Main
Lib. ASRICITLTTOAL Wfff*
THE BOOK OF CHEESE
Efje i&ural Eext-Boofe Series
EDITED BY L. H. BAILEY
Carleton : THE SMALL GRAINS.
B. M. Duggar: THE PHYSIOLOGY OF PLANT
PRODUCTION.
J. F. Duggar: SOUTHERN FIELD CROPS.
Gay : BREEDS OF LIVE-STOCK.
Gay : PRINCIPLES AND PRACTICE OF JUDGING
LIVE-STOCK.
Goff: PRINCIPLES OF PLANT CULTURE.
Guthrie: BOOK OF BUTTER.
Harper: ANIMAL HUSBANDRY FOR SCHOOLS.
Harris and Stewart: PRINCIPLES OF AGRON-
OMY.
Hitchcock : TEXT-BOOK OF GRASSES.
Jeffery : TEXT-BOOK OF LAND DRAINAGE.
Jordan: FEEDING OF ANIMALS. Revised.
Livingston: FIELD CROP PRODUCTION.
Lyon: SOILS AND FERTILIZERS.
Lyon, Fippin and Buckman : SOILS, THEIR
PROPERTIES AND MANAGEMENT.
Mann: BEGINNINGS IN AGRICULTURE.
Montgomery : THE CORN CROPS.
Morgan : FIELD CROPS FOR THE COTTON-BELT.
Mumford: THE BREEDING OF ANIMALS.
Piper : FORAGE PLANTS AND THEIR CULTURE.
Sampson : EFFECTIVE FARMING.
Thorn and Fisk : THE BOOK OF CHEESE.
Warren : THE ELEMENTS OF AGRICULTURE.
Warren : FARM MANAGEMENT.
Wheeler: MANURES AND FERTILIZERS.
White: PRINCIPLES OF FLORICULTURE.
Widtsoe : PRINCIPLES OF IRRIGATION PRAC-
TICE.
THE BOOK OF CHEESE
BY
CHARLES TfHOM
INVESTIGATOR IN CHEESE, FORMERLY AT CONNECTICUT
AGRICULTURAL COLLEGE
AND
WALTER W. FISK
ASSISTANT PROFESSOR OF DAIRY INDUSTRY (CHEESE-MAKING),
NEW YORK STATE COLLEGE OF AGRICULTURE
AT CORNELL UNIVERSITY
Nefo gorfc
THE MACMILLAN COMPANY
1918
All rights reserved
COPYBIGHT, 1918,
BY THE MACMILLAN COMPANY.
Set up and electrotyped. Published July, 191?
/%^< Cfe/StT
(/ibrory)
a lain 1 n>.
A^ric. Dent.
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J. 8. Cushing Co. Berwick & Smith Co.
Norwood, Mass., U.S.A.
PREFACE
CERTAIN products we associate with the manufactures
of the household, so familiar and of such long standing
that we do not think of them as requiring investigation
or any special support of science. The older ones of us
look back on cheese as an ancient home product; yet
the old-fashioned hard strong kind has given place to
many named varieties, some of them bearing little resem-
blance to the product of the kitchen and the buttery.
We have analyzed the processes; discovered micro-
organisms that hinder or help; perfected devices and
machines; devised tests of many kinds; studied the
chemistry ; developed ' markets for standardized com-
modities. Here is one of the old established farm in-
dustries that within a generation has passed from the
housewife and the home-made hand press to highly per-
fected factory processes employing skilled service and
handling milk by the many tons from whole communi-
ties of cows. This is an example of the great changes
in agricultural practice. Cheese-making is now a piece
of applied science; many students in the colleges are
study ing. the subject ; no one would think of undertaking
it in the old way : for these reasons this book is written.
This book is intended as a guide in the interpretation
of the processes of making and handling a series of im-
portant varieties of cheese. The kinds here considered
are those made commercially in America, or so widely
met in the trade that some knowledge of them is neces-
387241
VI PREFACE
sary. The relation of cheese to milk and to its production
and composition has been presented in so far as required
for this purpose. The principles and practices under-
lying all cheese-making have been brought together into
a chapter on curd-making. A chapter on classification
then brings together into synoptical form our knowledge
of groups of varieties. These groups are then discussed
separately. The problems of factory building, factory
organization, buying and testing milk, and the proper
marketing of cheese, are briefly discussed.
Such a discussion should be useful to the student, to
the beginner in cheese-making, as a reference book on
many varieties in the hands of makers who specialize in
single varieties, and to the housekeeper or teacher of
domestic science. The material has been brought to-
gether from the experience of the writers, supplemented
by free use of the literature in several languages. Stand-
ard references to this literature are added in the text.
No introduction to the subject of cheese should fail
to mention the work of J. H. Monrad, who has recently
passed away. Mr. Monrad never collected his material
into a single publication, but his contributions to cheese-
making information, scattered widely in trade literature
over a period of thirty years, form an encyclopedia of the
subject.
Bulletins of the Agricultural Experiment Stations and
United States Department of Agriculture have been
quoted extensively, with citation of the sources of the
material. Personal assistance from Professor W. A.
Stocking and other members of the Dairy Department of
Cornell University, and C. F. Doane of the United States
Department of Agriculture, is gladly acknowledged.
Students cannot learn out of books to make cheese.
PREFACE vii
They may, however, be aided in understanding the prob-
lems from such study. To make cheese successfully they
must have intimate personal touch with some person who
knows cheese. Sympathetic relations with such a teacher
day by day in the cheese-room are essential to suc-
cess in making cheese which, at its best, is one of the
most attractive of food-products.
THE AUTHORS.
TABLE OF CONTENTS
CHAPTER I
PAGES
GENERAL STATEMENT ON CHEESE . . . . . 1-4
Nature of cheese, 1 ; Cheese-making as an art, 2 ;
Cheese-making as a science, 3 ; Problems in cheese-
making, 4 ; History, 5.
CHAPTER II
THE MILK IN ITS RELATION TO CHEESE . . . 5-28
Factors affecting the quality, 6; Chemical com-
position, 7; Factors causing variation in composi-
tion, 8; Milk constituents, 9; Water, 10; Fat, 11;
Casein, 12; Milk-sugar, 13; Albumin, 14; Ash, 15;
Enzymes, 16 ; The flavor of feeds eaten by the cow,
17 ; Absorption of odors, 18 ; Effect of condition of
the cow, 19; Bacteria in the milk, 20; Groups of
bacteria in milk, 21 ; Acid fermentation of milk, 22 ;
Bacterium lactis-acidi group, 23; Colon-aerogenes
group, 24; Acid peptonizing group, 25; Bacillus
bulgaricus group, 26; Acid cocci or weak acid-
producers, 27; Peptonizing organisms, 28; Inert
types, 29; Alkali-producing bacteria, 30; Butyric
fermenting types, 31 ; Molds and yeasts, 32 ; Bacterial
contamination of milk, 33 ; Germicidal effect of milk,
34 ; Sources and control of bacteria in milk, 35 ; The
cow, 36; Stable air, 37 ; The milker, 38 ; Utensils, 39;
The factory, 40 ; The control of bacteria, 41 ; Fer-
mentation test, 42 ; The sediment test, 43.
CHAPTER III
COAGULATING MATERIALS 29-40
Ferments, 44 ; Nature of rennet, 45 ; Preparation
of rennet extract, 46; Pepsin, 47; Chemistry of
ix
TABLE OF CONTENTS
curdling, 48; Use of acid, 49; Robertson's theory,
50 ; Rennet curd, 51 ; Hammarsten's theory, 52 ;
Duclaux theory, 53 ; Bang's theory, 54 ; Bosworth's
theory, 55.
CHAPTER IV
LACTIC STARTERS . . ... ' . . . . 41-54
Acidifying organisms, 56; Starter, 57; Natural
starter, 58; Commercial starter or pure cultures,
59 ; Manufacturer's directions, 60 ; Selecting milk,
61; Pasteurization, 62; Containers, 63; Adding
cultures, 64; Cleanliness, 65; "Mother" starter
or startoline, 66; Examining starter, 67; Second
day's propagation, 68 ; Preparations of larger amount
of starter, 69 ; Amount of mother starter to use, 70 ;
Qualities, 71 ; How to carry the mother starter, 72 ;
Starter score-cards, 73; Use of starter, 74; The
amount of starter to use, 75 ; Starter lot-card, 76.
CHAPTER V
CURD-MAKING . . 55-80
The composition of the milk, 77 ; Cheese color, 78 ;
The acidity factor, 79 ; Acidity of milk when received,
80 ; The acid test, 81 ; Rennet tests, 82 ; Marschall
rennet test, 83; Comparison of acid and rennet
test, 84 ; Control of acid, 85 ; Acidity and rennet
action, 86 ; Acidity and expulsion of the whey, 87 ;
Acidity in relation to cheese flavor, 88 ; Acidity in
relation to body and texture of cheese, 89; Acidity
in relation to cheese color, 90 ; Control of moisture,
91 ; Relation of moisture to manufacture and
quality, 92; Relation of moisture to acidity, 93;
Setting temperature, 94 ; Strength of coagulating
materials, 95; Amount of coagulating materials to
use, 96 ; Method of adding rennet, 97 ; The curdling
period, 98 ; Cutting or breaking the curd, 99 ; Curd
knives, 100; Heating or "cooking," 101; Draining,
102 ; Application to cheese, 103.
TABLE OF CONTENTS
XI
CHAPTER VI
CLASSIFICATION . . . . . .
Basis of classification, 104; Processed cheeses,
105 ; Whey cheeses, 106 ; Soft and hard cheeses, 107 ;
Relation of moisture to classes, 108 ; Relation of
heat to classes, 109.
PAGES
81-88
CHAPTER VII
CHEESES WITH SOUR-MILK FLAVOR .... 89-110
Skim series, 110; Cottage cheese, 111; Household
practice, 112; Factory practice, 113; Buttermilk
cheese, 114; Neufchatel group, 115; Domestic or
American Neufchatel cheeses, 116; The factory,
117; Cans, 118; Draining racks, 119; Cloths, 120;
Molding machinery, 121 ; Milk for Neufchatel, 122 ;
Starter, 123; Renneting or setting, 124; Draining,
125; Cooling Neufchatel, 126; Pressing, 127;
Working and salting Neufchatel, 128 ; Storage, 129 ;
Molding, 130; Skimmed-milk Neufchatel, 131;
Baker's cheese, 132; Domestic Neufchatel, 133;
Partially skim Neufchatel, 134 ; Cream cheese, 135 ;
Neufchatel specialties, 136 ; Gervais, 137 ; European
forms occasionally imported, 138.
CHAPTER VIII
SOFT CHEESES RIPENED BY MOLD . .
Hand cheese and its allies, 139; Pennsylvania
pot cheese, 140 ; Appetitost (Appetite cheese), 141 ;
Ripened Neufchatel, French process, 142; The
Camembert group, 143 ; Camembert cheese, 144 ;
Description of Camembert, 145; Conditions of
making and ripening, 146 ; Outline of making pro-
cess, 147; Acidity, 148; Ripening the cheese, 149;
Composition, 150 ; Factory, 151 ; Economic factors,
152 ; French Brie, 153 ; Coulommiers, 154.
111-133
Xll
TABLE OF CONTENTS
CHAPTER IX
SOFT CHEESES RIPENED BY BACTERIA ....
The Isigny group, 155; Raffine", 156; Lieder-
. . kranz cheese, 157 ; Limburger cheese, 158 ; The
milk, 159; Making the cheese, 160; Draining and
salting, 161 ; Ripening, 162 ; Marketing and qualities
of Limburger, 163 ; Yield and composition of Lim-
burger, 164 ; Miinster cheese, 165.
CHAPTER X
SEMI-HARD CHEESES .
The green mold group, 166; Roquefort cheese,
167 ; Cow's milk or Fagons Roquefort, 168 ; Outline
of making Roquefort, 169; Ripening of Roquefort,
170 ; Gorgonzola, 171 ; Stilton cheese, 172 ; Gex,
173; Bacterially-ripened series, 174; Brick cheese,
175; Making of brick cheese, 176; Ripening brick
cheese, 177 ; Qualities of brick cheese, 178 ; Composi-
tion and yield, 179 ; Port du Salut cheese, 180.
CHAPTER XI
THE HARD CHEESES
The Danish group, 181 ; The Dutch group, 182 ;
Edam cheese, 183; Method of manufacture, 184;
Salting and curing Edam, 185; Equipment for
making Edam cheese, 186; Qualities and yield of
Edam cheese, 187; Gouda cheese, 188; Method of
manufacture, 189; Equipment for Gouda cheese,
190; Composition and yield, 191.
CHAPTER XII
CHEDDAR CHEESE-MAKING
The lot-card, 192 ; The milk, 193 ; Ripening the
milk, 194; Setting or coagulating, 195; Cutting,
196 ; Heating or "cooking" the curd, 197 ; Removing
the whey, 198 ; Hot-iron test, 199 ; Firmness of the
curd, 200; Gathering the curd together, 201;
PAGES
134-148
149-171
172-183
184-221
TABLE OF CONTENTS xiii
Matting or cheddaring, 202 ; Milling the curd, 203 ;
Salting, 204; Hooping the curd, 205; Pressing the
curd, 206 ; Dressing the cheese, 207 ; Handling over-
ripe and gassy milk, 208; Qualities of Cheddar
cheese, 209.
CHAPTER XIII
COMPOSITION AND YIELD OF CHEDDAR CHEESED . . 222-246
Composition of milk, whey and cheese, 210;
Relations of fat to casein in normal milk, 211 ;
Influence of fat in milk on yield of cheese, 212 ; Fat
loss in cheese-making, 213; Effect of bacterial-
content of milk on yield of cheese, 214; Factors
affecting the moisture-content of Cheddar, 215 ;
Variations of the Cheddar process, 216; Cheddar-
type cheese from pasteurized milk, 217 ; Club cheese,
218; The stirred-curd or granular process, 219;
California Jack cheese, 220; The washed-curd
process, 221 ; English dairy cheese, 222 ; Pineapple
cheese, 223; Leyden, 224; Cheddar cheese with
pimientos, 225; Sage cheese, 226; Skimmed-milk
cheese, 227; Full skimmed-milk Cheddar cheese,
228; Half skimmed-milk Cheddar cheese, 229;
Yield and qualities of skimmed-milk Cheddar cheese,
230.
CHAPTER XIV
CHEDDAR CHEESE RIPENING 247-275
Fat, 231; Milk-sugar, 232; The salts, 233;
Gases, 234; Casein or proteins, 235; Causes of
ripening changes, 236 ; Action of the rennet extract,
237; The action of the bacteria, 238; Conditions
affecting the rate of cheese ripening, 239; The
length of time, 240 ; The temperature of the curing-
room, 241 ; Moisture-content of the cheese, 242 ; The
size of the cheese, 243 ; The amount of salt used, 244 ;
The amount of rennet extract, 245; The influence
of acid, 246 ; Care of the cheese in the curing-room,
XIV
TABLE OF CONTENTS
247; Evaporation of moisture from the cheese
during ripening, 248; Paraffining, 249; Shipping,
250. Defects in Cheddar cheese: Defects in flavor,
251 ; Feedy flavors, 252 ; Acid flavors, 253 ; Sweet
or fruity flavors, 254 ; Defects in body and texture,
255; Loose or open texture, 256; Dry body, 25T;
Gassy textured cheese, 258; Acidy, pasty or soft
body and texture, 259; Defects in color, 260;
Defects in finish, 261. Cheddar cheese judging : Secur-
ing the sample, 262; How to determine quality,
263 ; Causes of variations in score, 264 ; The score-
card, 265.
CHAPTER XV
THE Swiss AND ITALIAN GROUPS
Swiss cheese: The Swiss factory, 266; The milk,
267 ; Rennet extract, 26.8 ; Starter, 269 ; The making
process, 270 ; Curing Swiss, 271 ; Block Swiss, 272 ;
Shipment, 273; Qualities of Swiss cheese, 274;
Composition and yield, 275 ; The Italian group :
Parmesan, 276 ; Regianito, 277.
CHAPTER XVI
MISCELLANEOUS VARIETIES AND BY-PRODUCTS
Caciocavallo, 278; Sap sago, 279; Albumin
cheese, 280 ; Mysost, Norwegian whey cheese, 281 ;
Whey butter, 282.
CHAPTER XVII
CHEESE FACTORY CONSTRUCTION, EQUIPMENT, ORGANI-
ZATION .........
Locating the site, 283 ; The building, 284 ; Heat-
ing plant, 285; Curing-rooms, 286; Light, 287;
Ventilation, 288; BoHer-room, 289; whey tanks,
290; Store-room, 291; The floors, 292; Arrange-
ment of machinery and rooms, 293 ; Arrangements
for cleanliness, 294 ; Equipment and supplies list, 295 ;
Factory organization, 296.
276-292
293-296
297-310
TABLE OF CONTENTS
XV
CHAPTER XVIII
HISTORY AND DEVELOPMENT OF THE CHEESE INDUSTRY
IN AMERICA ..... .
The factory system, 297 ; Introduction of factory
system in Canada, 298 ; Introduction of cheddaring,
299; Introduction of Swiss and Limburger, 300;
Number and distribution of cheese factories, 301 ;
Total production of cheese in the United States,
302; Rank of the leading cheese-producing states,
303; Exportation and importation of cheese by*the
United States, 304 ; Average yearly price of cheese,
305; Canadian cheese statistics, 306; Introduction
of cheese-making into new regions, 307.
311-326
CHAPTER XIX
TESTING
The fat test, 308 ; Sampling the milk, 309 ; Adding
the acid, 310; Centrifuging, 311; Reading the test,
312; testing whey for fat, 313; testing cheese for
fat, 314; Reading the test, 315; The Hart casein
test, 316; Solids in the milk, 317; the lactometer,
318; Calculating the solids not fat in the milk, 319;
Testing cheese for moisture, 320.
327-342
CHAPTER XX
MARKETING 343-361
Buying milk, 321 ; Cheese yield basis of buying
milk, 322; Fat basis for payment of milk, 323;
Weight basis or pooling method for payment of
milk, 324 ; Fat-plus-two method for payment of
milk, 325; Comparison of methods, 326; Laws
governing the production and sale of milk, 327;
Marketing of cheese, 328; Mercantile exchanges,
329; Marketing perishable varieties, 330; Dis-
tribution of price, 331 ; Standards, 332 ; Laws
relating to cheese marketing, 333 .
xvi TABLE OF CONTENTS
CHAPTER XXI
PAGES
CHEESE IN THE HOUSEHOLD ...'.. 362-381
Food value of cheese, 334 ; Digestibility of cheese,
335; Cheese flavor, 336; Relation to health, 337;
Cheese poisoning, 338; Proper place in the diet,
339; Care of cheese, 340; Food value and price,
341 ; Methods and recipes for using cheese, 342.
THE BOOK OF CHEESE
*
THE BOOK OF CHEESE
CHAPTER I
GENERAL STATEMENT ON CHEESE
CHEESE is a solid or semi-solid protein food product
manufactured from milk. Its solidity depends on the
curdling or coagulation of part or all of the protein and
the expulsion of the watery part or whey. The coag-
ulum or curd so formed incloses part of the milk-serum
(technically whey) or watery portion of the iftilk, part
of the salts, part or all of the fat, and an aliquot part
of the milk-sugar. The loss in manufacture includes
a small fraction of the protein and fat, the larger propor-
tion of the water, salts and milk-sugar.
1. Nature of cheese. Milk of itself is an exceedingly
perishable product. Cheese preserves the most important
nutrient parts of the milk in condition for consumption
over a much longer period. The duration of this period
and the ripening and other changes taking place depend
very closely on the composition of the freshly made
cheese. There is an intimate relation between the water,
fat, protein and salt-content of the newly made cheese
and the ripening processes which produce the particular
flavors of the product when it is ready for the consumer.
This relation is essentially biological. A cheese contain-
BOOK OF CHEESE
ing 60 to 75 per cent of water, as in " cottage cheese "
(the sour-milk cheese so widely made in the homes), must
be eaten or lost in a very few days. Spoilage is very rapid.
In contrast to this, the Italian Parmesan, with 30 to 32
per cent of water, requires two to three years for proper
ripening.
The cheeses made from soured skim-milk probably
represent the most ancient forms of cheese-making.
Their origin is lost in antiquity. The makers of Roque-
fort cheese cite passages from Pliny which they think
refer to an early form of that product. It is certain that
cheese in some form has been familiar to man throughout
historic times. The technical literature of cheese-making
is, however, essentially recent. The older literature may
be cited to follow the historical changes in details of
practice.
2. Cheese-making as an art has been developed to
high stages of perfection in widely separate localities.
The best known varieties of cheese bear the geographical
names of the places of their origin. The practices of
making and handling such cheeses have been developed
in intimate relation to climate, local conditions and the
habits of the people. So close has been this adjustment
in some cases, that the removal of expert makers of such
cheeses to new regions has resulted in total failure to
transplant the industry.
3. Cheese-making as a science has been a compara-
tively recent development. It has been partly a nat-
ural outgrowth of the desire of emigrant peoples to
carry with them the arts of their ancestral home, partly
the desire to manufacture at home the good things met
in foreign travel. Its development has been largely
coincident with the development of the agricultural school
GENERAL STATEMENT ON CHEESE 3
and the science of dairy biology. Even now we have but
a limited knowledge of a few of the 500 or more varieties
of cheese named in the literature. It is desirable to
bring together the knowledge of underlying principles as
far as they are known.
No technical description of a cheese-handling process can
replace experience. Descriptions of appearances and tex-
tures of curd in terms definite enough to be understood by
beginners have been found to be impossible. It is possible,
however, to lay down principles and essentials of practice
which are common to the industry and form the founda-
tion for intelligent work. Cheese-making will be a science
only as we depart from the mere repetition of a routine
or rule-of-thumb practice and understand the underlying
principles.
4. Problems in cheese-making. Any understanding
of these problems calls for a working knowledge of the
very complex series of factors involved. These include
the chemical composition of the milk, the nature of
rennet and character of its action under the conditions
met in cheese-making, the nature of the micro-organisms
in milk, and the methods of controlling them, their
relation to acidity and to the ripening of the cheese.
To these scientific demands must be added acquaintance
with the technique of the whole milk industry, from its
production and handling on the farm through the multi-
plicity of details of factory installation and organization,
to those intangible factors concerned with the texture,
body, odor and taste of the varied products made from
it. Some of these factors can be adequately described ;
others have thus far been handed on from worker to
worker but have baffled every effort at standardization
or definition.
4 THE BOOK OF CHEESE
5. History. --The recorded history of the common
varieties of cheese is only fragmentary. Practices at
one time merely local in origin followed the lines of
emigration. Records of processes of manufacture were
not kept. The continuance of a particular practice
depended on the skill and memory of the emigrant, who
called his cheese after the place of origin. Other names
of the same kind were applied by the makers for selling
purposes. The widely known names were thus almost
all originally geographical. Some of them, such as
Gorgonzola, are used for cheeses not now made at the
places whose names they bear. Naturally, this method
of development has produced national groups of cheeses
which have many common characteristics but differ in
detail. The English cheeses form a typical group of
this kind.
Emigration to America carried English practices across
the Atlantic. The story of cheese-making in America
has been so closely linked with the development of the
American Cheddar process that the historical aspects
of the industry in this country are considered under that
head in Chapter VIII.
CHAPTER II
THE MILK IN ITS RELATION TO CHEESE
THE opaque whitish liquid, secreted by the mam-
mary glands of female mammals for the nourishment
of their young, is known as milk. The milk of the
cow is the kind commonly used for cheese-making in
America.
6. Factors affecting the quality. The process of
cheese-making begins with drawing the milk from the
udder. The care and treatment the milk receives, while
being drawn, and its subsequent handling, have a decided
influence on its qualities. The process of cheese-making
is varied according to the qualities of the milk. There
are five factors that influence the quality of the milk
for cheese-making : (1) its chemical composition ; (2) the
flavor of feed eaten by the cow; (3) the absorption of
flavors and odors from the atmosphere; (4) the health
of the cow ; (5) the bacteria present. The first factor is
dependent on the breed and individuality of the cow.
The other four factors are almost entirely within the
control of man. Of these factors-, number five is of the
most importance, and is the one most frequently neg-
lected.
7. Chemical composition. The high, lt>w and average
composition of milk is approximately as follows:*
6
THE BOOK OF CHEESE
TABLE I
COMPOSITION OF MILK
WATER
PER
CENT
FAT
PER
CENT
CASEIN
PER
CENT
SUGAR
PER
CENT
ALBUMIN
PER
CENT
ASH
PER
CENT
High . . .
Low ....
88.90
85.05
5.50
3.00
3.00
2.10
5.00
4.60
.72
.70
.73
.70
Average . .
87.47
3.80
2.50
4.80
.71
.72
8. Factors causing variation in composition. The
composition of cow's milk varies according to several
factors. The composition of the milk of different breeds
differs to such a degree that whole series of factories
are found with lower or higher figures than these
averages on account of dominant presence of particular
kinds of cattle.
The following table shows the usual effect of breed on
fat and total solids of milk :
TABLE II
THE USUAL EFFECT OF BREED OF Cows ON FAT AND TOTAL
SOLIDS OF MILK
BREED OF Cows
Fat
Per Cent
Total Solids
Per Cent
Jersey
Guernsey
5.62
5 34
14.74
14 70
Shorthorn
4 17
13.41
Ayrshire
3.61
12.72
Holstein-Friesian
3 30
11.89
AVERAGES
THE MILK IN ITS RELATION TO CHEESE 7
The figures 1 in Tables I and II are compiled and aver-
aged from a large number of analyses made at different
agricultural experiment stations.
This variation not only affects the fat, but all con-
stituents of the milk. While there is a difference in the
composition of the milk from cows of different breeds,
there is almost as wide variation in the composition of
the milk from single cows 2 of the same breed. With
the same cow the stage of lactation causes a wide varia-
tion in the composition of the milk. 3 As the period of
lactation advances, the milk increases in percentage of
fat and other solids.
9. Milk constituents. From the standpoint of the
cheese-maker, the significant constituents of milk are
. Exp. Sta. Kept. 1890, pages 237-241.
Maine Exp. Sta. Kept. 1890, part II, pages 52-57.
Conn. (Storrs) Exp. Sta. Kept. 1886, pages 119-130.
Vt. Exp. Sta. Kept. 1890, pages 97-100.
Vt. Exp. Sta. Kept. 1891, pages 61-74.
N. Y. Exp. Sta. Kept. 1892, pages 299-392.
N. Y. Exp. Sta. Kept. 1893, pages 39-162.
Wis. Exp. Sta. Kept. 1890, pages 115-119.
Conn. (Storrs) Exp. Sta. Kept. 1907, pages 152-156.
N. Y. Exp. Sta. Kept. 1891, pages 139-142.
N. Y. Exp. Sta. Kept. 1894, pages 31-86, 118-121.
N. J. Exp. Sta. Kept. 1895, pages 136-137.
Eckles, C. H., and R. H. Shaw. The influence of breed and
individuality on the composition and properties of milk, Bur.
An. Ind. Bui. 156, 1913.
Eckles, C. H., and R. H. Shaw, Variations in the composition
and properties of milk from the individual cow, U. S. Dept.
Agr. Bur. An. Ind. Bui. 157, 1913.
2 Morrow, G. A., and A. G. Manns, Analyses of milk from
different cows, 111. Exp: Sta. Bui. 9, 1890.
3 Eckles, C. H., and R. H. Shaw, The influence of the stage of
lactation on the composition and properties of milk, U. S.
Dept. Agr. Bur. An. Ind. Bui. 155, 1913. N. Y. Exp. Sta.
Kept. 1892, pages 138-140.
8 THE BOOK OF CHEESE
water, fat, casein, milk-sugar, albumin, ash and enzymes.
These will be discussed separately.
10. Water. The retention of the solids and the elim-
ination of the water are among the chief considerations
in cheese-making. Water forms 84 to 89 per cent of milk.
Cheese-making calls for the reduction of this percentage
to that typical of the particular variety of cheese desired
with the least possible loss of milk solids. This final
percentage varies from 30 to 70 per cent with the variety
of cheese. The water has two uses in the cheese : (1) It
imparts smoothness and mellowness to the body of the
cheese ; (2) it furnishes suitable conditions for the action
of the ripening agents. To some extent the water may
supplement or even replace fat in its effect on the texture
of the cheese. If the cheese is properly made, the water
present is in such combination as to give no suggestion
of a wet or " leaky " product.
11. Fat. Fat is present in the milk in the form of
suspended small transparent globules (as an emulsion).
These globules vary in size with the breed and individ-
uality of the cow and in color from a very light yellow
to a deep yellow shade as sought in butter. Milk with
small fat globules is preferred for cheese-making, because
these are not so easily lost in the process. Milk-fat is
made up of several different compounds called glycerids, 1
which are formed by the union of an organic acid with
glycerine as a base.
Fat is important in cheese-making for two reasons :
(1) Its influence on the yield of cheese; (2) its effect
1 N. Y. Exp. Sta. Kept. 1891, pages 143-162, 316-318.
Wis. Exp. Sta. Kept. 1890, pages 238-247.
Van Slyke, L. L., Conditions affecting the proportions of fat
and protein in cow's milk, Jour. Am. Chem. Soc., 30 (1908),
no. 7, pages 1166-1186.
THE MILK IN ITS RELATION TO CHEESE 9
on the quality of the cheese. Many of the details of
cheese-making processes have been developed to prevent
the loss of fat in manufacture. The yield of cheese is
almost directly in proportion to the amount of fat in the
milk; nevertheless, because the solids not fat do not in-
crease exactly in proportion to the fat, the cheese yield
is not exactly in proportion to the fat. The fat, however,
is a good index of the cheese-producing power of the milk.
12. Casein. Cheese-making is possible because of
the peculiar properties of casein. This is the fundamental
substance of cheese-making because it has the capacity
to coagulate or curdle under the action of acid and rennet
enzymes. Casein is an extremely complex organic com-
pound. 1 Authorities disagree regarding its exact com-
position, but it contains varying amounts of carbon,
oxygen, nitrogen, hydrogen, phosphorus and sulfur, and
it usually is combined with some form of lime or cal-
cium phosphate. It belongs to the general class of
nitrogen-containing compounds called proteins. It is
present in milk in the form of extremely minute gelat-
inous particles in suspension. Casein is insoluble in
water and dilute acids. The acids, when added, cause
a heavy, white, more or less flocculent precipitate.
Rennet (Chapter III) causes the casein to coagulate
(curdle), forming a jelly-like mass called curd, which is
the basis of manufacture in most types of cheese. In
1 Van Slyke, L. L., and A. W. Bosworth, Composition and
properties of some casein and paracasein compounds and their
relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26, 1912.
Forbes, E. B., and M. H. Keith, A review of the litera-
ture of phosphorus compounds in animal metabolism, Ohio
Exp. Sta. Tech. Bui. 5, pages 32-36, 42-45.
Van Slyke, L. L., and A. W. Bosworth, Condition of casein
and salts in milk, N. Y. Exp. Sta. Tech. Bui. 39.
10 THE BOOK OF CHEESE
the formation of this coagulum (curd) , the fat is imprisoned
and held. The casein compounds in the curd hold the
moisture and give firmness and solidity of body to the
cheese. Casein contains the protein materials in which
important ripening changes take place. These changes
render the casein more soluble, and are thought to be
the source of certain characteristic cheese flavors.
13. Milk-sugar. Milk-sugar (lactose) is present in
solution in the watery part of the milk. It forms on the
average about 5 per cent of cow's milk. Since it is in
solution, cheese retains the aliquot part of the totaj
represented by the water-content of the cheese, plus any
part of the sugar which has entered into combination with
the milk solids during the souring process. The larger
part of the lactose passes off with the whey. Lactose 1
is attacked by the lactic-acid bacteria and by them is
changed to lactic acid. Cheeses in which this souring
process goes on quickly, soon contain a large enough
percentage of acid to check the rotting of the cheese by
decay organisms. Without this souring, most varieties
of cheese will begin to spoil quickly. For each variety
there is a proper balance between the souring, which
interrupts the growth of many kinds of putrefactive
bacteria, and the development of the forms which are
essential to proper ripening.
14. Albumin. This is a form of protein which is in
solution in the milk. Albumin forms about 0.7 per
cent of cow's milk. It is not coagulated by rennet. Most
rennet cheeses, therefore, retain only that portion of the
total albumin held in solution in the water retained, as
in the case of milk-sugar. Albumin is coagulated by heat,
forming a film or membrane upon the surface. There
1 Wis. Exp. Sta. Kept. 1901, pages 162-166.
THE MILK IN ITS RELATION TO CHEESE 11
are certain kinds of cheese, such as Ricotte, made by the
recovery of albumin by heating.
15. Ash. The ash or mineral constituents make up
about 0.7 per cent of cow's milk. This total includes
very small amounts of a great many substances. The
exact form of some of the substances is still unknown.
Of these salts, the calcium or lime and phosphorus salts
are most important in cheese-making. They are par-
tially or completely precipitated by pasteurization.
After such precipitation rennet fails to act * or acts very
slowly ; hence pasteurized milk cannot be used for making
rennet cheese unlesfe the lost salts are replaced, or the
condition of the casein is changed by the addition of some
substance, before curdling is attempted.
16. Enzymes. Milk also contains enzymes. These
are chemical ferments secreted by the udder. They have
the power to produce changes in organic compounds with-
out themselves undergoing any change. Minute amounts
of several enzymes are found in milk as follows : Diastase,
galactase, lipase, catalase, peroxidase and reductase.
Just what part they play in cheese-making is not definitely
known.
17. The flavor of feeds eaten by the cow. Unde-
sirable flavors in the milk are due many times to the use
of feed with very pronounced flavors. The most common
of these feeds are onions, garlic, turnips, cabbage, de-
cayed ensilage, various weeds and the like. These un-
desirable flavors reach the milk because the substances
are volatile and are able to pass through the tissues of
the animal. While feed containing these flavors is being
digested, these volatile substances are not only present
1 Sammis, J. L., and A. T. Bruhn, The manufacture of cheese
from pasteurized milk, Wis. Exp. Sta. Research Bui. 27, 1912.
12 THE BOOK OF CHEESE
in the milk, but in all the tissues of the animal. By the
time the process of digestion is completed, the volatile
flavors have largely passed away. Therefore, if the times
of milking and feeding are properly regulated, a dairy-man
may feed considerable quantities of strong-flavored prod-
ucts, such as turnip, cabbage and others, without any
appreciable effect on the flavor of the milk. To ac-
complish this successfully, the cows should be fed im-
mediately before or immediately after milking, preferably
after milking. This allows time for the digestive process
to take place and for the volatile substances to disappear.
If, however, milking is performed three or four hours
after feeding, these volatile substances are present in
the milk and flavor it. 1
In the case of those plants which grow wild in the
pasture, and to which the cows have continued access,
it is more difficult to prevent bad flavor in the milk.
The cows may be allowed to graze for a short time only,
and that immediately after milking, without affecting
the flavor of the milk. This will make it necessary to
supplement the pasture with dry feed, or to have another
pasture where these undesirable plants do not grow.
Undesirable flavors are usually noticeable in the milk
when the cows are turned out to pasture for the first
time in the spring; and when they are pastured on rank
fall feed, such as second growth clover.
18. Absorption of odors. Milk, especially when
warm, possesses a remarkable ability to absorb and
retain odors from the surrounding atmosphere. 2 For
1 Baer, U. S., and W. L. Carlyle, Quality of cheese as affected
by food, Wis. Exp. Sta. Bui. 115, 1904.
2 King, F. H., and E. H. Farrington, Milk odor as affected
by silage, Wis. Exp. Sta. Bui. 59, 1897.
THE MILK IN ITS RELATION TO CHEESE 13
this reason, the milk should be handled only in places
free from such odor. Some of the common sources of
these undesirable odors are bad-smelling stables, strong-
smelling feeds in the stable, dirty cows, aerating milk
near hog-pens, barn-yards and swill barrels. The only
way to prevent these undesirable flavors and odors is
not to expose the milk to them. The safest policy
is to remove the source of the odor.
