Cuprous acetate, 329
Currant catchup, 452
wine, 422-424
DAUBREE, experiments in heating
wood by, 235
Davis' s star apple grinder, 379, 380
Davy, J., discovery of, 3
Defecator, 462, 463
Denies-Dumont, directions for bottling
cider by, 408, 409
Destructive distillation of wood, execu-
tion of, 283-290
products of, 237-254
wood vinegar and other
by-products obtained
in, 233-254
Devonshire cider, 410
Diastase, 160
action of, upon starch, 164
effective, 164
formation of, 37
Dibasic cupric acid acetate, 333
Distillation, destructive, of wood, prod-
ucts of,
237-254
wood vinegar
and other by-
products ob-
tained in,
233-254
of cider, 417, 418
reservoirs for the product of, 279-
283
Distilled wood vinegar, 292-296
purifications of, 294-296
Distilling apparatus for sugar of lead, 337
wood waste, 271-274
test, determination of alcohol by,
215-217
INDEX.
535
Distilling wood vinegar in multiple
evaporators in vacuum, 293
Dobereiner, directions for making vine-
gar from sugar by, 170
study of acetic acid by, 3, 6
Durande, 3
Diisseldorf mustard, 494, 495
EBULLIOSCOPE, determination of
alcohol by, 217-220
Effervescing vinegar, 182, 183
Eggs, preservation of, 503-505
Elderberry flowers, 489
wine. 431
Elevator for apples, 385, 386
England, preparation of mustard in,
492, 493
English bamboo, 489, 490
mustard, 495
orange marmalade, 458
ventilating apparatus, 61 , 62
verdigris, 334, 335
Ether, light oxygenated, 7
Evaporating pans, 397
Evaporation of fruit, 465-486
principle of, 466-468
Evaporator, 463
Evaporators, 470-480
multiple, 293
Examination of vinegar as to the pres-
ence of foreign acids and of metals,
as well as to its derivation, 227-232
Extra-power cider press, 382, 383
Extract of lead, 344
FARMER'S cider press, 381, 382
Fatty acids in wood vinegar, 242,
243
Fermentation, 374-376
acetic, products of, 23-33
alcoholic, 8, 9
funnel, 404, 405
of fruit juices, 421
pectous, 363
products of, 374-376
second, 406
tumultuous, 404-406
vinous, 24
Ferrous acetate, 324-326
Fielding, 168
Filtering malt vinegar, 168
sodium acetate solution, 301
wine vinegar, 208
Filters, 155-158
Filtration of vinegar, 155-158
Fining vinegar, 159
Fish, preservation of, 502, 503
Formic acid, 243
Foucroy and Vauquelin, 3
Frankfurt mustard, 494
French, modern, method of preparing
wine vinegar, 196-200
mustard, 493
old, process of making wine vine-
gar, 193-196
verdigris, 333, 334
Fresenius, 3, 368
Fruit butter, 453, 454
drying of, in the oven, 4^5, 486
evaporated, packing of, 475, 476
evaporation of, 465-486
flesh, preservation of, 436-438
juice, composition of, 370
fermentation of, 421
free acid in, 370
preservation of, 435-465
ripening of, a chemical process, 365,
366
rules for preserving, 435, 436
selection of, for evaporating, 480
for wine, 421
stages of development and ripening
of, 367, 368
sun-drying apparatus for, 484, 485
wines, additions to, 360
clarification of, 421, 422
from stone-fruit, 433, 434
improving the flavor of. 420
mixture of juices for, 420
preparation of, 419-434
Fruits and their composition, 368-378
average content of sugar and free
acid in, 171
for canning, 439, 440
percentage of free acid in. 369
sugar in, 368
presses for, 380-383
proportion between acid, sugar, pec-
tine, gum in, 369
water, soluble and
• insoluble substan-
ces in, 369, 370
ripening of, 360-368
small, jelly, from. 459, 460
wine from. 419-433
vinegar from, 169-173
Furfurol, 244
Fusel oils, 115, 116
plALLAMOND, meat biscuit accord-
U ing to, 498, 499
Gas, yield of, from wood, 241, 242
Gaseous combinations formed at differ-
ent temperatures, 238
products of destructive distillation
of wood, 237-242
536
INDEX.
Gases, utilization of, 266, 282, 283
Generator, best form of, 40
common form of. 41
comparison of a, to a furnace, 35
controlling the work of a, 119, 120
cover for, 43, 44
daily conversion of alcohol into
acetic acid by a, 31, 32
development of heat in, 33, 34
discharge of collected fluid from,
45, 46
distribution of alcoholic fluid in,
46-52
experiments in conveying direct air
to every, 61-63
for cider vinegar, 174
Lenze's chamber, 80-82
Michaelis' revolving, 72, 73
plate, 82-86
protection of hoops and metallic
parts of, 42
quantity of fluid to be worked in a,
• 117, 118
regulating the temperature in, 36
Schulze's, 63, 64
Singer's, 69-72
sulphuring a, 138-140
thermometer for, 52
too feebly working of, 129, 130
vigorously working of, 130, 131
wood for construction of, 41, 42
Generators, 40-52
artificial ventilation of, 61-73
cause of heating of, 131
chemical examination of the fluid
running off from, 119, 120
dimensions of, 42
filling the, 52-55
materials for filling, 52, 53
most suitable, 43
sliming of shavings in, 131-133
with constant ventilation and con-
densation, 65-73
Gerber, discovery by, 2
Gherkins in mustard, 491
pickled, 490, 491
Glacial acetic acid, 3
preparation of, 309,
310, 811, 312
test for, 312, 313
Glucose, 371 , 390-392
determination of pure sugar in,
391,392
table for finding content of an-
hydrous sugar in saturated solu-
tions of, 392
Glycerin, 376, 377
for preserving eggs. 503, 504
Glycerin in vinegar, 232
Gooseberry catchup, 453
champagne, 427, 429
wine, 425-427
Gore, H. C., experiments regarding the
value of peaches as
vinegar stock by,
173
to develop a method
of sterilizing apple
juice, 399-401
investigations by, of the cold
storage of cider, 401, 402
Gould, H. T., kiln evaporator described
by, 470-480
Graduator, 39
Grain, fusel oil in spirits of wine from,
116
vinegar, manufacture of, 162-169
Grape must, potassium in, 371
stalks and skins for refining malt
vinegar, 168
stems for filling generators, 52, 53
sugar, 371
Grapes, conversion into raisins, 482
once pressed, after- wine from, 190-
192
vinegar from, 186. 187
Grinder for apples, 379, 380
Group system, principle of the operation
of, 122-125
with automatic contrivances,
operation of, 125-127
Gum in fruit, 372, 373
Gumpoldskirchner mustard, 493
HALLIDAY'S apparatus for distill-
ing wood waste. 271-273
Ham, invention by, 39
Hannibal, rocks dissolved with vinegar
by, 1, 2
Hassack. Paul, preparation of after-wine
according to. 190-192
Hassal, patented process of, 502
Heating apparatus, 57-59, 95, 96
utilization of gases for, 266
vinegar, 153-155
workroom. 57-59
Hehner's alcohol table, 506-508
Henry's vinegar, 181
Herb vinegar, 183
Hickock's cider mill. 378
Hippocrates, use of vinegar by, 1
Historical data. 1-6
Home-made cider vinegar, 174-178
Horizontal retorts, 263-267
Horseradish catchup, 452
Hydriodic acid, effect of, on wood, 236
INDEX.
537
Hydrocarbons of series CnH2U_6, prop- !
:erties of, 250, 251
Hydrochloric acid, detection of, in vin-
egar, 228
effect of, on wood, 236
process for decomposi-
tion of calcium ace-
tate, 305-308
Hygienic mustard, 494
vinegar, 181
1
NORGANIC constituents, 374
Iron acetate, 324-328
detection of, in vinegar, 229
JARS. 440
Jelly, 458-465
Jersey, island of, manufacture of cider
in, 409, 410
Juniperberry wine. 431
KILN evaporators, 476-480
Kilns, burning charcoal in, 256,
257
or ovens and retorts, 256-283
Klar, apparatus for evaporating and
drying calcium by, 298
three-still system devised by. 292.
293
yield of products from wood accord-
ing to, 289, 290
Kremser mustard, sour, 495
Kiitzing, investigation of mother of
vinegar by, 21
LACTIC acid, detection of, in vinegar,
228
Laragnais, experiments of, 2, 3
Lead acetates, 335-346
metallic, preparation of sugar of
lead from, 340. 341
sesquibasic acetate, 345
vinegar, 344
Lenze's chamber generator, 80-82
Liebig's theory of the formation of vin-
egar, 7
Lifting apparatus for vertical retorts,
269
Lime water, preserving eggs in, 503
Liquid products of destructive distilla-
tion of wood, 242-254
Lovage vinegar, 183
Low wine for alcoholic liquid, 111
Lowitz, strengthening of vinegar by, 3
M
AGNESIUM acetate, 319, 320
Malaga grapes, 482
wine, 412
Malic acid, 396
Malt, 163, 164
determination of vinegar from, 230.
231
vinegar, filtering of, 168
manufacture of, 162-169
Manganese acetate, 323, 324
Marc, wine vinegar from, 211, 212
Marmalade, 454-458
Mash, filtration of, 166, 167
Mashing, 1(14, 165
Massonfour's aerometer for must, 527
Maximum electrical thermometer, 59
Meat biscuit, 498, 499
canned, heating of, 496, 497
canning of, by Appert's method,
196-498
fish and eggs, preservation of, 496-
505
powdered, 502
preparation of, for canning, 496
quick salting of, 500
quick smoking of, 500-502
Mercuric acetate, 347
Mercurous acetate, 346, 347
Metacetone, 244
Metals, detection of, in vinegar, 229, 230
Matapectic acid, 364
Metapectine, 362
Methyl acetate, properties of, 249
alcohol, 243
preparation of, 348-352
properties of, 249, 250
Meyer's system for preparing pure ace-
tone, 355
of decomposition of calcium
acetate in vacuum, 310,
311
distilling wood vinegar in
multiple evaporators in
vacuum, 293
Michaelis' revolving generator, 72, 73
Minimum electrical thermometer, 60
Mixed pickles, 490
Mixture, 104
Mohr's volatile spirits of vinegar, 180
Mold ferment, development of, 101
formation of, 198, 199
Morello wine, 433
Mother of vinegar, 21, 22, 194
occurrence of, 22
Mothers, 193
Moutarde aromatise'e, 495
aux Apices, 495
desjesuites, 493
de maille, 495
Mucilage, vegetable, in fruit, 372, 373
Mulberry jelly, 459
538
INDEX.