19. Effect of condition of the cow. Any factor which
affects the cow is reflected in the composition and physi-
ological character of the milk. (1) Colostrum. Milk
secreted just before or just after parturition is different
in physical properties and chemical composition from that
secreted at any other time during the lactation period.
This milk is known as colostrum. It is considered unfit
for human food, either as milk or in products manu-
factured from the milk. Most states l consider colostrum
adulterated milk, and prohibit the sale of the product
for fifteen days preceding and for five days after par-
turition. (2) Disease. When disease is detected in
the cow, the milk should at once be discarded as human
food. Some diseases are common both to the cow and
to man, such as tuberculosis, foot-and-mouth disease.
If such diseases are present in the cow, the milk may act
as a carrier to man. Digestive disorders of any sort in
the cow are frequently accompanied by undesirable
flavors in the milk. These are not thought to be due
to the feed, but to the abnormal condition of the cow.
When the normal condition is restored, these undesirable
flavors disappear.
1 N. Y. Agricultural Law, 1913, section 30.
Mich. Agricultural Law, 1915, section 77.
Wis. Agricultural Law, 1913, section 4601.
14 THE BOOK OF CHEESE
20. Bacteria in the milk. Bacteria are microscopic
unicellular plants, without chlorophyll. Besides bacteria,
there are other forms of the lower orders of plants found
in milk, such as yeasts and molds. While the bacteria
are normally the more important, frequently yeasts and
molds produce significant changes in milk and other
dairy products. Bacteria are very widely distributed
throughout nature. They are so small that they may
easily float in the air or on particles of dust. Many
groups of bacteria are so resistant to adverse conditions
of growth that they may be present in a dormant or spore
stage, and, therefore, not be easily recognized ; when
suitable environments for growth are again produced,
development begins at once. They are found in all
surface water, in the earth and upon all organic matter.
There are a great many different groups of bacteria;
some are beneficial, and some are harmful. As they are
so small, it is difficult to differentiate between the bene-
ficial and harmful kinds, except by the results produced,
or by a careful study in an especially equipped laboratory.
The bacteria multiply very rapidly. This is brought
about by fission ; that is, the cell-walls are drawn in at
one place around the cell, and when the walls unite at the
center, the cell is divided. There are then two bacteria.
In some cases, division takes place in twenty to thirty
minutes. Like other plants, they are very sensitive to
food supply, to temperature and to moisture, as con-
ditions of growth. Inasmuch as the bacteria are plant
cells, they must absorb their food from materials in
solution. They may live on solid substances, but the
food elements must be rendered soluble before they can
be used. Most bacteria prefer a neutral or slightly acid
medium for growth, rather than an alkaline reaction.
THE MILK IN ITS RELATION TO CHEESE 15
Ordinary milk makes a very favorable medium for the
growth of bacteria, because it is an adequate and easily
available food supply.
In milk, certain groups of bacteria are commonly
present, but many others which happen to get into it
live and multiply rapidly. A favorable temperature is
very necessary for such organisms to multiply. There is
a range of temperature, more or less wide, at which
each group of bacteria grows and multiplies with the
greatest rapidity. This range varies with the different
groups, but most of them find temperatures between
75 F. and 95 F. the most favorable for growth. Ex-
cessive heat kills the bacteria. Low temperatures stop
growth, but kill few if any bacteria. Temperatures of
50 F. and lower retard the growth of most forms of
bacteria found commonly in milk. Many forms will
slowly develop, however, below 50 and some growth
will occur down to the freezing point. Milk held at 50
F. or lower will remain in good condition long enough
to be handled without injury to quality until received in
the cheese factory. In the place of seeds, some groups
of bacteria form spores. The spores are exceedingly
resistant to unfavorable conditions of growth, such
as heat, cold, drying, food supply and even chemical
agents. This property makes it difficult to destroy such
bacteria.
21. Groups of bacteria in milk. Milk when first
drawn usually shows an amphoteric reaction; that is,
it will give the acid and alkaline reactions with litmus
paper. Under normal conditions, milk soon begins to
undergo changes, due to the bacteria. Changes pro-
duced in this way are called " fermentations " ; the
agents causing them, "ferments." Normally the acid
16 THE BOOK OF CHEESE
fermentation takes place first, and later other fermenta-
tions or changes begin, which, after a time, so decom-
pose the milk that it will not be suitable for cheese-
making or human consumption.
The following grouping of the organisms in milk is
based on their effects on the milk itself l :
I. Acid-producing types.
II. Peptonizing types.
III. Inert types.
IV. Alkali-producing types.
V. Butyric fermenting types.
Each type of bacteria produces more or less specific
changes in the milk. As a general rule, the predominance
of one of these types is an aid in the interpretation of the
quality of the product at the time of analysis, such as
the age, the temperature at which it has been held, the
conditions under which it was produced and, in some
cases, the general source of the contamination. The
reaction due to certain bacteria is utilized in the manu-
facture and handling of dairy products; other groups
have deleterious effects. (See Fig. 2.)
1 Conn. (Storrs) Exp. Sta. Kept. 1899, pages 13-68.
Conn. (Storrs) Exp. Sta. Kept. 1903, pages 33-98.
Conn. (Storrs) Exp. Sta. Kept. 1904, pages 27-88.
Esten, W. M., and C. J. Mason, Sources of bacteria in milk,
Conn. (Storrs) Exp. Sta. Bui. 51, 1908.
Rogers, L. A., and B. J. Davis, Methods of classifying the
lactic acid bacteria, U. S. Dept. Agr. Bur. An. Ind. Bui. 154,
1912.
Bergey, D. H., The colon-aerogenes group of bacteria, Jour.
Med. Research, Boston, Vol. XIX, pages 175-200, 1908.
Conn, H. W., Classification of dairy bacteria, Conn. (Storrs)
Exp. Sta. Rept. 1906.
Rogers, L. A., Bacteria in milk, U. S, Dept. Agr., Farmers'
Bui. 490, 1912.
THE MILK IN ITS RELATION TO CHEESE 17
22. Acid fermentation of milk. By far the most
common and important fermentation taking place in
milk is due to the action of the lactic acid-forming bacteria
on the milk-sugar or lactose. The bacteria that bring
about this fermentation may be divided into several
groups on the basis of their morphology, proteolytic
activity, gas production, temperature adaptation and
FIG. 2. Effect of different fermentations of milk: U, Curd pitted with
gas holes ; G and 0, gassy curds which float ; K, smooth, solid
desirable curd.
production of substances other than lactic acid. The
larger number of organisms producing lactic acid in
milk also produce other organic acids in greater or less
abundance. Inasmuch as lactic acid is the principal sub-
stance produced, they are called lactic acid organisms.
This group contains different kinds of organisms which
may be subdivided into small groups as follows :
(a) Bacterium lactis-acidi group.
(b) Bacterium colon-aerogenes group.
18 THE BOOK OF CHEESE
(c) Acid peptonizing group.
(d) Bacillus bulgaricus group.
(e) Acid cocci or weak acid-producing group.
23. Bacterium lactis-acidi group. There are many
strains or varieties in this group which are closely related
in their activities. They are universally present in milk
and are commonly the greatest causal agent in its souring.
They are widely distributed in nature. At a temperature
of 65 F. to 95 F., these bacteria grow and multiply very
rapidly; at 70 F. (approximately 20 C.) these forms
usually outgrow all others. The total amount of acid
produced in milk by these organisms varies from 0.6 of
one per cent to 1 per cent acid calculated as pure
lactic acid. These forms coagulate milk to a smooth
curd of uniform consistency. In addition to the lactic
acid, there are produced traces of acetic, succinic, formic
and proprionic acids, traces of certain alcohols, alde-
hydes and esters. Substances other than lactic acid
are not produced by organisms of this group to such
an extent as to impart undesirable flavors to the milk.
The action of this group on the milk proteins is very
slight. They produce no visible sign of peptoniza-
tion. The B. lactis-acidi group of organisms are essential
to the production of the initial acidity necessary in most
types of cheese. The practical culture and utilization
of them for this purpose under factory conditions are
discussed in Chapter IV, entitled " Lactic Starters."
24. Colon-aerogenes group. This group takes its
name from a typical species, Bacterium coli communis,
which is a normal inhabitant of the intestines of man
and animals, and from Bacterium coli aerogenes, which
is similar in many respects to B. coli communis. The
THE MILK IN ITS RELATION TO CHEESE 19
initial presence of these bacteria in milk is indicative of
fecal contamination or unclean conditions of production.
These organisms, however, grow and develop in milk
very rapidly at high temperatures of handling. The
total acidity produced by these forms is less than that by
the Bacterium lactis-acidi group. Of the acid produced,
less than 30 per cent is lactic acid; the other acids are
formic, acetic, proprionic and succinic. The large per-
centage of these acids, with comparatively large amounts
of certain alcohols, aldehydes and esters, invariably im-
part undesirable flavors and odors to the milk. Mem-
bers of this group uniformly ferment the lactose with the
production of the gases, carbon dioxide and hydrogen.
The milk is coagulated into a lumpy curd, containing gas
pockets.
25. Acid peptonizing group. These are often as-
sociated with colon organisms. The group includes
those bacteria which coagulate milk with an acid curd
and subsequently partly digest it. They grow and mul-
tiply rapidly at a temperature between 65 and 98 F.
They impart undesirable flavors and odors to the milk,
which appear to be due to the formation of acids other
than lactic acid, and to action on the milk proteins.
26. Bacillus bulgaricus group. These organisms grow
best at a temperature of 105 to 115 F. They will de-
velop at lower temperatures, but not so rapidly. They
survive heating to 135 F. without loss of vigor, as occurs
in Swiss cheese-making. They produce from 1 to 4 per
cent of acid in milk, which is practically all lactic acid.
They do not produce gas. They impart no undesirable
flavors to the milk.
27. Acid cocci or weak acid-producers. This group
of organisms is not very well defined. It consists mostly
20 THE BOOK OF CHEESE
of coccus forms, commonly found in the air and in the
udder. Their presence in the milk may indicate direct
udder contamination. These are regarded as of little
importance, unless in very large number, and they
have been only partially studied. They produce little or
no lactic acid, and small amounts of acetic, proprionic,
butyric and caproic acids. These forms rarely create
enough acid to coagulate milk.
28. Peptonizing organisms. This group includes all
bacteria which have a peptonizing effect on the milk.
It includes the acid peptonizing organisms, although
they are of primary importance in the acid type of bac-
teria, because the acid-producing power is greater than
the peptonizing power. Some of the specific organisms
in this class are Bacillus subtilis, Bacterium prodigiosus and
Bacterium liquefaciens. These are commonly found in
soil water and in fecal material. The presence of these
organisms denotes contamination from such sources.
<T 29. Inert types. As the name indicates, these are
organisms not known to have an appreciable effect
on milk. The ordinary tests fail to connect them with
important processes; hence they appear to feed upon,
but not to affect the milk in any serious way. Milk
ordinarily contains more or less of these organisms, but
no particular significance is attached to their presence.
30. Alkali-producing bacteria. This group of organ-
isms has only recently been studied in relation to its
action on milk. Investigators still disagree as to the
usual percentage in the normal milk flora. Their pres-
ence in milk has been considered to be relatively un-
important.
31. Butyric fermenting types. Organisms causing
butyric fermentation may be present in the milk, but
THE MILK IN ITS RELATION TO CHEESE 21
seldom become active, because they are commonly an-
aerobic and so will not develop in milk kept under ordinary
conditions, and the rapid growth of the lactic acid-forming
bacteria prevents their growth. These organisms act
on the milk-fat, decomposing it. Butyric acid fermenta-
tions are more common in old butter and cheese. In
these, the fermentation causes a rancid flavor.
32. Molds and yeasts. The cattle feed and the air
of the barn always contain considerable numbers of yeasts
and mold spores. Yeasts have been found by Hastings 1
to cause an objectionable fermentation in Wisconsin
cheese. No further study of this group as factors in
cheese-handling has been reported. Mold spores, es-
pecially those of the blue or green molds (Penicillum sp.)
and the black molds (Mucors), are always abundant
in milk. These spores are carried into all cheeses made
from unpasteurized milk, in numbers sufficient to cover
the cheeses with mold if they are permitted to grow.
Pasteurization 2 kills most of them. The border-line
series commonly referred to as the streptothrix-acti-
nomyces group are also very abundant in all forage and
are carried in large numbers into all milk and its products.
33. Bacterial contamination of milk. When drawn
from the cow, milk is seldom if ever sterile. Organisms
usually work their way from the tip of the teat into the
udder and multiply there. The fore milk usually con-
tains more organisms than does that drawn later. Most
of the bacterial contamination of the milk is due to the
handling after it is drawn from the cow.
1 Hastings, E. G., Distribution of lactose-fermenting yeasts
in dairy products, Wis. Exp. Sta. Kept. 23, pages 107-115.
2 Thorn, C., and S. H. Ayers, Effect of pasteurization upon
mold spores, Jour. Agr. Research 6 (1916), no. 4, pages 153-156.
22 THE BOOK OF CHEESE
34. Germicidal effect of milk. Authorities agree
that when a bacterial examination of the milk is made,
hour by hour, beginning as soon as it is drawn from the
cow, there is no increase in the number of organisms for
a period of several hours at first, but an actual reduction
not infrequently takes place. This is called the " germi-
cidal " 1 property of milk. The lower the temperature
of the milk, the longer and less pronounced is the germi-
cidal action; the higher the temperature, the shorter
and more pronounced is this action.
This is explained as either: (1) a period of selection
within which types of bacteria entering by accident and
unadapted for growth die off ; or (2) an actual weak anti-
septic power in the milk-serum itself ; or (3) the forming
of clusters by the bacteria and so reducing the count.
In working on a small scale or on an experimental
basis, this property at times introduces a factor of
difficulty or error which is not to be lost sight of in the
selection of the milk for such purposes.
35. Sources and control of bacteria in milk. Most
of the bacterial infection of milk is due to lack of care
in handling. Some of the common sources 2 of con-
tamination are : the air in the stable ; the cow's body ;
the milker; the utensils; the method of handling the
milk after it is drawn from the cow; unclean cheese
factory conditions.
1 Hunziker, O. F., Germicidal action of milk, N. Y. (Cornell)
Exp. Sta. Bui. 197.
Stocking, W. A., Germicidal action of milk, Conn. (Storrs)
Exp. Sta. Bui. 37, 1905.
U. S. Treasury Dept., Hygienic Laboratory, Bui. 41, Milk
and its relation to the public health, 1908, also revised as Bui.
56, 1909.
2 U. S. Dept. Agr., Farmers' Bui. 602, Dairy Division, Pro-
duction of clean milk, 1914.
Lauder, A., and A. Cunningham, Some factors affecting the
THE MILK IN ITS RELATION TO CHEESE 23
Since bacteria cause various kinds of fermentation, not
only in the milk but in the products manufactured from
it, the question of their control is of prime importance.
There are two ways in which the bacterial growth in milk
used for cheese-making may be controlled: (1) pre-
vention of infection ; (2) the retardation of their develop-
ment when present. The former is accomplished by strict
cleanliness, the latter by adequate cooling.
36. The cow. The body of the cow may be a source
of bacterial contamination. Bacteria adhere to the hair
of the animal, and to the scales of the skin, and during
the process of milking these are very liable to fall into
the milk. To prevent this, the cow should be curried to
remove all loose material and hair. Just before milk-
ing, the udder and flank should be wiped with a damp
cloth ; this removes some of the material, and causes the
remainder to adhere to the cow.
37. Stable air. If the air of the stable is not clean,
it will be a source of contamination. Particles of dust
floating in the air carry more or less bacteria, and these
fall into the milk during the process of milking. To
bacteriological content of milk, Edinburgh and East of Scotland
Coll. of Agr. Kept. XXVIII, 1913.
Prucha, M. J., and H. M. Weeter, Germ content of milk,
111. Exp. Sta. Bui. 199, 1917.
Harding, H. A., et al., The effect of certain dairy opera-
tions upon the germ content of milk, N. Y. Exp. Sta. Bui.
365, 1913.
Fraser, W. J., Sources of bacteria in milk, 111. Exp. Sta. Bui.
91, 1903.
Frandsen, J. H., Care of milk and cream on the farm, Neb.
Exp. Sta. Bui. 133, 1912.
Conn, H. W., The care and handling of milk, Conn. (Storrs)
Exp. Sta. Bui. 26, 1903.
Stocking, W. A., Jr., Quality of milk as affected by certain
dairy operations, Conn. (Storrs) Exp. Sta. Bui. 42, 1906.
24 THE BOOK OF CHEESE
keep the stable air free from dust at milking time, all
operations which stir up dust, such as feeding, brushing
the cows, cleaning the floor, should be practiced after
milking or long enough before so that the dust will have
settled. It is a good plan to close the doors and to
sprinkle the floor just before milking.
38. The milker himself may be a source of contamina-
tion. He should be clean and wear clean clothing. The
hands should not be wet with milk during milking.
39. Utensils. The utensils are an important source
of bacterial contamination. The bacteria lodge in the
FIG. 3. Types of small-top milk pails.
seams and corners unless these are well-flushed with solder.
From these seams they are not easily removed. When
fresh warm milk is placed into such utensils, the bacteria
begin to grow and multiply. All utensils with which
milk comes in contact should first be rinsed with
cold water and then thoroughly washed and finally
scalded with boiling water, and drained or blown absolutely
dry. They should then be placed in an atmosphere
free from dust until wanted for use again. If an aerator
is used, this should be operated in pure air, free from
odors and dust. One of the greatest sources of bacterial
THE MILK IN ITS RELATION TO CHEESE 25
contamination of cheese milk is the use of the milk-cans
to return whey to the farms for pig feed. Frequently,
sour whey is left in the cans until ready to feed. These
cans are then not properly washed and scalded. The
practice of pasteurizing the whey at the cheese factory
is a great help in preventing this source of infection and
the spreading of disease.
The use of a small-top milk pail 1 is to be especially
recommended in preventing bacterial contamination.
Because of the small opening, bacteria cannot easily fall
into the milk in as large numbers as when the whole top
of the pail is open. (See Fig. 3.)
If a milking machine 2 is used, great care must be
exercised to see that all parts that come in contact
with the milk are cleaned after each milking, and then
put in a clean place until ready to use again.
40. The factory. . Another source of contamination
is the cheese factory itself. The cheese-maker should
keep his factory in the cleanest condition possible, not
only because of the effect on the milk itself, but as a stim-
ulus for the producers to follow his example. All doors
and windows in the factory should be screened to keep
out flies.
41. The control of bacteria. If, in spite of preven-
tive measures, bacteria get into the milk, their growth
can be retarded by controlling the temperature. If the
temperature of the milk, as soon as drawn, can be reduced
1 Harding, H. A., J. K. Wilson and G. A. Smith, Tests of
covered milk pails, N. Y. Exp. Sta. Bui. 326, 1910.
Stocking, W. A., Tests of covered milk pails, Conn. (Storrs)
Exp. Sta. Bui. 48, 1907.
2 Wing, L. W., Milking machines ; their sterilization and their
efficiency in producing clean milk, N. Y. (Cornell) Exp. Sta.
Circ. 18, 1913.
26 THE BOOK OF CHEESE
below that at which the bacteria grow and multiply
rapidly, it will retard their development. In general,
all milk should be cooled to 50 F. or below. In cooling
the milk, it should not be exposed to dust or odors. One
of the best methods of cooling is to set the can containing
the milk into a tub of cold running water, and then stir.
If running water is not available, cold well-water * may be
used, but the water should be changed several times.
If the milk is not stirred during the cooling process, it
will not cool so rapidly, because the layer of milk next
the can will become cold and act as an insulator to the
remainder in the center of the can.
One way to destroy many of the bacteria in milk is by
pasteurization. This consists in heating the milk to
such a degree that the bacteria are killed, and then quickly
cooling it. After pasteurization, the milk is so changed
that some kinds of cheese cannot be made successfully.
42. Fermentation test. When a cheese-maker is
having trouble with gas in his cheese, or bad flavors, he
can generally locate the source of difficulty. This can
be done by making a small amount of cheese from each
patron's milk, called a fermentation test. 2 Pint or
quart fruit jars or milk bottles make suitable containers.
They should be thoroughly washed and scalded, to be
sure they are clean and sterile, and then covered to pre-
vent contamination. As the milk is delivered to the
factory, a sample is taken of each patron's milk. The best
way to secure the sample is to dip the sterile jar in the
can of milk as delivered and fill two-thirds full of milk.
^uddick, J. A., and G. H. Barr, The cooling of milk for
cheese making, Ottawa t)ept. of Agr. Bui. 22, 1910.
2 Wis. Exp. Sta. Kept. 1895, pages 14-150, Fermentation
test for gas-producing bacteria in milk. This is commonly
called the Wisconsin curd test.
THE MILK IN ITS RELATION TO CHEESE 27
The jars are then set in water at 110 F. to bring the
temperature of the milk to 98 F. The jar should be kept
covered. A sink or wash-tub makes a convenient place
in which to keep the jars. When the temperature of the
milk is 98 F., ten drops of rennet extract or pepsin is added
to each jar. A uniform temperature of 98 F. should
be maintained in the jars. This will necessitate the
addition of warm water occasionally to the water sur-
rounding the jars. When the milk is coagulated, the
curd is broken up with a sterile knife. Precaution should
be taken to sterilize the
knife after using it in one
jar before putting it into
another. The best way
to do this is to hold the
knife for a minute in a
pail of boiling water, after
taking it out of each jar.
The same precaution
should be observed with
the thermometer. Unless
care is taken, contamina-
tion is liable to be carried from one jar to the other. After
cutting, the whey is poured off. The temperature should
be kept at 98 F. so that the organisms will have a suitable
temperature for growth. The whey should be poured
from the jars occasionally, usually about every half hour.
As the fermentation takes place, different odors will
be noticed in different jars. In ten to twelve hours the
jar should be finally examined for odors and the curd
taken out and cut to examine it for gas pockets. By
this means, bad flavors and gas in the cheese can be
traced to their sources.
FIG. 4. A gang sediment tester, one
tester removed.
28
THE BOOK OF CHEESE
43. The sediment test. The presence of solid material
or dirt in the milk is always accompanied by bacterial
contamination. By means of the sediment test, the
amount of solid material can be determined. The test
consists of filtering the milk through a layer of cotton ;
the foreign material is left on the cotton filter. Various
devices for filtering the milk have been
manufactured. (Figs. 4 and 5.) In
order to be able to compare the filters
from the different dairy-men's milk, the
same amount of each patron's milk is
filtered, usually about a pint. These
tests are usually made once or twice a
month at the factory and the filters
placed on a card where the dairy-men
can see them. Much improvement in
the quality of the milk has been accom-
plished by the use of the sediment test.
FIG. 5. A single sedi- m, , . , ,
ment tester. * ne purpose oi this test may be and
often is defeated by the use of effi-
cient strainers. Milk produced in an unclean way may be
rendered nearly free from sediment if carefully strained.
It must be remembered that the strainer takes out
only the undissolved substances and that bacteria and
soluble materials which constitute a very large part
of the filth pass through with the milk.
CHAPTER III
COAGULATING MATERIALS
AT the present time, two substances are used to coag-
ulate milk for cheese-making, rennet extract and com-
mercial pepsin. 1 Many substances will coagulate milk,
such as acids and other chemicals. Enzymes in certain
plants will also coagulate it.
The curing or ripening of the cheese seems to depend
on the physical and chemical properties of the curd, on
the activity of certain organisms and on enzymes pro-
duced by them or in the milk. Rennet extract and
pepsin are the only known substances which will produce
curd of such character as will permit the desired ripening
changes to take place. Until recently, rennet extract
was principally used to coagulate the milk, but because
of the scarcity, pepsin is now being substituted.
44. Ferments. Many of the common changes tak-
ing place in milk are due to fermentations. The souring
of milk is one of the most familiar cases of fermentation.
1 Stevenson, C., Pepsin in cheesemaking, Jour. Agr. (New
Zeal.) 14 (1917), pages 32-34.
Todd, A., and E. C. V. Cornish, Experiments in the prepara-
tion of homemade rennet, Jour. Bd. Agr. (London) 23 (1916),
no. 6, pages 549-555.
Besana, C., Lack of coagulating ferment in cheesemaking,
Staz. Sper. Agr. Ital. 49 (1916), pages 10-12.
Van Dam, W., Rennet economy and substitutes, Verslag.
Ver. Exploit. Proefzuivelboerderij. Hoorn, 1914, pages 45-46.
29
30 THE BOOK OF CHEESE
The important change taking place is the formation of
lactic acid from the milk-sugar. The change is brought
about by certain living organisms, namely, the lactic acid-
forming bacteria. Another familiar case of fermentation
is the coagulation of milk by rennet extract or pepsin.
In this case, the change is produced by a chemical sub-
stance, not a living organism. Fermentation may be
defined as a chemical change of an organic compound
through the action of living organisms or of chemical
agents.
There are two general classes of ferments : (1) living
organisms, or organized ferments; (2) chemical, or un-
organized ferments. Organized ferments are living micro-
organisms, capable, as a result of their growth, of causing
the changes. Unorganized ferments are chemical sub-
stances or ferments without life, capable of causing
marked changes in many complex organic compounds,
while the enzymes themselves undergo little or no change.
These unorganized ferments are such as rennin, pepsin,
trypsin, ptyalin. The rennet and pepsin must, there-
fore, be very thoroughly mixed into the milk to insure
complete and uniform results, because they act by con-
tact, and theoretically, if they could be recovered, might
be used over and over again. Practically, the amount
used is so small a percentage that recovery would be
impractical even if possible.
45. Nature of rennet. Two enzymes or ferments
are found in rennet extract, rennin and pepsin. They are
prepared from the secreting areas of living membranes
of the stomachs of mammalian young. For rennet-
making, these stomachs are most valuable if taken before
the young have received any other feed than milk. Ren-
nin at this stage appears to predominate over pepsin
COAGULATING MATERIALS 31
which is already secreted to some extent. With the
inclusion of other feed, the secretion of pepsin comes to
predominate. Rennin has never been separated entirely
from pepsin. Both of these enzymes are secreted by
digestive glands in the same area, perhaps even by the
same glands. They are so closely related that many
workers have regarded them as identical. In practical
work the effectiveness of rennet preparations has been
greatest when stomachs which have digested feed other
than milk are excluded. The differences, therefore,
however difficult to define, appear to be important in
the commercial preparation of rennet.
It was the practice until a few years ago for
each cheese-maker to prepare his own rennet extract.
Each patron was supposed to supply so many rennets.
Now commercial rennet extract and pepsin are on the
market ; however, some Swiss cheese-makers prefer to
make their own rennet extract. For sheep's and goat's
milk cheese, some makers hold that rennet made from kid
or lamb stomachs is best for handling the milk of the
respective species. The objection to the cheese-maker
preparing his own rennet extract is that it varies in
strength from batch to batch and is liable to spoil
quickly. Taints and bad odors and flavors develop
in it and so taint the cheese.
46. Preparation of rennet extract. This extract may
be manufactured commercially from digestive stomachs
of calves, pigs or sheep. An animal is given a full meal
just before slaughtering ; this stimulates a large flow of
the digestive juices, containing the desired enzymes.
The stomach is taken from the animal, cleaned, com-
monly inflated and dried. It may be held in the dry con-
dition until needed for use. Such stomachs are usually
32 THE BOOK OF CHEESE
spoken of as " rennets " in the trade. Such old rennets
may be seen to-day hanging from the rafters of some of
the older cheese factories. When wanted for use, rennets
are placed in oak barrels and covered with water. Before
placing them in the barrel, they are cut open so that the
water may have easy access. Salt is usually added to
the water at the rate of 3 to 5 per cent. They are stirred
and pounded in this solution from five to seven days.
At the end of this time, they are wrung through a clothes-
wringer to remove the liquid. The rennets are put back
into a fresh solution of salt and water, the object being
to obtain all the digestive juices possible. They are
usually soaked from four to six weeks. At the end of
this time, most of the digestive juices will have been re-
moved. The liquid portion is passed through a filter
made of straw, charcoal and sand. When clean, an excess
of salt is added to preserve it.
Such extracts cannot be sterilized by heat because
the necessary temperature would destroy the enzyme.
Effective disinfectants cannot be used in food products.
The extract, therefore, should be kept cool to retard bac-
terial growth. The extract is kept in wooden barrels,
stone jugs or yellow glass bottles to protect it from light,
which is able to destroy its activity. Rennet extract
should be clear, with a clean salty taste and a distinct
rennet flavor. There should be no cloudy appearance
and no muddy sediment in properly preserved rennet.
Rennet extract is on the market in the form of a liquid
and a powder, the former being much more common.
The commercial forms of rennet have the advantage in
the skill used in their preparation and standardization.
The combined product from large numbers of stomachs
may not be as effective a preparation as the most skillfully
COAGULATING MATERIALS 33
produced sample from the very choicest single stomach,
but it gives a uniformity of result which Improves the
average product greatly.
47. Pepsin. Pepsin is on the market in several
commercial forms, as a liquid, scale pepsin and in a
granular form known as spongy pepsin. Some commer-
cial concerns put out a preparation which is a mixture
of rennet extract and commercial pepsin.
48. Chemistry of curdling. The chemistry of casein l
and of curd formation under the influence of acid and
rennet extract and pepsin has been the subject of many
years' research. While many points remain unsettled,
the general considerations together with a large mass of
accepted facts may be presented and some of the unsolved
problems pointed out as left for future researches.
Casein is a white amorphous powder, practically
insoluble in water. It is an acid and as such readily
dissolves in solutions of the hydroxides or the carbonates
of alkalies and alkaline earths by forming soluble salts.
Pure casein salt solutions and fresh milk do not
coagulate on boiling, but in the presence of free acid
coagulation may take place below the boiling temperature.
1 The paragraphs on the chemistry of casein and on rennet
action have been selected from a complete discussion of the
subject by E. B. Forbes and M. H. Keith in Ohio Exp. Sta.
Tech. Bui. 5 entitled, "A review of the literature of phosphorus
compounds in animal metabolism." The original references
cited in this discussion are given at the end of the chapter in the
order of their citation in the text.
See also, Van Slyke, L. L., and D. D. Van Slyke, I, The
action of dilute acids upon casein when no soluble compounds
are formed; II, The hydrolyses of the sodium salts of casein,
N. Y. (Geneva) Exp. Sta. Tech. Bui. 3, pages 75-162, 1906.
Sammis, J. L., S. K. Suzuki and F. W. Laabs, Factors control-
ling the moisture content of cheese curds, U. S. Dept. Agr. Bur.
An. Ind. Bui. 122, pages 1-61, 1910.
34 THE BOOK OF CHEESE
The coagulum formed in the case of milk includes fat
and calcium phosphate. The slight pellicle which coats
over milk when it is warmed is of the same composition.
49. Use of acid. A commonly accepted explanation
of the precipitation of casein by acids is that the casein is
held in solution by chemical union with a base (lime in
the case of milk) ; that added acid removes the base,
allowing the insoluble casein to precipitate; and that
excess of acid unites with casein, forming a compound
which is more or less readily soluble.
50. Robertson's theory. According to Robertson's
conception, in a soluble solution of a protein or its salt,
the molecules of the protein unite with each other to a
certain extent, in this way forming polymers. The re-
action is reversible, and the point of equilibrium between
the compound and its polymeric modification varies
under the influence of whatever condition affects the
concentration of the protein ions. Addition of water,
or of acid, alkali or salt, or the application of heat has
such an effect, and consequently alters the relative num-
ber of heavier molecule-complexes. Robertson's experi-
ments give evidence that one of the effects of increase
of temperature on a solution of casein is a shifting of the
equilibrium in the direction of the higher complexes.
He explains coagulation as being a result of these molec-
ular aggregates becoming so large as to assume the prop-
erties of matter in mass and to become practically an
unstable suspension and then a precipitate. The acid
curd then is casein or some combination of casein with
the precipitant acid.
51. Rennet curd. Rennet extract and pepsin coagu-
lation differs from coagulation by acids, and cannot be
looked on as a simple removal of the base from a caseinate.
COAGULATING MATERIALS 35
The presence of soluble calcium salts (or other alkaline
earth salts) seems to be essential, and the precipitate
formed is not casein or a casein salt, but a salt of a slightly
different nucleoalbumin called " paracasein." Many
writers, following Halliburton, call this modification
produced by rennin the " casein " and that from which
it is derived, " caseinogen." Foster and a few others
have used the term " tyrein " for the rennet clot.
A number of investigations have been made on the
conditions essential or favorable to formation of the
coagulum, especially with regard to the effects of the
degree of acidity and of conditions affecting the amount
of calcium present, either as free soluble salt or bound to
the casein. Soluble salts of calcium, barium and stron-
tium favor or hasten coagulation, while salts of ammonium,
sodium and potassium retard or prevent coagulation.
The bulk of the coagulum from milk is a calcium para-
caseinate, but it carries down with it calcium phosphate
and fat, both of which bodies have been helped to remain
in their state of suspension in milk by the presence of
the casein salt. Lindet (1912) has concluded that about
one-half of the phosphorus contained in the rennet curd
is in the form of phosphate of lime (probably tricalcic),
the other half being organically combined phosphoric
acid.
52. Hammarsten's theory. According to Hammar-
sten (1877, 1896), whose view has been commonly held,
the distinctive effect of the ferment is not precipitation
but the transformation of casein into paracasein. This
is evidenced by the fact that if rennet be allowed to act
on solutions free from lime salts no precipitate occurs;
but there is an invisible alteration of the casein, for now,
even if the ferment be destroyed by boiling the solution,
36 THE BOOK OF CHEESE
addition of lime salts will cause immediate coagulation.
(See also Spiro, 1906.) Hence the process of rennet
coagulation is a two-phase process ; the first phase is the
transformation of casein by rennin, the second is the
visible coagulation caused by lime salts.
Furthermore, if the purest casein and the purest rennin
were used, Hammarsten always found after coagulation
that the filtrate contained very small amounts of a pro-
tein. This protein he designated as the " whey protein."
In accordance with these observations, Hammarsten
(1911) explains the rennin action " as a cleavage process,
in which the chief mass of the casein, sometimes more
than 90 per cent, is split off as paracasein, a body closely
related to casein, and in the presence of sufficient amounts
of lime salts the paracasein-lime precipitates out while
the proteose-like substance (whey-protein) remains in
solution."
By continued action of rennin on paracasein, a further
transformation has been found in several cases (Petry,
1906; Van Herwerden, 1907; Van Dam, 1909), but
perhaps due to a contamination of the rennin with pep-
sin, or to the identity of these two enzymes. The action
which forms paracasein and whey-protein takes place
in a short time (Hammarsten, 1896; Schmidt-Nielson,
1906). The composition and solubilities of paracasein
have received considerable attention. (See Loevenhart,
1904; Kikkoji, 1909; Van Slyke and Bosworth, 1912.)
It is more readily digested by pepsin-hydrochloric acid
than is casein (Hosl, 1910).
53. Duclaux theory. Duclaux (1884) and Loeven-
hart (1904) and others do not accept Hammarsten's
theory ; but to most workers it seems probable, at least,
that the action of the rennin is to cause a cleavage of
COAGULATING MATERIALS 37
casein with formation of paracasein. However, the
chemical and physical differences observed between casein
and paracasein appear to be so slight that Loevenhart
and some others think that they are only physical, per-
haps differences in the size of the colloid or solution
aggregates. Loevenhart conceives of a large part of the
work of the rennet (or of the acid, in acid and heat coagu-
lation) as being a freeing of the calcium to make it avail-
able for precipitation. Some think that the aggregates of
paracasein are larger than those of casein, but there is
more evidence of their being smaller, which idea cor-
responds with the findings of Bosworth, though he looks
on the change as a true cleavage.
54. Bang's theory. Another description of the pre-
cipitation is given by Bang (1911), who studied the prog-
ress of the coagulation process by means of interruptions
at definite intervals. His observations confirm the idea
that rennin causes the formation of paracasein, and
that the calcium salt serves only for the precipitation of
the paracasein ; the rennin has to do also with the mo-
bilizing of lime salts. According to Bang, before coagu-
lation occurs, paracaseins with constantly greater affinity
for calcium phosphate are produced. These take up in-
creasing amounts of calcium phosphate, until finally the
combination formed can no longer remain in solution.
55. Bosworth's theory. By a very recent work of
L. L. Van Slyke and A. W. Bosworth (Van Slyke and
Bosworth, 1912, 1913; and Bosworth and Van Slyke,
1913), in which ash-free casein and paracasein were com-
pared as to their elementary composition, and as to the
salts they form with bases, and the properties of these
salts, it is indicated that the two compounds are alike in
percentage composition and in combining equivalent, the
38 THE BOOK OF CHEESE
paracasein molecule being one-half of the casein mole-
cule. Moreover, Bosworth (1913) has shown that, if the
rennin cleavage be carried out under conditions which
avoid autohydrolysis, no other protein is formed ; also
that, if the calcium caseinate present be one containing
four equivalents of calcium, the paracaseinate does not
precipitate, save in the presence of a soluble calcium
salt, while, if the calcium caseinate be one of two equiva-
lents of base, rennin does cause immediate coagulation.
Bosworth concludes that the rennin action is a cleavage
(probably hydrolytic) of a molecule of caseinate into two
molecules of paracaseinate, the coagulation being a
secondary effect due to a change in solubilities, dicalcium
paracaseinate being soluble in pure water but not in water
containing more than a trace of calcium salt, and the mono-
calcium caseinate being insoluble in water. The alkali
paracaseinates, as well as casemates, are soluble. This
explanation seems to promise to harmonize the observa-
tions with regard to acidity and the effects of the presence
of soluble salts. This theory represents, therefore, many
years of continuous work at the New York Experiment
Station centered primarily on American Cheddar cheese.
Disputed points remain for further study but these
workers have contributed much toward a clear descrip-
tion of the chemical constitution of casein as affected by
rennet action and bacterial activity.
The investigations of these authors and of Hart with
regard to the changes which the paracasein, the calcium
and the phosphorus undergo during the ripening of cheese
(Van Slyke and Hart, 1902, 1905 ; Van Slyke and Bos-
worth, 1907, 1913; Bosworth, 1907) contributed to this
interpretation.
COAGULATING MATERIALS 39
BANG, IVAK, Ueber die chemische Vorgang bei der Milchgerin-
nung durch Lab, Skand. Arch. Physiol. 25, pages 105-144 ;
through Jahresb. u. d. Fortsch. d. Thierchem. 41, pages
221-222, 1911.
BOSWORTH, A. W., The action of rennin on casein, N. Y. Exp.
Sta. Tech. Bui. 31, 1913.
BOSWORTH, A. W., Chemical studies of Camembert cheese,
N. Y. Exp. Sta. Tech. Bui. 5, 1907.
BOSWORTH, A. W., and L. L. VAN SLYKE, Preparation and com-
position of basic calcium caseinate and paracaseinate,
Jour. Biol. Chem. Vol. 14, pages 207-210, 1913.
DUCLAUX, EMILE, Action de la presure sur le lait, Compt.
Rend. Acad. Sci. 98, pages 526-528, 1884.
HAMMARSTEN, OLOF, Zur Kenntnis des Caseins und der Wirkung
des Labfermentes, Nova. Acta Regiae Soc. Sci. Upsaliensis
in Memoriam Quattuor Saec. ab Univ., Upsaliensi Perac-
torum, 1877.
HAMMARSTEN, OLOF, Ueber das Verhalten des Paracaseins zu
dem Labenzyme, Zeit. physiol. Chem. 22, pages 103-126,
1896.
HAMMARSTEN, OLOF, A text book of physiological chemistry,
from the author's 7th German edition, 1911.
HOSL, J., Unterschiede in der tryptischen und peptischen Spal-
tung des Caseins, Paracaseins und des Paracaseinkalkes aus
Kuh- und Ziegenmilch, Inaug. Diss. Bern., 31 pp., 1910.
KIKKOJI, T., Beitrage zur Kenntniss des Caseins und Paracaseins,
Zeit. physiol. Chem. No. 61, pages 130-146, 1909.
LINDET, L., Solubilite des albuminoides du lait dans les elements
du serum ; retrogradation de leur solubilite sous 1'influ-
ence du chlorure, Bui. Soc. Chim. (ser. 4) 13, pages 929
935.
LINDET, L., Sur les elements mineraux contenus dans la caseine
du lait, Rep. Eighth Internat. Congr. of Applied Chem. 19,
199-207, 1912.
LOEVENHART, A. S., Ueber die Gerinnung der Milch, Zeit.
physiol. Chem. 41, pages 177-205, 1904.
PETRY, EUGEN, Ueber die Einwirkung des Labferments auf
Kasein, Beitrage z. Chem. Physiol. u. Path. 8, pages 339-
364, 1906.
ROBERTSON, T. BRAILSFORD, On the influence of temperature
upon the solubility of casein in alkaline solutions, Jour.
Biol. Chem. 5, pages 147-154, 1908.
SCHMIDT-NIELSON, SIGVAL, Zur Kenntnis des Kaseins und der
Labgerinnung, Upsala lakaref. Forh. (N. F.) No. 11, Suppl.
40 THE BOOK OF CHEESE
Hammarsten Festschrift No. XV, 1-26 ; through Jahresb.
u. d. Fortschr. d. Thierchem. No. 36, pages 255-256, 1906.
SPIRO, K., Beeinflussung und Natur des Labungsvorganges,
Beitrage z. Chem. Physiol. u. Path. 8, pages 365-369, 1906.
VAN DAM, W., Ueber die Wirkung des Labs Auf . Paracaseinkalks,
Zeit. physiol. Chem. No. 61, pages 147-163, 1909.
VAN HERWERDEN, M., Beitrag zur Kenntnis der Labwirkung
auf Casein, Zeit. physiol. Chem. 52, pages 184r-206, 1907.
VAN SLYKE, L. L., and A. W. BOSWORTH, I. Some of the first
chemical changes in Cheddar cheese. II. The acidity of
the water extract of Cheddar cheese, N. Y. Exp. Sta. Tech.
Bui. 4, 1907.
VAN SLYKE, L. L., and A. W. BOSWORTH, Composition and
properties of some casein and paracasein compounds and
their relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26,
1912.
VAN SLYKE, L. L., and A. W. BOSWORTH, Composition and
properties of some casein and paracasein compounds and
their relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26,
1912.
VAN SLYKE, L. L., and A. W. BOSWORTH, Method of preparing
ash-free casein and paracasein, Jour. Biol. Chem. Vol. 14,
pages 203-206, 1913.
VAN SLYKE, L. L., and A. W. BOSWORTH, Preparation and com-
position of unsaturated or acid caseinates and paracaseinates,
Ibid. Vol. 14, pages 211-225, 1913.
VAN SLYKE, L. L., and A. W. BOSWORTH, Valency of molecules
and molecular weights of casein and paracasein, Ibid. Vol.
14, pages 227-230, 1913.
VAN SLYKE, L. L., and A. W. BOSWORTH, Composition and prop-
erties of the brine-soluble compounds in cheese, Jour. Biol.
Chem. 14, pages 231-236, 1913.
VAN SLYKE, L. L., and E. B. HART, A study of some of the salts
formed by casein and paracasein with acids; their rela-
tions to American Cheddar cheese, N. Y. Exp. Sta. Bui. 214,
1902.
VAN SLYKE, L. L., and E. B. HART, Casein and paracasein in
some of their relations to bases and acids, American Chem.
Jour. 33, pages 461-996, 1905.
VAN SLYKE, L. L., and E. B. HART, Some of the relations of
casein and paracasein to bases and acids, and their applica-
tion to Cheddar cheese, N. Y. Exp. Sta. Bui. 261, 1905.
CHAPTER IV
LACTIC STARTERS
ACIDITY in cheese-making arises almost exclusively
from the lactic acid produced from the fermentation of
milk-sugar (lactose) by bacteria. Hydrochloric acid
is used in the Wisconsin l process of making pasteurized
milk cheese and sometimes for making skimmed-milk curd
for baking purposes. It is regularly used in precipitat-
ing casein not for food but for manufacturing purposes.
56. Acidifying organisms. Many species of bacteria
have been shown to possess the power to produce lactic
acid by fermenting lactose. In practice, however, the
cheese-maker seeks to control this fermentation by the
actual introduction of the desired organisms and by the
production of conditions which will insure this dominance
through natural selection. For this purpose the initial
souring for most types of cheeses is produced by some
variety of the species originally described by Esten 2
and commonly referred to as Bacterium lactis-acidi, but
variously named as B. acidi-lactici, Streptococcus lacticus,
B. guntheri by different authors. Organisms of this
series dominate all other species in milk which is in-
1 Sammis, J. L., and A. T. Bruhn, The manufacture of
Cheddar cheese from pasteurized milk, Wis. Exp. Sta. Research
Bui. 27, 1912.
2 Esten, W. M., Bacteria in the dairy, Conn. (Storrs) Kept.
1896, pages 44-52.
41
42 THE BOOK OF CHEESE
cubated at 70 F. They produce a smooth solid mass
without a sign of gas holes and without the separation
of whey from the curd, and develop in milk a maximum
acidity of about 0.90 of one per cent when titrated as
lactic acid. (For titration see Chapter V.) This species
is usually present in small numbers in fresh milk. There
are many varieties or strains of the species with differing
rates of activity and measurable differences in acid pro-
duced but with approximately the same qualitative
characters. Most commercial starters for cheese- and
butter-making belong to this group of species, although
special mixtures with other organisms are prepared
for special purposes. In addition to this group, most
varieties of cheese contain some members of the colon-
aerogenes group. When the milk is in proper condition,
the activity of this group should be held in check by the
early and rapid development of acid. Free development
of members of this group usually shows itself in the
presence of gas holes in the curd.
57. Starter. The practice of using pure cultures
in cheese-making has brought about the development
of factory methods of producing day by day cultures of
the organisms desired, in quantities sufficient to inoculate
the total quantity of milk used in manufacture. For
this purpose milk is mostly used and the product is known
as " starter." For cheese-making purposes, a starter
is a substance used in the manufacture of dairy products
having a predominance of lactic acid-forming micro-
organisms in an active state. There are two general
classes of starter: (1) Natural starter; (2) commercial
starter.
58. Natural starter. Milk, or other similar substance,
which has become sour or in which large numbers of
LACTIC STARTERS 43
lactic acid-forming organisms are present, is called a
natural starter when used in the manufacture of dairy
products. To secure clean-flavored milk, the cheese-
maker usually selects the milk of some producer who
usually brings good milk and allows it to sour natu-
rally for use the next day. There is often a variation
from day to day in the milk delivered by the same
producer, so that the cheese-maker is not certain of a
uniform quality in his fundamental material. While
the lactic acid-forming organisms are developing, other
organisms may also be present in numbers sufficient to
produce bad flavors. If a starter has any objectionable
flavor, it should not be used. Natural starters very
commonly develop objectionable flavors which at first
are very difficult to recognize. When natural starters
with objectionable but not easily recognizable odors are
used, the effect may be seen on the cheese. Milk, sour
whey and buttermilk are materials commonly used as
natural starter. A common difficulty in skimmed-milk
cheese is caused by the use of buttermilk as a starter.
59. Commercial starter or pure cultures. The alter-
native practice consists in the introduction of pure cul-
tures of known strains of lactic bacteria into special milk
to make the starter. Since these cultures must be pre-
pared by a bacteriologist, commercial laboratories have
developed a large business in their production. Many
such commercial brands are manufactured under trade-
marked names. Some of these cultures represent races
of lactic bacteria cultivated and cared for efficiently, hence
uniformly valuable over long periods of time. Others care-
lessly produced are worthless, or even a peril to the user.
These organisms are usually shipped in small quantities
in bottles of liquid or powder, or in capsules of uniform
44 THE BOOK OF CHEESE
size. The contents may be either the culture medium
upon which the organisms grew or inert substance designed
merely to hold the bacteria in inactive form. In either
solid or liquid form, the producer of the culture should
guarantee its activity up to a plainly stated date.
It is the problem 1 of the cheese-maker or butter-maker
to increase this small amount of lactic acid-forming or-
ganisms to such numbers and in such active condition
that it may be used in the factory; while being built
up, these organisms must be kept pure. The usual prac-
tice is to allow them to develop in some material, usually
whole milk or skimmed-milk ; dissolved milk powder may
be used in the place of milk.
60. Manufacturer's directions. The manufacturer
usually sends directions with his starter preparation,
telling how it should be used to secure the best result.
These directions apply to average conditions and must be
varied to suit the individual instances so that a good
starter will be the result. The directions usually state
the amount of milk necessary for the first inoculation.
It is usually a small amount, one or two quarts. After
the specific amount has been selected, this milk should
be pasteurized.
61. Selecting milk. The milk for use in starter-
making should be selected with very much care. Only
clean-flavored sweet milk, free from undesirable micro-
1 Bushnell, L. D., and W. R. Wright, Preparation and use of
butter starter, Mich. Exp. Sta. Bui. 246, 1907.
Hastings, E. G., Preparation and use of starter, Wis. Exp.
Sta. Bui. 181, 1909.
Larsen, C., and W. White, Preparation and use of starter,
S. D. Exp. Sta. Bui. 123, 1910.
Guthrie, E. S., and W. W. Fisk, Propagation of starter for
butter-making and cheese-making, N. Y. (Cornell) Exp. Sta.
Circ. 13, 1912.
LACTIC STARTERS 45
organisms, should be used in the preparation of starter.
The milk is ordinarily chosen from a producer whose
milk is usually in good condition. The quality of the
milk can be determined by the use of the fermentation
test. (See Chapter II.) It is better to choose only
the morning's milk for the making of starter, because
the bacteria have not had so much opportunity to
develop. In no case should the mixed milk be used in
the preparation of starter, as this eliminates all oppor-
tunity for selection. The flavor of the starter will be the
same as that of the milk from which it is made.
62. Pasteurization is the process of heating to a high
temperature for a given length of time and quickly cool-
ing. It kills most of the micro-organisms in the
milk. In other words, it makes a clean seed-bed for
the pure culture. The temperatures of pasteurization
recommended for starter-making differ with the authority.
A temperature of 180 F. for thirty minutes or longer
seems to be very satisfactory, since under these condi-
tions nearly all the micro-organisms in the milk are killed.
63. Containers. Various kinds of containers may
be used for starter-making. One-quart glass fruit jars or
milk bottles make very satisfactory containers, because
the condition of the starter may be seen at any time.
They are also easily cleaned. They have the disad-
vantage, however, of being easily broken, if the tem-
perature is suddenly changed, or if severely jarred.
Tin containers may also be used. Such containers are
not easily broken, but they are harder to clean and must
be opened to examine the contents; hence the liability
of contamination is very much greater.
This small amount of milk may be pasteurized by plac-
ing the container in water heated to the desired tempera-
46 THE BOOK OF CHEESE
ture. A very satisfactory arrangement is to cut off a
barrel, and place a steam pipe in it. The barrel can then
be filled partly full of water and heated by steam. The
bottles of milk to be pasteurized are hung in the water in
the barrel. Two or three more bottles should be prepared
than it is expected will be used as some of the bottles
are liable to be broken while cooling or heating. The
bottles should be filled about two-thirds full. This leaves
room enough to add the mother starter and later to break
up the starter to examine it. It is desirable not to have
the milk or starter touch the cover since contaminations
are more likely. It is a good plan when pasteurizing to
have one bottle as a check. This may be filled with
water and left open and the thermometer placed in it.
A uniform temperature may be obtained by shaking the
bottles.
64. Adding cultures. After being pasteurized, the
milk should be cooled to a temperature of 80 F. This
is a suitable temperature for the. development of the
lactic acid-forming organisms. The commercial or pure
culture should now be added to the milk at the rate
specified in the directions. Care should be exercised in
opening bottles not to put the covers in an unclean place.
A sterile dipper is a good place to put them. After the
culture has been added to the milk, it should be mixed
thoroughly by shaking the bottle. This should be re-
peated every fifteen or twenty minutes for four or five
times. This is done to make certain that the culture
is thoroughly mixed with the milk. The milk should
be placed in a room or incubator as near 80 F. as pos-
sible, in order to have a uniform temperature for the
growth of the organisms. The bacteria in the pure
culture are more or less dormant so that a somewhat
LACTIC STARTERS 47
higher temperature than the ordinary is necessary to
stimulate their activity. This milk should be coagulated
in eighteen to twenty-four hours, depending largely on
the uniformity of the temperature during incubation.
65. Cleanliness. To produce a good starter, great
care should be exercised that all utensils coming in
contact with the milk are sterile. After the milk is
in the container in which the starter is made, it
should be kept covered as continuously as possible.
Thermometers should not be put into it to ascertain the
temperature. When examining the starter, do not dip
into it, but pour out, as this prevents contamination.
The cover, when removed from the container, should be
put in a sterile place in such way that the dirt will
not stick to it and later get into the starter.
66. " Mother " starter or startoline. The thickened
sour milk obtained by inoculating the sweet pasteurized
milk with pure culture of lactic acid-forming bacteria
is known as " mother starter " or " startoline."
67. Examining starter. This starter should be ex-
amined carefully as to physical properties, odor and taste.
The coagulation should be smooth, free from whey and
gassy pockets or bubbles. Sometimes the first few in-
oculations from a new culture will show signs of gas,
but, usually, this will quickly disappear, and not injure
the starter. It should have a clean sour cream odor and
clean, mild, acid flavor. After breaking up it should be
thick and creamy, entirely free from lumps. This starter
may have an objectionable flavor, due to the media in
which the organisms were growing when shipped. In
such cases it is necessary to carry the starter one or two
propagations to overcome the flavor, to enliven the
micro-organisms and to secure the quantity desired.
48
THE BOOK OF CHEESE
68. Second day's propagation. For the second day,
the milk for the starter is selected as on the first day.
It is pasteurized, and this time cooled to 70 F. The
milk is cooled a trifle colder the second day than the
first, because the organisms have become more active
and hence do not require as high a temperature to grow.
Instead of inoculating with powder, as was done the
first day, the mother starter prepared the first day is
used. This requires only a very small amount, perhaps
a tablespoonful to a quart bottle. It should be thor-
oughly mixed with the milk. This starter may have the
flavor of the media used in
the laboratory culture,
therefore may need to be
carried one or two days
more to eliminate it. After
the flavor has become nor-
mal, the mother starter is
ready for commercial use.
69. Preparation of larger
amount of starter. The
first thing to determine is
the quantity of starter re-
quired. As much milk
should be carefully chosen
as the amount of starter
desired. This milk should
then be pasteurized. An
improved starter-can (Fig. 6) may be used in the pas-
teurization of the milk and the making of starter, or
a milk-can (Fig. 7) placed in a tub of water in which
there is a steam pipe. The former requires mechanical
power to operate the agitator, but the latter can be used
FIG. 6. An improved starter-can.
LACTIC STARTERS
49
FIG. 7. A simple device for
preparation of starter.
the
where mechanical power is not available. In the latter
the milk and starter are stirred by hand. This is the
kind of apparatus more
often found in cheese
factories.
If possible, this milk
should be pasteurized to
180 F. for thirty minutes ;
this kills most of the bac-
teria and spores. The
milk should be cooled to
60-65 F., the tempera-
ture of incubation. This
temperature may be varied
with conditions, so that
the starter will be ready for use at the desired time.
The higher the temperature, the less time is required to
ripen the starter.
70. Amount of mother starter to use. The mother
starter prepared the day before is now used to inoculate
the starter milk. The amount to use will depend on :
1 . Temperature of milk when mother starter is added ;
2. Average temperature at which the milk will be kept
during the ripening period ;
3. Time allowed for starter to ripen before it is to be used ;
4. Vigor and acidity of the mother starter added.
There is a very wide range as to the amount of mother
starter required, from 0.5 of one per cent to 10 per cent
being used under different conditions.
Some operators prefer to add the mother starter while
the milk is at a temperature of about 90 F., before it has
been cooled to the incubating temperature. This reduces
the amount of mother starter necessary.
50 THE BOOK OF CHEESE
If an even incubating temperature can be maintained,
it will require less mother starter than if the temperature
goes down.
If the ripening period is short, it will require a larger
amount of mother starter, than if the ripening period is
longer. If the starter has a low acidity or weak body
indicating that organisms 'are of low vitality, it will re-
quire more mother starter.
71. Qualities. The starter, when ready to use, may
or may not be coagulated ; a good idea of the quality of
the starter may be gained by the condition of the coagu-
lation. The coagulation should be jelly- or custard-like,
close and smooth, entirely free from gas pockets and
should not be wheyed off.
When broken up, the starter should be of a smooth
creamy texture and entirely free from lumpiness or
wateriness. It should have a slightly pronounced acid
aroma. The starter should be free from taints and all
undesirable flavors; the flavor should be a clean, mild
acid taste.
72. How to carry the mother starter. Some mother
starter must be carried from day to day to inoculate
the large starter. This may be carried or made in several
ways :
1. Independently; By this method a mother starter
is made and carried entirely separately from the large
starter. It requires more time and work, but is by far
the best method. With a good mother starter, there is
not so much danger of the larger starter becoming poor
in quality.
2. Mother starter may be made by dipping pasteurized
milk from that prepared for the large starter with sterile
jars and then inoculating these jars separately. By
LACTIC STARTERS 51
this method, if the milk selected for the large starter is
poor, the mother starter for the next day will be the same.
It is very difficult by this method to carry a uniform,
high quality mother starter.
There is danger that the container used for the mother
starter may not be sterile, and there is also danger of
contamination in transferring the milk.
3. Another practice is to hold over some of the large
starter used to-day for mother starter. This is by far
the easiest method. By this practice, there is no cer-
tainty of the quality of the starter, because there is little
or no control of the mother starter. If the large starter
is for some reason not good, there is no separate reserve
of mother starter on which to rely.
73. Starter score-cards. The use of a score-card tends
to analyze the observations in such a way as to emphasize
all the characteristics desired in the starter. Such an
analysis seeks to minimize the personal factor and pro-
duce a standardization of the quality. The score-card
finally reduces the qualities of the starter to a numerical
basis for ease of comparison. Many score-cards have
been proposed but the one preferred by the authors is
that used by the Dairy Department of the New York
State College of Agriculture, which is as follows :
CORNELL SCORE-CARD
Flavor 50 Clean, desirable acid.
Aroma 20 Clean, agreeable acid. No undesir-
able aroma.
Acidity 20 0.6 per cent-0.8 per cent.
Body 10 Before breaking up: jelly-like, close,
absence of gas holes. No free
whey. After breaking up :
smooth, creamy, free from gran-
ules or flakes.
52 THE BOOK OF CHEESE
The qualities mentioned in this score-card can be
quickly and easily determined by examining and tasting
the starter and by making an acid test of a sample. The
acid test is conducted as with milk (see Chapter II) ex-
cept the starter must be rinsed out of the pipette with
pure water. Some starter score-cards call for a bacterial
examination and counting of the starter organisms. This
takes a considerable period of time and is not entirely
necessary. The physical properties and acid test are
closely correlated with the presence of the desired organ-
isms.
74. Use of starter. If all milk could be clean and
sweet and the only fermentation from it were the clean
acid type, a starter would be useless. Such milk is hard
to obtain ; therefore, a starter is used to overcome the bad
fermentation. This improves the flavor, body and tex-
ture of the cheese. The common contaminations which
the starter will tend to correct are :
1. Gas-producing bacteria.
2. Yeasts.
3. Bad flavors or taints.
The length of time a starter may be carried depends
on the accuracy and carefulness of the maker. This
calls for scrupulous attention to the temperature, the
selection of milk and keeping out contaminations. The
maker must remember that a starter is not merely milk,
but milk full of a multitude of tiny plants, very sensi-
tive to food, temperature, clean surroundings and the
quantity of their own acid.
75. The amount of starter to use depends on the
amount of acid desired in the milk for any particular
kind of cheese. The great abuse of starter is the practice
LACTIC STARTERS 53
NEW YORK STATE COLLEGE OF AGRICULTURE AT CORNELL
UNIVERSITY
STARTER LOT-CARD Department of Dairy Industry.
Day and Date
MILK:
Kind % fat % solids not fat.
Flavor
Amount of milk ... Hours old._..
PASTEURIZATION :
Method
Milk when received : Temperature.
Acidity %
Heating : Turning on heat APM.
Desired temp, reached APM.
Turning off heat APM.
Length of time at desired temp
Beginning to cool
Cooled. APM ; to
Acidity: After pasteurization
When inoculated
INOCULATION :
Time Temperature
Amount Ibs %
INCUBATION :
Temperature Time .-.
MOTHER STARTER USED:
Source % used
Times propagated Acidity
Amount used. Appearance
Flavor
Comments _
STARTER :
Time of examining
Temperature
Flavor 50
Aroma -.20
Acidity 20
Body._ 10
Total .. 100
SCORE-CARD :
Clean, desirable acid.
Clean, agreeable acid. No undesirable aroma.
0.6%-0.75%.
Before breaking up : jelly-like, close, absence of gas
holes. No free whey.
After breaking up : smooth, creamy, free from granules
or flakes.
The above is a tentative score-card.
COMMENTS: ...
Work and observation by.
54 THE BOOK OF CHEESE
of using; too much. It is better and safer to add starter
a little at a time and several times than to add too much
at once. When starter is added to milk for cheese-making,
it should be strained to remove any lumps ; otherwise an
uneven color is likely to result.
76. Starter lot-card. For certain dairy operations,
a permanent record is desired. This is especially true
in the making of starter and certain varieties of cheese.
A lot-card not only serves as a record- but also points out
the succeeding steps of the operation. This latter is
especially useful for beginners and students. Page 53
shows a desirable lot-card to be used when making
starter. Each operation has been referred to the page
in the text where it is discussed. This makes this
particular lot-card an index to the whole process of starter-
making as here treated.
CHAPTER V
CURD-MAKING
ASIDE from the purely sour-milk cheeses, the coag-
ulum or curd resulting from rennet action is the
basis of cheese-making. The finished cheese, whatever
its final condition, is primarily dependent on a particular
chemical composition and fairly definite physical char-
acters in the freshly made curd mass* These characters
are determined by a series of factors under control of
the cheese-maker. Assuming the milk to be normal in
character, success depends on the use of a proper combina-
tion of these factors. The possible variations in each
factor together with their number makes an almost in-
finite series of such combinations possible. The essential
steps in the process are, therefore, presented as under-
lying all cheese-making. The special adaptations of
each factor are considered in the discussion of the vari-
eties group by group.
These factors follow :
A. The coagulation group :
1. Fat-content of the milk.
2. The acidity of the milk.
3. The temperature of renneting.
4. The effective quantity of rennet.
5. Curdling period or the time allowed for rennet
action.
55
56 THE BOOK OF CHEESE
B. The handling group :
6. Cutting or breaking the curd.
7. Heating (cooking) or not heating.
8. Draining (including pressing, grinding and
putting into hoops or forms).
77. The composition of the milk. The fat percentage
in the milk in the cheese- vat should be known to the
cheese-maker and be strictly under his control. The fat
tester and the separator make this clearly possible. He can
go further. Milk from particular herds whose quality is
a matter of record from the routine test of each patron's
milk may be selected and brought together for the manu-
facturer of cheese of special quality. Control of casein
or lactose, on the contrary, is not nearly so practicable.
The purchase of milk on the fat test has become so well
established in most dairy territories, as to insure the
presence and constant use of the tester. A fat test of the
mixed product in the cheese- vat in connection with estab-
lished tables thus insures an accurate knowledge of the
materials which go into each day's cheese. For some
varieties of cheese, whole milk should always be used.
For other Varieties, the addition or removal of fat is
regularly recognized as part of the making process. The
presence of added fat or the removal of fat affects the
texture of the product and the details of the process of
making.
78. Cheese color. An alkaline solution of annatto is
usually used as a cheese color. This colors both casein
and fat in contrast to butter color which is an oil solution
of the dye and mixes only with the fat. Cheese color
is added to the milk in making some varieties of
cheese, and not for others. When lactic starter is used,
CURD-MAKING 57
the color should be added after the starter and just before
the addition of the rennet. The amount is determined
by the color desired in the cheese. The usual amount
varies from one to four ounces to each thousand pounds
of milk. Before adding, the color should be diluted in
either milk or water, preferably water. It should then
be mixed thoroughly with the milk.
79. The acidity factor. Milk as drawn shows a meas-
urable acidity when titrated to phenolphthalein with
normal sodium hydroxide. This figure varies with the
composition of milk. Casein itself gives a weakly acid
reaction with this indicator. Calculated as lactic acid,
this initial acidity varies within fairly wide limits, records
being found from 0.12 to 0.21 of one per cent or even more
widely apart. Commonly, however, such titration shows
0.14 to 0.17 per cent. Some forms of cheese (Limburger,
Swiss, Brie) are made from absolutely fresh milk. Acidity
from bacterial activity is important as a factor in the
making of most types of cheese and probably in the
ripening of all types.
Increasing the acidity of the milk hastens rennet action
and within limits produces increased firmness of the curd.
If carried too high, acidity causes a grainy or sandy curd.
Normally fresh milk is sufficiently acid in reaction when
tested to phenolphthalein to permit rennet to act, but
the rate of action increases rapidly with the develop-
ment of acid. Increase of acidity may be accomplished :
(a) by the addition of acid as has been done by Sam-
mis l and Bruhn in pasteurized milk for Cheddar
cheese; or (6) by the development of acid through the
1 Sammis, J. L., and A. T. Bruhn, The manufacture of cheese
of the Cheddar type from pasteurized milk, U. S. Dept. Agr.
Bur. An. Ind. Bui. 165, pages 1-95, 1913.
58 THE BOOK OF CHEESE
activity of lactic organisms, which is the usual way.
For renneting, the acidity necessary for particular cheeses
runs from that of absolutely fresh milk still warm (as
in French Brie, Limburger, Swiss, Gorgonzola) through
series calling for increase of acidity, hundredth by hun-
dredth per cent calculated as lactic acid. This ranges
from 0.17 to 0.20 per cent as is variously used in Ameri-
can factory Cheddar to about 0.25 to 0.28 per cent as
obtained by adding acid in Sammis' method. This
method is discussed under the heading " Cheddar Cheese
from Pasteurized Milk " (p. 229) since it requires special
apparatus and has not thus far been used with other types
of cheese. For the development of acidity by the action
of bacteria, lactic starter is almost universally used.
This may be added in very small quantities and the
acidity secured by closely watching its development or
by adding starter 'in amount sufficient to obtain the re-
quired acidity at once. In either case, the cheese-maker
needs to know the rate of action of the culture to in-
sure the proper control of the process. The amount of
acid already present when the rennet is added affects not
only the texture of the curd as first found, but within
limits indicates also the rate at which further acidity may
be expected to develop.
A series of experiments in making Roquefort were tabu-
lated to show the rate of acidification from various initial
points. In the graphs (Fig. 8) the curves for acid de-
velopment are parallel after the determination reaches
0.30 per cent. These experiments were made at a tem-
perature 80 to 84 F. Milk at the lowest acidities tried
developed titratable acid very slowly. A period of several
hours was required to produce sufficient acid to affect the
curd texture. When the acid reached 0.25 per cent by titra-
CURD-MAKING
59
tion, the further rise was rapid and all the lines became
almost straight and parallel after the titration reached 0.30
.55
.50
.45
40
.35
.30
.25
.20
15
Hours
12345
FIG. 8. The acidification of Roquefort cheese.
per cent. If this rapid souring occurred after the comple-
tion of the cheese-making process, the texture of the
experimental cheese was not measurably affected. In
those cases, however, in which 0.30 per cent was reached
before the cheese reached its final form in the hoop, the
60 THE BOOK OF CHEESE
texture of the ripened cheese was entirely different from
that desired for this variety under experiment. These
curves apply directly to but one cheese process in which
a particular combination of acidity, rennet and time is
used to obtain a very delicately balanced result. In other
varieties it is equally important to obtain exactly the ad-
justment of these factors which will bring the desired result.
80. Acidity of milk when received. If proper care
has been taken, milk should be delivered to the factory
fresh, clean and without the development of acid. If
the milk has not been handled properly, the early stages
of souring or some other unfavorable fermentation will
have developed. Such milk may develop too much
acid, or gas, or any one of several objectionable flavors
during the making and ripening of the cheese. Some
cheese-makers become very expert in detecting the first
traces of objectionable qualities, but most makers are
dependent on standardized tests to determine whether
milk shall be accepted or rejected, and when accepted to
determine the rate at which it may be expected to respond
during the cheese-making process.
Various tests have been devised to determine the
amount of acid present in milk. There are two tests
commonly used in cheese-factories. One is known as
the " acid test " and the other the " rennet test."
81. The acid test 1 is made by titrating a known
amount of milk (Fig. 9) against an alkali solution of
1 Publow, C. A., An apparatus for measuring acidity in cheese-
making and butter-making, Cornell Exp. Sta. Circ. 7, pages 17-
20, 1909.
Hastings, E. G., and A. C. Evans, A comparison of the
acid test and the rennet test for determining the condition of
milk for the Cheddar type of cheese, U. S. Dept. Agr. Bur. An.
Ind. Circ. 210, pages 1-6, 1913.
CURD-MAKING
61
known strength, using phenolphthalein as an indi-
cator. The object of the indicator is to tell the con-
dition of the milk, whether i't is acid, alkaline or neutral.
The indicator does not change in an acid solution but
turns pink when the solution is or becomes alkaline.
To make the test, a known quantity of the material to
be tested is placed in a
white cup, and to this
several drops of indicator
are added. As an indi-
cator, a 1 per cent solu-
tion of phenolphthalein
in 95 per cent alcohol is
commonly used. As an
alkali solution, sodium
hydroxide (NaOH) is
used in the standardized
strength usually either
tenth (N/10) normal or
twentieth (N/20) normal.
This solution should be
obtained in some one of
the standardized forms
commercially prepared.
The alkali is added, drop
by drop, from a gradu- FIG. 9. An acid tester.
ated burette until a faint
pink color appears. This shows that the acid in the
milk has been neutralized by the alkali. The amount
of alkali that has been used can be determined from the
burette. Knowing the amount of milk and alkali solu-
tion used, it is easy to calculate the amount of acid in
the substance tested. The results are usually expressed
62
THE BOOK OF CHEESE
either as percentages of lactic acid or preferably as cubic
centimeters of normal alkali required to neutralize 100
or 1000 c.c. of milk. This kind of test is on the market
under different names> such as Mann's, Publow's, Far-
rington's and Marschall J s.
82. Rennet tests. Several rennet tests have been
devised, but the one most widely used is the Marschall
(Fig. 10). This consists of a 1 c.c. pipette to measure
the rennet extract, a small bottle in
which to dilute the extract, a special
cup to hold the milk and a spatula to
mix the milk with the rennet extract.
This cup has on
the inside from
top to bottom a
scale graduated
from at the top
to 10 at the bot-
tom. There is a
hole in the bottom
to allow the milk
to run out.
83. Marschall rennet test. To make a Marschall
rennet test, 1 c.c. of rennet extract is measured, with
the 1 c.c. pipette, and placed in the bottle. Care
should be exercised to rinse out the pipette. The bottle
is then filled to the mark with cold water. After the
milk has been heated to the setting temperature, 84-
86 F., the cup is filled with milk and set on the edge of
the vat so that the milk running out through the hole
in the bottom of the cup will flow into the vat. Just
as the surface of the milk reaches the mark on the cup,
the diluted rennet extract is added and thoroughly mixed
i ,
FIG. 10. Marsc
all rennet test.
CURD-MAKING 63
with the milk, using the small spatula to stir it.
The rennet and milk should be mixed until it has run
down at least one-half space on the scale in the cup. As
the rennet begins to coagulate the milk, it runs slower
from the hole in the bottom of the cup, until it finally
stops. When it stops, the point on the scale indicated
by the surface of the coagulated milk is noted. The
test is recorded by the number of spaces the surface of
the milk lowers from the time the rennet is added until
it is coagulated. This test depends on three factors :
the strength of the rennet extract, the temperature of
the milk, the acidity of the milk. The more acid, the
quicker the milk will coagulate. To measure any one
of these factors, the other two must be constant.
The variable factor is the acidity of the milk. This test
will not indicate the percentage of acid in the milk, but is
simply a comparative test to be used from day to day;
for example, if the rennet test to-day shows three spaces,
and the operator makes that milk into cheese and the
process seems to be normal, it shows that for good results
in this factory, milk should be ripened to show three
spaces every day. If the next day the milk showed four
spaces, it should be allowed to ripen more until it shows
three spaces. If it shows only two spaces, this indicates
that the milk has too much acid development or is over-
ripe. A cheese-maker will have to determine at what
point to set his milk, because the test will vary from one
factory to another.