Mulberry wine, 431
Multiple evaporators, 293
Mushrooms, pickled, 491
Must, 396
aerometers, 527
comparative synopsis of aerometers
for, 526
testing of, for acid and sugar, 387-
390
Mustard, gherkins in, 491
preparation of, 492-495
vinegar, 183
Mycoderma, 21
aceti, 12
Pasteurianum, 12
NAPHTHALENE, properties of, 251 ,
252
Neutral acetate of ammonia, 316, 317
lead, 335-344
cupric acetate, 329-332
ferric acetate, 326-328
Nickel acetate, 328
Nitric acid, detection of, in vinegar, 228
Normal aluminium acetate, 320
OECHSLE'S aerometer for must, 527
Operations in a vinegar factory,
96-104
Orange marmalade, English, 458
Ordinary mustard, 493. 494
Orleans process of making wine vinegar,
193-196
Oven, drying in, 468, 469, 485, 486
Reichenbach's, 259, 260
retort, 267
Schwartz's. 257-259
Swedish, 260-262
Ovens, 257-262
PARAFFIN, properties of, 251, 252
Paring machines, 480
Parsnip wine, 432
Pasteur, investigations by, 8, 11, 12
liquid for the propagation of the
vinegar ferment, recommended
by, 197
method of preparing wine vinegar
by, 196-200
Pasteurization, 198
of cider, 399-401
Pasteurizing bottled wine vinegar, 209,
210
Pathological tannin, 374
Peach wine, 434
Peaches as vinegar stock, 173
pickled, 491
Pear, acid in, 396
Pear, cider. 418, 419
essence, 115, 116
jelly, 459
Pears, drying of, in the oven, 486
pVeservation of, 438
pickled, 491
Pectase. 362, 363
Pectic acid. 363, 364
Pectine, 361, 362
Pectose, 361
Pectosic acid, 363
Pectous fermentation, 363
substances in fruit, 372
Pepper in vinegar, 232
Periodically working apparatus. 86-90
Persoon, investigation of mother of vin-
egar by, 21
Petiot, process of, for after-wine from
grapes once pressed, 190-192
Pettenkofer, composition of wood gases
by, 238
Phosphate, addition of, to alcoholic
liquid, 129
Physiological tannin, 373, 374
Picalilli, 490
Pickled gherkins, 490, 491
mushrooms, 491
onions, 491
peaches, 491
peas, 491
tomatoes, 491
walnuts, 492
Pickles, fruits and ingredients for, 489.
490
mixed, 490
preparation of. 487-492
Pineapple vinegar, 183
Pipette, 220
Plate generator, 82-86
Platinum black, formation of vinegar
by, 9, 10
preparation of vinegar
with the assistance of,
148, 149
Plum wine, 433, 434
Plums, treatment of, after evaporating.
482
Potato alcohol for making vinegar. 116
fusel oil, 115, 116
Potatoes, evaporating of, 483, 484
Potassium acetate, 314-316
acid acetate, 316
bitartrale, 371
diacetate, 316
Powdered meat, preparation of, 502
Preservation of fruit, 435-465
Preserving in air-tight cans, '438-449
Press cloths, 398
INDEX.
539
Presses, 380-383
Preventive vinegar, 181
Products, yield of, from wood, 288-290
Prunes, drying of, in the oven, 485, 486
Pumice for filling generators, 52
Pyroligneous acid, 3
U1CK process of manufacture of vin-
egar,
39-55
wine vinegar by
the, 210, 211
Q
Quince wine, 419
EACKS, 383-385
Raisin stalks and skins for refin-
ing malt vinegar, 168
Raisin^, 454
Kape vessels, 168
Raspberry jelly, 461
vinegar, 183. 184
wine, 429, 430
Raw materials, chemical examination
of, and control of operations in a
vinegar factory, 213-226
tar. 247
Red apple wine, 408
mordant, 320
Refining vessels, 168
Reichen bach's oven, 259, 260
Reservoirs for the product of distilla-
tion, 279-283
Retort-ovens, arrangement of, 268-271
tar, 247
Retorts, 262-271
bricking in of, 264, 265
horizontal, 263-267
vertical, 267-271
wrought iron, 283-266
Rhubarb wine, 432
River water, 115
Rothe. experiments by, 289
method for purification of wood
vinegar by, 294-296
OACCHAROMETER, use of, in jelly
O boiling, 459
Saccharometers, 213
Saccharomyces ellipsoidus, 403
mesembryanthemum. 13
Sackett, Walter G., directions for home-
made cider vinegar by, 174-178
Salting meat, quick, 500
Sand, filtering, 156
Saussure. determination of the chemical
constitution of alcohol by, 3
Schizomycetes, 11, 12
Schiibler and Neuffler, quantities of
water in wood found 'by, 233
Schulze's generator, 63, 61
ventilating apparatus, 63-65
Schutzenbach, introduction of the quick
process by, 3, 39
Schwartz's oven, 257-259
Sesquiacetate of iron, 326-328
Sesquibasic cupric acetate, 332
Sexbasic acetate of lead, 346
Shavings, accelerated acetification of,
97-99
effect of sodium sulphide on, 237
quantity of vinegar for acetification
of, 96
saturation of, with vinegar, 99
sliming of, 131-135
Sherry wine, 412
Silicate of soda for preserving eggs, 504,
505
Silver acetate, 347. 348
Singer's generator, 69-72
Siphon barrel, 88, 89
Slicers, 481
Sliming of shavings. 131-135
Slow process of making vinegar, 143-
149
Smoking meat, quick process of, 500-
502
Soda test liquor, 221
Sodium acetate. 316
preparation of, 299-304
sulphide, effect of, on shavings, 237
Soup tablets, 499, 500
Sparger, 50-52
Spirits of wine, 115
content of alcohol in, 112
determination of true
strengths of, 513-518
of vinegar from, 230
fusel oils in, 115, 116
specific gravity of, 112
Stahl, strengthening vinegar by. 2
Starch, action of diastase upon, 164
vinegar from, 160. 161
Starr. Richard T. . canning tomatoes
described by, 445-449
Stein's method of preparing sugar of
lead. 337-340
Still for rectification of wood spirit. 349,
350
Stolze, methods for purification of wood
vinegar by, 294
yield of products from wood accord-
ing to. 288. 290
Stone fruit, evaporating of, 482
jelly from, 460
wine from, 433, 434
Stoves, 167
Strawberry jelly, 461
540
INDEX.
Strawberry wine, 424, 425
Strontium acetate, 319
Succinic acid, 376
in vinegar, 232
wine, 376
Sugar beets, vinegar from. 169
determination of, 213
of lead, 335-344
testing must for. 387-390
vinegar from, 169, 170
Sulphuric acid, detection of. in vinegar,
227, 228
effect of, on cellulose, 235.
236
process for decomposition
of calcium acetate, 305-
308
Sulphuring generators, 138-140
vinegar. 158. 159
Sulphurous acid, detection of, in vine-
gar, 228, 229
Sun-drying apparatus, 484, 485
Swedish oven. 260-262
Syrup for canning, 442
TABLE for comparing different aerom-
eters with Tralles's
alcoholometer, 512
percent, of sugar with
per cent, of extract
and the specific
gravity, 527
Reau mui's, Cel-
sius's, and Fahr-
enheit's ther-
mometers,
530
determining content of per
cent, of acetic acid con-
tained in a vinegar, 528,
529
determination of true volume
of alcoholic
fluids from
apparent
volume.
520
true strengths
of spirits,
514-518
reduction of specific gravities
to saccharometer per cent.,
523-525
Hehner's alcohol, 506-508
of actual content of alcohol and
water in mixtures of
both fluids.and contrac-
tion in mixing, 511
Table of comparative synopsis of aero-
meters for must, 526
proportion between per cent, by
weight and by volume of alco-
holic fluids, 510
specific gravity of mixtures of al-
cohol and water, 509
to Massonfoar's aerometer, 527
Oechsle's aerometer for must, 527
vinegars, 181-184
Tannin in fruit, 373, 374
Tar, 244-248
oils, preparation of 355-359
products of distillation of, 356, 357
properties of, 250-254
separation of, from wood vinegar. 291
Tarragon vinegar, 182
Tartar, crude, 371
Tereil and Chateau, method for purifica-
tion of wood vinegar by, 294
Terrace system, 75-80
Thenard, demonstration by, 3
Thermometer, maximum electrical, 59
minimum electrical, 60
Thermometers, comparison of, 530
Three-group system, 8(5-96
Three-still system, 292, 293
Tilting trough, 49
modification of, 86-88
Tin acetate, 346
cans, 440, 441
detection of, in vinegar, 229. 230
Toilet vinegars, 180, 181
Tomato catchup, 450, 451
wine, 432
Tomatoes, canning of, 445-449
evaporating of, 482, 483
pickled, 491
Tower evaporators, 470-474
drying in, 482
Tralles's alcoholometer, comparison o
different aerometers with. 512
Tribasic acetate of lead. 345, 346
cupric acetate, 333
Triplumbic tetracetate, 345
Tutti-frutti, 458
TTRANIUM acetate, 346
VATS for liquid products of distilla-
tion, 279-281
Vegetable mucilage in fruit, 372, 373
Vegetables, canning of, 444, 445
Ventilating apparatus, English, 61, 62
Schulze's, 63-65
Ventilation, artificial of generators, 61-
INDEX.
541
Ventilation constant, and condensa-
tion, generators with, 65-73
Verdigris, 338-335
crystallized, 329-332
Vertical retorts, 267-271
Vidal-Malligaud's ebullioscope, 218,
219
Vinaigre des quatre voleurs, 181
Vinegar, acme of formation of, 33
addition of volatile oils to, 5
apparatus, automatic, 73-96
continuously working, 75-86
periodically working, 86-90
bacteria, factors for the settlement
of, upon a fluid, 16, 17
rapidity of propagation of,
It)
coloring, 159, 160
conversion of wine into, 13-15
derivation of, 230-232
determination of acetic acid in,
113, 528, 529
anhydride in,
220-224
difference in, from various mate-
rials, 37
disturbing influences in the manu-
facture of, 128-142
eels, appearance of, in making wine
vinegar, 199
disturbances due to, 135-140
remedies for the suppression of,
137-140
structure of, 135, 136
essence, 4, 5
examination of, as to the presence
of foreign acids and of metals, as
well as to its derivation, 227-232
factory, arrangement of a, 56-60
chemical examination of raw
materials and control of
operations in a, 213-226
operations in a, 96-104, 116-
127
working according to the auto-
matic principle, arrange
ment of, 90-96
ferment, 8
and its conditions of life, 13-23
composition of nutrient fluid
for, 17-19
conditions for nutriment of,
16-20
constitution of, 23
disturbances in pure culture of,
103, 104
effect of defective nutriment
on, 128, 129
Vinegar ferment, effect of temperature
on, 19, 20
fluids for the nutriment of,
100, 101
induction of operation with
artificial culture of, 99-104
origin of, 13
Pasteur's liquid for the propa-
gation of, 197
pure culture of, 100-104, 201,
202
sensitiveness of, 74
supply of air for, 19
field, 193
filtration of, 155-158
fining, 159
for domestic use, 170
formation of acetic ether in, 184
of, by fermentation, a chemico-
physiological process, 23
freshly-prepared, further treatment
of, 149-160
odor of, 149
from beer-wort, 161, 162
starch, 160, 161
sugar beets, 169
various materials, preparation of,
160-178
wine, composition of, 187, 188
heating of, 153-155
high-graded, 107
historical data on, 1-6
household manufacture of, 147,
148 ,
improving the odor of, 150, 151
induction of the formation of, 143
introduction of the quick process of
making, 3, 39
lice, disturbances due to, 140-142
Liebig's theory of the formation
of, 7
materials for. 36, 37
methods of manufacture of, 36-38
mites, disturbances due to. 140-142
ordinary, constitution of, 1
perfumed, dissolving volatile oils
for, 178-180
points of theoretical conditions of
formation of, 22, 23
preparation of, with platinum black,
148, 149
principal defects of manner of
manufacturing, 5, 6
production of strongest, 121, 122
progress essential for the manufac-
turer of, 4
quantity of, for acetification of
shavings, 96
542
INDEX.
Vinegar, quick process of manufacture,
39-55
role of, in alcoholic fluid, 105
saturation of shavings with, 99
specialties, 178-185
spiced, 488
stock, peaches as, 173
stored, constituents of, 151-153
removal of sediment from, 151
sulphuring, 158, 159
tester, 224-226
theory of formation of, 6-1 2
time for making, by slow process,
145
yeast, 8
Vinous fermentation, 24
products of, 375-378
Vitruvius, 2
Volkel's method of preparing sugar of
lead, 335
Volumetric analysis, determination of
acetic acid by, 222-224
WAGMANN, invention by, 39
Walnut catchup, 451, 452
Wash, 104, 114
preparation of, 143, 144
Water glass for preserving eggs, 504, 505
Well-waters, 114
White lead, 344
Williams evaporator, 472-474
Wine, acetic degeneration of, 189, 190
acetificatiou of, 202
composition of, 187, 188
conversion of, into vinegar, 18-15
definition of, 360
determination of vinegar from, 231
from cider, 408
small fruits, 419-433
glycerin in, 376
mustard, 494
sick, 188, 189
slow acetification of, 192
succinic acid in, 376
vinegar by the quick process, 210,
211
bottled, pasteurizing of, 209,
210
bottling, 209, 210
composition of, 187, 188
disturbances in the production
of, 208
factory, operations in a, 206,
207
filtering, 208
from marc, 211, 212
manufacture of, 186 212
oldest method for making, 193
Wine vinegar, potassium bitartrate in,
231
reasons for superiority of, 187
storage of, 208
vats foi- ruaking, 204
yeast, elliptic, 403
Wines, artificial, cider as basis for, 411,
412
best, for making vinegar, 203
Witherite, preparation of barium acetate
from, 317-319
Wood, air-dry, average composition of,
234
percentage of water in , 98
yields from, 247, 248
constitution of, 233, 234
decomposition of, 234-237
destructive distillation of. bodies
appearing
in. 246
execution of, 283-296
properties of combi-
nations formed in.
248-254
effect of chemicals on, 235-237
heating on, 235
gases, composition of, 238
illuminating gases from, 253
installation of plant for utilizing, in
a thermo-chemical way, 254-256
preservation of, 234, 235
spirit for denaturing, 351, 352
preparation of. 348
properties of, 249. 250
rectification of, 349, 350
specific gravity of, 233, 234
tar, 244-248
character of, 247
combinations in, 244-246, 253,
254
creosote, 252, 253
distillation of. 355, 356
products of distillation of, 356,
357
separation of various combina-
tions in, 24(5. 247
working the, 855-359
yield of, 246
vinegar, 242-244
and other by-products obtained
in the destructive distillation
of wood, 233-254
constituents of, 292
distilled, 292-296
purification of, 294-296
distilling of, in multiple evap-
orators in vacuum, 293
fatty acids in, 242, 243
INDEX.
543
Wood vinegar, freshly prepared, pro-
perties of, 293, 294
production of pure acetic acid
from, 296-313
separation of tar from, 291
treatment of, 290-313
waste, distilling apparatus for, 271-
274
water in, 233
yield of gas from, 241 , 242
Wood, yield of wood vinegar from,
244
yields of products from, 288-290
Workroom, control of temperature iir,
59,60
heating the, 57-59
principal requisites for, 56
Z
INC acetate, 329
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Edited chiefly from the German of Prof. Hans Hoefer and Dr.
Alexander Veith by Wm. T. BRANNT. Illustrated by 3
Plates and 284 Engravings. 743pp. 8vo $12.50
BRANNT. — The Practical Dry Cleaner, Scourer and
Garment Dyer:
Comprising Dry, Chemical, or French Cleaning; Purifica-
tion of Benzine; Removal of Stains, or Spotting; Wet Clean-
ing; Finishing Cleaned Fabrics; Cleaning and Dyeing Furs,
Skin Rugs and Mats; Cleaning and Dyeing Feathers; Clean-
ing and Renovating Felt, Straw and Panama Hats; Bleach-
ing and Dyeing Straw and Straw Hats; Cleaning and Dyeing
Gloves; Garment Dyeing; Stripping; Analysis of Textile
Fabrics. Edited by WILLIAM T- BRANNT, Editor of "The
Techno-Chemical Receipt Book." Fourth Edition, Revised
6 HENRY CAREY BAIRD & CO.'S CATALOGUE
and Enlarged. Illustrated by Forty-One Engravings. 12
mo. 371 pp $2.50
CONTENTS : I. Dry Chemical or French Cleaning. II. Removal
of Stains or Spotting. III. Wet Washing. IV. Finishing Cleaned
Fabrics. V. Cleaning and Dyeing Furs, Skin Rugs and Mats. VI.
Cleaning and Dyeing Feathers. VII. Cleaning and Renovating Felt,
Straw and Panama Hats ; Bleaching and Dyeing Straw and Straw
Hats. VIII. Cleaning and Dyeing Gloves. IX. Garment Dyeing.
X. Stripping Colors from Garments and Fabrics. XI. Analysis of
Textile Fabrics. Index.
BRANNT. — The Soap Maker's Hand-Book of Materials,
Processes and Receipts for every description of Soap; includ-
ing Fats, Fat Oils and Fatty Acids; Examination of Fats and
Oils; Alkalies; Testing Soda and Potash; Machines and
Utensils; Hard Soaps; Soft Soaps; Textile Soaps; Washing
Powders and Allied Products; Toilet Soaps, Medicated
Soaps, and Soap Specialties; Essential Oils and other Perfum-
ing Materials; Testing Soaps. Edited chiefly from the Ger-
man of DR. C. DEITE, A. ENGELHARDT, F. WILTNER, and
numerous other Experts. With Additions by WILLIAM T.
BRANNT, Editor of "The Techno-Chemical Receipt Book."
Illustrated by Fifty-four Engravings. Second edition, Re-
vised and in great part Re- Written. 535 pp. 8vo $6.00
BRANNT. — Varnishes, Lacquers, Printing Inks and Seal-
ing Waxes:
Their Raw Materials and their Manufacture, to which is
added the Art of Varnishing and Lacquering, including the
Preparation of Putties and of Stains for Wood, Ivory, Bone,
Horn, and Leather. By WILLIAM T. BRANNT. Illustrated
by 39 Engravings, 338 pages. 12mo $3.00
BRANNT-WAHL.— The Techno-Chemical Receipt Book:
Containing several thousand Receipts covering the latest,
most important, and most useful discoveries in Chemical
Technology, and their Practical Application in the Arts and
the Industries. Edited chiefly from the German of Drs.
Winckler, Eisner, Heintze, Mierzinski, Jacobsen, Koller and
Heinzerling, with additions by WM. T. BRANNT and WM. H.
WAHL, Ph. D. Illustrated by 78 engravings. 12mo. 495
pages $2.00
BROWN. — Five Hundred and Seven Mechanical Move-
ments :
Embracing all those which are most important in Dynamics,
Hydraulics, Hydrostatics, Pneumatics, Steam Engines, Mill
and other Gearing, Presses, Horology, and Miscellaneous
Machinery; and including many movements never before
published, and several of which have only recently come into
use. By HENRY T. BROWN $1.00
HENRY CAREY BAIRD & CO.'S CATALOGUE 7
BULLOCK.— The Rudiments of Architecture and Build-
ing:
For the use of Architects, Builders, Draughtsmen, Machin-
ists, Engineers and Mechanics. Edited by JOHN BULLOCK,
author of "The American Cottage Builder." Illustrated
by 250 Engravings. 8vo $2.50
BYRNE. — Hand-Book for the Artisan, Mechanic, and
Engineer:
Comprising the Grinding and Sharpening of Cutting Tools,
Abrasive Processes, Lapidary Work, Gem and Glass En-
graving, Varnishing and Lacquering, Apparatus, Materials
and Processes for Grinding and Polishing, etc. By OLIVER
BYRNE. Illustrated by 185 wood engravings. 8vo $4.00
BYRNE. — Pocket-Book for Railroad and Civil Engineers:
Containing New, Exact and Concise Methods for Laying out
Railroad Curves, Switches, Frog Angles and Crossings; the
Staking out of work; Levelling; the Calculation of Cuttings;
Embankments; Earthwork, etc. By OLIVER BYRNE. 18mo.,
full bound, pocketbook form $1.50
BYRNE.— The Practical Metal- Worker's Assistant:
Comprising Metallurgic Chemistry; the Arts of Working all
Metals and Alloys; Forging of Iron and Steel; Hardening and
Tempering; Melting and Mixing; Casting and Founding;
Works in Sheet Metals; the Process Dependent on the Duc-
tility of the Metals; Soldering; etc. By JOHN PERCY. The
Manufacture of Malleable Iron Castings, and Improvements
in Bessemer Steel. By A. A. FESQUET, Chemist and En-
gineer. With over Six Hundred Engravings, Illustrating
every Branch of the Subject. 8vo $3.50
CABINET MAKER'S ALBUM OF FURNITURE:
Comprising a Collection of Designs for various Styles of
Furniture. Illustrated by Forty-eight Large and Beauti-
fully Engraved Plates. Oblong, 8vo $1.50
CALLINGHAM.— Sign Writing and Glass Embossing:
A complete Practical Illustrated Manual of the Art. By
JAMES CALLINGHAM. To which are added Numerous Alpha-
bets and the Art of Letter Painting Made Easy. By JAMES
C. BADENOCH. 258 pages. 12mo $1.50
CAREY.— A Memoir of Henry C. Carey:
By DR. WM. ELDER. With a portrait. 8vo., cloth 75
CAREY.— The Works of Henry C. Carey:
Manual of Social Science. Condensed from Carey's
"Principles of Social Science." By KATE McKEAN 1 vol.
12mo ..$2.00
8 HENRY CAREY BAIRD & CO.'S CATALOGUE
Miscellaneous Works. With a Portrait. 2 vols. 8vo. $10.00
Past, Present and Future. 8vo $2.50
Principles of Social Science. 3 volumes, 8vo $10.00
The Slave-Trade, Domestic and Foreign; Why it Exists,
and How it may be Extinguished (1853). 8vo $2.00
The Unity of Law: As Exhibited in the Relations of Phys-
ical, Social, Mental and Moral Science (1872). 8vo $2.50
COOLEY.— A Complete Practical Treatise on Perfumery:.
Being a Hand-book of Perfumes, Cosmetics and other Toilet
Articles, with a Comprehensive Collection of Formulae. By
ARNOLD COOLEY. 12mo $1.00
COURTNEY. — The Boiler Maker's Assistant in Drawing,
Templating, and Calculating Boiler Work and Tank
Work, etc.