84. Comparison of acid and rennet test. Each of
these tests has its advantages and disadvantages. The
advantage of the acid test is that it can be made as
well of warm as cold milk. This is of great impor-
tance in determining whether the milk delivered by any
64 THE BOOK OF CHEESE
patron is too ripe to be received. The acidity of other
materials, such as whey and starter, can be determined
as well as that of milk. The disadvantages are that it
is difficult to get the alkali solution of the proper strength
and the solution is liable to deteriorate on standing. It
requires a careful exact operator to make the test.
The advantages of the rennet test are that it is easy to
make, and it requires no materials that are hard to re-
place. The disadvantage is that the milk must be
warmed to the same temperature before a comparative
test can be made. The size of the outlet in cups varies.
It does not indicate the percentage of acid present in the
milk. It is simply a comparative test. To obtain the
best result, both tests should be used in conjunction.
85. Control of acid. The control of acidity in curd and
cheese is dependent on the control of the moisture or
water-content. The control of both factors is very impor-
tant in relation to the quality 1 of the cheese. Often acio>
ity is spoken of when moisture is really intended, and
vice versa. The close relation between the moisture and
acidity is due to the presence of the milk-sugar in solution
in the milk-serum which becomes the whey of cheese-
making. Water or moisture in cheese consists of the
remnant of this whey which is not expelled in the making
process. During manufacture and the ripening process,
the milk-sugar is changed to lactic acid. A cheese may
be sweet when first made and after a time become sour
because it contains too much moisture in the form of
whey. Excess of whey carries excess of milk-sugar
from which fermentation produces intense acidity.
1 Doane, C. F., The influence of lactic acid on the quality of
cheese of the Cheddar type, U. S. Dept. Agr. Bur. An. Ind. Bui.
123, pages 1-20, 1910.
CURD-MAKING 65
Various tests have been devised to determine the
amount of acid developed at the different stages of manu-
facture. These tests are described on page 61. By the
use of such tests, the development of acid during the
manufacturing process can be very accurately determined.
There is no quick, accurate test to determine the amount
of moisture in the curd. The cheese-maker has to rely
on his own judgment, guided largely by the appearance,
feeling and condition of the curd.
After the rennet extract has been added, all control
of the acid development is lost. The cheese-maker can
determine rather accurately how fast the acid will de-
velop during the ripening of the milk. This shows the
importance of the proper ripening. The amount of acid
developed during the different stages of the manufactur-
ing process can be approximately followed with the various
acid tests. The manufacturing process should then be
varied to obtain the proper relation between the moisture
and the acid present. The only time that the acidity
may be controlled is when the milk is being ripened.
If too much acid is developed before the rennet is added,
there is apt to be too much acid at each stage of the manu-
facturing process. This is liable to hurry the cheese-
making process and to cause a loss, both in quality and
quantity of cheese, and may cause a high acid or sour
cheese. If sufficient acid is not developed at the time
the rennet is added or if the milk is not sufficiently ripened,
the acid is liable not to develop fast enough so that there
will not be sufficient at each step in the cheese-making
process. Such a cheese is called " sweet." There are
several conditions which will cause an over-development
of acid. Such a cheese is called " acidy " or " sour."
These factors are within the control of the cheese-maker,
66 THE BOOK OF CHEESE
hence should be avoided. A sour cheese shows lack of
skill and care on the part of the cheese-maker.
Conditions canning an acidy or sour cheese:
Receiving sour or high acid milk at the cheese -factory.
Use of too much starter.
Ripening the milk too much before the rennet is added.
Removing the whey before the curd is properly firmed,
hence leaving it with too much moisture.
Development of too much acid in the whey before the
whey is removed.
Improper relationship between the moisture and acidity
at the time of removing the whey.
Conditions causing deficient acid:
Adding the rennet before sufficient acid has developed.
Not using sufficient starter.
Not developing sufficient acid in the whey.
86. Acidity and rennet action. The rennet extract
acts only in an acid medium. The greater the acid de-
velopment, within certain limits, the faster the action of
the rennet. If enough acid has developed to cause a
coagulation of the casein, the rennet will not coagulate the
milk. This is one reason why Cheddar cheese cannot
be made from sour milk.
87. Acidity and expulsion of the whey. The con-
traction of the curd and expulsion of the whey are so
closely related that they may be treated under the
same heading. The more acid, the faster the whey
separates from the curd, other conditions being uniform.
The relation of acidity and firmness of the curd to temper-
ature of the curd is another important factor in the suc-
cessful manufacture of cheese. The higher the acidity,
the faster the temperature of the curd can be raised with-
CURD-MAKING 67
out any harmful effects. If the temperature is raised
too fast in relation to the acidity, the film surrounding
each piece of curd will become toughened so that the
moisture will not be able to escape. When this condition
exists, the curd will feel firm but when the pieces are
broken open the inside is found to be very soft. This
results in a large loss later or may cause a sour cheese.
It usually causes an uneven texture and color in the cheese.
88. Acidity in relation to cheese flavor. Just what
part the acid plays in the development of cheese flavor
is not known. If a certain amount of acid is not present,
the characteristic cheese flavor does not develop. If too
much acid is developed, it gives the cheese a sour flavor
which is unpleasant. If sufficient acid is not developed,
the other undesirable factors seem to be more active,
causing very disagreeable flavor and may cause the cheese
to putrefy. A cheese with a low acid usually develops
a very mild flavor, and if carried to extremes, as in the
case of some washed curd cheese, the true cheese flavor
never develops.
89. Acidity in relation to body and texture of cheese.
If a cheese is to have a close, smooth, mellow, silky
body and texture, a certain amount of acid develop-
ment is necessary. If too much acid is developed, the
body and texture will be dry, harsh, sandy, mealy,
corky. If the acid is not sufficient the cheese may be
soft or weak bodied, and is usually characterized by
" Swiss curd holes," which are spaces of various sizes
usually more or less round and very shiny on the inside.
90. Acidity in relation to cheese color. An over-
development of acidity affects the color of a cheese. If
this development of acidity is uniform throughout the
cheese, it causes the color to become pale or bleached.
68 THE BOOK OF CHEESE
If this development is uneven, due to the uneven distri-
bution of moisture, the color will be bleached in spots,
causing a mottled effect.
91. Control of moisture. 1 The cheese-maker must
use skill and judgment in regulating the amount of mois-
ture in relation to the firmness of the curd and the acid.
Since there are no quick accurate tests to determine
the amount of moisture, this is left entirely to the judg-
ment of the operator. Certain methods of handling
the curd reduce the moisture-content, while others in-
crease it. The cheese-maker must decide how to handle
the curd. If the curd becomes too dry, methods should
be employed to increase the moisture, and vice versa.
Causes of excessive moisture:
Cutting the curd coarse.
Cutting the curd after it has become too hard.
Setting the milk at a high temperature.
Use of excessive amount of rennet extract.
Low acid in the curd at the time of removing the whey.
Not stirring the curd with the hands as the last of the
whey is removed.
High piling of the curd during the cheddaring process.
Piling the curd too quickly after removing the whey.
Use of a small amount of salt.
Holding the curd at too low a temperature after the
whey is removed.
Soaking the curd in water previous to salting.
Allowing the curd to remain in the whey too long so
that it reabsorbs the whey.
Heating the curd too rapidly.
1 Fisk, W. W., A study of some factors influencing the yield
and moisture content of Cheddar cheese, Cornell Exp. Sta. Bui.
334, 1913.
CURD-MAKING 69
Causes of insufficient moisture:
Cutting the curd too fine or breaking up the pieces
with the rake into too small pieces.
Cutting the curd too soft.
Stirring the curd too much by hand as the last of
the whey is being removed.
Developing high acid in the curd at the time of
removing the whey.
Insufficient piling of the curd during the cheddaring
process.
Using a large amount of salt.
High temperature and low humidity in the curing
room.
92. Relation of moisture to manufacture and quality.
(1) Flavor: If the cheese contains too much moisture,
it is likely to develop a sour or acidy flavor. A cheese
with a normally high moisture-content usually ripens or
develops a cheese flavor much faster than one with a
lower moisture^ontent, other conditions being uniform.
A cheese with a high moisture-content is much more
liable, during the curing process, to develop undesirable
flavors than is one with a lower moisture-content. (2)
Body and texture: A cheese containing too much mois-
ture is very soft and is difficult to hold in shape. Such
a product breaks down very rapidly and is usually pasty
and sticky in texture. If too .little moisture is present,
the cheese is very dry and hard, and cures or ripens very
slowly because of the lack of moisture together with milk-
sugar from which acid may be formed. Dry cheeses
are usually harsh, tough and rubbery in texture. Such
cheeses also have poor rinds. (3) Color: If the ideal
conditions exist, the moisture will be evenly distributed
throughout the cheese. The spots containing more
70 THE BOOK OF CHEESE
moisture will be lighter in color. If a cheese con-
tains so much moisture that it becomes " acidy," the
effect is the same as when too much acid is developed,
that is, the color becomes pale from the action of the
acid. (4) Finish: A cheese containing too much moisture
is usually soft. A good rind does not form. Such a
cheese loses its shape very easily, especially in a warm
curing room. (5) Quality: A cheese with a high mois-
ture-content is usually marketable for only a very short
period. Such a product usually develops flavor very
quickly in comparison to a dry cheese. It must be
sold very soon because if held too long, the flavor be-
comes so strong as to be undesirable, and objectionable
flavors are liable to develop. In some cases, such
cheeses rot.
93. Relation of moisture to acidity. From the pre-
ceding discussion, it is evident that the relation between
the moisture and acidity is very close, in fact so intimate
that in some cases it is difficult to distinguish one from
the other when the quality of the cheese is considered.
The proper relation of the moisture and the acidity de-
termines the quality of the resulting cheese. If too much
acid is developed during the manufacturing process, the
product will be sour. If too much moisture is retained
in the form of whey, the cheese will be sour. The less
acid in the curd, the more moisture in the form of
whey may be retained in the curd without causing a
sour cheese. The proper relationship between the mois-
ture and the acidity must be maintained or a sour cheese
will result.
The relation of the moisture to the acidity also has an
influence on the curing. If the cheese has a low develop-
ment of acidity and a low moisture-content, it will cure
CURD-MAKING 71
very slowly. The increasing of either the acidity or
moisture usually increases the rate of cheese ripening,
other factors being the same.
The relation of the acidity and the moisture is so im-
portant that it cannot be neglected without injuring
both the quality and quantity of cheese. This knowl-
edge can be obtained only by experience.
94. Setting temperature. The temperature of ren-
neting makes very much difference in the texture of
the product. The enzyme rennin is sensitive to very
slight changes in temperature. Below 70 F., its rate of
action is very slow. Beginning with approximately
20 per cent of its maximum effectiveness at 70 F. (the
curdling point for Neufchatel), it has risen to 65 per cent
at 84 F., to 70 per cent at 86 F., as used in Cheddar,
to about 80 to 85 per cent at 90-94 F., as used in Lim-
burger. At 105 F. it reaches its maximum effective
working rate to fall from that efficiency to about
50 per cent at 120 F. Curdling at low temperature
lengthens the time required for the same amount of ren-
net to curdle a given quantity of the same milk. The
texture of curd produced at temperatures between 70 F.
and 84 F. is soft, jelly-like, friable rather than rubbery.
At 86 F. it begins to show toughening or rubbery char-
acters which become very marked at 90 F. to 94 F.
as used in Limburger. With the increased Vigor of
action as it passes its maximum rate of action at
105 F., the texture tends to become loose, floccose to
granular. Aside from the Neufchatel group, the work-
ing range of temperatures for the renneting period
runs from about 84 F. to about 94 F., a range of
barely 10 F., or the use of 65 per cent to 80 or pos-
sibly 85 per cent of the maximum efficiency of the
72 THE BOOK OF CHEESE
rennet. Within this range of temperature, the curd has
the physical characters demanded for making most vari-
eties of cheese.
95. Strength of coagulating materials. Rennet and
pepsin preparations vary in strength and in keeping
quality. With a particular stock, changes go on to such
a degree that the last samples from a barrel of rennet are
much weaker than the earlier ones. Each sample, barrel,
keg or bottle should be tested before used. In continuous
work the results of each day's work furnish the guide for
the next day's use of a particular lot of rennet.
96. Amount of coagulating materials to use. For
most varieties of cheese, sufficient rennet extract or
pepsin is added to the milk to give a firm curd in twenty-
five to forty minutes. Of the ordinary commercial rennet
extract, this requires from two and one-half to four
ounces to one thousand pounds of milk. This gives a
maximum of one part rennet for each four to six thousand
parts of milk. The great strength of the rennet extract
is thus clearly shown.
97. Method of adding rennet. Before rennet is
added to the milk, it is diluted in about forty times its
volume of cold water, which chills the enzyme and retards
its action until it can be thoroughly mixed with the milk.
If the material is added without such dilution, the
concentrated extract produces instant coagulation in
the drops with which it comes in contact, forming solid
masses from which the enzyme escapes only slowly to
diffuse throughout the mass. Uniform coagulation thus
becomes impossible. After the rennet extract has been
diluted with cold water, it should be distributed the
entire length of the vat in an even stream from a pail.
It should then be mixed with the milk by stirring from
CURD-MAKING 73
top to bottom for about three to four minutes. For
this purpose, either a long-handled dipper or a wooden
rake may be used. A dipperful should be drawn from
the gate and stirred into the vat, otherwise the milk in
the gate will fail to coagulate properly because the rennet
diffuses too slowly to reach and affect all the milk at that
point. The milk should be stirred on the top, preferably
with the bottom of a dipper, until signs of coagulation
begin to appear. This stirring keeps the cream from
rising. There are various ways or signs to indicate
when the coagulation has gone to the stage at which
the mix is about to become thick : (1) The milk becomes
lazy or thicker as the finger is passed through it; (2)
bubbles caused by moving the finger remain on the milk
longer, usually until one can count ten when ready to
thicken.
If the milk is stirred too long or after it begins to thicken,
the result is a granular sort of curd, and there will be an
abnormally large loss of fat in the manufacturing process.
The addition of the rennet and subsequent stirring re-
quire the exercise of great care and constant attention to
details. The cheese-maker can do nothing else for those
few minutes. When through stirring, it is a good plan
in cold weather to cover the vat with a cloth as this will
keep the surface of the curd warm. In summer the same
cover will keep out the flies.
Causes of a delayed coagulation :
(1) Weak rennet extract or too small an amount.
(2) Low temperatures due to inaccurate thermometers.
(3) Pasteurized milk.
(4) Presence of abnormal bacterial ferments.
(5) Presence of preservatives.
74; THE BOOK OF CHEESE
(6) Heavily watered milk.
(7) Use of badly rusted 1 cans.
(8) Milk containing small amounts of casein or cal-
cium salts.
Causes of uneven coagulation:
(1) Uneven temperature of the mix in the vat, due
to lack of agitation.
(2) Uneven distribution of the rennet extract.
(3) Adding rennet to vat too soon after heating, while
the sides and bottom are still hot, causes curd to stick
to sides and bottom of the vat making cutting difficult.
(4) Sloshing after the milk begins to thicken breaks
the curd and causes it to whey off.
98. The curdling period. The time allowed for
rennet action also affects the texture of the 'curd. The
enzymes of rennet (rennin and pepsin) do not cease acting
with the thickening of the milk. In many cheeses, the
handling process begins as soon as the curd has become
solid enough to split cleanly before a finger thrust into
it. If let stand further, the same curd mass will con-
tinue to harden with the progressive separation of whey ;
this shows first as drops (" sweating ") on its surface,
which then increase in number and size until they run
together and form a sheet of whey. The limit of such
action is difficult to measure. The solidifying process
ceases in a period of hours. The further action of the
enzymes is digestive in character and goes on slowly. It
requires a period of weeks or even months to accomplish
measurable results at the working temperatures in use
in the trade. Other ripening agents with more rapid
1 Olson, G. A., Rusty cans and their effect upon milk for
cheese-making, Wis. Exp. Sta. Bui. 162, pages 1-12, 1908.
CURD-MAKING 75
action intervene to shape the final result. It follows
that the rennet factor in the ripening changes found at
the end of the period is almost negligible for most varieties
of cheese, although it appears to be measurable in some
varieties.
99. Cutting or breaking l the curd. As soon as curd
is formed, separation of whey begins upon the surface
and perhaps around the sides of the vessel. This is
accompanied by shrinkage and hardening of the mass.
If the curd remains unbroken, the separation is extremely
slow. In cheese-making practice, such curd masses may
be dipped at once into hoops as in Camembert, dumped
in mass into cloths for drainage as in Neufchatel or, as
in the larger number of cheeses, cut or broken in some
characteristic manner. After the curd mass is firm, the
rate at which subsequent changes take place depends
largely on the size of the particles into which the curd is
cut. The smaller the particles, the quicker the water is
expelled. Consequently the development of the acidity
and other changes take place more slowly. For this
reason the curd should be cut into pieces of uniform size.
If the work is not properly performed, the pieces of curd of
various sizes will be at different stages of development.
The fine particles will be firm and elastic while the larger
particles are still soft and full of whey and may be de-
veloping too much acid. The knives should be inserted
into the curd obliquely so that they will cut their way
1 The term " broken " is included here because the use of some
curd-breaking tool has always formed a step in certain com-
mercially successful processes. In every case in which careful
experimental work has been done the curd knife has been suc-
cessfully substituted for the breaking tool and has reduced the
losses of fat and casein and in addition aided in obtaining more
uniform cheese.
76 THE BOOK OF CHEESE
into the curd and not break it. The horizontal knife
is used lengthwise of the vat and cuts the curd into layers
of uniform thickness. The perpendicular knife then is
used lengthwise and crosswise of the vat. It first cuts
the curd into, strips and then into cubes. The knives
may have wire blades or steel blades, some operators
preferring one and some the other. Whichever is used,
the blades should be close enough together to give the
fineness of curd desired.
After the knife passes through, the cut faces quickly
become covered with a smooth coating, continuous
over all exposed areas. This surface has the ap-
pearance of a smooth elastic coating or film. This
can be seen by carefully breaking a piece in the
hand. It is this film which holds the fat within the
pieces of curd. If the film is broken, some of the fat
globules are lost because the rennet extract acts only
on the casein and that in turn holds the fat. All the
fat globules which come in contact with the knives as
they pass through the curd will be left between the
pieces of curd and will pass off in the whey. If care is
exercised in cutting, the loss of fat will be confined to what
may be called a mechanical loss. This is similar to the
loss of the sawdust when sawing a board. This loss in
American Cheddar is about 0.3 per cent and cannot be
avoided. If it is greater than this, it is due to negligence
on the part of the cheese-maker or the poor condition of
the milk. The cutting of the curd into small pieces may
be considered a necessary evil. If the moisture could
be expelled from the whole mass without disturbing it,
this fat loss could be prevented. The cutting, breaking
or turning should be done with the greatest care, that
the loss may be as small as possible.
CURD-MAKING
77
100. Curd knives. For cutting curd, special knives
have been devised (Fig. 11). They consist of series of
parallel blades fixed in a frame to make cuts equidistant.
The blades run vertically in one, horizontally in another.
Horizontal
Perpendicular Horizontal Perpendicular
FIG. 11. Blade and wire curd knives.
They are spaced according to the demands of the variety
of cheese to be made. Wires stretched in a frame take
the place of blades in some makes of curd knife.
101. Heating or " cooking." Curdling by rennet
has already been shown to be markedly hastened by
moderate heating. After the coagulum or curd is
formed, the making process may be completed without
the application of further heat, as in Neufchatel,
Camembert and related forms (Fig. 12) and in some
practices with Limburger. In other forms and especially
in the hard cheeses in which cutting of curd is a prominent
78
THE BOOK OF CHEESE
part of the process, the curd after being cut is reheated
or " cooked." The cooking process hastens the removal
of the whey, thus shortening the time required to reduce
12545
FIG. 12. The heat relation. See pages 77 and 87.
the water-content of the mass to the percentage most
favorable for the type of cheese desired. The process
also produces marked changes in the physical character
CURD-MAKING 79
of the curd mass. With the rise in temperature the casein
becomes elastic first, then approaches a melting condition
and assumes a tough, almost rubbery consistency. The
final texture is the result of the combination of the
amount of rennet added, the temperature, the acidity
reached during the process, and the final water-content
of the mass.
102. Draining (including grinding, putting into hoops
or forms and pressing) . The reduction of the water
in the curd begins almost as soon as the curd becomes
firm. It is aided by cutting or breaking, by the retention
of the heat applied before renneting and by the second-
ary heating or cooking used in making certain groups of
cheeses. In many varieties special apparatus is provided
in the form of draining boards, draining racks or bags
to hasten the removal of the whey as fast as it separates.
The draining process continues until the cheese has
reached its final form and weight. The intervening
process of matting in the Cheddar group involves a com-
bination of a souring process with the removal of whey,
during which the cubes of curd become fused into semi-
solid masses. If such masses are formed, they must be
ground up before the cheese can be given its final form
in the hoop. The draining process, therefore, may take
any one of many forms varying from the direct transfer
of freshly formed curd into hoops in which the entire
draining process is completed, to an elaborate series of
operations which end in pressing curd drained to approxi-
mately its final condition before it is placed in the hoop.
103. Application to cheese. From the discussion of
these factors, it is evident that the cheeses produced
will differ widely with the differences in manipulation. If
one considers essential constituent substances separately,
80 THE BOOK OF CHEESE
the water-content of the finished product is found
to vary from 30 per cent in Parmesan to 75 per cent
in cottage cheese. The fat-content runs from a trace
in some varieties to 60 per cent in some cream cheeses.
The texture of the casein, which gives character to the
product, varies from the tough or glue-like consistency
of freshly made Swiss to the buttery condition of a cream
or Neufchatel cheese. Inside such limits the tastes of
different peoples have led to the manufacture of many
kinds of cheese. Each of these varieties represents some
particular combination of curd-making factors and
ripening conditions which produces a cheese suited to
the taste of the maker and consumer of that country or
community.
CHAPTER VI
CLASSIFICATION
THE literature of cheese-making contains reference
to more than 500 names for varieties of cheese. Many
of these can be thrown readily into great groups or fam-
ilies in which there are variations in unessential detail
without modifying the characteristic texture and flavor
of the product. Many varietal names are attached to
the product of single factories or factory groups. Such
varieties frequently differ only slightly in size or shape,
or in stage of drainage or of ripening, from widely known
varieties or other similar local forms. The descriptions
recorded for such varieties commonly emphasize minor
differences in manipulation without showing differences
in essential factors. Vessels of particular size are pre-
scribed to be made of wood, earthenware, or of a special
metal. These details specify the exact size and shape of
hoops, the use of particular styles of cutting or breaking
instruments and of certain stirring tools, the material
and construction of mats and draining racks.
The descriptions themselves are very commonly in-
adequate. The variable factors in cheese-making are
fat-content of the milk, acidity, temperature of setting,
amount of rennet, time allowed for curdling and the
method of draining the curd. The differences in practice
lie, with few exceptions, in the amount or intensity of
particular factors, not differences in kind or quality of
G 81
82 THE BOOK OF CHEESE
treatment. Such contrasts are quantitative, not qualita-
tive. A great number of combinations is possible by
small variations of these factors.
Varieties selected as types of groups give marked con-
trasts in character, but comparison of large numbers of
forms shows that almost every gradation from group to
group can actually be found. Within groups frequently
the same physical results in texture and flavor can be
obtained by combinations or adjustments of factors
for the purpose of offsetting or counteracting the effects
of one change in practice by the manipulation of other
factors. In ripening, an equally large range of practices
makes possible the development of very different qual-
ities in mature cheeses from the same lot.
Only a few of the large number of described varieties
have obtained even national importance; fewer still
are known outside the country of origin. In spite of the
success of special products when properly advertised,
the largest place in the market is clearly accorded to
the standard forms which are widely known.
104. Basis of classification. A series of these widely
known forms has been chosen as typical of groups in a
system of classification adapted from the French of Pouriau.
No completely satisfactory scheme of classifying all of these
varieties has been devised. The grouping proposed here is
based on the principles of curd-making already discussed
together with consideration of the ripening processes to be
discussed with each group. 'The factors that actually
influence the quality of the final product are separated as
completely as possible from non-essential operative details.
The common use of the terms " soft " and " hard "
cheese is based on the single arbitrary fact of texture.
The term " semi-hard " cheese may be conveniently
CLASSIFICATION 83
applied to a miscellaneous group of unrelated families
which are intermediate in texture between such soft
forms as Neufchatel or Camembert and really hard
cheeses like Cheddar or Parmesan. Although these
terms are not made the main basis of the proposed
grouping, their application to sections is indicated.
Classification based on the essential facts of manufac-
ture is, however, really helpful.
ANALYTICAL TABULATION OP GROUPS
Section I. Cheeses with sour milk flavor only (Eaten fresh).
(Soft cheeses 45 to 75 % water) PAGE
1. Curdled by souring, Cottage cheese and
its allies in America, many related
varieties in Europe 90
2. Curdled by souring and rennet the
Neufchatel group 95
a. Skim Skim-milk Neufchatel . . . 105
6. Part skim to whole milk American or
Domestic Neufchatel 106
c. With fat added the cream cheeses of
the Neufchatel group (both American
and European) such as Cream, Ger-
vais, Malakoffs, etc 108
Section II. Cheeses ripened.
Subsection A. Soft cheeses (40 to 50% water).
1. Curdled by souring, heated, then
ripened.
Hand cheese, Pennsylvania pot
cheese, Harz, etc 112
2. Curdling by souring and rennet,
ripened
Ripened (French) Neufchatel . .114
3. Curdled primarily by rennet.
a. Ripened by mold Camembert,
Brie and their allies . . .117
6. Ripened by bacteria.
* Made from soft or friable curd
d'Isigny, Liederkranz, etc. 134
** Made from firm or tough curds
Limburger and allies . . 139
84 THE BOOK OF CHEESE
Subsection B. Semi-hard cheeses, firm, well-drained
(38 to 45% water). , PAQB
a. Curd not cooked, ripened by molds.
* Made from friable curd
Roquefort 150
** Made from firm or tough curd
Gorgonzola, Stilton and
such French forms as Gex,
Septmoncel 158
6. Curd cooked and ripened by bac-
teria, brick, Munster, Port
du Salut (Oka) . . . . . 164
Subsection C. Hard cheeses, cooked and pressed (30 to
40% water).
a. Ripened without gas holes.
1. Dutch Edam, Gouda ... 173
2. Danish.
3. The Cheddar group.
* English Cheddar and numer-
ous related forms known
principally in Great Britain 184
** American the factory Ched-
dar of United States and
Canada ....... 184
6. Ripened with the development of
gas holes.
* Holes large Swiss-Emmen-
thal, Gruy^re, American
Swiss 276
** Holes small Parmesan and
related varieties .... 288
Such a classification brings together series of products
in which there is essential similarity in the final output,
however great the differences in manipulation. It does
not consider all varieties and specialties. Some of these
groups are important enough to demand special mention.
105. Processed cheeses. Cheese of any group may
be run through mixing and molding machines and re-
packaged in very different form from that characteristic
of the variety. In such treatment, the texture and
CLASSIFICATION 85
appearance may be so changed as to give the effect of a
new product. Substances (such as pimiento) are added
to change the flavor. Or the product may be canned
and sterilized with equally great change of flavor and tex-
ture. One thus finds Club made from Cheddar; Pimi-
ento from Cream, Neufchatel or Cheddar; similarly
olive, nut and other combinations are made. The
possible variations are numerous.
106. Whey cheeses. Several products bearing cheese
names are made from whey. These take the forms of
the recovery of the albumin and casein separately or in
a single product, and the recovery of the milk-sugar
either alone or with the albumin. Whey cheeses have
been especially developed by the Scandinavian people,
although some of them have their origin in the south of
Europe. Certain of these varieties are produced on a
limited scale in America.
There are a number of forms fairly widely known that
are difficult to place in this scheme of groups. Among
these are Caciocavallo, Sap Sago.
107. Soft and hard cheeses. Another . commonly
used classification makes two groups: (1) soft cheeses;
(2) hard cheeses. In such a classification the semi-hard
^roup presented here is included with the soft cheeses.
Some cheeses of this group are soft in texture. This is
correlated with high water-content, high fat-content or
both together.
108. Relation of moisture to classes. In this classi-
fication the water-content reflected in the texture of the
cheese assumes first place. To carry the analysis some-
what further by showing the correlation between water-
content and certain factors, a tabulation of well-known
varieties of typical groups is presented (Table III). In
86
THE BOOK OF CHEESE
this table the series of typical dairy products are first
arranged according to water-content of the final product.
Approximate limits of percentages of milk-fat are also
given, because milk-fat frequently affects texture to
a degree almost equal to water. Column 4 gives the
period within which the more quickly perishable cheeses
are usable, and the length of the ripening for the more
solid forms. The correlation between water-content,
texture and the time of keeping is clearly shown for most
varieties.
TABLE III
CORRELATION WATER- AND FAT-CONTENT WITH RIPENING
VARIETY op
PER
CENT
WATER
PER
CENT
FAT
PERIOD
REQUIRED
RIPENING
AGENT
Cheese: Soft,
Cottage ....
70
trace
a few days
Bacteria
Skim Neufchatel .
70
trace
a few days
Bacteria
Neufchatel . . .
50-60
12-28
a few days
Bacteria
Camembert . . .
50
22-30
3-5 weeks
Molds
Cream cheese . .
40-50
35-45
a few days
Primarily
bacteria
Semi-hard :
Limburger . . .
40-45
24-30
3-6 months
Bacteria
Roquefort . . .
38-40
31-34
3-6 months
Mold
Brick
37-42
31-35
3-6 months
Bacteria
Hard:
Cheddar ....
30-39
32-36
6-12 months
Bacteria
Swiss
31-34
28-31
9-18 months
Bacteria
and yeasts
Parmesan . . .
30-33
2-3 years
Bacteria
The soft cheeses are quickly perishable products.
Bacteria and molds find favorable conditions for growth
CLASSIFICATION 87
in products with 45 to 75 per cent of water. If such
growth is permitted, enzymic activities follow quickly
with resultant changes in appearance, texture, odor
and taste. Refrigeration is necessary to transport such
cheeses to the consumer, if properly ripened. Trade in
these forms may continue throughout the year in cool
climates and in places where adequate refrigeration is
available. Practically, however, outside the large cities
this trade in America is at present limited to the cold
months; inside the large cities much reduced quantities
of these cheeses continue to be handled through the year.
In the stricter sense, the soft group of cheeses falls
naturally into two series: (1) the varieties eaten fresh;
and (2) the ripened soft cheeses. Those eaten fresh have
a making process which commonly involves the develop-
ment of a lactic acid flavor by souring, but no ripening
is contemplated after the product leaves the maker's
hands. In the ripened series, after the making process
is completed, the essential flavors and textures are de-
veloped by the activity of micro-organisms during ripen-
ing periods varying in length but fairly well-defined for
each variety.
In contrast to the soft cheeses, the hard kinds are
low in water-content, ripen more slowly and may be
kept through much longer periods. They retain their
form through a wider range of climatic conditions. They
develop flavor slowly and correspondingly deteriorate
much more slowly. Such cheeses are in marketable con-
dition over longer periods. In their manufacture the
cooking of the curd takes a prominent place.
109. Relation of heat to classes. The close relation
between the heat applied and the product sought forms
the basis of a striking series of graphs (Fig. 12, page 78).
88 THE BOOK OF CHEESE
These show the changes hour by hour in the heat relation
during the making process of a series of widely known
forms, each of which is chosen as typical. In some of
these forms, heat is applied but once to bring the milk
to the renneting temperature typical for the variety.
Subsequent manipulations are accompanied by a steady
fall in temperature. In other forms, the curd when
solid is specially heated or " cooked " to bring about
the changes characteristic of the variety. These con-
trasts are clearly brought out by the graphs which rep-
resent practices well recognized for the varieties. The
detailed process for these groups is considered in suc-
ceeding chapters.
CHAPTER VII
CHEESES WITH SOUR-MILK FLAVOR
THE cheeses with flavor of sour milk are probably more
widely used than any other group. Historically and to
a very large degree at present, they are farm cheeses. 1
No estimate of volume of such production in the house-
hold has ever been made. The utilization of surplus
milk in this way is of ancient origin.
With the introduction of the factory system of han-
dling milk, the manufacture of such cheese in the house-
hold was largely dropped. The rise in price of all food
substances and increasing appreciation of the food value
of milk products have made the recovery of all surplus
milk in some form very necessary. The manufacture
of cottage, Neufchatel and cream cheese is one of the
best forms of such recovery which may be adapted to
utilize any grade from skimmed-milk to cream. Large
quantities of skimmed-milk have frequently been lost
from the total of human food by the manufacture of
casein for industrial uses, and by use as stock feed.
110. Skim series. The kinds of cheeses eaten fresh
have in common a very soft texture and the flavor of
1 Frandsen, J. H., and T. Thorsen, Farm cheese-making, Univ.
Neb. Ext. Serv. Bui. 47, pages 1-16, 1917.
Michels, J., Improved methods for making cottage and
Neufchatel cheese, N. C. .Exp. Sta. Bui. 210, pages 29-38.
Fisk, W. W., Methods of making some of the soft cheeses,
Cornell Exp. Sta. Circ. 30, pages 41-62, 1915.
89
90 THE BOOK OF CHEESE
sour milk, principally lactic acid. The group falls natu-
rally into two sections : (1) the cheeses made from milk
curdled by souring ; (2) those for which the milk is curdled
by souring and rennet. In the latter group both agencies
are necessary to the resulting product. The time required
to curdle by souring alone is longer than when rennet
is used; this period is usually longer than necessary for
the cream to rise by gravity; hence the cream is either
skimmed off or removed with the separator beforehand.
The curd, therefore, is essentially a skimmed-milk curd.
Casein curdled in this way tends to become granular
or " rough," to feel " sandy " when rubbed between the
fingers. Heating is commonly necessary to lower the
water-content of the mass even to 75 per cent. Such
curd tends to become hard or rubbery when heat is ap-
plied. In this group, the best known form is variously
called " cottage " cheese, " clabber " cheese, schmier-
kase.
111. Cottage cheese is made from skimmed-milk,
soured by lactic bacteria until a curd is formed. This
is done preferably at about 20 C. (70 F.), because at
this temperature the purely lactic type of organism has
been found to outgrow competing forms which may be
present. Starter containing the desired culture, if prop-
erly used, saves much time in the curdling period. Such
curdling requires at least twelve to twenty-four hours,
frequently much longer unless abundant starter is intro-
duced.
112. Household practice. The details of cottage
cheese making in the home differ widely in separate sec-
tions and even in different families in the same part
of the country. The essentials of the practice, common
to all, include : (1) curdling the whole milk by natural
CHEESES WITH SOUR- MILK FLAVOR 91
souring; (2) removing the sour cream which is usually
used for butter-making ; (3) scalding the curdled skimmed-
milk either by slowly heating it in the original vessel
surrounded by hot water or by actually pouring an
approximately equal volume of boiling water into the
curdled mass; (4) bagging and draining the mass until
it reaches the desired texture; (5) the kneading of the
mass with the addition of salt and cream. The result-
ing product varies greatly in quality. Unfavorable fer-
mentations frequently affect the flavor. 1 The " scalding "
varies from a temperature of 90 F. almost to boiling
with a resultant texture varying from almost the smooth
buttery consistency of Neufchatel to hard coarse granular
lumps. The best practice, using clean well-cared-for
milk and draining at low temperature, produces a very
attractive cheese. Such cheese is heated to 90 to 100 F.
on the maker's judgment, drained carefully, kneaded well
by hand or by machine with the addition of cream to give
it an attractive texture and flavor.