Revised by D. K. CLARK. 102 ills. Fifth edition 80
COURTNEY.— The Boiler Maker's Ready Reckoner:
With Examples of Practical Geometry and Templating. Re-
vised by D. K. CLARK, C. E. 37 illustrations. Fifth edi-
tion $1.60
CRISTIANI. — A Technical Treatise on Soap and Candles:
With a Glance at the Industry of Fats and Oils. By R. S
Cristiani, Chemist. Author of "Perfumery and Kindred
Arts." Illustrated by 176 Engravings. 581 pages, 8vo
$15.00
CROSS. — The Cotton Yarn Spinner:
Showing how the Preparation should be arranged for Differ-
ent Counts of Yarns by a System more uniform than has hith-
erto been practiced; by having a Standard Schedule from
which we make all our Changes. By RICHARD CROSS. 122
pp. 12mo * 75
DAVIDSON.— A Practical Manual of House Painting,
Graining, Marbling, and Sign -Writing:
Containing full information on the processes of House Paint-
ing in Oil and Distemper, the Formation of Letters and
Practice of Sign- Writing, the Principles of Decorative Art,
a Course of Elementary Drawing for House Painters, Writers,
etc., and a Collection of Useful Receipts. With nine colored
illustrations of Woods and Marbles, and numerous wood en-
gravings. By ELLIS A. DAVIDSON. 12mo $2.00
DAVIES. — A Treatise on Earthy and Other Minerals and
Mining:
By D. C. DAVIES. F. G. S., Mining Engineer, etc. Illustrated
by 76 Engravings. 12mo $5.00
HENRY CAREY BAIRD & CO.'S CATALOGUE 9
DAVIES.— A Treatise on Metalliferous Minerals and
Mining:
By D. C. DAVIES, F. G. S., Mining Engineer, Examiner of
Mines, Quarries and Collieries. Illustrated by 148 engrav-
ings of Geological Formations, Mining Operations and Ma-
chinery, drawn from the practice of all parts of the world.
Fifth Edition, thoroughly Revised and much Enlarged by
his son, E. Henry Davies. 12mo. 524 pages $5.00
DAVIS. — A Practical Treatise on the Manufacture of
Brick, Tiles and Terra-Gotta:
Including Stiff Clay, Dry Clay, Hand Made, Pressed or
Front, and Roadway Paving Brick, Enamelled Brick, with
Glazes and Colors, Fire Brick and Blocks, Silica Brick, Carbon
Brick, Glass Pots, Retorts, Architectural Terra-Cotta, Sewer
Pipe, Drain Tile, Glazed and Unglazed Roofing Tile, Art Tile,
Mosaics, and Imitation of Intrarsia or Inlaid Surfaces. Com-
prising every product of Clay employed in Architecture, En-
gineering, and the Blast Furnace. With a Detailed Descrip-
tion of the Different Clays employed, the Most Modern Ma-
chinery, Tools, and Kilns used, and the Processes for Handling
Disintegrating, Tempering, and Moulding the Clay into Shape,
Drying, Setting, and Burning. By CHARLES THOMAS DAVIS.
Third Edition. Revised and in great part rewritten. Il-
lustrated by 261 engravings. 662 pages (Scarce.)
DAVIS. — The Manufacture of Paper:
Being a Description of the various Processes for the Fabrica-
tion, Coloring and Finishing of every kind of Paper, Includ-
ing the Different Raw Materials and the Methods for De-
termining their Values, the Tools, Machines and Practical
Details connected with an intelligent and a profitable prose-
cution of the art, with special reference to the best American
Practice. To which are added a History of Paper, complete
Lists of Paper-Making Materials, List of American Machines,
Tools and Processes used in treating the Raw Materials, and
in Making, Coloring and Finishing Paper. By CHARLES T.
DAVIS. Illustrated by 156 Engravings. 608 pages. 8vo . $6.00
DAWIDOWSKY-BRANNT.— A Practical Treatise on the
Raw Materials and Fabrication of Glue, Gelatine,
Gelatine Veneers and Foils, Isinglass, Cements,
Pastes, Mucilages, etc.:
Based upon Actual Experience. By F. DAWIDOWSKY, Tech-
nical Chemist. Translated from the German, with extensive
additions, including a description of the most Recent Ameri-
can Processes, by WILLIAM T. BRANNT. 2d revised edition,
350 pages. (1905) Price $3.00
10 HENRY CAREY BAIRD & CO.'S CATALOGUE
DEITE. — A Practical Treatise on the Manufacture of
Perfumery:
Comprising directions for making all kinds of Perfumes,
Sachet Powders, Fumigating Materials, Dentrifices, Cos-
metics, etc., with a full account of the Volatile Oils, Balsams,
Resins, and other Natural and Artificial Perfume-substances,
including the Manufacture of Fruit Ethers, and tests of their
purity. By DR. C. DEITE, assisted by L. BORCHERT, F.
EICHBAUM, E. KUGLER, H. TOEFFNER, and other experts.
From the German, by WM. T. BRANNT. 28 Engravings.
358 pages. 8vo $3.00
DE KONINCK-DIETZ.— A Practical Manual of Chemical
Analysis and Assaying:
As applied to the Manufacture of Iron from its Ores, and to
Cast Iron, Wrought Iron, and Steel, as found in Commerce.
By L. L. DEKONINCK, Dr. Sc., and E. DIETZ, Engineer. Ed-
ited with Notes, by ROBERT MALLET, F. R. S., F. S. G., M.
I. C. E., etc. American Edition, Edited with Notes and an
Appendix on Iron Ores, by A. A. FESQUET, Chemist and
Engineer. 12mo $1.00
DIETERICHS. — A Treatise on Friction, Lubrication,
Oils and Fats:
The Manufacture of Lubricating Oils, Paint Oils, and of
Grease, and the Testing of Oils. By E. F. DIETERICHS,
Member of the Franklin Institute; Member National Associa-
tion of Stationary Engineers; Inventor of Dietrichs' Valve-
Oleum Lubricating Oils. 12mo. (1906.) A practical book
by a practical man $1.25
DUNCAN. — Practical Surveyor's Guide:
Containing the necessary information to make any person 9*
common capacity, a finished land surveyor, without the aid
of a teacher. By ANDREW DUNCAN. Revised. 72 Engrav-
ings. 214 pp. 12mo $1.50
DUPLAIS. — A Treatise on the Manufacture and Dis-
tillation of Alcoholic Liquors:
Comprising Accurate and Complete Details in Regard to
Alcohol from Wine, Molasses, Beets, Grain, Rice, Potatoes,
Sorghum, Asphodel, Fruits, etc.; with the Distillation and
Rectification of Brandy, Whiskey, Rum, Gin, Swiss Absinthe,
etc., the Preparation of Aromatic Waters, Volatile Oils or
Essences, Sugars, Syrups, Aromatic Tinctures, Liqueurs,
Cordial Wines, Effervescing Wines, etc., the Ageing of Brandy
and the Improvement of Spirits, with Copious Directions
and Tables for Testing and Reducing Spirituous Liquors, etc.,
HENRY CAREY BAIRD & CO.'S CATALOGUE 11
etc. Translated and Edited from the French of MM. Du-
PLAIS. By M. McKENNiE, M. D. Illustrated. 743
8vo $1
EDWARDS. — A Catechism of the Marine Steam-Engine:
For the use of Engineers, Firemen, and Mechanics. A Prac-
tical Work for Practical Men. By EMORY EDWARDS, Me-
chanical Engineer. Illustrated by sixty-three Engravings,
including examples of the most modern Engines. Third
edition, thoroughly revised, with much additional matter.
12mo. 414 pages $1.50
EDWARDS.— American Marine Engineer, Theoretical
and Practical:
With Examples of the latest and most approved American
Practice. By EMORY EDWARDS. 85 Illustrations. 12mo. $1.50
EDWARDS. — Modern American Locomotive Engines:
Their Design, Construction and Management. By EMORY
EDWARDS. Illustrated. 12mo $1.50
EDWARDS.— Modern American Marine Engines, Boilers,
and Screw Propellers:
Their Design and Construction. 146 pp. 4to $2.00
EDWARDS.— 900 Examination Questions and Answers:
For Engineers and Firemen (Land and Marine) who desire
to obtain a United States Government or State License.
Pocket-book form, gilt edge $1.50
EDWARDS. — The American Steam Engineer:
Theoretical and Practical, with examples of the latest and
most approved American practice in the design and con-
struction of Steam Engines and Boilers. For the use of
Engineers, machinists, boiler-makers, and engineering stu-
dents. By EMORY EDWARDS. Fully illustrated. 419 pages.
12mo $1.50
EDWARDS.— The Practical Steam Engineer's Guide:
In the Design, Construction, and Management of American
Stationary, Portable, and Steam Fire-Engines, Steam Pumps,
Boilers, Injectors, Governors, Indicators, Pistons and Rings,
Safety Valves and Steam Gauges. For the use of Engineers,
Firemen, and Steam Users. By EMORY EDWARDS. Illus-
trated by 119 engravings. 420 pages. 12mo $2.00
ELDER. — Conversations on the Principal Subjects of
Political Economy:
By DR. WILLIAM ELDER. 8vo . .$1.50
12 HENRY CAREY BAIRD & CO.'S CATALOGUE
ELDER.— Questions of the Day:
Economic and Social. By DR. WILLIAM ELDER. 8vo..$3.00
ERNI AND BROWN.— Mineralogy Simplified:
Easy Methods of Identifying Minerals, including Ores, by
Means of the Blow-pipe, by Flame Reactions, by Humid
Chemical Analysis, and by Physical Tests. By HENRI
ERNI, A. M., M. D. Fourth Edition, revised, re-arranged
and with the addition of entirely new matter, including Tables
for the Determination of Minerals by Chemicals and Pyrog-
nostic Characters, and by Physical Characters. By AMOS
P. BROWN, A. M., Ph. D. 464 pp. Illustrated by 123 En-
gravings, pocket-book form, full flexible morocco, gilt edges.
$2.50
FAIRBAIRN.— The Principles of Mechanism and Machi-
nery of Transmission :
Comprising the Principles of Mechanism, Wheels, and Pul-
leys, Strength and Proportion of Shafts, Coupling- of Shafts,
and Engaging and Disengaging Gear. By SIR WILLIAM
FAIRBAIRN, Bart., C E. Beautifully illustrated by over 150
wood-cuts. In one volume. 12mo $2.00
FLEMING. — Narrow Gauge Railways in America:
A Sketch of their Rise, Progress, and Success. Valuable
Statistics as to Grades, Curves, Weight of Rail, Locomotives,
Cars, etc. By HOWARD FLEMING. Illustrated. 8vo. .$1.00
FLEMMING. — Practical Tanning:
A Handbook of Modern Processes, Receipts, and Sugges-
tions for the Treatment of Hides, Skins, and Pelts of Every
Description By LEWIS A. FLEMMING, American Tanner.
630 pp. 8vo. 1910 $6.00
FORSYTH. — Book of Designs for Headstones, Mural, and
other Monuments :
Containing 78 Designs. By JAMES FORSYTH. With an In-
troduction by CHARLES BOUTELL, M. A. 4to. Cloth. .$3.00
GARDNER. — Everybody's Paint Book:
A Complete Guide to the Art of Outdoor and Indoor Paint-
ing 38 Illustrations. 12mo. 183 pp $1.00
GARDNER. — The Painter's Encyclopedia:
Containing Definitions of all Important Words in the Art of
Plain and Artistic Painting, with Details of Practice in Coach,
Carriage, Railway Car, House, Sign, and Ornamental Paint-
ing, including Graining, Marbling, Staining, Varnishing,
Polishing, Lettering, Stenciling, Gilding, Bronzing, etc. By
FRANKLIN B. GARDNER. 158 illustrations. 12mo. 427 pp
$2.00
HENRY CAREY BAIRD & CO.'S CATALOGUE 13
GEE. — The Goldsmith's Handbook:
Containing full instructions for the Alloying and Working of
Gold, including the Art of Alloying, Melting, Reducing, Color-
ing, Collecting, and Refining; the Processes of Manipulation,
Recovery of Waste; Chemical and Physical Properties of
Gold; with a New System of Mixing its Alloys; Solders, En-
amels; and other Useful Rules and Recipes. By GEORGE E.