113. Factory practice. When cottage cheese is made
in the factory, 2 separated milk is taken; it should be
pasteurized and then soured by a lactic starter. The
souring can be accelerated by the use of a starter, which
may be added at the rate of 0.5 to 5 per cent of the
skimmed-milk used, depending on the amount of starter
that can be made. Generally, the more starter added,
the more rapid will be the coagulation and the better
will be the flavor of the cheese. As soon as the milk
has thickened, the curd is ready to be broken up and
1 Tolstrup, R. M., Cheese that farmers should make, Iowa
Agr. 15 (1914), 2, pages 89-90.
2 Van Slyke, L. L., and Hart, E. B., Chemical changes in the
souring of milk and their relations to cottage cheese, N. Y.
(Geneva) Exp. Sta. Bui. 245, pages 1-36, 1904.
92 THE BOOK OF CHEESE
separated from the whey. This separation is hastened
by the application of heat. Usually the temperature
of the curd is raised slightly before it is broken up ; since
this makes the curd firmer, there will be a smaller loss of
curd particles in the whey. The curd may be cut with
coarse Cheddar cheese knives or broken with a rake.
The temperature of the curd should be raised very slowly,
at least thirty minutes being taken to reach the desired
final temperature. No set rule can be given as to the
exact temperature to which the curd should be heated.
The temperature should be raised until a point is reached
at which the curd, when pressed between the thumb and
the fingers, will stick together and not go back to the
milky state. This temperature is usually from 94 to
100 F., but the cheese-maker must use his own judgment
in this respect. If the curd is heated too much, it will
be hard and dry ; on the other hand, if it is not heated
sufficiently, the whey will not separate from the curd and
the latter will be very soft and mushy.
When the curd has been heated sufficiently and has
become firmed in the whey, it should be removed from
the whey. This may be done either by letting down one
end of the vat and piling the curd in the upper end, or
by dipping out the curd into a cloth bag and allowing the
whey to drain, which it does very rapidly. No treatment
can prevent the " roughness " of an acid curd (this is
a fine gritty feeling when rubbed between the fingers),
but the coarse hard grainy texture and lumps charac-
teristic of the highly heated curd do not develop.
Experimental workers have agreed that to have the
proper texture, such curd should contain when finished
about 70 to 75 per cent of water. It should have a mild
but clean acid flavor. Such a cheese will carry about 1
CHEESES WITH SOUR-MILK FLAVOR 93
to 2 per cent of salt, without an objectionably salty
taste. This cheese is commonly sold by measure, some-
times in molds or cartons. The manufacture of all forms
of cottage cheese has been largely superseded by the
making of skimmed-milk Neufchatel or Baker's cheese.
The yield from one hundred pounds of skimmed-milk
runs up to fourteen to nineteen pounds of cheese, when
made very wet or from pasteurized milk. The yield
varies with the moisture-content of the cheese, being
greater for cheese with a high content. Too much
moisture or whey should not be left in the curd, how-
ever, as this will render it too soft to be handled.
Cottage cheese made by either the home or factory
practice is a quickly perishable article. Although the
acid restrains bacteria at first, the high percentage of
water favors the growth of molds which tolerate acidity,
especially Oidium (Oospora) lactis and the Mucors or
black molds. These molds destroy acidity rapidly and
thus permit the bacteria of decay to develop and to
produce objectionable taste and odors. Spoilage in
these products is accelerated by the kneading process
which distributes air throughout the mass and with it
all forms of microbial contamination.
114. Buttermilk cheese. A cheese closely resembling
cottage may be made from buttermilk. If the buttermilk
came from cream which was churned before it became
sour, the process is the same as that already described
for the making of cottage cheese from skimmed-milk. If
the buttermilk came from sour cream the process of
manufacture is much more difficult. The casein of sour
cream has already been coagulated with acid and broken
during churning into very minute rather hard particles.
These fine particles are difficult to recover. They are so
94 THE BOOK> OF CHEESE
fine that they pass through the draining cloth or at
other times clog it and prevent drainage. They do not
stick together at ordinary temperatures. They cannot
be collected by the use of acid because they have already
been coagulated with acid. After casein has been
coagulated with acid, rennet extract will not recoagu-
late the particles. The buttermilk may be mixed with
sweet skimmed-milk ; then as the latter coagulates, it locks
in the casein of the buttermilk so that it can be collected.
If buttermilk from soured cream is used alone, the casein
may be collected 1 by neutralizing and heating to 130
to 150 F., and holding until the casein gathers together.
The whey can then be drawn off. Often there is further
difficulty in getting the casein to collect, since the pieces
remain so small that they go through the strainer.
Cheese made entirely from buttermilk is sandy in
texture and often not palatable. If the buttermilk with
good flavor is mixed with skimmed-milk, it makes a good
cheese closely resembling cottage.
115. Neufchatel group. 2 The Neufchatel process
originated in northern France where a number of varieties
are included under this as a group name. Among these
are Bondon, Malakoff, Petit Suisse, Petit Carre. The
name designates a general process of curd-making which
is applied to skimmed-milk, whole milk or cream. Some of
the resultant cheeses are ripened ; some are eaten fresh.
The Neufchatel cheeses of France gained such wide recog-
nition for quality that the process of making has become
widely known. In America the manipulations of the
1 Sammis, J. L., Three creamery methods for making butter-
milk cheese, Wis. Exp. Sta. Bui. 239, 1914.
2 Matheson, K. J., C. Thorn and J. N. Currie, Cheeses of
the Neufchatel group, Conn. (Storrs) Exp. Sta. Bui. 78, pages
313-329, 1914.
CHEESES WITH SOUR-MILK FLAVOR 95
French process were early dropped. The essentials were
made the basis of a successful factory practice which
has been widely adopted. TJie American factory prac-
tice is discussed here and the French process briefly
considered under the heading Ripened Neufchatel. (See
Chapter VIII.)
116. Domestic or American Neufchatel cheeses are
soft, have clean sour milk (lactic acid) flavor and are
quickly perishable. In all but the coldest weather, they
require refrigeration to reduce deterioration and loss.
They range in fat-content from traces only to 50 per
cent and more ; in water from 40 to 75 per cent, accord-
ing to the milk used. In texture Neufchatel is smooth,
free from gas, free from lumps or roughness when rubbed
between the fingers. This flavor and texture is obtained
by a combination of slow rennet curdling with develop-
ing acidity. No further ripening is permitted.
117. The factory. Neufchatel factories require
the standard dairy equipment for receiving, weighing,
testing, separating, heating, pasteurizing and cooling the
milk. Since many factories produce several products,
the same general dairy equipment may serve for all. In
addition to such equipment, Neufchatel requires a cur-
dling apparatus which can be held at 70-75 F. This
may be a room properly controlled, or a tank where tem-
perature control is obtained by water and steam. For
draining, a room kept at 60 F. gives nearly the ideal
temperature, which must be supplemented by relative
humidity high enough to prevent the exposed surface of
curd from drying during periods of twelve to twenty-four
hours. This requires almost a saturated atmosphere.
A room with special molding machinery is required and
tables for wrapping, labeling and boxing the product
96
THE BOOK OF CHEESE
CHEESES WITH SOUR-MILK FLAVOR 97
are necessary. Box-making machinery is usually an
economic necessity for work on a large scale. Adequate
refrigeration is requisite both to chill the curd before
molding and to preserve it after packaging.
118. Cans. For curdling, the " shot-gun " can, about
nine inches in diameter and twenty inches deep, is gen-
erally used. This holds thirty to forty pounds of milk.
Increased capacity is dependent, therefore, on the number
of units installed, not on changes in the units themselves.
119. Draining racks. A draining rack is required
for each can of curd. These racks also are standardized
units whose num-
ber limits the
capacity of the
factory. The de-
sign of these
racks (Figs. 13,
14) and their ar-
rangement in the
draining room are
taken from Bul-
letin 78 of the
Storrs Agricul-
. FIG. 14. Detail of a Neufchatel draining rack.
tural Experiment
Station : " The racks are rectangular, thirteen inches
wide, thirty-six inches long and ten inches deep. The
corner posts extend one and one-half inches beyond the
strips at top and bottom with the tops rounded as a rule
as seen in the photograph. The bottom slats fit loosely
into notches, hence are removable for washing purposes.
The materials required are four corner posts one and
one-half by one and one-half inches; nine strips one by
three-eighths by thirty-six inches ; six strips one by three-
98
THE BOOK OF CHEESE
eighths by thirteen inches, two strips one by three-eighths
by twelve and a quarter inches, notched to receive the
bottom slats; all made from pine."
120. Cloths. For each draining rack, a cloth one
yard wide and one and one-half yards long is required.
Cotton sheeting is satisfactory for the purpose ; " even-
count, round-thread, unmercerized voile " is suggested
by Dahlberg. 1
121. Molding machinery. For work on a large scale,
special power machines 2 are regularly used. These
consist of a hopper
and worm delivering
a standard size stream
of curd through a
proper size and shape
of delivery tube. This
curd stream is cut by
an automatic device
into the proper lengths
to form the standard
cheese. In this way a
uniform size of cheeses
is obtained. Experi-
mental work with hand
apparatus showed that a worm six inches in diameter is
required to deliver curd in a smooth column one and
one-half inches square. If the pressure is not sufficient,
1 Dahlberg, A. 0., The manufacture of cottage cheese in
creameries and milk plants, U. S. Dept. Agr. Bui. 576, pages 1-16,
1917.
2 Since the number of factories has continued small, the manu-
facture of this type of machine has remained a monopoly in
which each machine is made to order by the Van Eyck Machine
Co. of Holland, Mich.
FIG. 15. Neuf chattel and cream cheese
molds.
CHEESES WITH SOUR- MILK FLAVOR 99
the column will frill at the edges. Such irregular surfaces
cannot be wrapped smoothly enough to delay spoilage.
On a small scale, a fair grade of product can be molded
through a tin tube (see Fig. 15) one and three-quarters
inches in diameter and ten inches long in which the curd
is compressed by a close fitting plunger operated by hand.
122. Milk for Neufchatel should be clean, free from
gas and taint. Such milk should preferably be not more
than twelve hours old when received and in no case show
higher than 0.20 per cent lactic acid by titration. Milk
testing 4 per cent fat or higher will produce a higher qual-
ity of product than lower grade milk, although every
grade from skimmed-milk to cream is used in producing
some form of Neufchatel. This milk should be pasteur-
ized unless shown to be free from tuberculosis by proper
test of the cattle. Evidence 1 that the organism of tuber-
culosis will withstand the regular handling process for
cheeses of this group, and retain its ability to cause dis-
ease in experimental animals makes the introduction of
pasteurization necessary in this whole group of cheeses.
Any effective pasteurization may be used, but tempera-
tures of 140-145 F. for thirty minutes have been
effective with less changes in the milk than higher tem-
peratures for shorter periods. The milk should be cooled
to curdling temperature and the starter and rennet added
and stirred into the milk in bulk. The milk may then be
quickly distributed into the curdling cans with a hose
or from the gate valve of the mixing vat.
123. Starter. To insure the development of a clean
acid flavor, a small amount of lactic starter should be
1 Presented by Dr. E. C. Schroeder of the U. S. Dept. Agr.
to the International Association of Dairy and Milk Inspectors,
at Washington, Oct. 17, 1917, published Jour. Am. Vet. Med.
Assoc'n 52, N. S. 5, no. 6, pages 674-685, 1918.
100 THE BOOK OF CHEESE
used. The quantity to use depends on the quality of the
milk. With skimmed-milk, a pint for each thirty-pound
can is recommended by Matheson and Cammack 1 and
by Dahlberg. (See page 98.) For whole-milk Neufchatel,
2 c.c. to a thirty-pound can of milk commonly gives good
results. On this basis 2 ounces of starter would be suf-
ficient if properly stirred into about 1000 pounds of milk.
Too slow development of acid is preferable to over-rapid
souring.
124. Renneting or setting. The milk should be
cooled after pasteurizing to between 70 and 75 F. Ren-
net is added at the rate of f c.c. to a thirty-pound can
(roughly J ounce to 1000 pounds). This will thicken
the milk sufficiently in the first few hours to reduce the
separation of the cream. For completion of the curdling
and souring process, twelve to eighteen hours are required.
Usually the cans stand overnight at uniform temperature.
When ready to drain, the curd should be firm, smooth
and mildly acid. Whey separating from it should not
titrate above 0.35 per cent titrated as lactic acid.
125. Draining. A cloth is spread over a draining
rack and the contents of one " shot-gun " can poured
upon the cloth with as little breaking as possible. In
this way a large surface is exposed. The room must be
kept wet to prevent the surface of the curd drying to
form crusts which stop draining. A temperature of 60
F. is favorable to the maintenance of proper texture and
humidity without the development of objectionable
organisms, especially Oidium lactis, which tends to cover
every exposed surface in such rooms. Draining may be
1 Matheson, K. J., and F. R. Cammack, How to make cottage
cheese on the farm, U. S. Dept. Agr., Farmers' Bui. 850, pages
1-15, 1917.
CHEESES WITH 8OV&MIJ&R
hastened by turning the curd or changing the position of
the cloth. In factory practice, the large draining surface
reduces the necessity of handling the curd and reduces
the loss of fat. About twelve hours are required upon
the draining racks.
On a small scale with a few cans of curd in the home,
any form of draining rack may be used, such as a potato
or berry crate, or the corners of the cloth may be brought
together, tied and the mass hung up. The curd must
be turned by pulling up the corners of the cloth to prevent
drying at the edges and stoppage of draining from the
center of the mass. Such treatment produces much more
rapid drainage than the factory practice and involves
proportionately more labor and larger fat losses.
126. Cooling Neufchatel. When whey ceases to
separate readily, the corners of the cloth are loosed from
the rack, folded diagonally or tied, and the curd cooled
on ice or in refrigerators. When thoroughly chilled the
bags of curd are put into presses, where light but in-
creasing pressure forces more whey out of the mass.
Tests at this time should show about 0.60 per cent acid
in the whey. With low-fat curd every step of the process
may be hastened, but with high-fat care must be exer-
cised to prevent loss of fat during pressing especially.
Any pressing device permitting continuous pressure with
ease of manipulation may be used.
127. Pressing. The ideals of the maker must deter-
mine the extent of pressing. A high yield is obtained
by leaving whey in the curd. If immediate consumption
is certain, such cheese may be satisfactory, but if the
cheese is to be held some days the extra whey carrying
more milk-sugar favors increased acid development.
This produces very sour cheese with much more danger
102
THE BOOK OF CHEESE
of other fermentations which cause objectionable flavor.
Too much water favors more active bacterial growth as
well as produces cheese too soft for the necessary handling
in the market.
In the press, several bags of curd may be piled together.
The press should be released and the bags turned from
time to time to insure even drainage. Several hours of
pressing are usually required. The danger of insufficient
pressing is due to the difference of texture between the
worked and unworked curd. Before working, curd carry-
ing 10 per cent excess moisture resembles the finished
product sufficiently to deceive any but the experienced
maker. But if this curd is transferred to the worker and
to the molding machine, it is found to become soft,
pasty and sticky, to
lack "body," hence to
make very unsatis-
factory packages and
to spoil very quickly.
The masses of curd
should come out of
the press as dry and
hard flat cakes.
128. Working and
salting Neufchatel.
The cakes of curd go
from the press to the
working table. Here
they are broken by
hand or by a butter-
worker or kneading
machine (Fig. 16). Salt at the rate of one and one-
half pounds to 100 pounds of curd is added. If the
FIG. 16. Working Neufchatel.
CHEESES WITH SOUR-MILK FLAVOR 103
curd is not sufficiently pressed, the masses become
mushy or pasty during the working process. The work-
ing is continued until the whole mass is uniformly
smooth and buttery.
129. Storage. The draining and working processes
permit the contamination of the curd with organisms
from the air and from the apparatus. These are dis-
tributed throughout the mass. Air is also worked
thoroughly into the curd. Such a product spoils quickly.
Distributing houses find the Neufchatel trade uncertain
in volume from day to day, hence many of them store
the cheese in bulk and package only fast enough to fill
orders. This minimizes the loss due to spoilage. Such
curd may be packed into tubs and kept for considerable
time in cold storage. If molded for the retail trade, it
is more quickly perishable. When packed solidly in
mass, curd is largely protected from spoilage by the ex-
clusion of air and perhaps the quick exhaustion of free
oxygen through the respiration of the micro-organisms
present and by its acidity. This must be supplemented
by low temperature to reduce the loss to a minimum.
Even when spoilage begins, it is easily confined to the
slight growth of Oidium lactis or green mold and bacteria
on exposed areas. These can be removed with minimum
loss and damage to the mass. On the other hand, such
curd molded into the commercial package of 3 to 6
ounces and wrapped in paper, with tin-foil or carton for
protection, still presents enormously increased surface
for the growth of aerobic forms especially Oidium
lactis, green mold (Roquefort mold is the usual green
species) and accompanying bacteria. Curd in tubs may
be kept some days; in commercial packages lowering
of quality (flavor) begins almost at once.
104 THE BOOK OF CHEESE
130. Molding. When the standard molding ma-
chine (Fig. 17) is provided, curd is brought directly from
the refrigerator to the machine. If permitted to be-
come warm, the mass becomes sticky; when cold it
is more readily handled. The machine is fitted with
the special delivery tube for the variety to be handled,
cylindrical for Neufchatel in its various forms, rectangular
in section for cream. Enough workers should be pro-
vided to wrap and label the cheese without leaving it
FIG. 17. Molding Neufchatel.
exposed to contamination or heat. Parchment paper
and tin-foil cut the proper size for each variety and bear-
ing printed labels are readily obtainable. Each cheese
should be wrapped with paper and tin-foil and put directly
into a flat box which holds a standard number (usually
12 or 24) of the special product.
In working with the hand molding tube (Fig. 15)
the same care is required. Chilled curd is forced into a
firm smooth mass with the plunger. It is removed
CHEESES WITH SOUR-MILK FLAVOR 105
and wrapped when it reaches the regular size of the
variety.
All forms when molded go directly into the boxes and
then back to the refrigerators until demanded for actual
use. The details of the process differ according to the
form made.
131. Skimmed-milk Neufchatel. Separator skimmed-
milk is frequently made into curd by the Neufchatel
process. The absence of fat eliminates the largest element
of loss in manufacture. Each stage of the making process,
therefore, may be shortened. The demand that the curd
shall be smooth and buttery in texture rather than rough
or gritty requires the exercise of care in curdling of milk.
The draining and pressing of the curd may be accomplished
much more rapidly than in the fatty cheeses. The final
product should differ from cottage cheese in smoother
texture, milder acidity and, as a rule, cleaner flavor. In
composition, the absence of fat must be largely compen-
sated by leaving more water in the cheese. Such a
product reaches the market with 65 to 75 per cent of water
and perhaps 1.25 per cent of salt. Casein forms 20 to 30
per cent of the mass.
These cheeses are very perishable on account of their
high water-content. The destructive effect of micro-
organisms both in the interior of the cheese and upon its
surface is rapid.
Cheeses of this description may be found in the trade
as cottage cheese, Neufchatel style, and as Neufchatel
made from skimmed-milk ; skimmed-milk Neufchatel
would be a strictly proper labeling.
132. Baker's cheese. There is considerable market
for skimmed-milk curd as Baker's cheese. This product
is essentially skimmed-milk Neufchatel curd, partially
106 THE BOOK OF CHEESE
drained and sold in bulk. When the bakery is near by, the
curd is frequently shoveled into milk-cans in very wet
condition and sent directly from the factory to the bakery.
If the distance is such as to require considerable time
for transportation, the same care is frequently given
as for Neufchatel curd packed in bulk for storage and
transportation.
Great variations in practice are found among the
makers of this type of product. In some cases low grade
skimmed-milk is handled on a large scale. Curdling is
done quickly and little care is given to the details of flavor
and texture in the curd. Working in this manner, two
men are able to make a ton of such curd, and ship it out
in milk-cans each day. The resulting product, although
very deficient in flavor and texture, goes into manufac-
tured specialties which conceal its deficiencies if con-
sidered as cheese.
133. Domestic Neufchatel. The name Neufchatel,
unless limited clearly by the label, should designate a
cheese made from fresh whole milk. Cheeses of this
group are produced in a small number of well-equipped
factories scattered widely through the dairy states of
the North and Northeast. Every factory uses one or
more trade names for its product. The same product is
frequently relabeled by the distributor who uses his own
trade name instead of that of the maker.
The usual form of package is cylindrical, about if
inches in diameter and 2^ inches long, or sometimes
rectangular 2^ by 1| by 1^ inches. The cheese is pro-
tected by wrapping in parchment paper closely surrounded
by tin-foil. These packages vary from 2^ to 4 ounces.
In some cases screw-topped glass jars are substituted for
the tin-foil package. They are objectionable, first, be-
CHEESES WITH SOUR-MILK FLAVOR 107
cause of cost and, second, because they are so commonly
associated with less perishable products as to mislead
either dealer or consumer into holding the product for
too long a time. The paper or tin-foil package can be
kept only at refrigerator temperature, hence automat-
ically keeps its possessor reminded of the perishable nature
of its contents.
Neufchatel of the best quality made from whole milk
testing about 4 per cent fat may be expected to fall
within the following limits ; 1 many grades contain more
water than this at the expense of flavor and keeping
quality :
Water 50-55 per cent
Fat 23-28 per cent
Casein 18-21 per cent
Salt . , 0.5-1.25 per cent
Yield 12-14 Ib. per 100 Ib. of milk.
134. Partially skim Neufchatel. Brands of Neuf-
chatel made from milk that would test every gradation
from whole milk to separator skimmed-milk may be
found. The quality of the product varies with the skill
of the maker from brands no better than cottage cheese
to products scarcely distinguishable from the best whole-
milk Neufchatel. Many factories that produce more
than one quality of Neufchatel use labels of different
color, different design or both to separate them; for
example, blue labels usually stand for whole milk, red
labels represent lower grades. Sometimes the difference
in material is indicated by a clear cut grade mark. Fre-
quently color, a design of label or both are the only
definite marks upon the cheese. The consumer un-
familiar with the trade practice commonly has no means
of knowing the quality of the product offered. Such
1 Taken from Conn. (Storrs) Exp. Sta. Bui. 78, page 328.
108 THE BOOK OF CHEESE
cheeses vary in water-content from 55 to 70 per cent;
in fat from 10 to 25 per cent; in casein from 18 to 25
per cent.
135. Cream cheese. The Neufchatel process is also
used to make cream cheese. The material utilized is
commonly what has been called double cream. This is
produced by separating about half of a given volume of
milk and running the cream into the other half. Usually
cream cheese is made in the same factory as various
grades of Neufchatel. No material is lost. In some
instances, cream cheese is prepared by working thick
cream into the Neufchatel type of curd from practically
skimmed-milk. In working with high percentages of fat in
curd, care must be taken to avoid loss of fat in draining
and pressing. The curd is carefully chilled before press-
ing to reduce this loss. This may be done under refriger-
ation or upon cracked ice. Otherwise the manipulations
of the process are unchanged. The cheeses are commonly
molded in the Neufchatel machine into square cakes
weighing about 4 ounces and measuring approximately
3 by 2 J by | inches. These are wrapped in paper and
tin-foil and handled exactly as Neufchatel.
Cream cheese of high quality made from reenforced
milk testing 7 to 9 per cent fat may be expected to test
approximately as follows : l
Water 38-43 per cent
Fat 43-48 per cent
Protein 13-16 per cent
Salt 0.5-1.25 per cent
Yield 16-18 Ib. per 100 Ib. of cream.
Increases of water, hence greater yields, are very com-
mon but usually associated with loss in quality both as
1 Taken from Conn. (Storrs) Exp. Sta. Bui. 78, page 328.
CHEESES WITH SOUR-MILK FLAVOR 109
to flavor and texture, and in more rapid spoilage ; certain
brands regularly carry 50 to 60 per cent of fat but their
increased cost of manufacture and sale restricts them to
the role of specialties with closely limited distribution.
Trade names such as Philadelphia Cream, Cow Brand,
Eagle Brand, Square Cream, Blue Label and many other
factory brands are on the market.
136. Neufchatel specialties. Neufchatel or cream
cheese curd is frequently mixed with some flavoring
substance, such as pimiento (pickled Spanish peppers),
olives, nuts, spices or other cheeses, such as Roquefort.
These bear appropriate trade names and form a very
attractive addition to our varieties of cheese. Among
the names found are Pimiento, Olive, Nut, and Pirn-olive
or Olimento.
137. Gervais is a brand of cream cheese made in Paris
and sold widely in France and even in other continental
countries. It occasionally comes to America. As made
in Paris, these cheeses are flat cakes containing approx-
imately 40 per cent water and 35-45 per cent fat. It
clearly differs only in detail from the square cream cheeses
made in America. The name Gervais is the property
of a particular company. Since the cheese differs in no
essential feature from other cream cheeses, this name
should not be applied to a domestic cream brand.
138. European forms occasionally imported. Among
the cheeses related to Neufchatel as they reach the market
are the " White " cheeses of southern Europe. These
differ greatly in quality according to their source and
to their content of cow, sheep, goat's milk or some com-
bination of these. This texture and flavor link them
with unripened Neufchatel. The time required for
importation puts a minimum possible period of ten to fif-
110 THE BOOK OF CHEESE
teen days between production and consumption with a
probable period of at least one month for most samples.
As they come to America, these forms usually show
fermentive changes beyond those tolerated in the do-
mestic product. This may take either of several forms :
(1) intensification of acid flavor with the intensification
of the characteristic flavors of the particular brand;
(2) the development of old or rancid flavors ; (3) the de-
velopment of Oidium and partial softening of the mass
through its agency; (4) the growth of Roquefort mold
and development of the flavor associated with that
organism. This last form was found in a shipment of
Hungarian Briuse which showed about 40 per cent fat,
14 per cent protein and 43 per cent water.
CHAPTER VIII
SOFT CHEESES RIPENED BY MOLD
THE ripened soft cheeses include a series of groups of
varieties which, in addition to initial souring, have been
subjected to special ripening processes, and which in
the ripened condition are soft in texture and mostly have
high flavors. The varieties in each group have in com-
mon some essential principles of manufacture together
with a ripening process dominated by a characteristic
group of organisms. In certain groups, the ripening is
dominated by a yellowish or orange viscid surface slime
containing Oidium lactis and bacteria; in another series,
the characteristic organism is a mold of the genus Pen-
icillium (P. Camemberti). Referring to the analysis of
groups (page 83), the ripened soft cheeses are found to
fall into three well-marked groups, one of which may per-
haps be subdivided as indicated. The series curdled by
souring alone begins with approximately cottage cheese
curd and develops high flavors by ripening, as in " hand "
cheese. Ripened Neufchatel curdled by souring and
rennet together finds its basis in Neufchatel curd also
but modifies the final product until the familiar flavor
and texture of the unripened form are no longer recogniz-
able. Among the forms curdled by rennet alone the
Camembert series contains one form, Coulommiers, which
is occasionally used unripe, but represents in general a
mold-ripened group of highly flavored forms. The series
111
112 THE BOOK OF CHEESE
of soft rennet cheeses ripened by bacteria may be broadly
designated the Limburger group.
139. Hand cheese and its allies. Among skim
cheeses, there is a series of forms largely German in
origin in which curd not far removed from cottage cheese
is the basis of the product. Harz cheese "is one of the
best-known of these forms as studied by Eckles and Rahn. 1
One of these forms, hand cheese, 2 is manufactured on
a commercial basis in farm dairies among families of
German descent principally in Pennsylvania, and on a
factory basis in a few places in New York, northern
Illinois and Wisconsin. On the small scale, curd is made
by natural souring or by use of starter, heated to expel
water, cooled and molded by hand into cakes two to three
inches in diameter and one-half to three-quarters inch in
thickness. The freshly formed cakes are placed upon a
shelf to dry. There they are turned daily until fairly firm,
then packed in rolls into wooden boxes and ripened in a
cool damp room. In this ripening there is a prompt
development of a heavy viscous slime, which consists of
Oidium and bacteria. Other molds forming loose cottony
mycelium are brushed off if they appear. The proper
consistency of this slimy covering depends on a close
adjustment of water-content in the cheese with tempera-
ture and relative humidity in the ripening room. If
conditions are too dry, the cheeses harden quickly or if
less dry they are attacked by green or blue-green molds.
If too wet, the slimy covering becomes too soft and watery,
or secondarily covered with loose shimmering masses of
1 Eckles, C. H., and O. Rahn, Die Reifung des Harzkases,
Centralb. f. Bakt. etc. 2 abt. 14 (1905), pages 676-680.
2 Monrad, J. H., Hand cheese, N. Y. Produce Rev. etc. 25
(1908), 16, page 644.
SOFT CHEESES RIPENED BY MOLD 113
mold (Mucor sp.). Ripening should proceed slowly and
occupy a period of six to eight weeks.
140. Pennsylvania pot cheese. A form of " pot "
cheese is made in certain counties of Pennsylvania, prin-
cipally for local use. Production of this cheese on a fac-
tory basis is now being attempted. The steps in manu-
facture are about as follows : * (1) The home-made type of
cottage cheese curd is prepared, put into a crock or pot
and covered carefully; (2) kept in a warm place (in
kitchen usually) ; (3) stirred from time to time, until
it has ripened to a semi-liquid condition. This occurs
very rapidly under the attack of Oidium lactis accompanied
by bacteria. Within a period of three to seven days,
according to the temperature and to the water-content
of the mass, the granules of curd become covered with a
wrinkled gelatinous almost viscid mass of mold mycelium
beneath which is a layer of semi-liquid curd with a strong
characteristic odor and taste. This ripened or semi-
liquid part reaches about half the total mass in four or
five days at favorable temperatures. (4) The vessel
is then placed in a larger vessel of water and heated over
the fire with constant stirring until the whole mass is
melted and smooth. (5) Butter or cream, and salt or
other flavor is finally added, stirred in and the liquid cheese
poured into molds or jelly glasses to cool. If properly
made and cooked, the resultant cheese has a soft buttery
consistency with an agreeable flavor, which frequently
resembles that of Camembert cheese.
1 The authors are under obligations to Mrs. E. E. Kiernan
for her description of this process (in the Somerset County
Leader, Jan. 10, 1908) and her letters concerning it. The
statement of the process given here combines the published
statement with the results of our own experiments.
114 THE BOOK OF CHEESE
141. Appetitost (Appetite cheese). A Danish butter-
milk cheese is made under this name. Sour buttermilk
is heated, by some to boiling temperature but others
(Monrad l ) prefer 120 F., stirred thoroughly and allowed
to settle. The whey is removed as far as possible. The
semi-liquid mass is covered and set in a warm place.
Fermentation becomes active. This tends to make the
curd more viscous or sticky. It is then kneaded and
allowed to ferment again. This process is repeated until
the mass is yellowish and soft but tough or viscous.
When thoroughly fermented, the mass is again heated
to 120 F., and 6 per cent salt is added together with
spice ; both are worked in and the cheese is formed into
fancy shapes for sale.
142. Ripened Neufchatel, French process. Neuf-
chatel as a ripened cheese is made rather widely in France
but it is produced on an especially large scale in Seine-
Inferieure. 2 Some factories use whole milk, or milk with
added cream, others skimmed-milk. 3 The whole-milk
brands of Neufchatel are those which have the widest
reputation. For making this cheese, the working room
is held as closely as possible at 15-16 C. (58-60 F.).
The milk is strained into earthen vessels holding twenty
liters. Rennet is added to the freshly drawn milk at
about 30 C. (86 F.) in amount sufficient to produce
coagulation in about twenty-four hours. Draining racks
1 Monrad, J. H., Appetitost, N. Y. Produce Rev. etc. 25
(1908), 16, page 644.
2 Pouriau, A. F., La Laiterie, sixiSme ed. par Marcel Mon-
teran, page 453, Paris, 1908.
3 Among the varietal names for Neufchatel cheese from whole
milk or with added cream are Petits Bondons, Malakoffs,
Carres affines. Among low fat or skim forms, Petit Suisse,
Gournay.
SOFT CHEESES RIPENED BY MOLD 115
of various forms are covered with cloth. The vessels of
curd are dumped upon the racks. The whey separates
slowly and drains off through the cloth. About twelve
hours are allowed for this process. The corners of the
cloth are then brought together and folded in or tied and
the mass pressed to complete the drainage. The finished
curd is worked or kneaded to produce a smooth and
uniform texture. This process of curd-making is essen-
tially the same as the American factory process of making
Neufchatel. The ripening process has been entirely
dropped in America. The curd is finally molded in
metal forms 5 cm. (2 inches) in diameter and about
6.7 cm. (about 3 inches) high, open at both ends. These
molds are filled, the freshly formed cheeses are pressed
out with a plunger or piston and their surfaces smoothed
with a wooden knife.
After molding is completed, the cheeses are salted
by sprinkling the entire surface with fine dry salt as the
cheese is held in the hand. In this way each cheese re-
ceives and absorbs 3 to 4 per cent salt. After salting,
the cheeses are arranged upon boards and allowed to drain
twenty-four hours. They are then removed to the first
or drying room. The frames of the drying room (secherie)
are covered with straw and the cheeses are placed care>
fully upon the straw to avoid contact with each other.
They are turned each day to present a fresh surface to
the straw during a period of two to three weeks in the
drying room (secherie). Mold begins to show as white
cottony mycelium after five to six days, and slowly turns
to "blue" (bluish green). When the cheeses are well
covered with this moldy rind, they are removed to the
ripening cellar. In the ripening cellar also the cheeses
stand upon straw. They are turned over every three or
116 THE BOOK OF CHEESE
four days at first, then allowed to stand for a longer
period.
When ripe, a Neufchatel cheese so made weighs about
125 grams. One liter of milk makes 225 grams of such
cheese. The ripening of Neufchatel has never been fully
studied, but a series of these cheeses were obtained by one
of the authors ; cultures were made and examined. 1 The
salt-content in the first place was found to be so high
that Oidium lactis was eliminated as an active factor
in the ripening. The mold proved to be on some
cheeses Penicillium Camemberti, the typical mold of
Camembert as it is made in Normandy, on others P.
Camemberti var. Rogeri, the pure white form as used
under the patents of M. Georges Roger in the region of
Seine-et-Marne to the eastward of Paris and called by
him and by Maze P. candidum. The physical condition
of the ripened curd and the flavors encountered were
those associated with these two species by many hundreds
of experiments during the Camembert investigation in
Connecticut. 2 These facts justify the conclusion that
ripened Neufchatel is first soured by lactic organisms,
then so salted as to eliminate or reduce to a minimum
the characteristic activities of Oidium lactis, while the
proteolytic action and the physical changes are closely
similar to those of Camembert which is ripened primarily
by the same molds.
1 Thorn, C., J. N. Currie and K. J. Matheson, Studies relat-
ing to the Roquefort and Camembert types of cheese, Conn.
(Storrs) Exp. Sta. Bui. 79, page 392.
2 Full discussion of this product is found in U. S. Dept. Agr.
Bur. An. Ind. Bui. 115. Camembert cheese problems in the
U. S. also published as Storrs Exp. Sta. Bui. 58 with the
same title. Also a supplementary paper in Bui. 79 of Storrs
Exp. Sta.
SOFT CHEESES RIPENED BY MOLD 117
143. The Camembert group. The soft cheeses ripened
by molds are French in origin. Their manufacture has
spread into Germany, Italy and America. Of the series, the
most widely known is Camembert, which will be described
as typical for the group. Brie, Coulommiers, Robbiola
and Ripened Neufchatel belong to this series.
144. Camembert cheese. The origin of Camembert
is given by French authorities as 1791 in the Commune
of Camembert near Vimoutiers in Orne, France. From
a very restricted production at first, Camembert-making
has spread through the region from Caen in the west
to Havre, Rouen and a considerable area east of Paris.
In America Camembert began to be made in one factory
about 1900. Several other factories followed by 1906.
The difficulties and losses encountered led to the abandon-
ment of these undertakings, until at the outbreak of the
European war in 1914 but one factory was making Ca-
membert and that only on an experimental scale. Mean-
while the United States Department of Agriculture and
the Storrs Experiment Station had taken up and solved,
on an experimental basis, most of the problems arising
in these commercial failures. A shortage of product
at the outbreak of the war brought about the re-estab-
lishment of a series of factories. The product as put
on the market indicates that a permanent establishment
of Camembert-making is entirely practicable.
Camembert cheese is made from cow's milk either whole
or very slightly skimmed ; the removal of about 0.5 per cent
of fat has been found to be desirable if not actually necessary.