GEE. 12mo $1.25
GEE. — The Jeweler's Assistant in the Art of Working in
Gold:
A Practical Treatise for Masters and Workmen. 12mo $3.00
GEE. — The Silversmith's Handbook:
Containing full instructions for the Alloying and Working of
Silver, including the different modes of Refining and Melting
the Metal; its Solders; the Preparation of Imitation Alloys;
Methods of Manipulation; Prevention of Waste; Instructions
for Improving and Finishing the Surface of the Work; together
with other Useful Information and Memoranda. By GEORGE
E. GEE. Illustrated. 12mo $1.25
GOTHIC ALBUM FOR CABINET-MAKERS:
Designs for Gothic Furniture. Twenty-three plates. Ob-
long $1.00
GRANT.— A Handbook on the Teeth of Gears:
Their Curves, Properties, and Practical Construction. By
GEORGE B. GRANT Illustrated. Third Edition, enlarged
8vo $1.00
GREGORY. — Mathematics for Practical Men:
Adapted to the Pursuits of Surveyors, Architects, Mechan-
ics, and Civil Engineers. By OLINTHUS GREGORY. 8vo.,
plates $3.00
GRISWOLD.— Railroad Engineer's Pocket Companion
for the Field:
Comprising Rules for Calculating Deflection Distances and
Angles, Tangential Distances and Angles and all Necessary
Tables for Engineers; also the Art of Levelling from Prelim-
inary Survey to the Construction of Railroads, intended
Expressly for the Young Engineer, together with Numerous
Valuable Rules and Examples. By W. GRISWOLD 12mo
Pocketbook form $1.50
GRUNER. — Studies of Blast Furnace Phenomena:
By M. L. GRUNER, President of the General Council of Mines
of France, and lately Professor of Metallurgy at the Ecole
des Mines. Translated, with the author's sanction, with an
Appendix, by L. D. B. GORDON, F. R. S. E., F. G. S. 8vo.
$2.50
14 HENRY CAREY BAIRD & CO.'S CATALOGUE
Hand-Book of Useful Tables for the Lumberman, Farmer
and Mechanic:
Containing Accurate Tables of Logs Reduced to Inch Board
Measure, Plank, Scantling and Timber Measure; Wages and
Rent, by Week or Month; Capacity of Granaries, Bins and
Cisterns; Land Measure, Interest Tables with Directions
for finding the Interest on any sum at 4, 5, 6, 7 and 8 per
cent., and many other Useful Tables. 32mo., boards. 186
pages 25
HASERICK.— The Secrets of the Art of Dyeing Wool,
Cotton and Linen:
Including Bleaching and Coloring Wool and Cotton Hosiery
and Random Yarns. A Treatise based on Economy and
Practice By E. C. HASERICK. Illustrated by 323 Dyed
Patterns of the Yarns or Fabrics 8vo $4 50
HATS AND FELTING:
A Practical Treatise on their Manufacture. By a Practical
Hatter. Illustrated by Drawings of Machinery, etc. 8vo.
$1.00
HAUPT. — A Manual of Engineering Specifications and
Contracts :
By LEWIS M. HAUPT, C. E. Illustrated with numerous
maps. 328 pp. 8vo $2.00
HAUPT. — Street Railway Motors:
With Descriptions and Cost of Plants and Operation of the
various systems now in use. 12mo $1.50
HAUPT.— The Topographer, His Instruments and Meth-
ods:
By LEWIS M. HAUPT, A. M., C. E. Illustrated with numer-
ous plates, maps and engravings. 247 pp. 8vo $2.00
HULME. — Worked Examination Questions in Plane
Geometrical Drawing:
For the Use of Candidates for the Royal Military Academy,
Woolwich; the Royal Military College, Sandhurst; the In-
dian Civil Engineering College, Cooper's Hill; Indian Public
Works and Telegraph Department; Royal Marine Light In-
fantry; the Oxford and Cambridge Local Examinations, etc.
By F. EDWARD HULME, F. L. S., F. S. A., Art-Master Marl-
borough College. Illustrated by 300 examples. Small
quarto $1.00
KELLEY. — Speeches, Addresses, and Letters on Industrial
and Financial Questions:
By HON. WILLIAM D. KELLEY, M. C. 544 pages. 8vo $2.00
HENRY CAREY BAIRD & CO.'S CATALOGUE 15
KEMLO.— Watch Repairer's Hand-Book:
Being a Complete Guide to the Young Beginner, in Taking
Apart, Putting Together, and Thoroughly Cleaning the
English Lever and other Foreign Watches, and all American
Watches. By F. KEMLO, Practical Watchmaker. With
Illustrations. 12mo $1.25
KICK. — Flour Manufacturer:
A Treatise on Milling Science and Practice By FREDERICK
KICK, Imperial Regierungsrath, Professor of Mechanical
Technology in the Imperial German Polytechnic Institute,
Prague. Translated from the second enlarged and revised
edition with supplement by H. H. P. POWLES, Assoc. Memb.
Institution of Civil Engineers. Illustrated with 28 Plates,
and 167 Wood-cuts. 367 pages. 8vo $7.50
KINGZETT.— The History, Products, and Processes of
the Alkali Trade:
Including the most Recent Improvements. By CHARLES
THOMAS KINGZETT, Consulting Chemist. With 23 illustra-
tions. 8vo $2.00
KIRK. — A Practical Treatise on Foundry Irons:
Comprising Pig Iron, and Fracture Grading of Pig and Scrap
Irons; Scrap Irons; Mixing Irons; Elements and Metalloids;
Grading Iron by Analysis; Chemical Standards for Iron;
Castings; Testing Cast Iron; Semi-Steel; Malleable Iron;
Etc., Etc. By EDWARD KIRK, Practical Moulder and Melter,
Consulting Expert in Melting. Illustrated. 294 pages.
8vo. 1911 $3.00
KIRK.— The Cupola Furnace:
A Practical Treatise on the Construction and Management of
Foundry Cupolas. By EDWARD KIRK, Practical Moulder and
Melter, Consulting Expert in Melting. Illustrated by 106
Engravings. Third Edition, revised and enlarged. 482
pages. 8vo. 1910 $3.50
KOENIG.— Chemistry Simplified:
A Course of Lectures on the Non-Metals, Based upon the
Natural Evolution of Chemistry. Designed Primarily for
Engineers. By GEORGE AUGUSTUS KOENIG, Ph. D., A. M ,
E. M., Professor of Chemistry, Michigan College of Mines,
Houghton. Illustrated by 103 Original Drawings. 449 pp.
12mo. (1906) $2.25
LANGBEIN. — A Complete Treatise on the Electro-Deposi-
tion of Metals:
Comprising Electro-Plating and Galvanoplastic Operations,
The Deposition of Metals by the Contract and Immersion
16 HENRY CAREY BAIRD & CO.'S CATALOGUE
Processes, the Coloring of Metals, the Methods of Grinding
and Polishing, as well as the Description of the Voltaic Cells,
Dynamo-Electric Machines, Thermopiles, and of the Materi-
als and Processes Used in Every Department of the Art.
Translated from the latest German Edition of DR. GEORGE
LANGBEIN, Proprietor of a Manufactory for Chemical Pro-
ducts, Machines, Apparatus and Utensils for Electro-Platers,
and of an Electro-Plating Establishment in Leipzig. With
Additions by WILLIAM T. BRANNT, Editor of "The Techno-
Chemical Receipt Book." Seventh Edition, Revised and
Enlarged. Illustrated by 163 Engravings. 8vo. 725 pages.
1913 $5.00
LARKIN.— The Practical Brass and Iron Founder's
Guide:
A Concise Treatise on Brass Founding, Moulding, the Metals
and their Alloys, etc.; to which are added Recent Improve-
ments in the Manufacture of Iron, Steel by the Bessemer
Process, etc., etc. By JAMES LARKIN, late Conductor of the
Brass Foundry Department in Reany, Neafie & Co.'s Penn
Works, Philadelphia. New edition, revised, with extensive
additions. 414 pages. 12mo $2.50
LEHNER. — The Manufacture of Ink:
Comprising the Raw Materials, and the Preparation of
Writing, Copying and Hektograph Inks, Safety Inks, Ink
Extracts and Powders, etc. Translated from the German
of SIGMUND LEHNER, with additions by WILLIAM T. BRANNT.
Illustrated. 12mo $2.00
LEROUX.— A Practical Treatise on the Manufacture of
Worsteds and Carded Yarns:
Comprising Practical Mechanics, with Rules and Calcula-
tions applied to Spinning; Sorting, Cleaning, and Scouring
Wools; the English and French Methods of Combing, Draw-
ing, and Spinning Worsteds, and Manufacturing Carded
Yarns. Translated from the French of CHARLES LEROUX,
Mechanical Engineer and Superintendent of a Spinning-Mill,
by HORATIO PAINE, M. D., and A. A. FESQUET, Chemist and
Engineer. Illustrated by twelve large Plates. 8vo $3.00
LESLIE.— Complete Cookery:
Directions for Cookery in its Various Branches. By Miss
LESLIE. Sixtieth thousand. Thoroughly revised, with the
additions of New Receipts. 12mo $1.00
LE VAN.— The Steam Engine and the Indicator:
Their Origin and Progressive Development; including the
Most Recent Examples of Steam and Gas Motors, together
HENRY CAREY BAIRD & CO.'S CATALOGUE 17
with the Indicator, its Principles, its Utility, and its Applica-
tion. By WILLIAM BARNET LE VAN. Illustrated by 205
Engravings, chiefly of Indicator-Cards. 469 pp. 8vo. $2.00
LIEBER.— Assayer's Guide:
Or, Practical Directions to Assayers, Miners, and Smelters,
for the Tests and Assays, by Heat and by Wet Processes, for
the Ores of all the principal Metals, of Gold and Silver Coins
and alloys, and of Coal, etc. By OSCAR M. LIEBER. Re-
vised. 283 pp. 12mo $1.50
Lockwood's Dictionary of Terms :
Used in the Practice of Mechanical Engineering, embracing
those Current in the Drawing Office, Pattern Shop, Foundry,
Fitting, Turning, Smith's and Boiler Shops, etc., etc., com-
prising upwards of Six Thousand Definitions. Edited by a
Foreman Pattern Maker, author of "Pattern Making." 417
pp. 12mo $3.75
LUKIN.— The Lathe and Its Uses:
Or Instruction in the Art of Turning Wood and Metal. In-
cluding a Description of the Most Modern Appliances for the
Ornamentation of Plane and Curved Surfaces, an Entirely
Novel Form of Lathe for Eccentric and Rose-Engine Turn-
ing. A Lathe and Planing Machine Combined; and Other
Valuable Matter Relating to the Art. Illustrated by 462
engravings. Seventh Edition. 315 pages 8vo $4.25
MAUCHLINE.— The Mine Foreman's Hand-Book:
Of Practical and Theoretical Inf9rmation on the Opening,
.Ventilating, and Working of Collieries. Questions and An-
swers on Practical and Theoretical Coal Mining. Designed
to Assist Students and Others in Passing Examinations for
Mine Foremanships. By ROBERT MAUCHLINE. 3d Edition.
Thoroughly Revised and Enlarged by F. ERNEST BRACKETT.
134 Engravings. 8vo. 378 pages'. (1905.) $3.75
MOLESWORTH.— Pocket-Book of Useful Formula and
Memoranda for Civil and Mechanical Engineers:
By GUILFORD L. MOLESWORTH, Member of the Institution of
Civil Engineers, Chief Resident Engineer of the Ceylon
Railway. Full-bound in Pocketbook form $1.00
MOORE.— The Universal Assistant and the Complete
Mechanic:
Containing over one million Industrial Facts, Calculations,
Receipts, Processes, Trades Secrets, Rules, Business Forms,
Legal Items, etc., in every occupation, from the Household
to the Manufactory. By R. MOORE. Illustrated by 500
Engravings. 12mo $2.50
18 HENRY CAREY BAIRD & CO.'S CATALOGUE
NAPIER.— A System of Chemistry Applied to Dyeing:
By JAMES NAPIER, F. C. S. A New and Thoroughly Revised
Edition. Completely brought up to the present state of the
Science, including the Chemistry of Coal Tar Colors, by A.
A. FESQUET, Chemist and Engineer. With an Appendix on
Dyeing and Calico Printing, as shown at the Universal Ex-
position, Paris, 1867. Illustrated. 8vo. 422 pages . . . $2.00
NICHOLLS.— The Theoretical and Practical Boiler-Maker
and Engineer's Reference Book:
Containing a variety of Useful Information for Employers
of Labor, Foremen and Working Boiler-Makers, Iron, Copper,
and Tinsmiths, Draughtsmen, Engineers, the General Steam-
using Public, and for the Use of Science Schools and classes
By SAMUEL NICHOLLS. Illustrated by sixteen plates. 12mo.
$2.50
NYSTROM. — On Technological Education and the Con-
struction of Ships and Screw Propellers
For Naval and Marine Engineers. By JOHN W. NYSTROM,
late Acting Chief Engineer, U. S. N. Second Edition, Re-
vised, with additional matter. Illustrated by seven En-
gravings. 12mo $1.00
O'NEILL. — A Dictionary of Dyeing and Calico Printing:
Containing a brief account 9f all the Substances and Pro-
cesses in use in the Art of Dyeing and Printing Textile Fabrics;
with Practical Receipts and Scientific Information. By
CHARLES O'NEILL, Analytical Chemist. To which is added
an Essay on Coal Tar Colors and their application to Dyeing
and Calico Printing. By A. A. FESQUET, Chemist and En-
gineer. With an appendix on Dyeing and Calico Printing,
as shown at the Universal Exposition, Paris, 1867. 8vo.
491 pages $2.00
ORTON.— Underground Treasures:
How and Where to Find Them. A Key for the Ready De-
termination of all the Useful Minerals within the United
States. By JAMES ORTON, A. M., Late Professor of Natural
History in Vassar College, N. Y.; author of the "Andes and
the Amazon," etc. A New Edition, with An Appendix on
Ore Deposits and Testing Minerals. (1901.) Illustrated.
$1.50
OSBORN. — A Practical Manual of Minerals, Mines and
Mining:
Comprising the Physical Properties, Geologic Position; Local
Occurrence and Associations of the Useful Minerals, their
Methods of Chemical Analysis and Assay; together with
Various Systems of Excavating and Timbering, Brick and
HENRY CAREY BAIRD & CO.'S CATALOGUE 19
Masonry Work, during Driving, Lining, Bracing and other
Operations, etc. By PROF. H. S. OSBORN, LL. D., Author of
"The Prospector's Field-Book and Guide." 171 Engravings.
Second Edition, Revised. 8vo $4.50
OSBORN.— The Prospector's Field Book and Guide:
In the Search For and the Easy Determination of Ores and
Other Useful Minerals. By PROF. H. S. OSBORN, LL. D,
Illustrated by 66 Engravings. Eighth Edition. Revised
and Enlarged. 401 pages. 12mo (1910.) $1.50
OVERMAN.— The Moulder's and Founder's Pocket Guide:
A Treatise on Moulding and Founding in Green-sand, Dry-
sand, Loam, and Cement; the Moulding of Machine Frames,
Mill-gear, Hollow Ware, Ornaments, Trinkets, Bells, and
Statues; Description of Moulds for Iron, Bronze, Brass, and
other Metals; Plaster of Paris, Sulphur, Wax, etc.; the Con-
struction of Melting Furnaces, the Melting and Founding of
Metals; the Composition of Alloys and their Nature, etc.,
etc. By FREDERICK OVERMAN, M. E. A new Edition, to
which is added a Supplement on Statuary and Ornamental
Moulding, Ordnance, Malleable Iron Castings, etc. By A.
A. FESQUET, Chemist and Engineer. Illustrated by 44
engravings. 12mo $2.00
PAINTER, GILDER, AND VARNISHER'S COMPANION:
Comprising the Manufacture and Test of Pigments, the Arts
of Painting, Graining, Marbling, Staining, Sign-writing,
Varnishing, Glass-staining, and Gilding on Glass; together
with Coach Painting and Varnishing, and the Principles of
the Harmony and Contrast of Colors. Twenty-seventh
Edition. Revised, Enlarged, and in great part Rewritten.
By WILLIAM T. BRANNT, Editor of "Varnishes, Lacquers,
Printing Inks and Sealing Waxes." Illustrated. 395 pp.
12mo $1.50
PERCY.— The Manufacturing of Russian Sheet-Iron:
By JOHN PERCY, M. D., F. R. S. Paper 25
POSSELT. — Cotton Manufacturing:
Part I. Dealing with the Fibre, Ginning, Mixing, Picking,
Scutching and Carding. By E. A. POSSELT. 104 Illustra-
tions, 190 pp $3.00
Part II. Combing, Drawing, Roller Covering and Fly Frame,
$3.00
POSSELT. — The Jacquard Machine Analysed and Ex-
plained :
With an Appendix on the Preparation of Jacquard Cards, and
Practical Hints to Learners of Jacquard Designing. By E.
A. POSSELT. With 230 Illustrations and numerous diagrams.
127 pp. 4to $3.00
20 HENRY CAREY BAIRD & CO.'S CATALOGUE
POSSELT.— Recent Improvements in Textile Machinery
Relating to Weaving:
Giving the Most Modern Points on the Construction of all
Kinds of Looms, Warpers, Beamers, Slashers, Winders,
Spoolers, Reeds, Temples, Shuttles, Bobbins, Heddles, Heddle
Frames, Pickers, Jacquards, Card Stampers, Etc., Etc. By
E. A. POSSELT. 4to. Part I, 600 ills.; Part II, 600 ills.
Each part $3.00
POSSELT.— Recent Improvements in Textile Machinery,
Part III:
Processes Required for Converting Wool, Cotton, Silk, from
Fibre to Finished Fabric, Covering both Woven and Knit
Goods; Construction of the most Modern Improvements in
Preparatory .Machinery, Carding, Combing, Drawing, and
Spinning Machinery, Winding, Warping, Slashing Machinery,
Looms, Machinery for Knit Goods, Dye Stuffs, Chemicals,
Soaps, Latest Improved Accessories Relating to Construc-
tion and Equipment of Modern Textile Manufacturing Plants
By E. A. POSSELT. Completely Illustrated. 4to $7.50
POSSELT.— Technology of Textile Design:
The Most Complete Treatise on the Construction and Appli-
cation of Weaves for all Textile Fabrics and the Analysis of
Cloth. By E. A. POSSELT. 1,500 Illustrations. 4to. .$5.00
POSSELT.— Textile Calculations:
A Guide to Calculations Relating to the Manufacture of all
Kinds of Yarns and Fabrics, the Analysis of Cloth, Speed,
Power and Belt Calculations. By E. A. POSSELT. Illus-
trated. 4to $2.00
REGNAULT.— Elements of Chemistry:
By M. V. REGNAULT. Translated from the French by T.
FORREST BETTON, M. D., and edited, with Notes, by JAMES
C. BOOTH, Melter and Refiner U. S. Mint, and WILLIAM L.
FABER, Metallurgist and Mining Engineer. Illustrated by
nearly 700 wood-engravings Comprising nearly 1,500 pages.
In two volumes, 8vo., cloth $5.00
RICH. — Artistic Horse-Shoeing:
A Practical and Scientific Treatise, giving Improved Methods
of Shoeing, with Special Directions for Shaping Shoes to Cure
Different Diseases of the Foot, and the Correction of Faulty
Action in Trotters. By GEORGE E. RICH. 362 Illustrations.
217 pages. 12mo $2.00
RICHARDSON.— Practical Blacksmithing :
A Collection of Articles Contributed at Different Times by
Skilled Workmen to the columns of "The Blacksmith and
Wheelwright," and Covering nearly the Whole Range of
Blacksmithing, from the Simplest Job of Work to some of the
HENRY CAREY BAIRD & CO.'S CATALOGUE 21
most Complex Forgings. Compiled and Edited by M. T.
RICHARDSON.
Vol. I. 210 Illustrations. 224 pages. 12mo $1.00
Vol. II. 230 Illustrations. 262 pages. 12mo $1.00
Vol. III. 390 Illustrations. 307 pages. 12mo $1.00
Vol. IV. 226 Illustrations. 276 pages. 12mo $1.00
RICHARDSON.— Practical Carriage Building:
Comprising Numerous Short Practical Articles upon Carriage
and Wagon Woodwork; Plans for Factories; Shop and Bench
Tools; Convenient Appliances for Repair Work; Methods of
Working; Peculiarities of Bent Timber; Construction of
Carriage Parts; Repairing Wheels; Forms of Tenons and Mor-
tises; Together with a Variety of Useful Hints and Sugges-
tions to Woodworkers. Compiled by M. T. RICHARDSON.
Vol. I. 228 Illustrations. 222 pages $1.00
Vol. II. 283 Illustrations. 280 pages $100
RICHARDSON.— The Practical Horseshoer:
Being a Collection of Articles on Horseshoeing in all its
Branches which have appeared from time to time in the col-
umns of "The Blacksmith and Wheelwright," etc. Compiled
and edited by M. T. RICHARDSON. 174 Illustrations, $1.00
RIFFAULT, VERGNAUD, and TOUSSAINT.— A Practical
Treatise on the Manufacture of Colors for Painting:
Comprising the Origin, Definition, and Classification of Colors,
the Treatment of the Raw Materials; the best Formulae and
the Newest Processes for the Preparation of every description
of Pigment, and the Necessary Apparatus and Directions for
its use; Dryers; the Testing, Application, and Qualities of
Paints, etc., etc. By MM. RIFFAULT, VERGNAUD, and
TOUSSAINT, Revised and Edited by M. F. MALPEYRE, Trans-
lated from the French by A. A. FESQUET. Illustrated by
Eighty Engravings. 659 pp. 8vo $5.00
ROPER. — Catechism for Steam Engineers and Elec-
tricians :
Including the Construction and Management of Steam En-
gines, Steam Boilers and Electric Plants. By STEPHEN
ROPER. Twenty-first edition, rewritten and greatly enlarged
by E. R. KELLER and C. W. PIKE. 365 pages. Illustrations.
18mo.f tucks, gilt $2.00
OPER.— Engineer's Handy Book:
Containing Facts, Formulae, Tables and Questions on Power,
its Generation, Transmission and Measurement; Heat, Fuel,
and Steam; The Steam Boiler and Accessories; Steam Engines
and their Parts; Steam Engine Indicator; Gas and Gasoline
Engines; Materials; their Properties and Strength; Together
with a Discussion of the Fundamental Experiments in Elec-
tricity, and an Explanation of Dynamos, Motors, Batteries,
etc., and Rules for Calculating Sizes of Wires. By STEPHEN
22 HENRY CAREY BAIRD & CO.'S CATALOGUE
ROPER. 15th edition. Revised and Enlarged by E. R.