145. Description of Camembert. 1 These cheeses are
made in sizes 2| to 4^ inches in diameter and li to 1^
1 Thorn, C., U. S. Dept. Agr. Bur. An. Ind. Circ. 145 (1909),
page 339.
118 THE BOOK OF CHEESE
inches in thickness. They are ripened by the agency of
molds and bacteria which form a felt-like rind over their
whole surface, Tg- to J of an inch in thickness. This
rind may be dry and gray or grayish-green, consisting
of a felt-like surface of mold on the outside, below which
a harder portion consists of mold embedded in partially
dried cheese, or the moldy part may be more or less com-
pletely overgrown or displaced by yellowish or reddish
slime composed mainly of bacteria. Good cheeses may
have either appearance.
Inside the rind, the cheese is softened progressively
from the rind toward the center from all sides, so that a
fully ripe cheese has no hard sour curd in the center,
but is completely softened. No mold should be visible
inside the rind, but the moldy rind itself is necessary
because the ripening is caused by the enzymes secreted
by the organisms of the rind into the cheese. As the
curd ripens, the changed portion assumes a slightly deeper
color than the unripe curd as a result of chemical changes.
Well-ripened cheeses vary from nearly a fluid texture to
the consistency of moderately soft butter. The ripen-
ing of Camembert is finished in wooden boxes which pro-
tect the cheeses from breaking after they become soft
and during the market period.
146. Conditions of making and ripening. These pro-
cesses depend on a very close adjustment between the com-
position of the freshly made cheese and the temperature
and humidity of the rooms in which the cheeses are made
and ripened. Very slight failures in control bring loss
in ultimate results. The room for making Camembert
should be maintained between 60 and 70 F. and should
be wet enough to reduce drying to a minimum. The
essentials of apparatus are comparatively inexpensive.
SOFT CHEESES RIPENED BY MOLD
119
Work on a factory basis calls, however, for the installa-
tion of special tables and other apparatus to utilize space
and labor to advantage. Rooms are protected from
change of weather by double sash in the windows. Flies
must be excluded by close-meshed screens for all doors
120
THE BOOK OF CHEESE
and windows with movable sash. The equipment in-
stalled in such a room is shown in Fig. 18. Curdling cans
are ranged on a shelf a few inches above the floor along
one side of the room below an open tin trough with side
branches. This open trough brings the milk from the
mixing vat to the curdling cans. (The open tin trough
offers no lodgment for dirt.) The cans hold about 200
pounds of milk, are about 12 inches in diameter at bottom,
and 20 to 24 inches at top. They are heavily tinned.
Iron trucks as high as the shelf and with tops the same
diameter as the
bottoms of the
cans form a con-
venient method
of bringing cans
of curd to the
very edge of the
draining tables.
The wooden
draining tables
are placed about
32 inches above
the floor; they
FIG. 19. Draining mat for Camembert cheese. are usually made
of 2-inch lumber,
have raised edges and slope slightly toward the wall.
Whey and wash water are thus carried to a draining trough
along the wall. For cheese-making, each is covered with
a strip of matting consisting of wooden strips held together
by thread (Fig. 19). The strip of matting should be
exactly the width and length of the table. The hoops
used are heavy tin, with edges turned and soldered, about
5 inches high, 4f inches in diameter with three rows of
SOFT CHEESES RIPENED BY MOLD 121
holes about A inch in diameter and 2 inches apart in the
row. These hoops are placed as thickly as possible upon
the mats.
147. Outline of making process. The making process l
is summarized as follows (Thorn, 1909) :
Starter. From 0.5 to 1.0 per cent of active starter
is added to milk kept overnight below 60 F.
Acidity at renneting. Milk titrated to phenol-
phthalein should test 0.20 to 0.23 per cent calculated
as lactic acid.
Temperance of renneting. 84 86 F. is used for
Camembert.
Rennet. From 3 to 5 oz. of standard rennet extract to
1000 Ib. milk (10-15 c.c. per 100 Ib. milk) produces a
curd of proper texture.
Curdling time. To reach the proper condition for
handling, 1^ to 1^ hours or longer is required. This
is indicated by the onset of " sweating " or the separa-
tion of large drops of whey on the surface of the
solid curd.
Dipping. A long-handled dipper is used to transfer
curd from cans to hoops. This can be lowered into the
hoop. This transfer is to be done with the least pos-
sible breaking. One dipperful is transferred at a time
to each of a series of hoops. By the time the series is
covered, some drainage has occurred and a second dip-
perful is added to the contents of the hoop. In this
way the hoop is filled within a period of two to four
hours.
Draining. Hoops when properly filled have taken
in approximately 2 quarts of milk each. No pressure
1 Lot record cards for the making and ripening of Camembert
are given on pages 124 and 125.
122 THE BOOK OF CHEESE
is used. Cheeses drain by gravity. They stand un-
turned until the following morning when they should
be firm enough to permit turning without removing the
hoops. The cheeses when firm enough to handle (usually
on the third morning) are salted by dusting the entire
surface with coarse salt and permitting all that adheres
to remain. The cheeses should then be removed to a
room at about 58 F. to prevent too rapid leakage of water
and salt from their surfaces. Ripe cheeses of good qual-
ity show a total salt-content varying from 2.25 to 3 per
cent with an average of about 2.5 per cent. When so
handled there is slight, if any, loss of water and salt in the
salting period of twenty-four to forty-eight hours. At
the end of the salting period such cheeses should carry
55 to 57 per cent water or slightly more.
148. Acidity. The essential biological factor in the
making period of Camembert is proper souring. The
milk should be free from gassy organisms. The lactic
starter required should introduce the typical lactic organ-
ism (Streptococcus lacticus) in numbers sufficient to sup-
press all other forms during the next twenty-four hours.
The amount of acid starter introduced, however, plus the
acid resulting from growth during the curdling period,
should not produce a grainy acid curd. The tempera-
tures of handling are such as to favor this group of organ-
isms if properly introduced and permit the development
of nearly 1 per cent of acid (estimated as lactic) by the
second morning. Cheeses with such acid are fairly free
from further danger from bacterial activity. Members
of the high-acid group (B. Bulgaricus and allies) may be
found in these cheeses but do not appear to develop in
numbers sufficient to affect the cheese to any marked
degree.
SOFT CHEESES RIPENED BY MOLD 123
149. Ripening the cheese. The cheese is now ready
for the ripening rooms (Fig. 20). For this process tem-
peratures between 52 and 58 F. are desirable ; lower
FIG. 20. Halloir, the first ripening room for Camembert in an American
factory.
124 THE BOOK OF CHEESE
CAMEMBERT CHEESE RECORD
Date Set No.
Amt. milk No. cheese Milk per cheese...
Producer of milk
Apparent cleanliness of milk
Acidity :
Before adding starter
After adding starter
After acidity period
Whey at dipping
Starter :
Kind a...- Age Amt.
Color :
Amount
Curdling :
Temperature used
Amount of rennet
Time at which rennet is added
Time at which milk is curdled
Time of curdling
Quality of curd -
Dipping :
Cut or uncut
Amt. of cutting
Draining :
Temperature of room during
Condition of cheese after.
Salting :
Time of Total amt. of salt used.. Kind of salt.
Amt. of salt per cheese
Mold inoculation :
Form of culture used
Method of inoculation
Time of inoculation
Remarks on making :
Curing :
Transfer of curing rooms
Condition of cheese
Rooms
Dates....
SOFT CHEESES RIPENED BY MOLD 125
Mold growth :
Date of first appearance
Purity and vigor
Date of changing color
Surface of slimy growth :
Extent of
General character of
Surface contamination :
Mold
Oidium
Yeast
Bacterial.
Wrapping :
Date Material
Condition of cheese
Ripening :
Rapidity of
Texture
Flavor :
Ripened curd
Unripened curd
Special treatment and reasons for same :
Record of treatment by days
Room Date Observations.
ID 16 D.
2D . 17 D.
3 D 18 D.
4 D 19 D.
5 D 20 D.
6 D 21 D.
7 D 22 D.
8 D ... 23 D.
9 D 24 D.
10 D 25 D.
11 D 26 D.
12 D 27 D.
13 D 28 D.
14 D 29 D.
15 D.... 30 D.
31 D.
126 THE BOOK OF CHEESE
temperatures only delay the process; higher temper-
atures favor undesirable fermentations. The cheeses
rest upon coarse matting (Fr. clayons) consisting of
round wooden rods about the size of a pencil separated
1-1-J- inches and held in position by wire strands. As-
suming cheeses of optimum composition as indicated above,
the relative humidity of the ripening rooms should be
86 to 88 per cent. Higher humidities produce too rapid
development of slimy coatings; too low. humidity is
indicated by drying, shrinkage and the growth of green
molds on the surface. A slight and very slow evapora-
tion is demanded ; by this the water-content of the cheeses
is reduced 3 to 6 per cent in two weeks. During the
first two weeks of ripening, the cheeses commonly show
some growth of yeast and Oidium lactis first, followed
by cottony white areas of Camembert mold (Penicillium
Camemberti). This mold must be introduced by inocu-
lation in new factories but once firmly established in
the factory will propagate itself if conditions are kept
favorable. Climatic conditions in most dairy sections
of America have been sufficiently unfavorable to make
more or less continuous use of pure cultures desirable.
At the end of two weeks, Camembert cheeses should show
a well-established rind, consisting of a well-matted felt
work of mold hyphse through the outer 2 mm. (^ inch)
of the whole surface of the cheese. More or less of
the pale gray-green fruit of the characteristic Penicillium
Camemberti can usually be seen. Beginning at about
twelve to fourteen days, 1 a softening of the curd is first
1 Bosworth, A. W., Chemical studies of Camembert cheese,
N. Y. (Geneva) Exp. Sta. Tech. Bui. 5, pages 23-39, 1907.
Dox, A. W., Proteolytic changes in the ripening of Camembert
cheese, U. S. Dept. Agr. Bur. An. Ind. Bui. 109, pages 1-24,
1908.
SOFT CHEESES RIPENED BY MOLD 127
directly detectable under the rind. This is preceded by
the disappearance of the acidity of the curd, which pro-
gresses inward. The softening of the curd follows closely
the lowering of the acidity. Thus a litmus test taken
along the cut face of a Camembert cheese at any stage
of softening will always show a sharp acid reaction in
the solid sour portion which changes to alkaline just
before the softening due to proteolytic action becomes
noticeable. These two changes appear to be due to en-
zymes secreted by the mycelium of the Penicillium Cam em-
berti and Oidium lactis which constitute the most active
factors in the ripening. Some accessory bacterial action
is indicated but of minor importance in the changes found.
To avoid loss from breaking, after the softening of the
curd has fairly begun, the cheeses must be removed from
the coarse matting to smooth boards where they are
watched and turned repeatedly, or as in the more common
practice, wrapped at once in parchment paper and boxed.
The ripening may be completed in either way. The
conditions necessary are such as to favor the extension
of slimy areas of bacteria over part or all of the rind to
the exclusion of further development of gray-green fruit-
ing areas of mold.
Complete softening may occur in three weeks in cheeses
in which evaporation has gone on too slowly. Such
cheeses are found to contain 51 to 55 per cent of water
when ripe and decay very quickly. If handled properly,
the water-content should fall from about 57 per cent at
the beginning of ripening to 48 per cent at its completion
which should require a minimum period of about four
weeks. It is more desirable that a cheese four weeks old
show a thin core of sour curd in the center than that it
be entirely liquid at that age.
128
THE BOOK OF CHEESE
150. Composition. Properly ripe Camembert shows
about the following range of composition : Water 47 to
49 per cent ; fat 25 to 28 per cent ; protein 18 to 21 per
cent; salt 2.2 per cent to 2.8 per cent. Variations out-
side these limits are usually associated with less desirable
qualities. The approximate limits and characters out-
lined for Camembert still leave a considerable latitude
for variations in practice which characterize the output
of particular factories in a producing group. At one
FIG. 21. Very soft Camembert cheese.
extreme are brands of Camembert cheese which are very
soft (Fig. 21), some of them actually liquid when ripe, and
which have very strong odor and taste ; one such brand
has held first place in the trade of certain American
cities for years. Another popular brand when fully ripe
is w r ell covered with yellow-orange viscid slime 1 but is
1 Esten, W. M., and C. J. Mason, Bact. Stud, of Camembert
cheese, Storrs Exp. Sta. Bui. 83 (1915), pages 103-111.
SOFT CHEESES RIPENED BY MOLD
129
fairly firm in texture with high flavor; still others show
dry moldy surfaces and mild flavors. The product of
certain factories is always characterized by the presence
and characteristic ammoniacal odor of Penicillium br&vi-
caule.
Each of these forms seems to appeal to some classes
of consumers, so that in handling imported Camembert
the trade comes to assign the product to specific groups
of purchasers according to the conditions observed at
its arrival from Europe.
151. Factory. The type of factory to be used in
making and ripening Camembert must be adjusted to
wiiwaii.
f i
II
MM
FIG. 22. Camembert cheese factory at Lisieux, France. The square
windows are seen in the second-floor rooms.
the climate. This product originated in the Normandy
section of France which is but a few feet above sea level,
is swept by winds from the Gulf Stream, and has a narrow
range of temperature, with highly humid conditions. In
that region, every effort must be made to secure ventila-
130 THE BOOK OF CHEESE
tion to carry off the necessary amount of evaporation
water. In contrast, most of the dairy sections of America
have land instead of sea breezes, much higher altitudes,
much greater extremes of temperature and a lower range
of relative humidities. The conditions of an upstairs
room full of windows in Normandy (Fig. 22) are most
readily reproduced in rooms partly or completely be-
low ground in this country. The industry calls for the
production and maintenance of a specific set of working
conditions. These are furnished by nature in northern
France, probably also in certain Pacific coast areas, but
must be artificially obtained where the climate is un-
favorable.
152. Economic factors. Camembert cheeses show
a yield of about 13 pounds to 100 pounds of milk testing
4 per cent fat. At roughly one-half pound each, the
number of cheeses will be approximately twenty-six.
Assuming no losses and a wholesale price of 15 cents
each, the wholesale value of 100 pounds of milk would
be $3.90. The labor cost of production is high, the pack-
age represents (box, wrapping and label) at least 1-J
cents a cheese. The time between the purchase and the
consumption of the cheese will average about one month.
Few cheeses actually remain this length of time in the
possession of the maker. This short investment period,
therefore, is a distinct advantage of Camembert. Among
disadvantages, however, the extremely perishable char-
acter of the fully ripe cheese makes provision of an ade-
quate and constant market essential. Losses due to
failures in manufacturing or ripening conditions are also
frequent. Excessive heat in summer and very cold
periods in winter are both unfavorable. The Camembert-
maker cannot, therefore, use the cheapest milk of the
SOFT CHEESES RIPENED BY MOLD 131
summer months at all and the losses entailed by failure
of control in winter fall on the most costly milk of the
year. Camembert requires, therefore, careful selection
of the location for manufacture and ripening, effective
control of conditions throughout the period and adequate
marketing facilities. Camembert at its best is one of
the finest of all cheeses ; when bad, it becomes quickly
inedible and is a total loss.
153. French Brie. 1 Brie cheese has its center of
production in Seine-et-Marne, east of Paris in northern
France. The apparatus, arrangement of the factories
and details of manipulation differ from those described
for Camembert, but the final product is in flavor and
texture closely related to Camembert. Brie cheeses are
the same thickness as Camembert, 1 to \\ inches ; in diam-
eter, however, there are three or more sizes varying
from 8 to 16 inches, or even greater. The largest cheeses
weigh 5 to 6 pounds. As in Camembert, practices of
making and ripening vary to such a degree as to produce
various qualities of product. These run from whole milk
through all shades of skimming. Perhaps the best
established practice puts the cheese -making room next
to the "stalls of the cows. The milk is drawn, strained
directly into the curdling cans and renneted while still
warm, 86-92 F. (30-33 C.). No lactic starter is
added and no ripening period is given to the milk. The
other manipulations differ only in detail from Camembert.
Ripening of Brie follows the same course with the same
organic agents, namely, Camembert mold (Penicillium
Camemberti) and Oidium lactis with the accompaniment
of a mixture of slimy organisms upon the surface of the
1 See page 134 for domestic or American use of the name
Brie.
132 THE BOOK OF CHEESE
cheese. The process admits of many minor modifications
each capable of affecting the product in a characteristic
way. The judgment and skill of the maker is given
a wide opportunity to establish and work toward a par-
ticular ideal of appearance and texture and flavor. Brands
with characteristic qualities, therefore, command their
own market.
Brie as known in France must not be confused with the
American " dTsigny," or with the particular sizes of that
type which have been called Brie on account of diameter
only. Very little Brie as known in France has been made
in America and only a limited amount has been imported
for very restricted trade.
154. Coulommiers. Another member of the Camem-
bert group is called, from its place of origin, Coulommiers.
This form is made at the same thickness as Camembert
and about 5j inches in diameter. It appears as either
a ripened or unripe cheese. As a ripened cheese, Coulom-
miers is not essentially different from Camembert except
that some brands are made without salting. As a cheese
eaten unripe, it has certain advantages over the other
cheeses with the flavor of sour milk only. The cottage
and (American) Neufchatel group of cheeses comprises the
best known forms with the acid flavor. These cheeses are
very perishable in nature. On the other hand, Coulom-
miers as eaten fresh can be held and used over a much
longer time without loss. Coulommiers 1 in this sense
is simply a fresh Camembert. Such a cheese, when ready
for the salting process, is a firm sour mass, close textured,
almost impervious to air and but slowly permeable to
liquids. Spoilage in such a cheese begins only on the
1 McNaughton, J., Coulommier cheese, Dept. Agr. Ottawa,
Canada, Dairy and Cold Storage Ser. Bui. 25, 1910.
SOFT CHEESES RIPENED BY MOLD 133
outside, and not throughout the mass as in cottage cheese
or Neufchatel. Successive portions of such a cheese can
be removed daily over a considerable period with no
loss of substance aside from slight scraping at times and
little or no change in flavor. This product has very tan-
gible merit for manufacture and use on the farm in many
sections of America.
CHAPTER IX
SOFT CHEESES RIPENED BY BACTERIA
A BACTERIALLY-RIPENED series of cheeses parallels the
mold-ripened group as typified by Camembert. Although
the varieties overlap, these may be roughly grouped as :
(1) those made from friable or soft curd; (2) those made
from firm or rubbery curd. In the first group, the curd
is set at 86 F., or below; in the second, the rennet is
added at 90 F. or above. In the first, the lower tem-
perature and long curdling time with ripened milk gives a
soft friable curd which may be toughened somewhat by
cutting and stirring in the whey. This section is typified
by dTsigny, American Brie, Liederkranz. In the second,
curdling of unripened milk at temperatures of 90 F.
or above insures a smooth elastic curd which fuses more
or less completely into the firm rubbery "mass typified
by freshly made Limburger.
155. The Isigny group. A series of names, dTsigny,
Brie, Brie dTsigny, combined with trade names, are
used for a domestic cheese, made in a small number
of factories distributed over New York, Pennsylvania,
Michigan, Illinois, Wisconsin, Iowa and California.
The cheeses sold under the separate varietal names differ
only in diameter; their thickness is fairly uniform; the
process of manufacture and ripening with resultant
textures and flavors furnishes no fundamental varietal
134
SOFT CHEESES RIPENED BY BACTERIA 135
characters, although the products of the several factories
show noticeable differences in market quality. D'Isigny,
while the name of a French town famous for butter
production, is not used to designate a cheese in France. It
may, therefore, be accepted as a French name arbitrarily
applied to a domestic product. Brie as used in France
is a markedly different cheese (p. 131), and the name
should be dropped from this form as made in America.
As used for a member of this series made in America, it
merely means cheese 7 to 15 inches in diameter. The
cheese partakes of the characters of French Livarot, and
of Pont 1'Eveque without exactly reproducing either form.
The milk varies from separator skim to whole
milk, with resultant differences in quality. Freedom
from gas is essential to the best results. The milk is
curdled at 85 to 86 F. with sufficient rennet to produce
a very firm curd within a period of one and one-half
hours. Curd is then cut in two directions, allowed to
stand a few minutes or gently agitated to produce a very
slight toughness or " worked " condition, then scooped
into hoops 4^ to 5 inches in height and varying in diameter
from 2j to 15 inches according to the size selected for
manufacture. To aid in the escape of whey, three rows
of holes -T2 inch in diameter and 2 inches apart in the
row are made in each hoop. The hoops are arranged
upon draining tables with more or less corrugated surface,
which for best drainage should be covered with matting.
The cheeses are allowed to drain without pressure. They
are commonly turned the second morning, although they
are sometimes solid enough to turn within the first day.
When fully drained, the cheeses are salted by rubbing
coarse salt on the surface, after which they stand an
extra day. They are then arranged upon shelves in a
136 THE BOOK OF CHEESE
ripening room held between 50 and 60 F. with humidity
so high that evaporation is kept at a minimum. In this
room, a surface slime develops quickly. This consists
of bacteria of several forms, yeasts, Oidium lactis and
accidental species of other molds'. During this ripening,
the cheeses are turned, rubbed with the hands, washed
with salt water and scraped if infected with molds which
produce colored colonies. In the course of ripening, the
slimy surface layer acquires a yellowish orange color
with the strong odor and taste characteristic of the series.
Brands of d'Isigny are made from every grade between
separator skim and whole milk. They reach the market
in' condition all the way from "Kosher" forms 1 which
are eaten entirely unripe, to brands which approximate
the qualities of Limburger and others which approach
Port du Salut.
The biology and chemistry of the ripening of this type
of cheese have not been completely followed. An initial
souring process always takes place quickly. Oidium
lactis is always present in some degree on the surface,
but the organisms in the yellowish to orange slime on the
surface of the cheese appear to produce the characteristic
odor and taste. These appear to be due to the develop-
ment of volatile fatty acids, such as valerianic and ca-
proic, which diffuse throughout the cheese, even pene-
trating the unripened sour portions. The same odor
and taste in varying intensity are present in Limburger,
Brick, and a long series of German varieties not handled
in America.
High-flavored cheeses such as these, form an acceptable
part of the meal in cases in which the intensity of other
1 Kosher forms are prepared in compliance with the Mosaic
law as demanded by the Jewish trade.
SOFT CHEESES RIPENED BY BACTERIA 137
flavors is such as to mask entirely the milder flavors of
Camembert or cream cheese.
In composition, a characteristic whole-milk brand
of this group showed the following analysis : 1 water,
45.5 per cent; fat, 25.28 per cent; protein, 18.22 per
cent.
156. Raffine. 2 This cheese is made in the French
settlement of the Isle of Orleans in the St. Lawrence
River. The practice seems to have been brought from
France and represents an intermediate product between
Camembert and perhaps Livarot, a cheese on the border-
line between Camembert and Isigny as made in America.
The outline of the making process as given follows:
Milk freshly drawn is curdled without cooling, at approxi-
mately 90 F. The rennet is prepared on the farm.
About one-half hour is required for curdling. The curd
is cut into 2-inch cubes. Whey is removed as fast as
it separates. About two hours are required for draining.
The curd then goes into the hoops. The metal hoops,
which are closed at one end, are 6 inches high, 4| inches
in diameter, with holes about rg- inch at intervals of about
J inch, and stand upon three legs about 1 inch in height.
When filled, the cheeses are left on a draining table.
Some salt is put on top while draining. When the volume
is reduced to one-half, the cheese is turned. The drain-
ing room is kept at about 70 F. After they are firm
enough to handle, drainage is completed on racks covered
with rush matting. These are arranged on special racks.
The cheeses are turned twice a day, and washed in slightly
1 Unpublished analysis of the -Stores Exp. Sta.
2 Chapais, J. C., Monographic, Le Fromage Raffine de L'Isle
d'Orleans. Quebec, 1911. Published by Ministry of Agricul-
ture, pages 1-31.
138 THE BOOK OF CHEESE
salted water every two days. After each washing, they
are drained for two hours on cloth, and placed on clean
matting. This treatment continues about fifteen days.
After fifteen days on the matting, the cheeses are ready
for ripening. They are first covered with cold brine
and let stand twenty-four hours. The cheeses are packed
in rolls or tiers in boxes, covered with cloth and ripened
at 45 F. They must be kept moist ; if signs of drying
appear, moisture must be added. If the cheeses develop
yellow slime, they are washed with clear water and rinsed
in water with salt added. After a ripening period of
three weeks, the cheeses should begin to be soft when
pressed with the finger. The growth of molds must be
prevented by washing the boxes, cloths, and washing
and scraping the cheeses if necessary. When the cheeses
are ready for the market, they are scraped clean and
white, wrapped separately in cheese-cloth or parchment
paper and packed into the boxes. Ripe cheeses are
about 5 inches in diameter, 1 inch thick and weigh a little
over 5 ounces.
The outline of the Raffine process follows :
coagulation by rennet 30 minutes
cutting and draining curd .... 2 hours
draining in hoops . 10 hours
stand on mats 15 days
ripening in boxes 21 days
Total period 36 days
The treatment described closely resembles the handling
of Livarot cheese in the department of Calvados, France.
157. Liederkranz cheese. Among the specialties in
the bacterial group is Liederkranz, made from curd with
the soft friable texture of a Camembert, molded in rec-
SOFT CHEESES RIPENED BY BACTERIA 139
tangular blocks of about 4 ounces in weight and ripened
very completely. Although this name is the private
brand of a single factory, it has become widely known with
the effect of creating a type name in the American market.
Analysis of this brand of cheese gives about 55 per cent
water, 25 per cent fat, 17 per cent protein, which in-
dicates a whole milk cheese.
158. Limburger cheese l derives its name from the
town of Limburg in Belgium. The manufacture of this
cheese is now widely practiced in Europe and in certain
parts of the United States, especially in New York and
Wisconsin. Practically no cheese of this name is at
present imported, and the practices described are limited
to those in American factories.
159. The milk. Limburger cheese is probably best
known on account of its pronounced odor. Because
of this characteristic pungent smell, it is often thought
that the cheese is made in dirty or unsanitary places.
On the contrary, Limburger cheese is usually made in
small factories which are clean and sanitary. Because
of the constant attention required, a cheese-maker can
handle only about 2000-2500 pounds of milk a day,
and then some help is necessary to care for the cheeses
in the curing room. 2 The discussion of the milk given
in Chapter II applies to that to be made into Limburger
cheese; however, Limburger requires sweeter milk than
do some of the other types. To be sure of obtaining
very sweet milk, it is the usual practice for the milk
to be delivered without cooling morning and evening
1 The authors acknowledge the assistance of Mr. Louis Get-
man in preparing this description.
2 Zumkehr, P., Limburger cheesemaking, Wis. Cheese-makers
Association, 15th Annual Meeting, 1907, page 62.
140
THE BOOK OF CHEESE
at the cheese factory. The cheese is made twice a day.
Because the milk must be delivered twice daily, it is
obtained from only a few producers near the factory.
A factory usually does not have more than eight to twelve
patrons. Because of the small number of patrons, it
is comparatively easy to obtain a supply of fresh clean
milk.
The factories are variously built. A common type
takes advantage of sloping ground so that the floor at
FIG. 23. A common type of Limburger cheese factory.
one end may be on the ground level and run backward
into a hillside until the other end is a cellar with small
windows at the ceiling opening at the ground level (Fig.
23). The family of the cheese-maker often lives in the
same building above the factory.
160. Making the cheese. Limburger cheese is made
from the whole milk. When the milk is received at the
factory, it is placed in the cheese vat. As the milk is
delivered both morning and evening without cooling,
it reaches the factory at a temperature of 90 to 96 F.
SOFT CHEESES RIPENED BY BACTERIA 141
In some cases the night's and morning's milk is mixed
and then warmed to about 94 F. This practice is not
recommended but is frequently adopted, when the supply
of milk becomes too small to work in two lots. As soon
as all of the milk has .been delivered, the cheese-making
process begins. No starter is used. The milk is not
ripened because no acid development during the making
process is desired. > The milk is set or curdled at the
temperature at which it is received at the factory, usually
from 90 to 96 F. Sufficient rennet extract is used to give
a firm coagulation in twenty to thirty minutes. This
usually requires 2j to 3 ounces of rennet extract for
each 1000 pounds of milk: This is diluted in about
forty times its own volume of cold water and added to
the milk. (For method of adding rennet extract to milk,
see Chapter V.) When the coagulum has become firm
so that it will split clean over the finger, the curd is
ready to cut. Coarse Cheddar cheese knives are used.
Sometimes only the perpendicular knife is employed,
and the curd is broken up while being stirred with
the hands and rake. This usually causes a large fat
loss. After cutting, the curd is stirred first by hand
and later with an ordinary wooden hay rake. Usually
the curd is not " cooked " or heated after setting,
though occasionally it is brought up as high as 96 F. to
98 F. If the curd does not firm up, the temperature
may be raised to 98 to 100 F. to aid in expelling the
moisture.
When ready to dip, the curd should still be in large
soft shiny pieces. It requires from one hour to an hour
and thirty minutes from the time the rennet extract
is added until the curd is ready to dip. When, in the
judgment of the cheese-maker, the curd has become suffi-
142 THE BOOK OF CHEESE
ciently firmed in the whey, the whey is drawn down to
the surface of the curd. The curd is then dipped into
the Limburger molds. These molds are 5 inches square
by 8 inches deep without top or bottom. Usually there
are five or six of these molds built together into a section.
These molds are placed on a draining table beside the
vat and the curd is ladled into them with a large tin
ladle. The draining table has strips on both sides and
one end and slants toward the other end so that the
whey will drain from the curd and yet not go on the
floor except at the one end. This makes it easy to
save and catch the whey for stock feed.
161. Draining and salting Limburger. In some fac-
tories, a clean piece of burlap is put on the draining table
and the molds and curd placed on the burlap. This aids
in the rapid draining of the whey from the curd and pre-
vents the loss of curd particles. The curd should be
turned frequently in the mold to obtain uniform draining.
The molds are transferred to the salting room as soon as
well drained, usually in about twelve hours, but sometimes
they are left until the following morning. Here they
are placed on another draining table, which has strips
about 5 inches high on the sides and one end. The
cheeses are placed along this board, each cheese being
separated by a piece of board 4 inches high and 5 inches
wide. When the row is filled, a long strip the length of
the table is placed against the row. Another row is
laid down against this strip in the same manner as the
first, and so on until several rows are on the table.
The last long strip is held firmly in place by sticks
wedged between it and the opposite side of the table.
These strips and pieces form a mold for each cheese while
draining. Usually the cheeses are turned several times
SOFT CHEESES RIPENED BY BACTERIA 143
in this period to obtain a uniform expulsion of whey.
In about twenty-four hours the cheeses are ready to be
salted. This is done by applying the salt to the outside
of the cheese. The edges are rolled in a box of salt and
the salt then rubbed on the two broad surfaces. Any
excess salt is brushed from the cheese with the hand.
The cheeses are then laid on a draining table in single
layers. The second day, they are salted again in the
same way and piled two deep ; they are salted again the
third day and piled three or four layers deep. The
salting room or cellar should have a temperature of 60
F. and be fairly damp. The amount of salt used is
very important. The tendency is to use too much salt.
This retards the ripening process and in extreme cases
gives the cheese a salty taste. If not enough salt is
used, the cheese will deteriorate very rapidly on ac-
count of the development of undesirable types of fer-
mentation. The cheeses when salted are then placed in
the curing room, which is a cellar, usually beyond the
salting room. This cellar should have a temperature of
58 to 64 F. and a relative humidity of 95 per cent of
saturation. In winter it is necessary to have a fire to keep
the rooms warm, otherwise the cheese would cure very
slowly or not at all. In some factories the curing and
salting cellars are a single room.
162. Ripening Limburger. When first placed in the
curing cellar, the cheeses are put on edge close together,
and as they cure are gradually separated. While in the
curing cellar, the cheese must be rubbed frequently by
hand and washed, usually with salt water. The object
of the rubbing is to keep the surface of the cheese moist
and prevent the growth of molds. The drier the cheese
and the more mold, the oftener the cheeses must be
144 THE BOOK OF CHEESE
rubbed. The drying or the evaporation from the cheese
can be retarded by sprinkling the floor of the cellar with
water. When first placed in the curing cellar, they are
usually rubbed daily; after a few days they are rubbed
every other day and finally as often as the cheese-maker
can find time to work at them. The more the cheeses
are rubbed, the better the rind.
In the curing of Limburger cheese, protein compounds
are attacked by the micro-organisms. Certain highly-
flavored fatty acids are commonly produced. 1 This
change works most rapidly near the outside and more
slowly toward the center of the cheese. The stage of
ripening can be determined by examining the cheese.
When first made, a cheese is harsh and hard and the
outside is more or less white : as the curing changes take
place, the cheese becomes soft and pasty or buttery.
The outside color changes from a whitish to a yellowish
and finally even a reddish brown. It requires consider-
able time for the ripening agents to work from the outside
to the center of the cheese. As ripening progresses,
Limburger cheeses tend to become soft enough to break
in handling. If such cheeses are wrapped in manila
paper after three to four weeks of ripening and packed
in boxes, losses from handling are eliminated. One
loose board is left on each box and the boxes remain in
the ripening cellar until the cheese-maker decides by
removal and examination of cheeses from time to time
that they are ready for shipment. When fully ripe,
the cheese spoils very quickly. Unless handled very
carefully, the outer part may actually rot before the
interior is fully ripe. The cheeses are shipped from the
1 Currie, J. N., Flavor of Roquefort cheese, Jour. Agr. Re-
search 2 (1914), no. 1, pages 1-14.
SOFT CHEESES RIPENED BY BACTERIA 145
factory when they are eight to ten weeks old. They are
then placed in cold storage, which checks the action of
the ripening agents and so lengthens the commercial life
of the cheese.
163. Marketing and qualities of Limburger. As
shipped from the factory, each cheese is wrapped in
heavy manila paper and frequently also in tin -foil. The
cheeses are packed in boxes which hold forty-eight.
Each cheese weighs about two pounds.
Limburger cheese should be regular in shape. The
rind should not be cracked or broken nor the sides bulged,
nor should it be lopsided. It should have the pronounced
characteristic flavor, without other objectionable flavors
due to undesirable fermentations. The body should be
uniform throughout. It is common to find cheeses that
have not a uniform body, due to lack of curing ; a small
part of the interior at the center will be hard and not
cured, while the remainder of the cheese will be soft and
buttery. The color should be uniform. When not en-
tirely cured, the uncured part at the center is usually of
a lighter color.
The cheese should contain the proper amount of
salt. The most common defect is in the flavor. If the
milk is not free from bad odors and flavors, these are
apt to be more pronounced in the cheese than in the milk.
.(For care of milk see Chapter II.) Gas-forming fer-
mentations are very bad in this variety of cheese as they
cannot be controlled and give the cheese a bad flavor
and a " gassy body." When a cheese is gassy, the sides
are most liable to be bulged and the body is full of gas
holes or pockets. Another defect is a sour cheese. This
is caused by the development of too much acid in the
milk or during the manufacturing process. A sour
146 THE BOOK OF CHEESE
cheese usually cures slowly and has a pronounced sour
taste. The body is hard and bitter.
If the cheese contains too much moisture, it will cure
rapidly and the body will be very soft and pasty. In
extreme cases it will be so soft that it will run when the
rind is broken. On the other hand if the cheese does not
contain sufficient moisture, it will cure very slowly and
the body will be hard and dry and sometimes crumbly.
There is no standard score-card for judging Limburger
cheese. The Wisconsin Cheese-makers Association l
uses the following score -card for Limburger :
Flavor 40
Texture 40
Color 10
Salt 5
Style __5 .
Total 100
164. Yield and composition of Limburger. The yield
of cheese depends on : (1) the amount of fat and other
solids in the milk from which it is made ; (2) the amount
of moisture incorporated into cheese; (3) the loss of
solids during the manufacturing process.
The yield varies from 12 to 14 pounds of cheese from
100 pounds of milk. The more fat and other solids in
the milk, the more cheese can be made from 100 pounds-
of the milk. The more moisture incorporated into the
cheese, the larger the yield. The quality of the cheese
and the amount of solids determine the amount of mois-
ture that can be incorporated into the cheese. The
greater the losses during the manufacturing process, the
1 Wis. Cheese-makers Assoc., 12th Annual Meeting and Report,
1906, page xxviii.