KELLER, M. E., and C. W. PIKE, B. S. With numerous
Illustrations. Pocket-book form. Leather $3.50
ROPER. — Hand-Book of Land and Marine Engines:
. Including the Modeling, Construction, Running, and Man-
agement of Land and Marine Engines and Boilers. With
Illustrations. By STEPHEN ROPER, Engineer. Sixth Edition.
12mo., tucks, gilt edge. $3.50
ROPER. — Hand-Book of the Locomotive:
Including the Construction of Engines and Boilers, and the
Construction, Management, and Running of Locomotives.
By STEPHEN ROPER. Eleventh Edition. 18mo., tucks, gilt
edge $2.50
ROPER. — Hand-Book of Modern Steam Fire-Engines;
With Illustrations. By STEPHEN ROPER, Engineer. Fourth
Edition, 12mo., tucks, gilt edge. $3.50
ROPER. — Instructions and Suggestions for Engineers and
Firemen:
By STEPHEN ROPER, Engineer. 18mo., Morocco $2.00
OPER. — Questions and Answers for Stationary and
Marine Engineers and Electricians:
With a Chapter of What to Do in Case of Accidents. By
STEPHEN ROPER, Engineer. Sixth Edition, Rewritten and
Greatly Enlarged by EDWIN R. KELLER, M. E., and CLAYTON
W. PIKE, B. A. 306 pp. Morocco, pocketbook form, gilt
edges $2.00
ROPER. — The Steam Boiler: Its Care and Management:
By STEPHEN ROPER, Engineer. 1 3mo., tuck, gilt edges. $2.00
ROPER. — Use and Abuse of the Steam Boiler:
By STEPHEN ROPER, Engineer. Ninth Edition, with Illus-
trations. 18mo., tucks, gilt edge $2.00
ROPER. — The Young Engineer's Own Book:
Containing an Explanation of the Principle and Theories on
which the Steam Engine as a Prime Mover is based. By
STEPHEN ROPER, Engineer. 160 Illustrations, 363 pages.
18mo., tuck $2.50
ROSE. — The Complete Practical Machinist:
Embracing Lathe Work, Vise Work, Drills and Drilling, Taps
and Dies, Hardening and Tempering, the Making and Use of
Tools, Tool Grinding, Marking out work, Machine Tools, etc.
By JOSHUA ROSE. 395 Engravings. Nineteenth Edition,
greatly Enlarged with New and Valuable Matter. 12mo.,
504 pages $2.50
ROSE.— Mechanical Drawing Self -Taught:
Comprising Instructions in the Selection and Preparation of
Drawing Instruments, Elementary Instruction in practical
HENRY CAREY BAIRD & CO.'S CATALOGUE 23
Mechanical Drawing, together with Examples in Simple
Geometry and Elementary Mechanism, including Screw
Threads, Gear Wheels, Mechanical Motions, Engines and
Boilers. By JOSHUA ROSE, M. E. Illustrated by 330 En-
gravings. 8vo. 313 pages $3.50
ROSE.— The Slide- Valve Practically Explained:
Embracing simple and complete Practical Demonstrations of
the operation of each element in a Slide-valve Movement,
and illustrating the effects of Variations in their Proportions
by examples carefully selected from the most recent and
successful practice. By JOSHUA ROSE, M. E. Illustrated
by 35 Engravings $1.00
ROSE. — Steam Boilers:
A Practical Treatise on Boiler Construction and Examination,
for the Use of Practical Boiler Makers, Boiler Users, and In-
spectors; and embracing in plain figures all the calculations
necessary in Designing or Classifying Steam Boilers. By
JOSHUA ROSE, M. E. Illustrated by 73 Engravings. 250
pages. 8vo $2.00
ROSS.— The Blowpipe in Chemistry, Mineralogy and
Geology:
Containing all Known Methods of Anhydrous Analysis, many
Working Examples, and Instructions for Making Apparatus.
By LIEUT. COLONEL W A. Ross, R. A., F. G. S. With 120
Illustrations. 12mo $2.00
SCHRIBER. — The Complete Carriage and Wagon Painter:
A Concise Compendium of the Art of Painting Carriages,
Wagons, and Sleighs, embracing Full Directions in all the
Various Branches, including Lettering, Scrolling, Ornament-
ing, Striping, Varnishing, and Coloring, with numerous Re-
cipes for Mixing Colors. 73 Illustrations. 177 pp. 12mo.
$1.00
SHAW. — Civil Architecture:
Being a Complete Theoretical and Practical System of Build-
ing, containing the Fundamental Principles of the Art. By
EDWARD SHAW, Architect. To which is added a Treatise on
Gothic Architecture, etc. By THOMAS W. SILLOWAY and
GEORGE M. HARDING, Architects. The whole illustrated by
102 quarto plates finely engraved on copper. Eleventh Edi-
tion 4to $5.00
SHERRATT. — The Elements of Hand-Railing:
Simplified and Explained in Concise Problems that are Easily
Understood. The whole illustrated with Thirty-eight Ac-
curate and Original Plates, Founded on Geometrical Principles,
and showing 'how to Make Rail Without Centre Joints, Mak-
ing Better Rail of the Same Material, with Half the Labor,
24 HENRY CAREY BAIRD & CO.'S CATALOGUE
and Showing How to Lay Out Stairs of all Kinds. By R. J.
SHERRATT. Folio $2.50
SHUNK. — A Practical Treatise on Railway Curves and
Location for Young Engineers:
By W F. SHUNK, C. E. 12mo. Full bound pocket-book
form $2.00
SLOANE. — Home Experiments in Science:
By T. O'CON9R SLOANE, E. M., A. M., Ph. D. Illustrated
by 91 Engravings. 12mo $1.00
SLOAN. — Homestead Architecture:
Containing Forty Designs for Villas, Cottages, and Farm-
houses, with Essays on Style, Construction, Landscape Gar-
dening, Furniture, etc., etc. Illustrated by upwards of 200
Engravings. By SAMUEL SLOAN, Architect. 8vo $2.00
SMITH.— The Dyer's Instructor:
Comprising Practical Instructions in the Art of Dyeing Silk,
Cotton, Wool, and Worsted, and Woolen Goods; containing
nearly 800 Receipts. To which is added a Treatise on the
Art of Padding; and the Printing of Silk Warps, Skeins, and
Handkerchiefs, and the various Mordants and Colors for the
different styles of such -work. By DAVID SMITH, Pattern
Dyer. 12mo $1.00
SMITH.— A Manual of Political Economy:
By E. PESHINE SMITH. A New Edition, to which is added
a full Index. 12mo $1.25
SMITH. — Parks and Pleasure- Grounds:
Or Practical Notes on Country Residences, Villas, Public
Parks, and Gardens. By CHARLES H. J. SMITH, Landscape
Gardener and Garden Architect, etc., etc. 12mo $2.00
SNIVELY. — The Elements of Systematic Qualitative
Chemical Analysis:
A Hand-book for Beginners. By JOHN H. SNIVELY, Phr. D.
16mo $2.00
STOKES. — The Cabinet Maker and Upholsterer's Com-
panion :
Comprising the Art of Drawing, as applicable to Cabinet
Work; Veneering, Inlaying, and Buhl- Work; the Art of Dye-
ing and Staining Wood, Ivory, Bone, Tortoise-Shell, etc.
Directions for Lacquering, Japanning, and Varnishing; to
make French Polish, Glues, Cements, and Compositions;
with numerous Receipts, useful to workmen generally. By
J. STOKES. Illustrated. A New Edition, with an Appendix
upon French Polishing, Staining, Imitating, Varnishing, etc.,
etc. 12mo $1.25
STRENGTH AND OTHER ROPERTIES OF METALS:
Reports of Experiments on the Strength and other Properties
HENRY CAREY BAIRD & CO.'S CATALOGUE 25
of Metals for Cannon With a Description of the Machines
for Testing Metals, and of the Classification of Cannon in
service. By Officers of the Ordnance Department, U. S.
Army. By authority of the Secretary of War. Illustrated
by 25 large steel plates. Quarto $3.00
SULZ. — A Treatise on Beverages:
Or the Complete Practical Bottler. Full Instructions for
Laboratory Work with Original Practical Recipes for all
kinds of Carbonated Drinks, Mineral Waters, Flavoring
Extracts, Syrups, etc. By CHARLES HERMAN SULZ, Tech-
nical Chemist and Practical Bottler. Illustrated by 428
Engravings. 818 pp. 8vo $7.50
SYME. — Outlines of an Industrial Science:
By DAVID SYME. 12mo $2.00
TABLES SHOWING THE WEIGHT OF ROUND, SQUARE
AND FLAT BAR IRON, STEEL, ETC.
By Measurement. Cloth 63
TEMPLETON. — The Practical Examinator on Steam and
the Steam-Engine:
With Instructive References relative thereto, arranged for
the Use of Engineers, Students, and others. By WILLIAM
TEMPLETON, Engineer 12mo $1.00
THALLNER.— Tool-Steel :
A Concise Hand-book on Tool-Steel in General. Its Treat-
ment in the Operations of Forging, Annealing, Hardening,
Tempering, etc., and the Appliances Therefor. By OTTO
THALLNER, Manager in Chief of the Tool-Steel Works, Bis-
marckhutte, Germany. From the German by WILLIAM T.
BRANNT. Illustrated by 69 Engravings. 194 pages 8vo.
1902 $2.00
THAUSING.— The Theory and Practice of the Preparation
of Malt and the Fabrication of Beer:
With especial reference to the Vienna Process of Brewing.
Elaborated from personal experience by JULIUS E. THAUSING,
Professor at the School for Brewers, and at the Agricultural
Institute, Modling, near Vienna. Translated from the Ger-
man by WILLIAM T. BRANNT. Thoroughly and elaborately
edited, with much American matter, and according to the
latest and most Scientific Practice, by A. SCHWARZ and DR.
A H. BAUER. Illustrated by 140 Engravings. 8vo. 815
pages $10.00
TOMPKINS.— Cotton and Cotton Oil:
Cotton: Planting, Cultivating, Harvesting and Preparation
fpr Market. Cotton Seed Oil Mills: Organization, Construc-
tion and Operation. Cattle Feeding: Production of Beef
and Dairy Products, Cotton Seed Meal and Hulls as Stock
26 HENRY CAREY BAIRD & CO.'S CATALOGUE
Feed. Fertilizers: Manufacture, Manipulation and Uses.
By D. A. TOMPKINS. 8vo. 494pp. Illustrated $7.50
TOMPKINS.— Cotton Mill, Commercial Features:
A Text-Book for the Use of Textile Schools and Investors.
With Tables showing Cost of Machinery and Equipments
for Mills making Cotton Yarns and Plain Cotton Cloths. By
D. A. TOMPKINS. 8vo. 240 pp. Illustrated $5.00
TOMPKINS.— Cotton Mill Processes and Calculations:
An Elementary Text-Book for the Use of Textile Schools and
for Home Study. By D. A. TOMPKINS. 312 pp. 8vo.