SOFT CHEESES RIPENED BY BACTERIA 147
less is the yield. The composition of Limburger cheese
is affected by the same factors as the yield. The average
cheese probably carries from 40 to 42 per cent of moisture.
Limburger cheeses will vary in composition from this
analysis about as follows : water 38 to 44 per cent, protein
21 to 25 per cent, fat 25 to 30 per cent. The differences
in practice in factory groups are considerable. Certain
markets call for more solid brands, others for the very soft
forms.
165. Munster cheese originated in Germany near
the city whose name it bears. There is a limited de-
mand for this variety in America; therefore it is not
extensively made. It is usually manufactured from
whole milk in a Limburger or Brick cheese factory.
The process of manufacture is between that of these two
varieties in temperatures used, firmness of curd and amount
of moisture in the curd and cheese. The process is prob-
ably more like that of Limburger. The curd is firmed
more in the whey than for Limburger, and more acid is
developed. The cheeses are pressed or drained in round
forms 7 inches in diameter and 6 inches high. The hoops
are lined with cloth to prevent the loss of curd particles
while draining. When the cheeses are sufficiently drained,
until they are firm enough to hold their shape, the cloths
are removed. The cheese is salted by rubbing dry salt
on the surface or soaking the cheese in brine. The prod-
uct is handled in the curing room very much the same
as Limburger or Brick cheese. When sufficiently ripe,
each cheese is wrapped in parchment paper and placed
in a separate wooden box. This cheese, when cured, has
a characteristic flavor which is between that of Limburger
and Brick. The body is more or less open. The essential
factor in the manufacture of Munster cheese is clean
148 THE BOOK OF CHEESE
milk. Bad fermentations, such as produce gas and bad
flavors, seriously interfere with the manufacture and
sale of the product. The cheese is usually made in the
late fall and winter, when it is difficult to manufacture
Limburger.
CHAPTER X
SEMI-HARD CHEESES
BETWEEN the quickly perishable soft cheeses and the
typical hard group, are two series of varieties, one
ripened by green mold and best known by Roquefort,
the other ripened by bacteria and typified by Brick
cheese. These cheeses are fairly firm, hold their shape
well, ripen over a period varying from a few weeks to
several months and their marketable period is com-
paratively long. In texture they are intermediate be-
tween the conditions known as " soft " and " hard."
In water-content, they range at their best from 37 to
45 per cent. Outside these limits, the cheeses are often
marketable but they lose in quality l and trueness to type.
166. The green mold group. There are three well-
known semi-hard cheeses ripened by green or blue-green
mold. 2 The mold is an incidental factor in certain other
forms but none of these forms has won larger than local
or purely national recognition. French Roquefort, on the
contrary, is probably the most widely known of all cheeses.
Stilton, to a small degree at least, has followed the English
to the many lands they inhabit. Gorgonzola, although
1 Currie, J. N., The relation of composition to quality in
cheese, American Food Jour. 11 (1916), no. 9, page 458. See also
Dox on the True Composition of Roquefort Cheese, Ztsch.
Untersuch. Nahr. u. Genussmtl. 22 (1911), pages 239-242.
2 Thorn, C., and Matheson, K. J., Biology of Roquefort cheese,
Storrs Exp. Sta. Bui. 79, pages 335-347, 1914.
149
150 THE BOOK OF CHEESE
made in Italy alone, has a large market in other parts of
Europe and in America. In the manipulations of manu-
facture, these forms are not closely related but they re-
semble each other in that each becomes streaked or
marbled by the growth of green mold (Penicillium Roque-
forti) through open spaces within the cheese. The
" blue-veined " or marbled cheeses have a characteristic
taste which is developed in its most typical form in
Roquefort.
167. Roquefort cheese. This is a rennet cheese
made from sheep's milk (with occasional and minor
admixture of goat's and cow's milk) in the section of
southern France centering about Roquefort in Aveyron.
The practices are standardized and controlled by a few
companies, thus reaching exceptional uniformity. Roque-
fort is uncolored, open, made from firm but brittle or
crumbly, not tough or waxy curd. Each cheese is about
7J inches (20 cm.) in diameter and 3J inches (9 cm.) in
thickness without a definite rind, and when ripe enough
for market is scraped carefully, closely covered with
tin-foil and kept in refrigerators. The cut cheese shows
extensive open spaces which are lined with green mold.
This cheese, in addition to a strong cheesy odor and taste,
has a peppery or burning quality which according to
Currie 1 is due to the formation of volatile fatty acids
such as caproic, caprylic and capric from the butter -fat
of the sheep's milk used. A series for Roquefort cheeses
selected for excellent quality was found by Dox 2 to show
the following composition :
1 Currie, J. N., Flavor of Roquefort cheese, Jour. Agr. Re-
search, 2 (1914), 1, pages 1-14, Washington.
2 Dox, A. W., Die Zusammensetzung des echten Roquefort-
Kases, in Ztschr. Untersuch. Nahr. u. Genussmtl. Bd. 22, Heft.
4, pages 239-242, 1911.
SEMI-HARD CHEESES
151
TABLE IV
COMPOSITION OF ROQUEFORT CHEESE
WATER
PER
CENT
FAT
PER
CENT
PROTEIN
PER
CENT
ASH
PER
CENT
SALT
PER
CENT
Average ....
Minimum . . .
38.69
37.49
32.31
31.50
21.39
19.14
6.14
5.18
4.14
3.64
Maximum . . .
40.10
33.53
23.06
6.81
4.88
The composition of the sheep's milk of the Roquefort
producing region is reported by Marre : 1
TABLE V
COMPOSITION OF SHEEP'S MILK
WATER
PER
CENT
CASEIN
PER
CENT
FAT
PER
CENT
LACTOSE
PER
CENT
ASH
PER
CENT
Range ....
Average ....
76-83
79.5
5-8
6.5
5.5-10.5
8.0
4 to 5
4.5
0.8-1.2
1.0
The cheeses when properly made in the local factories
are transported to Roquefort for ripening in the famous
caves which have made possible the development of a
great industry.
The Roquefort caves were originally natural openings
leading back into the face of a cliff until they reached a
deep, narrow fault or crack in the rock leading to the
plains above. The cooler air from the plains came down
this crack over moist and dripping rocks and issued
through these clefts in a cold moisture-laden current
which kept the caves about 50 to 55 F. and moist enough
to ripen the cheeses without shrinkage. As the business
1 Marre, E., Le Roquefort, Rodez, 1906. This is the authorita-
tive monograph on Roquefort cheese problems.
152 THE BOOK OF CHEESE
outgrew the natural caves, great cellars, some of them
five or six floors deep, were excavated and tunnels were
dug back to the crack so that the strong ventilating
current reaches every part of the cellars and keeps both
temperature and relative humidity favorable to the
ripening of the cheeses.
168. Cow's milk or Facons Roquefort. The supply
of Roquefort is automatically limited by the supply of
sheep's milk. The sheep gives milk only about five
months in the year and at best a scant average of about
a pint a day to a sheep. Sheep's milk for cheese-making
is not produced, therefore, outside of very limited regions.
Some cow's and goat's milk unavoidably finds its way
regularly into the industry itself. Attempts were nat-
urally made to substitute cow's milk. Outside the con-
trolled area, factories were established for this purpose.
The quality of the product did not equal that of the
Roquefort factories, and French courts decreed that the
name Roquefort should not be used for such products.
Although some local success was obtained, not much prog-
ress was made against the intrenched Roquefort industry.
Similar attempts to make such a product in Germany 1
were tried on an extensive scale but failed. More re-
cently, under the inspiration of Conn, the United States
Department of Agriculture and the Storrs Experiment
Station have studied the possibilities of such an industry.
Although the work is not completed, the preliminary
reports 2 have indicated the fundamental principles
which must underlie such development.
1 Reported on the word of Prof. Fleischmann.
2 Thorn, C., J. N. Currie and K. J. Matheson, Studies relating
to the Roquefort and Camembert types of cheese, Storrs Exp.
Sta. Bui. 79, pages 335-394, 1914.
SEMI-HARD CHEESES ' 153
169. Outline of making Roquefort. Some of the
results of these experiments are summarized in the fol-
lowing paragraphs :
Milk. Clean-flavored fresh milk testing 4-4.2 per
cent fat and up to 2.8 percent casein gives the best results.
The milk with a high percentage of cheese-making solids
forms a firmer curd, hence works up better in the process
than milk of lower quality.
Acidity. The milk is ripened by lactic starter up to
an acidity of 0.23 per cent titrated as lactic acid at the
time rennet is added. This gives a firm curd, which
drains to the desired water-content but is low enough
to prevent the toughening effect of too high acid. A
very slight increase in initial acid 1 to 2 hundredths
per cent combined with the rate at which acidity is
developing introduces such physical changes in texture
as to make the final texture of Roquefort impossible.
Temperature. Rennet is added at or below 84 F.
Every degree of heat adds definitely to the efficiency of
rennet. Below 82 F., curdling becomes slower and the
coagulum softer and more difficult to drain. The sheep's
milk curd is made from 76 to 84 F. but sheep's milk
has about twice the cheese solids found in cow's milk.
It was found necessary to raise the temperature as high
as texture would permit. However, at 86 F. the physical
character of the curd tends to become tough or waxy
in handling. At 84 F. the curd remains brittle and
crumbly. It was, therefore, necessary to keep the cur-
dling temperature down to 84 F.
Renneting or setting. Rennet at a rate of 3 to 4
ounces of standard liquid rennet to 1000 pounds (10 to 12
c.c. to 100 pounds) was found to give the best curd
under experimental conditions.
154 ' THE BOOK OF CHEESE
Curdling time. One and one-half to two hours gave
most satisfactory results in forming curd. This should
be very firm and stand until it begins to " sweat/' until
beads of whey have begun to collect upon its surface.
Cutting. The cow's milk curd gave best results when
cut in two directions with the half-inch curd knife. The
resulting columns, a half inch square in cross-section,
may be handled without excessive losses.
Draining. The cut curd is dipped to a draining rack
covered with cloth with as little breaking as possible.
During the draining process, a certain amount of turning
is necessary to facilitate the separation and escape of
the whey. If handled too much, losses of fat are in-
creased and the curd becomes tough or waxy instead of
remaining brittle or crumbly. When properly handled,
not over 0.35 per cent of fat is lost. Under favorable
conditions, four-ninths to two-thirds of the original weight
of curd will separate and run off as whey in twenty to
thirty minutes. The curd meanwhile is exposed to the
air of the room and cools toward room temperature. If
cooling goes too far, further drainage is interfered with.
Hence the curd is put into the hoop and the drainage
completed while the cheese is reaching its final form.
Hoop. Hoops for cow's milk Roquefort must be
7 J inches in diameter and about 5f inches high to hold
curd enough to produce a cheese the size of the standard
Roquefort when completely drained. Sheep's milk with
its higher percentage of solids does not require such
high hoops. The curd as it goes into the hoop should
be a soft, pulpy mass with no suggestion of toughness.
Inoculation with mold. The mold for Roquefort
cheese (Penicillium Roqueforti 1 ) is readily grown in pure
1 Thorn, C., U. S. Dept. Agr. Bur. An. Ind. Bui. 82, 1905.
SEMI- HARD CHEESES 155
culture in ordinary loaves of bread. For this purpose
loaves hot from the oven are quickly drenched with or
immersed in hot paraffine to form an impervious crust
to retain moisture as well as to keep out contaminations.
It is then allowed to cool. The interior of each loaf is
inoculated by drawing a suspension of P. Roqueforti
spores in water into a sterile pipette (10 c.c.) which is
then thrust through the paraffined crust to the center of
the loaf of bread and allowed to empty there. The hole
is sealed up with paraffine. These loaves are incubated
for about a month at room temperature. When cut,
every open space should be found lined with the green
spores of the mold. When dry enough, the mass may be
powdered, and put into an ordinary pepper box. When
the curd is ready to go into the hoop, this mold powder
is sprinkled upon it from the pepper box.
Handling. Freshly made cheeses are turned within
the first hour to insure the proper smoothness of both
sides. Further draining is best accomplished in a room
at about 64 F. with a relative humidity of 85 to 90 per
cent. If the surface of the cheese becomes too dry, a rind
is formed. No real rind is permitted on Roquefort.
If the temperature is too high, slime forms quickly and
unfavorable fermentation may occur. Slime (bacteria and
Oidium lactis usually) must be scraped when it becomes
too heavy.
Salting. 1 Experimental cheeses were found to give
the best results when at the end of about three days'
drainage they contained about 50 per cent water. Such
cheeses were salted by sprinkling the entire surface
lightly, replaced upon the drain boards for one day,
1 Thorn, C., The salt factor in the mold ripened cheeses,
Storrs Exp. Sta. Bui. 79, pages 387-394, 1914.
156 THE BOOK' OF CHEESE
salted again and piled in two's. After another day they
received the third salting and were piled in three's for
two days longer. A total of about 10 per cent by weight
of salt was used to secure an absorption of 4 per cent.
At the same time the water-content dropped to 40 to
43 per cent. After salting is completed, the cheeses
are brushed and punched with holes to permit oxygen
to enter. 1 They are then ready for ripening.
170. Ripening of Roquefort. The ripening of ex-
perimental Roquefort has required four to six months
at a relative humidity of 85 to 90 per cent. This relative
humidity is just below the equilibrium relative humidity
of the cheese, hence permits a shrinkage of 2 to 4 per
cent in the water-content of the cheese. This makes it
possible to control the amount of surface slime developed.
If the relative humidity goes too high, the surface slime
of bacteria and yeasts becomes very heavy, soft and
almost liquid, and follows the openings into the cheese
with resultant damage to appearance and flavor. Even
under the conditions at Roquefort, this slime must be
removed by rubbing or scraping several times to avoid
injury to the cheeses, together with the production of
bad odor and taste. If the humidity becomes too low,
the surface becomes dry, hard and cracks open, the
friable crumbly texture is injured, and there is consider-
able loss in weight. Salt forms about 4 per cent of the
cheese. This is in solution in the water present, which
is about 40 per cent, and makes a brine of about 10 per
cent strength. This strength of brine does not prevent
the growth of the Roquefort mold (Penicillium Roqueforti)
but does hinder the development of Oidium lactis in the
1 Thorn, C., and Currie, J. N., The dominance of Roquefort
mold in cheese, Jour. Biol. Chem. 15 (1913), no. 2, pages 247-258.
SEMI-HARD CHEESES 157
open spaces within the cheese. Accurate adjustment of
temperature and relative humidity in the ripening rooms
to salt and water-content in the cheese is essential to
proper ripening. These conditions are furnished by the
unique natural conditions of the caves of Roquefort.
The production of such cheeses elsewhere depends either
on the discovery of another locality with closely similar
conditions or on the artificial production and control of
the necessary temperature and relative humidity. This
has been done on an experimental basis by the use of
cold storage apparatus combined with proper humidifiers.
The differences between working with sheep's and
with cow's milk lie in the making process rather than in
the ripening. Sheep's milk freshly drawn shows a higher
acidity than cow's milk, probably on account of the acid
reaction of its greater casein content. With nearly
double the total solids of cow's milk, the yield to one
hundred pounds is much greater, consequently the drain-
age of the curd is much more easily handled.
Once made and salted, the cheeses require very nearly
the same conditions of ripening. The resultant products
are alike in appearance and texture. In flavor, cow's
milk Roquefort differs in character from sheep's milk
cheese to such a degree as to be recognized by taste.
The difference was found by Currie l to be due to an actual
difference in the combination of fatty acids present.
Although these differences in character are recognizable
by the expert in testing the cheese, as well as by chemical
analysis, cow's milk Roquefort would satisfy that large
proportion of consumers who use such cheese only in
connection with other fairly high flavored foods. The
1 Currie, J. N., The composition of Roquefort cheese fat,
Jour. Agr. Research, 2 (1914), 6, pages 429-434.
158 THE BOOK OF CHEESE
demands for technical skill and factory equipment are
not naturally greater than for many other lines of cheese-
making. The gradual development of a cow's milk
Roquefort may be anticipated.
171. Gorgonzola * is a rennet cheese made from fresh
whole cow's milk, in northern Italy. It takes its
name from the village of Gorgonzola, a few miles from
Milan, but the manufacture of the cheese has spread
FIG. 24. Gorgonzola ripening establishment in valley near Lecco.
over a wide area. The cheeses are made on farms and
in factories from which they are transported for ripening
to cool valleys of the Alps, principally near Lecco (Fig. 24).
Boeggild introduced the making of a cheese after the
Gorgonzola process into Denmark about 1885. This
industry has been successful on a small scale since that
time. Gorgonzola cheeses are about 30 cm. (12 inches)
in diameter and 18 cm. (7 inches) thick and weigh 15
to 20 pounds. As exported they are usually heavily
1 Thorn, C., Soft cheese studies in Europe, U. S. Dept. Agr.
Bur. An. Ind. Kept. 22, pages 79-109, 1905.
SEMI-HARD CHEESES 159
coated l with a mixture usually barite, tallow and lard
colored with annatto or other cheese color. This coating
prevents shrinkage or mold on the surface of the cheese in
transit. When cut these cheeses vary greatly. All show
marbling with mold (Roquefort mold). During their
ripening they become very slimy at the surface. To
open up air spaces for mold growth, this slime is scraped
off and holes are punched into the cheeses. These holes
are readily seen in the final product. Some show crumbly
texture, well distributed mold, as in Roquefort, with
flavor approaching that cheese; in others .the texture
is waxy rather than crumbly, a condition correlated
regularly with different character in the flavor. Fre-
quently in whole areas or in small pockets, slime consist-
ing of bacteria and Oidium has followed the openings
into the cheese and affects its odor and taste.
Experimental Gorgonzola cheeses comparable with
the Italian product were made with cow's milk ripened
as for Roquefort or higher, to 0.25-0.30 per cent (titrated
as lactic acid), curdled at 86 F. (30 C.), cut into cubes
and slightly stirred, then dipped to a draining board for
about one-half hour, and put into the hoop. The cheeses
drained quickly to about 50 per cent water and developed
a surface rind as in the harder cheeses. Cut surfaces
showed a fairly open cheese in which mold grew readily.
These cheeses were salted to taste, not to a specified
percentage. They ripened with the same irregular
results and the characteristic range of flavors found in
Gorgonzola. To avoid the rotting of the cheese by sur-
1 Frestadius, A., Nord. Mejeri Tid. 17 (1912), 14, page 159,
Abs. N. Y. Produce Rev. 34 (1912), 2, page 54, and Cutting,
W. B., The use of baritine in cheese rinds, Mo. Commerce and
Trade Repts. 1908, 337, page 144, also in Practical Dairyman, 2
(1908), 7, page 76.
160 THE BOOK OF CHEESE
face growths, they were exposed to low humidities for a
time and cracks opened at the surfaces, as seen in the
ripening rooms at Lecco (Fig. 24). The texture was
more or less waxy or tough, which was correlated with
the slightly higher heat at renneting together with the
stirring or " working " of the curd. Comparative an-
alyses of a series of imported cheeses confirm the inter-
pretation that the salt-content of Roquefort, 4 per cent
FIG. 25. Gorgonzola cheese curing-room.
approximately, prevents the invasion of the interior of
the cheese by Oidium. No complete study of the ripen-
ing of Gorgonzola -has been made. As far as followed,
it consists in an initial souring process followed by ripen-
ing by molds and slime organisms. At its best, Gorgon-
zola is nearly equal to Roquefort but the percentage of
SEMI-HARD CHEESES 161
such quality is low. In spite of its irregular quality,
England has used larger amounts of Gorgonzola than of
Roquefort. Considerable quantities have been imported
for the Italian trade in the United States.
172. Stilton cheese bears the name of an English
village 1 in which it was first sold. It is made from cow's
milk and is typically a whole milk cheese, although part
skim cheeses are regularly made and sold as lower grades.
In the Stilton-making counties, the milk from Shorthorn
cattle testing about 3.5 to 4.0 per cent fat is preferred
to richer or poorer grades. Such milk is curdled with
rennet at about 86 F. in about one hour; the curd is
cut, dipped to a draining table covered with cloth and
drained slowly over a period of several hours, commonly
overnight. During this period considerable acidity is
developed. The curd is then milled or broken by hand,
salted, packed into hoops 15 to 16 inches high and 7
inches in diameter. These hoops are made from heavy
tin (Fig. 26) with four rows of holes about T$ inch in
diameter. The freshly filled hoops are allowed to
stand and drain without pressure in a room at about
70 F. (Fig. 26). Such cheeses are turned every day
for several days. When solid enough to stand the hoops
are removed, the cheeses are scraped or rubbed with a
knife until the surface is smooth, and commonly wrapped
with a cloth bandage to maintain the shape, if the
cheese is still too soft to stand firmly. In the factories,
several rooms are used with varying temperature and
relative humidities, which makes it possible to place each
1 Stilton Cheese J. P. Sheldon from abs. by New York
Produce Rev. 28 (June 16, 1909), no. 8, pages 362-363. Stilton is
said to have originated with Mrs. Paulet, Wymondham, Co. of
Leicester, and to have been sold by her brother Host of the
"Bill" at Stilton from which village it derived its name.
162
THE BOOK OF CHEESE
cheese under the condition best suited to its texture and
condition of ripeness. In general, the dairy sections of
England are much more humid than those of America
and there are less violent changes in temperature. Stilton
FIG. 26. Stilton cheeses in hoops, draining.
cheese-making has grown up to take advantage of this
climatic factor in handling the product. Transplanta-
tion of such an industry necessitates a mastery not only
of the manipulations but a grasp of the fundamental
principles underlying the process and a readjustment of
practices to preserve those principles.
SEMI-HARD CHEESES 163
Stilton is, then, a soured curd cheese in whose ripening
a very prominent part is played by the green mold (usu-
ally some strain of P. Roqueforti) which grows throughout
the cavities of its mass. 1 At its best, it has attractive
texture and flavor. Much of it fails to reach high quality
on account of the invasion of bacteria, Oidium lactis,eind
very frequently myriads of cheese mites. The following
analysis was furnished as typical for ripe cheese by
Miles Benson, 2 late professor of dairying at Reading,
England : Water 31 per cent, fat 36 per cent, casein
29 per cent, mineral constituents including salt about
4 per cent. Approximately the same figures are given
by Primrose McConnell (Agricultural Note Book). The
low percentage of salt is another factor of uncertainty
in the control of this Stilton product, as in Gorgon-
zola, since these cheeses are commonly high in water-
content at first and are thus subject to invasion by
Oidium.
Stilton has been made on a small scale in Canada 3
and occasionally attempted in the United States. No
serious effort to develop an industry of commercial im-
portance has been made in America. Comparative study
of the cheeses ripened by green mold tends to the con-
viction that the adaptation of the Roquefort practice to
the use of cow's milk offers a more satisfactory basis for
experiment than efforts to establish a Stilton or a Gorgon-
zola industry.
1 Percival, J., and G. Heather Mason, The microflora of Stil-
ton cheese, Jour. Agr. Sci. 5 (1913), part 2, pages 222-229. See
also Thorn, C., Soft cheese studies in Europe, U. S. Dept. Agr.
Bur. An. Ind. Kept. 22 (1905), pages 79-109.
2 Benson, Miles, in personal letter from analyses of cheeses
selected for the purpose.
3 Dean, H. H., The Creamery Journal, Nov. 1904.
164 THE BOOK OF CHEESE
173. Gex. A cheese under this name made in southern
France resembles, in its general character as a ripened
cheese, the English Stilton and Italian Gorgonzola. Al-
though it has no commercial importance, reference is made
to this cheese to show that mold-ripened cheeses have been
developed entirely independently in different countries to
bring about the same general character of product.
174. Bacterially ripened series. The semi-hard cheeses
ripened by bacteria stand half-way between true Lim-
burger and the hard forms. In fact, brands of Lim-
burger are readily found which approach the texture and
ripening of Brick cheese. In the same way, Brick cheeses
are often found which have the appearance, texture and
much of the flavor of the Cheddars with only a trace of
the taste of Limburger. Port du Salut, Oka, Munster,
in France Livarot, in the Balkan regions Kascoval, belong
in this series.
175. Brick cheese. The name of this cheese is
probably due to the finished product being about the size
and shape of a brick. It is similar to the German cheese
Backstein and may have been developed from it. It is
typically a sweet-curd cheese, made from milk freshly
drawn, without permitting the development of appre-
ciable quantities of acidity until after the curd has been
put into the hoop. In the making process-, it is inter-
mediate between Limburger and the cheeses of the Cheddar
group. Some cheese-makers use an ordinary cheese vat,
others a copper kettle in manufacturing.
It is the usual practice to deliver the milk to the cheese
factory both morning and evening, without cooling.
Cheese is made twice a day. In some cases the milk
is delivered only once a day, and extra precautions must
then be taken to care for the milk properly.
SEMI-HARD CHEESES 165
The discussion of the care of milk in Chapter II
applies to that for Brick cheese. For the best
quality of cheese, the milk in the vat should show
about 0.15 of 1 per cent acidity and never above 0.18 of
1 per cent. 1
176. Making of Brick cheese. 2 The milk is received
at the cheese factory at a temperature of about 92 to
96 F. For the best results, the acidity should be deter-
mined (by the acid test) to decide on the amount of
starter to use. Few Brick cheese-makers use an acid
test or a starter but these precautions would improve the
product of many factories. For method of using the acid
test, see Chapter V. Chapter IV discusses the prepa-
ration and use of starter. Usually 0.25 to 0.50 of 1
per cent of starter is the amount required. A small
amount of starter is used to aid the development of lactic
acid and for the beneficial effect 'it has on the flavor.
A very small development of acid is desired after adding
the starter; therefore the change in acidity should be
very carefully watched with the acid test. The vat is
usually set when the acid test shows 0.16 of 1 per cent
acidity. The more acid in the milk, the less starter should
be employed. Sufficient rennet extract should be used
to give a coagulation suitable for cutting in thirty to
thirty-five minutes. For method of adding the rennet
extract, see Chapter V. When the coagulum is firm
1 N. Y. Produce Rev. etc., Vol. 32, no. 14, page 536.
2 N. Y. Produce Rev. etc., Vol. 30, no. 5, page 188; Vol. 30,
no. 14, page 534 ; Vol. 31, no. 5, page 182.
Marty, G., Brick cheesemaking, Wis. Cheese-makers Assoc.,
15th Annual Meeting, 1907, page 66.
Wuethrich, F., The manufacture of Brick cheese, Wis. Cheese-
makers Assoc., 14th Annual Meeting, 1906, page 50.
Schenk, C., Brick cheesemaking, Wis. Cheese-makers Assoc.,
13th Annual Meeting, 1905, page 38.
166 THE BOOK OF CHEESE
enough for the curd to break clean over the finger, it is
ready to cut. The curd is cut with coarse knives into
I- or i-inch cubes. After cutting, the curd is let stand
three to five minutes, then stirred with the hands for a
few minutes until the whey begins to separate and then
stirred with the rake. Some makers do not stir by hand
but use the rake directly after cutting. When this is
done, great care must be exercised to stir the curd with-
out breaking up the pieces, because this causes a loss of
fat. After cutting the curd is stirred for twenty to thirty
minutes before the steam is turned on. The curd is
heated very slowly at first and more rapidly during the
last stages of cooking. The curd is cooked to a tempera-
ture of 110 to 115 F. The lower the temperature that
can be used to produce firm curd, the better the texture
of the cheese. After cutting and during the cooking,
the curd must be constantly stirred so that lumps will
not form. When the curd forms lumps, the moisture is
not evenly expelled. This results in uneven texture and
curing. Sometimes some salt is added to the curd in
the vat to restrain souring. The curd is stirred after
cooking until it is sufficiently firm. It remains usually
in the whey for a total period of one and one-fourth to
one and one-half hours from the time of cutting. It is
then dipped into forms 10 inches long by 5 inches wide
by 8 inches deep. The forms are without top or bottom
and are placed on a draining table. This table is so
constructed that the whey can be saved for stock feed.
When ready to " dip," the whey is drawn down to the
surface of the curd in the vat, then the curd is dipped
into the forms or hoops. Care must be taken to get the
same amount of curd into each form to produce the cheeses
of uniform size. Each cheese is turned several times
SEMI-HARD CHEESES 167
to insure even draining and even reduction of the temper-
ature. While draining, a follower is placed in each hoop
and a weight placed on each cheese. Usually a brick
is used for this weight. A cheese is allowed to drain or
press for ten to fifteen hours. It is then placed on the
salting table and rubbed with coarse salt. While on the
salting table, a cheese is placed on its broad side. Some
cheese-makers prefer to salt their cheeses by soaking them
in a salt brine. This brine should be strong enough to
float an egg. Salting requires three days. The cheeses
are then brushed free from excess salt and taken to the
cellar to cure or ripen.
177. Ripening Brick cheese. For this process, the
cellars are kept at about 90 per cent relative humidity and
a temperature of 60 to 65 F. Some prefer a tempera-
ture for curing as high as 68 F. During the curing, the
surfaces of the cheese are kept moist and mold growths-
kept down by rubbing or brushing the cheese with pure
water or salt and water. In the curing cellars the cheeses
are placed on shelves ; at first they are set close together
and as they cure, they are separated. During curing,
the color changes from a whitish to a reddish brown.
The cheese cures from the outside toward the center.
When first made, the product is harsh and hard in texture
but during the ripening process it becomes mellow and
smooth. The cheeses remain on the curing shelves for
four to six weeks, after which they are wrapped in heavy
waxed paper and boxed. A cheese ready for market
usually weighs about five pounds. A Brick cheese box is
5 inches deep by 20 inches wide by 3 feet long, and holds
110 to 115 pounds of cheese.
178. Qualities of Brick cheese. The cheeses should
be neat and attractive and the rind not cracked or broken.
168 THE BOOK OF CHEESE
The sides should be square and not bulged. The cheese
should have a clean, characteristic Brick cheese flavor.
The body and texture should be mellow and smooth and
when rubbed between the thumb and forefinger, should
break down like cold butter. The color should be uni-
form. The cheese should contain the proper amount of
salt and moisture. One of the worst faults with Brick
cheese is bad flavor. This is many times due to the
cheese-maker not using clean flavored starter. It may
also be due to bad flavored milk. A Brick cheese-maker
has no means of controlling gassy fermentations. These
show themselves in the bad flavor of the cheese and in
the porous body. They also cause the cheese to bulge.
If detected, gassy milk should be rejected. If too much
acid is developed, a sour cheese is the result. This will
not cure normally and usually has a sour flavor. The
body will be brittle and mealy. If too much salt is used,
the cheese njay have a salty taste and it will cure very
slowly. If not enough salt is used, the cheese may cure
too rapidly and undesirable flavors and fermentations
develop. The cheese must have the proper moisture-
content; if too much moisture is present, the cheese
cures too fast and is soft and pasty in body ; if not enough
moisture, then the reverse is true. Tabulation of cheeses
of special quality, as submitted in scoring contests, show
an average water-content of 37 to 38 per cent, with
occasional cheeses verging toward Limburger in texture
and flavor with 40 to 42 per cent water, and others in-
distinguishable from Cheddar, with water-content as
low as 34 per cent.
The Wisconsin Cheese-makers Association uses the
following score-card for the judging of Brick cheese on a
scale of 100 :
SEMI-HARD CHEESES 169
Flavor , . . 40
Texture 40
Color 10
Salt . i 5
Style _5^
100
179. Composition and yield. The composition of
Brick cheese varies within wide limits. The average
cheese probably contains from 37 to 39 per cent of water,
although many cheeses are above and below this average ;
Doane and Lawson x give the fat as 28.86 per cent, pro-
teins 23.8 per cent and total ash 4.20 per cent.
The composition and yield are both affected by : (1) the
moisture-content of the cheese; (2) composition of the
milk from which made; and (3) losses during the manu-
facturing process. The average yield of Brick cheese
is 11 to 13 pounds to 100 pounds of milk.
180. Port du Salut cheese. The Trappist monks
originated this type of cheese in their monasteries in
France. Under the name of their community Oka, it
has been made and sold widely by the Trappist Fathers
of Quebec. In recent years, factories independent of
the order have made such cheese both in America and
in Europe.
The following outline of the making process indicates
the close relationship between Port du Salut and Brick
cheeses. Whole milk or milk not over one-fifth skimmed
is ripened to medium acidity, then heated to 90 to 95 F.
according to season and acidity. Rennet enough is
1 Doane, C. F., and H. W. Lawson, Varieties of cheese, de-
scriptions and analysis, U. S. Dept. Agr. Bur. of An. Ind. Bui.
146, 1911.
170 THE BOOK OF CHEESE
added (see Chapter V) to curdle in thirty to forty min-
utes, although some makers shorten the time to twenty
minutes. When formed, the curd is cut into small cubes
and excess of whey is dipped away. The constantly
stirred mass is then heated or cooked to 100 to 105 F.
within a period of ten to twelve minutes or according to
some makers twenty to thirty minutes. It is allowed
to stand a few minutes to settle. Most of the whey is
then drawn and the mass is stirred vigorously to prevent
fusion of the curd granules. The curd is ready for the
hoop when the particles are about the size of grains of
wheat and do not stick together when squeezed with the
hand. The individual grains of curd should crumble
easily between the fingers. The hot curd is transferred
directly to the hoops without cooling. For this purpose,
a hoop is set upon the table covered with a cloth and the
curd dipped into the cloth. The edges of the cloth are
then folded over. In this condition the cheese is trans-
ferred to the press where gradually increasing pressure
begins with 3 to 4 pounds and reaches about 70 pounds.
To insure proper shape, cheeses are turned and put into
fresh cloths at the end of the first hour and turned subse-
quently several times during the pressing period of about
twelve hours. 1
Port du Salut cheeses are salted by rubbing fine salt
on the surface by hand at the rate of 1.2 to 2 per cent
of the weight of the cheese. After about two days in
the salting process, they are put into the ripening cellars.
The cellars are wet, since they reach 90 to 95 per cent
relative humidity at a temperature of about 55 F.
After two days in the cellar, the cheeses are plunged
1 Ligeon, X., Herstellung des Port Salut Eases, Milchztg. 38
(1909), no. 39, pages 459-460.
SEMI-HARD CHEESES 171
into a tank of saturated brine to which a trace of cheese
color has been added. As they come out of these tanks,
they are yellowish and greasy or slimy. They are re-
turned to the shelves where they are rubbed every day
with a cloth or by hands wet in brine. After about one
week they are again plunged in the brine. Treatment
with brine tends to insure a firm rind. The cheeses are
rubbed more or less regularly with brine through the
whole ripening period.
After six weeks, such cheese may be eaten. The cut
surface of Port du Salut is creamy in color, may or may
not show small holes. In texture it is soft enough to
spread readily under pressure without losing its shape
in handling. In flavor the cheese is a mild form belong-
ing to the Limburger group.
Port du Salut cheeses as imported from France usually
are firm round cakes about 1^ inches thick, weighing
about 3 pounds.
CHAPTER XI
THE HARD CHEESES
THE hard cheeses form a great series of groups, whose
most prominent physical character is their firm or hard
texture. This is correlated with comparatively low
water-content, which is usually between 30 and 40 per
cent. Although certain varieties occasionally test above
40 per cent water, this deviation is accompanied by
quick ripening and rapid spoilage. These varieties of
cheese are staple products with long marketable periods ;
therefore they may be handled in large lots, shipped,
carted and stored freely without the losses such treat-
ment would entail in soft cheese. The retailer frequently
buys hard cheese by the ton, not by the cheese or by
the box.
In making, these varieties are characterized as cooked
and pressed cheeses. Although both the heating of a
curd and the pressing of a newly made cheese occur among
semi-hard forms, these practices appear in their most
typical forms in the hard cheeses.
The hard cheeses show two types of texture. A cut
cheese may appear smooth, free from holes or with a few
angular cracks or seams, or it may show round holes or
"eyes." In the smooth textured forms every effort is
made to prevent gassy fermentations, usually by control-
ling the fermentation of the curd in the making process.
172
THE HARD CHEESES 173
When " eyes " are present, the end sought has been a
development of a particular form of gassy fermentation
which gives this appearance and brings about the char-
acteristic ripening texture and flavor.