Illustrated $5.00
TURNER'S (THE) COMPANION:
Containing Instructions in Concentric, Elliptic, and Eccen-
tric Turning; also various Plates of Chucks, Tools, and In-
struments; and Directions for using the Eccentric Cutter,
Drill, Vertical Cutter, and Circular Rest; with Patterns and
Instructions for working them. 12mo $1.00
VAN CLEVE.— The English and American Mechanic:
Comprising a Collection of Over Three Thousand Receipts,
Rules, and Tables, designed for the Use of every Mechanic
and Manufacturer. By B. FRANK VAN CLEVE. Illustrated.
500 pp. 12mo $2.00
VAN DER BURG.— School of Painting for the Imitation
of Woods and Marbles :
A Complete, Practical Treatise on the Art and Craft of Grain-
ing and Marbling with the Tools and Appliances. 36 Plates.
Folio, 12x20 inches $6.00
VILLE.— The School of Chemical Manures:
Or, Elementary Principles in the Use of Fertilizing Agents
From the French of M. GEO. VILLE, by A. A. FESQUET,
Chemist and Engineer. With Illustrations. 12mo $1.25
VOGDES.— The Architect's and Builder's Pocket-Com-
panion and Price- Book:
Consisting of a Short but Comprehensive Epitome of Deci-
mals, Duodecimals, Geometry and Mensuration; with Tables
of United States Measures, Sizes, Weights, Strength, etc., of
Iron, Wood, Stone, Brick, Cement and Concretes, Quanti-
ties of Materials in given Sizes and Dimensions of Wood,
Brick and Stone; and full and complete Bills of Prices for
Carpenter's Work and Painting; also, Rules for Computing
and Valuing Brick and Brick Work, Stone Work, Painting,
Plastering, with a Vocabulary of Technical Terms, etc. By
FRANK W. VOGDES, Architect, Indianapolis, Ind. Enlarged,
Revised and Corrected. In one volume 368 pages, full-
bound, pocketbook form, gilt edges $2.00
Cloth.. $1.50
HENRY CAREY BAIRD & CO.'S CATALOGUE 27
WAHNSCHAFFE.— A Guide to the Scientific Examina-
tion of Soils:
Comprising Select Methods of Mechanical and Chemical
Analysis and Physical Investigation. Translated from the
German of DR F. WAHNSCHAFFE. With additions by WIL-
LIAM T. BRANNT. Illustrated by 25 Engravings. 12mo.
177 pages $1.50
WARE.— The Sugar Beet:
Including a History of the Beet Sugar Industry in Europe,
Varieties of the Sugar Beet, Examination, Soils, Tillage
Seeds and Sowing, Yield and Cost of Cultivation, Harvest-
ing, Transportation, Conservation, Feeding Qualities of the
Beet and of the Pulp, etc. By LEWIS S. WARE, C. E.,
M. E. Illustrated by ninety Engravings. 8vo . . : $2.00
WARN. — The Sheet-Metal Worker's Instructor:
For Zinc, Sheet-Iron, Copper, and Tin-Plate Workers, etc.
Containing a selection of Geometrical Problems; alsa Prac-
tical and Simple Rules for Describing the various Patterns
required in the different branches of the above Trades. By
REUBEN H. WARN, Practical Tin-Plate Worker. To which is
added an Appendix, containing Instructions for Boiler-Mak-
ing, Mensuration of Surfaces and Solids, Rules for Calculat-
ing the Weights of different Figures of Iron and Steel, Tables
of the Weights of Iron, Steel, etc. Illustrated by thirty-
two Plates and thirty-seven Wood Engravings. 8vo. . . $2.00
WARNER. — New Theorems, Tables, and Diagrams, for
the Computation of Earth- work:
Designed for the use of Engineers in Preliminary and Final
Estimates, of Students in Engineering and of Contractors
and other non-professional Computers. In two parts, with
an Appendix. Part I. A Practical Treatise; Part II. A
Theoretical Treatise, and the Appendix Containing Notes to
the Rules and Examples of Part I.; Explanations of the Con-
struction of Scales, Tables, and Diagrams, and a Treatise
upon Equivalent Square Bases and Equivalent Level Heights.
By JOHN WARNER, A. M., Mining and Mechanical Engineer.
Illustrated by 14 Plates. 8vo $3.00
WATSON.— A Manual of the Hand-Lathe:
Comprising Concise Directions for Working Metals of all
kinds, Ivory, Bone and Precious Woods; Dyeing, Coloring,
and French Polishing; Inlaying by Veneers, and various
methods practised to produce Elaborate work with dispatch,
and at Small Expense. By EGBERT P. WATSON, Author of
"The Modern Practice of American Machinists and En-
gineers. " Illustrated by 78 Engravings $1.00
WATSON.— The Modern Practice of American Machinists
and Engineers:
Including the Construction, Application, and Use of Drills
28 HENRY CAREY BAIRD & CO.'S CATALOGUE
Lathe Tools, Cutters for Boring Cylinders, and Hollow-work
generally, with the most economical Speed for the same; the
Results verified by Actual . Practice at the Lathe, the Vise,
and on the floor. Together with Workshop Management,
Economy of Manufacture, the Steam Engine, Boilers, Gears,
Belting, etc., etc. By EGBERT P. WATSON Illustrated by
eighty-six Engravings. 12mo $2.00
WEATHERLY.— Treatise on the Art of Boiling Sugar,
Crystallizing, Lozenge-making, Comfits, Gum Goods :
And other processes for Confectionery, including Methods
for Manufacturing every Description of Raw and Refined
Sugar Goods. A New and Enlarged Edition, with an Appen-
dix on Cocoa, Chocolate, Chocolate Confections, etc. 196
pages. 12mo. (1903.) $1.50
WILL.— Tables of Qualitative Chemical Analysis:
With an Introductory Chapter on the Course of Analysis
By PROFESSOR HEINRICH WILL, of Giessen, Germany. Third
American, from the eleventh German Edition. Edited by
CHARLES F. HIMES, Ph. D., Professor of Natural Science,
Dickinson College, Carlisle, Pa. 8vo $1.00
WILLIAMS.— On Heat and Steam:
Embracing New Views of Vaporization, Condensation and
Explosion. By CHARLES WYE WILLIAMS, A. I. C. E. Illus-
trated. 8vo $2.00
WILSON.— The Practical Tool-Maker and Designer:
A Treatise upon the Designing of Tools and Fixtures for
Machine Tools and Metal Working Machinery, Comprising
Modern Examples of Machines with Fundamental Designs
for Tools for the Actual Production of the work; Together
with Special Reference to a Set of Tools for Machining the
Various Parts of a Bicycle. Illustrated by 189 Engravings
(1898) $2.50
CONTENTS : Introductory. Chapter I. Modern Tool Room and
Equipment. II. Files, Their Use and Abuse. III. Steel and Tem-
pering. IV. Making Jigs. V. Milling Machine Fixtures. VI. Tools
and Fixtures for Screw Machines. VII. Broaching. VIII. Punches
and Dies for Cutting and Drop Press. IX. Tools for Hollow-ware.
X. Embossing : Metal, Coin and Stamped Sheet-Metal Ornaments.
XI. Drop Forging. XII. Solid Drawn Shells or Ferrules ; Cupping
or Cutting and Drawing ; Breaking Down Shells. XIII. Annealing,
Pickling and Cleaning. XIV. Tools for Draw Bench. XV. Cutting
and Assembling Pieces by Means of Ratchet Dial Plates at One
Operation. XVI. The Header. XVII. Tools for Fox Lathe. XVIII.
Suggestions for a set of Tools for Machining the Various Parts of
a Bicycle. XIX. The Plater's Dynamo. XX. Conclusion — With a
few Random Ideas. Appendix. Index.
WORSSAM.— On Mechanical Saws:
From the Transaction of the Society of Engineers, 1869. By
S. W. WORSSAM, JR. Illustrated by Eighteen large Plates.
8vo ..$1.50
BRANNTS "SOAP MAKERS HAND BOOK."
The most helpful and up-to-date book on the Art of Soap
Making in the English language.
In one volume, 8vo, 535 pages, illustrated by 54 engravings.
Price $6.00 net, Free of Postage to any Address in the World,
or by Express C. O. J>. freight paid to any Address in the
United States or Canada.
PUBLISHED APRIL, 1912.
THE
SOAP MAKER'S HAM) BOOK
OF
MATERIALS, PROCESSES AND RECEIPTS FOR
EVERY DESCRIPTION OF SOAP
INCLUDING
FATS, FAT OILS, AND FATTY ACIDS ; EXAMINATION OF FATS AND OILS J
ALKALIES ; TESTING SODA AND POTASH ; MACHINES AND UTENSILS J
HARD SOAPS ; SOFT SOAPS ; TEXTILE SOAPS J WASHING POWDERS
AND ALLIED PRODUCTS ; TOILET SOAPS, MEDICATED SOAPS,
AND SOAP SPECIALTIES ; ESSENTIAL OILS AND OTHER
PERFUMING MATERIALS ; TESTING SOAPS.
EDITED CHIEFLY FROM THE GERMAN OF
DR. C. DEITE, A. ENGELHARDT, F. WILTNER,
AND NUMEROUS OTHER EXPERTS.
WITH ADDITIONS
BY
WILLIAM T. BRANNT,
EDITOR OF "THE TECHNO CHEMICAL RECEIPT BOOK."
ILLUSTRATED BY FIFTY-FOUR ENGRAVINGS.
SECOND EDITION. REVISED AND IN GREAT PART RE-WRITTEN.
PHILADELPHIA :
HENRY CAREY BAIRD & CO.,
INDUSTRIAL PUBLISHERS, BOOKSELLERS, AND IMPORTERS,
810 WALNUT STREET.
1912
KIRK'S CUPOLA FURNACE.
An Eminently, Practical) TTp-to-Date Book, by an Expert*
Third Thoroughly Revised and Partly Re-written Edition*
In one volume, 8vo., 482 pages, illustrated by one hundred
and six engravings. Price $3.50. Free of Postage to any
Address in the World, or by Express C. O. D., freight paid to
any Address in the United States or Canada.
PUBLISHED AUGUST, 1910.
THE CUPOLA FURNACE
A PRACTICAL TREATISE ON THE
CONSTRUCTION AND MANAGEMENT
OF
FOUNDRY CUPOLAS:
COMPRISING
IMPROVEMENTS IN CUPOLAS AND METHODS OF THEIR CONSTRUCTION AND MANAGE-
MENT; TUYERES; MODERN CUPOLAS; CUPOLA FUELS; FLUXING OF IRON; GETTING
UP CUPOLA STOCK; RUNNING A CONTINUOUS STREAM; SCIENTIFICALLY
DESIGNED CUPOLAS; SPARK-CATCHING DEVICES; BLAST-PIPES AND
BLAST; BLOWERS; FOUNDRY TRAM RAIL, ETC., ETC.
BY
EDWARD KIRK,
PRACTICAL MOULDER AND MELTER, CONSULTING EXPERT IN MELTING.
Author of " The Founding of Metals? and of Numerous Papers on Cupola Practice.
ILLUSTRATED BY ONE HUNDRED AND SIX ENGRAVINGS.
THIRD THOROUGHLY REVISED AND PARTLY RE-WR.TTEN EDITION.
PHILADELPHIA :
HENRY CAREY BAIRD & CO.,
INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS,
810 WALNUT STREET.
14 DAY USE
RETURN TO DESK FROM WHICH BORROWED
LOAN DEPT.
• This book is due on the last date stamped below, or
on the date to which renewed.
Renewed books are subject to immediate recall.
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