The hard cheeses have been developed in groups of
national varieties. The best known of these groups are
those which may be represented by English Cheddar,
American Factory Cheddar, Danish, the Edam of Hol-
land, Swiss and Parmesan with many related varieties
in Italy and neighboring countries of southern Europe.
181. The Danish group. The Danish cheeses are
related in appearance and flavor to the English group
represented by Cheddar. The demand for butter in
Europe has been so great that the Danish cheese-makers
have developed skim and part skim varieties largely to
the exclusion of the whole milk form. Skillful handling
of their process has resulted in a product which has had
a very large and appreciative market in England and
Germany.
182. The Dutch group. Edam and Gouda are the
two forms of cheese made in Holland and most widely
known among other peoples. Both reach America in con-
siderable quantities; both are shipped in large amounts
to tropical countries. Although attempts have been
made to manufacture them in America, no commercial
production of these cheeses has been successful. Al-
though whole milk grades of these cheeses are known,
they are to a large measure part skim in manufacture.
The presence of one or both of these forms in every large
market in America makes the general facts of their produc-
tion of general interest. Parts of a report on experimental
work in the making of Edam and Gouda are, therefore,
given here.
174 THE BOOK OF CHEESE
183. Edam cheese 1 is a sweet-curd type, made from
partially skimmed-milk. It comes to the market in the
form of round red balls, each weighing from 3^ to 4
pounds when cured. It is largely manufactured in
northern Holland and derives its name from a town
famous as a market for this kind of cheese. 2 Milk from
which one-fourth to one-third of the fat has been re-
moved is used. Too great pains cannot be taken in
regard to the condition of the milk. It should be fresh,
free from every trace of taint ; in brief, it should be in
as perfect condition as possible.
184. Method of manufacture. The following para-
graphs give the steps in the manufacture of Edam cheese :
Treatment of milk before adding rennet. The tempera-
ture of the milk should be brought up to a point not
below 85 F. nor much above 88 F. When the desired
temperature has become constant, the coloring matter
should be added. Cheese color is used at the rate of 1 J
to 2 ounces for 1000 pounds of milk. The coloring matter
should, of course, be added to the milk and thoroughly
incorporated by stirring before the rennet is added.
Addition of rennet to milk. The rennet should not be
added until the milk has reached the desired temperature
(85 to 88 F.) and this temperature has become constant.
1 These paragraphs were taken from N. Y. Exp. Sta. Bui. 56,
Experiments in the manufacture of cheese ; Part I. The manu-
facture of Edam cheese, 1893. See also, Haecker, T. L., Experi-
ments in the manufacture of cheese, Minn. Exp. Sta. Bui. 35,
1894.
2 Boekhout, F. W. J., and J. J. O. de Vries, Cracking of Edam,
Verslag. Landbouwk.- Onderzoek. Rykslandboupoef stat. (Nether-
lands), 20 (1917), pages 71-78, fig. 1.
Boekhout, F. W. F., and J. J. O. de Vries, Sur le de"faut
"Knijpers" dans le fromage d'Edam, Rev. Gen. Lait, 9 (1913),
no. 18, pages 420-427.
THE HARD CHEESES 175
When the temperature reaches the desired point and re-
mains there stationary, the rennet extract is added.
Rennet extract may be used, 4^ to 5 J ounces being taken
for 1000 pounds of milk, or enough to coagulate the milk
in the desired time, at the actual temperature used.
The milk should be completely coagulated, ready for
cutting, in about twelve to eighteen minutes from the
time the rennet is added. The same precaution observed
in making Cheddar cheese should be followed in making
Edam cheese with reference to care in adding the rennet,
such as careful, accurate measurement, dilution with
pure water before addition to milk.
Cutting the curd for Edam. When the curd breaks
clean across the finger, it should be cut ; it is cut a very
little softer than in the Cheddar process as ordinarily prac-
ticed. As stated, this stage of hardness in the curd which
fits it for cutting should come in twelve to eighteen min-
utes after the rennet is added. First, a vertical knife
is used and the curd is cut lengthwise, after which it is
allowed to stand until the slices of curd begin to show the
separation of whey. Then the vertical knife is used in
cutting crosswise, after which the horizontal knife is at
once used. Any curd adhering to the bottom and sides
of the vat is carefully removed by the hand, after which
the curd-knife is again passed through the mass of curd
lengthwise and crosswise, continuing the cutting until
the curd has been cut as uniformly as possible into very
small pieces.
Treatment of Edam curd after cutting. When the cutting
is completed, one commences at once to heat the curd up
to the temperature of 93 to 96 F. The heating is done
as quickly as possible. While the heating is in progress,
the curd is kept constantly agitated to prevent settling
176 THE BOOK OF CHEESE
and consequent overheating. As soon as the curd shows
signs of hardening, which the experience of the worker
will enable him to determine, the whey is drawn off until
the upper surface of the curd appears, when one should
commence to fill the press molds.
Filling molds, pressing and dressing Edam. The
molds, which are described later in detail, are well soaked
in warm water previous to use, in order to prevent too
sudden chilling of curd and consequent checking of sepa-
ration of whey. As soon as whey is drawn off, as indi-
cated above, one begins to fill the pressing molds (Fig. 27) .
The filling should be done as rapidly as possible to prevent
too great cooling of curd. When the curd has been put
into the molds, its temperature should
not be below 88 F. Unless care is taken
to keep the curd covered, the portion
that is last put into the molds may be-
come too much cooled. In making Edam
FIG. 27. Edam cheese on a small scale, it is a good plan
cheese mold. , i , ^1.111
to squeeze the moisture out with the hands
as much as possible and then break it up again before put-
ting in the molds, when the curd should be pressed into
the mold firmly by the hands. The molds should be filled
as nearly alike as possible. The cheese should weigh from
5 to 5J pounds each when ready for the press. When the
filling of molds is completed, they are put under continual
pressure of 20 to 25 pounds for about twenty-five or thirty
minutes. While the cheese is being pressed, some sweet
whey is heated to a temperature of 125 or 130 F., and
this whey should not be allowed to go below 120 F. at
any time while it is being used. When the cheeses are
taken from their molds, each is put into the warm whey
for two minutes, then removed and dressed. For dress-
THE HARD CHEESES 177
ing Edam cheese, the ordinary cheese bandage cloth is
used. This is cut into strips, which should be long enough
to reach entirely around the cheese and overlap an inch
or so, and which should be wide enough to cover all but
a small portion of the ends of the cheese when put in
place. Before putting on the bandage, all rough pro-
jections should be carefully pared from the cheese. In
putting on, the cheese is held in one hand and the bandage
is wrapped carefully around the cheese, so that the whole
is covered, except a small portion on the upper and lower
surface of the cheese. These bare spots are covered by
small pieces of bandage cloth of a size sufficient to fill
the bare surface. The bandage is kept wet with the warm
sweet whey, thus facilitating the process of dressing.
After each cheese is dressed, it should be replaced in the
dressing mold, care being taken that the bandage remains
in place and leaves no portion of the surface of the cheese
uncovered and in direct contact with the mold. The
cheese is then put under continual pressure of 60 to 120
pounds and kept for six to twelve hours.
185. Salting and curing Edam. There are two
methods which may be employed in salting, dry and
wet. In dry-salting, when the cheese is finally taken from
the press, it is removed from the press mold, its bandage
is removed completely, and the cheese placed in another
mold, quite similar, known as the salting mold. Each
cheese is placed in a salting mold with a coating of fine
salt completely surrounding it. The cheese is salted in
this way once each day for five or six days. Each day
the cheese should be turned when it is replaced in the
mold, so that it will not be rounded on one end more
than the other.
In the method of wet-salting, the cheese is placed in a
178 THE BOOK OF CHEESE
tank of salt brine, made by dissolving common salt in
water in the proportion of about 1 pound of salt to 2|
quarts of water. Each cheese is turned once a day and
should be left in the brine seven or eight days. When
the cheese is taken from the salting mold or salt bath, it
is placed in warm water and given a vigorous, thorough
brushing in order to remove all slimy or greasy substances
that may have accumulated on the outer surface. When
the surface is well cleansed, the cheese is carefully wiped
dry with a linen towel and placed upon a shelf in the cur-
ing-room. In being put on the shelves, the cheeses should
be placed in contact so as to support one another, until
they have flattened out at both ends so much that they
can stand upright alone. Then they are moved far
enough apart to allow a little air space between them.
Another method of securing the flattened ends is to sup-
port each cheese on opposite sides by wedge-shaped pieces
of wood. After being placed on the shelves in the curing-
room, they are turned once a day and rubbed with the
bare hand during the first month, twice a week during the
second month and once a week after that. When any
slimy substance appears on the surface of the cheese, it
should be washed off at once with warm water or sweet
whey. The special conditions of the curing-room will
be noticed in detail below. When the cheeses are about
two months old, they can be prepared for market in the
following manner: They are first made smooth on the
surface by being turned in a lathe or in some other manner,
after which the surface is colored. For coloring, some
carmine is dissolved in alcohol or ammonia to secure the
proper shade, and in this color-bath the cheeses are placed
for about one minute, when they are removed and allowed
to drain, and as soon as they are dry the outside of each
THE HARD CHEESES 179
cheese is rubbed with boiled linseed oil, in order to pre-
vent checking. They are then wrapped in tin-foil, which
is done very much like the bandaging. Care must be
taken to put on the tin-foil so that it presents a smooth,
neat appearance. The cheeses are finally packed in boxes,
containing twelve cheeses in each box, arranged in two
layers of six each with a separate partition for each
cheese.
186. Equipment for making Edam cheese. Careful
attention must be given to the moisture and temperature
of the curing-room. This room should be well venti-
lated, quite moist and its temperature kept between 50
and 65 F. These are conditions not easy to secure in
any ordinary room. Some form of cellar is best adapted
for these conditions. The amount of moisture can be
determined by an instrument known as a hygrometer.
In a curing-room suited for Edam cheese, the moisture
should be between 85 and 95 per cent, or a little short of
saturation. When the temperature is between 50 and
65 F., the moisture is between 85 and 95 per cent if
the wet-bulb thermometer is from 1 to 2 F. (or J
to 1 C.) below the dry-bulb thermometer. Cheese will
check or crack and be spoiled for market, if the degree
of moisture is not kept high enough.
Aside from the molds, press and salting vat, the same
apparatus that is used in making Cheddar can be used for
Edam cheese. The pressing mold is turned preferably
from white wood or, in any case, from wood that will
not taint. Each mold consists of two parts; the lower
constitutes the main part of the mold, the upper portion
is simply a cover. The lower portion or body of the mold
has several holes in the bottom, from which the whey
flows when the cheese is pressed. Care must be taken
180 THE BOOK OF CHEESE
to prevent these holes being stopped up by curd. This
part of the mold is about six inches deep and six inches
in diameter across the top. The salting mold has no cover
and the bottom is provided with only one hole for the
out-flow of whey; in other respects it is much like the
pressing mold.
187. Qualities and yield of Edam cheese. The
flavor of a perfect Edam cheese is difficult to describe.
It is mild, clean, and pleasantly saline. In imperfect
Edams, the flavor is more or less sour and offensive. In
body, a perfect Edam cheese is solid, rather dry and
mealy or crumbly. In texture, it should be close and free
from pores. In the experiments here reported the amount
of fat in 100 pounds of the partially skimmed-milk varied
from 2.45 to 3.20 pounds and averaged 2.77 pounds. Of
this amount, from 0.30 to 0.51 pound of fat was lost
in the whey, with an average of 0.39 pound. The yield
of cheese from 100 pounds of milk varied from 9.60 to
11.82 pounds and averaged 10.56 pounds.
188. Gouda cheese. 1 This Dutch variety is a sweet-
curd cheese made from whole milk. In shape, the Gouda
cheese is somewhat like a Cheddar with the sharp edges
rounded off and sloping toward the outer circumference
at the middle from the end faces. They usually weigh
10 or 12 pounds, though they vary in weight from 8 to
16 pounds. They are largely manufactured in southern
1 Paragraphs taken from N. Y. Exp. Sta. Bui. 56, Experi-
ments in the manufacture of cheese ; Part II. The manufacture
of Gouda cheese, 1893. See also, Hay ward, H., Method of
making Gouda cheese, Pa. Exp. Sta. Kept. 1890, pages 79-81,
and Haecker, T. L., Experiments in the manufacture of cheese,
Minn. Exp. Sta. Bui. 35, 1894, and Monrad, J. H., in N. Y.
Produce Rev. 25 (1907), no. 8, page 336, where a home process
of making this cheese is given.
THE HARD CHEESES 181
Holland, and derive their name from the town in which
they were first made. Fresh sweet milk that has been
produced and cared for in the best possible manner should
be used.
189. Method of manufacture. The processes of
manufacturing Gouda cheese are as follows :
Treatment of milk before adding rennet. The tempera-
ture of the milk should be brought up to a point not below
88 F. nor much above 90 F. When the desired tempera-
ture has been reached and has become constant, the color-
ing matter is added. One ounce of cheese color for about
1200 pounds of milk may be used. The coloring matter
should be thoroughly incorporated by stirring before
the rennet is added.
Addition of rennet to milk. The rennet should not
be added until the milk has reached the desired tempera-
ture (88 to 90 F.) and this temperature has become con-
stant. The milk should be completely coagulated, ready
for cutting, in fifteen or twenty minutes. The same
precautions should be used in adding rennet as those
previously mentioned in connection with the manufac-
ture of Edam cheese.
Cutting the curd. The curd should be cut when it is
of about the hardness generally observed for cutting in
the Cheddar process. The cutting is done as in the Ched-
dar process except that the curd is cut a little finer in the
Gouda cheese. Curd should be about the size of peas
or wheat kernels when ready for press and as uniform in
size as possible.
Treatment of curd after cutting. After the cutting is
completed, heating and stirring is begun at once. The
heating and constant stirring is continued until the curd
reaches a temperature of 104 F., which should require
182 THE BOOK OF CHEESE
from thirty to forty minutes. When the curd becomes
rubber-like in feeling, the whey should be run off. The
whey should be entirely sweet when it is removed.
Pressing and dressing Gouda. After the whey is off,
the curd is put in molds at once without salting
(Fig. 28). Pains should be taken in this process to keep
the temperature of the curd as near 100 F. as possible.
Each cheese is placed under continuous pressure amount-
ing to ten or twenty times its own weight and kept for
about half an hour. The first bandage is put on in very
much the same manner as in Edam cheese making. The
cheese is then put in press again for about one hour.
The first bandage is then taken off and
a second one like the first put on with
great care, taking pains to make the
bandage smooth, capping the ends as
before. The cheese is then put in press
again and left twelve hours or more.
Salting and curing. When Gouda
FIG. 28. Gouda cheese is taken from the press, the band-
cheese mold. . . . . . , ,
age is removed and it is placed tor
twenty-four hours in a curing-room like that used for
Edam cheese, as previously described. Each cheese is
then rubbed all over with dry salt until the salt begins to
dissolve, and this same treatment is continued twice a
day for ten days. At the end of that time, each cheese
is carefully and thoroughly washed in warm water and
dried with a clean linen towel. The cheeses are then
placed on the shelves of the curing-room, turned once a day
and rubbed. The temperature and moisture are con-
trolled as described in the curing process of Edam
cheese. If the outer surfaces of the cheese become slimy
at any time, they are carefully washed in warm water
THE HARD CHEESES 183
and dried with clean towels. Under these conditions,
cheese ripens in two or three months.
190. Equipment for Gouda cheese. The molds, press
and curing-room are the only equipment needed in the
making of Gouda cheese that differ from that employed
in making Cheddar cheese. The mold used for Gouda
cheese consists of two portions, which .are shown sepa-
rately in Fig. 28. These molds are made of heavy pressed
tin. The inside diameter at the middle is about 10 inches,
that of the ends about 6 J inches. The height of the mold
is about 5^ inches, and this represents the thickness of
the cheese, but by pushing the upper down into the
lower portion, the thickness can be decreased as desired.
191. Composition and yield of Gouda. In work with
milk averaging 4.2 per cent of fat there were lost in the
whey from 0.29 to 0.43 per cent with an average of 0.35 per
cent of fat. The loss of fat appears to be not much
greater than the average loss met with in cheese factories
in making Cheddar cheese. From 100 pounds of milk,
there were made from 11.60 to 13.35 pounds of green
cheese, with an average of 12.50 pounds. The per-
centage of water in the experimental cheese varied
from 41.25 to 45.43 per cent and averaged 43.50 per
cent.
CHAPTER XII
CHEDDAR CHEESE-MAKING
CHEDDAR is the best known cheese throughout the
United States and the one most commonly made in
factories. The Cheddar process was brought to America
by English immigrants. Similar to Cheddar cheese are
Pineapple, English Dairy, Sage cheese, skimmed -milk
and California Jack cheese made in this country, and
Derbyshire, Leicestershire, Wensleydale and Cheshire made
in England. The Cheddar cheese process as employed
in the factories to-day has been modified and improved
since it was first introduced into this country by the
early immigrants. The following description 1 includes
only the practices as found in the factories to-day if
whole milk is used. Skimined-milk Cheddar cheese
is discussed later.
192. The lot-card. The Cheddar process involves
several hours of manipulation and includes many details
which should be closely and accurately observed and
recorded. The necessity of carrying observations of
Several different factors at the same time makes a scheme
of recording data essential to convenient work. For
this purpose, a lot-card for Cheddar cheese is introduced
here and the pages given to particular factors are in-
dicated in the space intended for the recording of observa-
1 The authors acknowledge here the helpful suggestions and
criticisms of G. C. Button, New York State Cheese Instructor.
184
CHEDDAR CHEESE-MAKING
185
&
186 THE BOOK OF CHEESE
tions. The manufacture of Cheddar cheese is a compli-
cated process, because several factors must be given
attention at the same time. A careful record of the
observations of each step in the successive handling of
each lot of milk puts the operator in possession of a per-
manent record of his experience. This record has several
uses. It may help to convince patrons of the importance
of eliminating faults in the milk ; it furnishes the cheese-
maker a cumulative record of his experiences in handling
milk with special qualities, such as high or low fat-content,
over-acidity or taints. Since Cheddar ripening covers a
period of weeks and months, no operator can remember
particular lots of milk sufficiently well to be able to
use his experience on the interpretation of the qualities
found in the ripened product.
193. The milk. It is the usual practice to deliver the
milk to the cheese factory each morning (Fig. 29). The
night's milk is cooled and kept clean and cold until de-
livered at the factory. It is advisable not to mix the cold
night's milk and the warm morning's milk, but to deliver
them in separate cans to the cheese factory at the same time.
The milk is weighed, sample for fat test taken and then
run into the vat (Fig. 30). The receiving or taking in
of the milk is one of the most important parts of the
cheese factory work. It is practically as important as
the actual manufacturing of the cheese.
Any milk high in acid or with a bad flavor should be
avoided. It is often bad policy to reject the milk, for
a neighboring factory will accept it and the factory not
only loses the milk but also the patron. Factories should
have an agreement to prevent this. The acidity can be
determined by the acid test, but the detection of flavors
must be made by the cheese-maker himself with the aid
CHEDDAR CHEESE-MAKING
187
21 CHEESE. This card must remain with lot from the milk room until
the finished product is ready to leave the building, then it should be handed to
instructor.
MAKING Day and Date . Vat
Milk
Used
Milk
Appearance of Milk
Taste
Weather conditions.
Total pounds
% fat Ibs. fat
.% solids not fat Ibs. s. n. f.
.% casein Ibs. casein.
Starter
Kind used
Flavor
Acidity
Amount used % used-
Minutes
Time of
adding starter.... \
adding rennet ....
coagulation
cutting ._
turn'g on steam.,
turn'g off steam
dipping
packing ._
milling
salting
hooping
pressing.
dressing
Total time from 1
setting to pressing J "
% Acid
In Milk
when received
before adding starter.
after adding starter....
when rennet added
In Whey
after curd is cut
at dipping._
at packing
at milling
at salting
Temperature
of milk when received
when starter added....
when rennet added ....
when whey removed....
at pressing
Rennet Test
when milk received....
after adding starter....
when rennet added
Hot Iron Test
at dipping
at packing
at milling
at salting
Condition of Curd
when cut
when packed
when milled
when salted
when pressed
Amount per
1000 Ibs. milk
Total Amount
Color Rennet
Salt
% fat in Ibs. fat esti-
whey mated so lost.
% of total milk
fat lost in whey
Assisted by
If comments are added on
reverse side, put cross here
Work and
Observations by
YIELD Day and Date Time
Serial
Weight of cheese when removed from press to curing room,. Ibs. No.
Ibs. milk for Kind of cheese made Ibs. cheese per
one Ib. cheese. 100 Ibs. milk
Ibs. cheese for one No. of cheese made. Ibs. cheese for one
Ib. fat in milk. Ib. total solid
If comments are added on reverse side put cross here
Work and observations by -
Arranged by W. W. Hall.
188
THE BOOK OF CHEESE
|
CHEDDAR CHEESE-MAKING 189
of smell and taste. Many of the bad flavors in the cheese
can be traced to the poor quality of the milk. One of
the worst qualities in milk and cheese is the presence of
gas-producing organisms. 1 Any milk which shows gassy
fermentation should be rejected, for it is difficult to make
cheese from this and at best there will be a large loss
during the manufacturing process. The cheese may have
a bad flavor and develop " pin-holes " and in extreme
cases may puff up like a ball. The person receiving the
milk should talk to the farmers or dairy-men about the
proper care of the utensils and milk. He must see that
the cans are kept clean. One very bad practice is to
deliver milk and take home whey in the same cans. The
cans, as they are brought back from the cheese factory
full of whey, are often left in the barn or near a hog-pen
until the whey is fed. Unless such cans are emptied
immediately on returning to the farm and then rinsed
out with cold water, thoroughly washed and scalded, bad
flavors may develop in the cheese. It is thought that
this causes " fruity " or sweet flavor, which resembles that
of fruits such as raspberries, strawberries or pineapples.
194. Ripening the milk. A slight development of
acidity is required : (a) to obtain the formation of a firm
curd; and (b) to establish immediate dominance of a
desirable type of lactic organism which will produce the
large amount of acid required later in the cheddaring
process. The development of this acidification before
the addition of rennet is known as the ripening of the
milk. The extent of ripening advised by different
1 Russell, H. L., Cheese as affected by gas-producing bacteria,
Wis. Exp. Sta. Kept. 1895, pages 139-146.
Marshall, C. E., Gassy curd and cheese, Mich. Exp. Sta.
Bui. 183, 1900.
190 THE BOOK OF CHEESE
schools of makers has varied from an acidity of 0.20 of
1 per cent or even slightly higher percentage titrated
as lactic acid, to about 0.17 of 1 per cent as now preferred
by some of the most successful groups of workers. The
ripeness of the milk can also be determined by the use of
the rennet test.
The milk may be ripened by allowing the lactic organisms
already present in the milk to develop naturally. This
requires considerable time and while the lactic acid-forming
bacteria are developing, other and undesirable fermenta-
tions may be taking place, so that the good results which
should follow the uninterrupted development of the lactic
acid-forming organisms are lost. Starter is commonly used
to produce the desired ripening of the milk. (For the
preparation of starter see Chapter IV.)
Some makers put the starter into the empty vat (Fig.
31) and add the milk as it is received; others add it to
FIG. 31. Steel cheese vat.
the total volume of cold milk and then begin to heat it.
Whenever the starter is used, it should be strained to
remove lumps. These lumps might cause a mottled
color in the cheese. The best practice calls for an acidity
or a rennet test of the mixed milk after it has been
brought to the setting temperature in the vat. With
milk tested at this stage and the volume of milk in the
CHEDDAR CHEESE-MAKING 191
vat known, the cheese-maker is able to calculate
closely the amount of starter needed. When the
quantity of starter to use is in doubt, the amount added
should be under rather than over the estimate, since the
need of more can be determined by making frequent ren-
net and acid tests in a very few minutes without damage
to the cheese. If too much starter has been used, acid
or sour cheese is usually obtained, with loss in market
quality.
An over-development of acidity at any stage of the man-
ufacturing process affects the flavor, body and texture,
color and finish of the cheese. The product is known as
a sour cheese, and can usually be identified by its sour
taste and smell. A sour cheese while curing will seldom
develop a normal Cheddar flavor and the texture will
be hard and harsh and very brittle. The body will not
be smooth but harsh and grainy. The over-development
of acid will show by fading or bleaching the color. A
sour cheese usually leaks whey for a few days after being
placed on the curing-room shelves.
Ripening the milk is one of the most important parts
of cheese-making. Proper ripening places the acid fer-
mentations under the control of the cheese-maker so
that he may know what results will follow his labors.
The operator can control the acidity while ripening the
milk, but after the rennet is added all control of the acidity
is lost. From that time, the moisture must be regulated
in proportion to the acidity.
Before setting, the milk should be ripened to such a
point as to leave at least two and one-half hours from the
time that the rennet extract is added until the acid de-
velopment has reached the stage at which it is necessary
to remove the whey. By the acid test the milk may vary
192 THE BOOK OF CHEESE
from 0.16 to 0.18 of 1 per cent, but no definite statement
can be given for the rennet test. This can be determined
only by comparison from day to day. For opera-
tion of rennet test see Chapter V. During this period
of two and one-half hours, the curd is formed, then cut,
and the temperature is raised from 84 or 86 F. (the
temperature at which the rennet extract is added) to about
98 to 100 F. The curd must be kept agitated so that
the particles will not mat together; this is necessary to
obtain sufficient contraction of the particles of curd with
the proper reduction of water-content. If the milk
becomes too ripe (too sour) before the rennet is added,
there will not be sufficient time for these steps to take
place naturally. In such cases special means are re-
quired to firm the curd. These result in a loss of both
quality and quantity of cheese. On the other hand, if
the milk is not ripened, but the rennet extract added,
regardless of the acid development, one of the important
natural forces for expelling the moisture is lost. The
time required for the particles of curd to contract is much
prolonged, the expulsion of whey is usually inadequate and
the curd remains in a soft or wet condition. Using too
much starter is almost equally bad, for although it hastens
the making process, it produces a sour or acid cheese.
195. Setting or coagulating. The milk for Cheddar
cheese-making is heated to 86 to 88 F. or occasionally
a slightly lower temperature. This temperature is found
by experiment to give the texture of curd most favorable
for the desired results. Although some cheese-makers
work as low as 84 F., the texture of such curd is too soft
and coagulates too slowly. The very slight change of
2F. produces curd which coagulates more quickly and
is tougher and firmer.
CHEDDAR CHEESE-MAKING 193
If the cheeses are to be colored, the color should be
added after all the starter. It should be thoroughly
and evenly mixed with the milk to insure an even color
in the cheese. If the color is added before the starter,
there are likely to be white specks in the cheese, on account
of the coagulated casein in the starter. The amount of
color to use depends on the tint desired in the cheese.
It varies from J to \ ounce to 1000 pounds of milk for a
light straw color to \\ to 2 ounces for 1000 pounds of
milk for a deep red color.
Enough rennet should be used to produce a curd firm
enough to cut in twenty-five to thirty-five minutes.
The necessary amount will vary with the strength of the
rennet extract itself, with the acidity, the temperature,
the nature of the lot of milk, and with the individual
aims of the maker in which he adjusts the other factors
to his preferences as to rapidity of rennet action. With
the usual commercial extract, the needed amount ranges
from 2.5 to 4 ounces for 1000 pounds of milk. As for all
varieties of cheese, the rennet extract should be diluted
in cold water at about one part rennet to forty parts
water and thoroughly stirred into the milk. (See
Chapter V.)
196. Cutting. The object of cutting is to obtain
an even expulsion of the moisture from the curd. The
curd is cut as soon as it becomes firm enough. To
determine this, various tests may be used. Some opera-
tors test it by pressing it away from the side of the vat,
considering it ready to cut when it separates cleanly from
the metal. The test most commonly used is to insert
the index finger obliquely into the curd, then to start
to split the curd with the thumb and finally to raise the
finger gently ; if ready to cut, the curd will split cleanly
194 THE BOOK OF CHEESE
over the finger and clear whey will separate to fill the
opened crack. Another arbitrary but more or less satis-
factory rule is that the time from adding the rennet until
cutting should be two and one-half times that from the
addition of rennet until the first sign of coagulation is
observed.
The condition of the curd itself is the best guide
to show when it is ready to cut. The condition of
the curd is constantly changing, so that in a large vat,
if the cutting is not begun until the curd is in the best
condition, by the time the last of the curd is cut it will be
too hard or firm. It is better to begin while the curd
is a trifle too soft so that the cutting will be taking place
while the curd is at the proper stage. At best the last
of the curd may become too hard. If too hard, it will
break ahead of the knife instead of cut. Breaking
causes more fat loss than cutting because there is more
surface exposed and hence more fat globules. The
softer the curd when cut, the quicker and easier the
moisture can be expelled.
If the curd is cut when soft, care must be exercised not
to stir it too hard immediately after cutting. Soft curd
breaks very easily. When the curd is cut soft and then
stirred vigorously, there is a larger loss of fat than
when the curd becomes hard before it is cut.
Two knives are used to cut the curd. (See Fig. 11.)
These knives may have either wire or blades for cutting.
The space between the wires or blades varies from A to f
inch. Knives used should have blades or wires close
enough together to cut the pieces as small as desired,
without a second cutting. When the curd has to be cut a
second time it usually results in pieces of uneven sizes, be-
cause the pieces already cut cannot be evenly split in two.
CHEDDAR CHEESE-MAKING
195
One set of knives has horizontal and the other per-
pendicular blades or wires. The curd is cut the long way
of the vat with the horizontal knife and lengthwise and
crosswise with the perpendicular knife so that the result
is small cubes or oblongs of curd. Some cheese-makers
prefer to use one knife first and some the other, but the
result should be a curd cut into pieces of uniform size.
The smaller the particles of curd or cubes are cut, the
quicker the curd will firm up or cook. If not cut uniformly,
the changes taking place later in the curd particles will
not be uniform, the small pieces will be hard and dry
while the large ones will be soft and mushy.
Care should be taken to let the knife cut its way into
the curd (Fig. 32). If the knife is pushed into the curd,
FIG. 32. ^The proper way to put the knife into the curd.
it will break it and cause a large loss of fat. The same
is true when taking the knives out of the curd. The loss
of fat due to cutting is very similar to the loss of sawdust
when sawing a board. It may be considered a necessary
evil. The loss due to cutting is about 0.3 of 1 per cent
of fat in the whey and the loss of casein about 0.1 of 1
per cent in the whey.
197. Heating or "cooking" the curd. After the
curd is cut, the pieces (cubes) rapidly settle to the bottom
196
THE BOOK OF CHEESE
FIG. 33. Acme curd rak(
of the vat and tend to mat together. To prevent this,
the curd must be kept stirred. When stirring first begins,
the curd is soft and very readily broken. Some cheese-
makers prefer to stir by hand for the first few minutes
after cutting, while
the curd is soft.
The importance of
careful handling
can hardly be over-
emphasized. No
matter how well
the curd has been
cut, if the stirring
is performed in a
careless manner in the early stages, it will be broken into
uneven sized pieces and a considerable loss of fat will
result. A wooden hayrake or a McPherson curd agitator
(Figs. 33, 34) may be used to stir the curd. Me-
chanical curd agitators are used in some cheese factories.
There are several makes.
(See Fig. 35.) These
agitators save much
hand labor, although
some stirring by hand
must be done in connec-
tion with them. The
mechanical agitators do
not stir the curd in the
corners of the vat ; this must be done with the hand rake.
It is the usual practice to stir the curd immediately after
cutting for five to ten minutes before the mechanical
agitators are used. This is necessary to give the curd a
slight chance to firm as the mechanical agitators tend to
FIG. 34. McPherson curd agitator.
CHEDDAR CHEESE-MAKING
197
198 THE BOOK OF CHEESE
break it up. After cutting, a thin film forms on each
piece of curd. This film holds the curd particles, especially
the fat. Breaking the films on the cubes causes loss of
fat. If lumps form at the early stage, by matting of the
curd particles, violent stirring is required to separate
them. When such lumps are broken up, new cleavage
lines are formed with loss of fat, because the original
films surrounding the soft curd fuse so firmly that the
curd cubes do not separate but actually break. New
surfaces are thus formed with consequent fat loss. Rapid
shrinkage with expulsion of whey takes place during the
first few minutes of gentle agitation. Before any heat is
applied to the vat, sufficient whey should have separated
or formed to float each piece of curd separately. This
will require ten to fifteen minutes from the time of cutting.
Thus far the first of three distinct factors which expel
the moisture from the curd has been considered : (1) the
action of the rennet; (2) the development of the lactic
acid; and (3) the application of heat. These forces
must have time to act naturally. If heat is applied too
soon after the curd is cut or if the temperature is raised
too rapidly, it causes a thick film to form on the pieces
of curd which interferes with the escape of the whey.
The outside of the curd becomes firm but the inside re-
mains very soft. A curd which is cooked on the outside
only feels firm when stirred by hand in the whey, but
when a handful is squeezed the soft centers are noticed.
To firm such curd masses requires violent stirring, which
will break the thick tough film. This allows the mois-
ture to escape and also increases the fat loss. The
rapidity of heating should depend on the condition of
the curd and the amount of acid developed. The heat
should keep pace with these. When ready to raise the
CHEDDAR CHEESE-MAKING 199
temperature, the least amount of steam possible should
be allowed to pass through the valve. This should
raise the temperature very gradually. If heat is applied
too quickly at first, it will cause the curd to lump. A
safe rule is to raise the temperature one degree in the
first five minutes after the steam has been turned on.
The heating should progress slowly until the whole mass of
curd in the vat has reached a temperature of 90 to 92 F.
The usual temperature to which the curd is heated or
cooked is 98 F. to 100 F. The lower the temperature
that can be used and properly firm the curd, the better
will be the body of the cheese. If the curd is heated too
high, it will become hard, which causes a dry hard
"corky" cheese. After this temperature has been reached,
there is not such a tendency for the curd particles to
stick together nor are they so easily broken in stirring.
It should require, under normal conditions, not less than
thirty to forty-five minutes, from the time <the steam is
turned on, to raise temperature of the curd from the
setting temperature to that necessary to " firm " the
curd. If a shorter time is allowed to raise the temperature,
the curd will not have opportunity to contract naturally.
The temperature required to expel the moisture properly
varies with the percentage of fat in the milk. If rich
in fat (4.5 to 5.5 per cent) milk requires a temperature of
98 to 104 F. to firm the curd, while the same result can
be accomplished with milk testing 3.0 to 3.5 per cent fat
at a temperature of 94 to 96 F. A higher temperature
is needed in winter than in summer because the milk is
usually richer in fat. In a water- jacketed vat, allowance
must always be made for the rise in temperature due
to the water surrounding it. The water may be removed
if there is danger of the temperature going too high.
200 THE BOOK OF CHEESE
However, it is better to gauge the heat so that the water
may be left, as this helps to hold the curd at an even
temperature, especially in cold weather. In a steam-
heated vat there is not so much danger of the tempera-
ture running up.
The stirring must be kept up after the steam has been
turned off until the curd has reached such a stage of
contraction that it will not readily pack or mat in the
bottom of the vat. After the curd reaches this stage it
may be allowed to settle to the bottom and stirred only
occasionally until it is time to remove the whey. If the
cheese room is not warm and there is danger of the curd
cooling, a cover should be placed on the vat. The curd
should not be allowed to settle for more than fifteen
minutes without stirring to keep each piece separate.
This is necessary to obtain uniform contraction of all
curd masses.
198. Removing the whey. To permit the normal
changes in the curd to take place naturally, two and one-
half hours from the time the rennet extract is added is
ordinarily required before the whey is drawn. The time
of removing the whey is determined by two factors : one,
the acid development, and the other, th*e firmness of the
curd. For the best results, it is better to have the firmness
of the curd a trifle ahead of the acid development. When
the proper acid development has been reached, the whey
must be removed, regardless of the firmness of the curd.
If the curd has not become firm enough by natural forces,
when the acid development has reached the proper stage
to remove the whey, it must be firmed by other means.
If it is not firm enough, either by natural or artificial
means, when the whey is removed, a sour cheese is
the result. The acid development should not be al-
CHEDDAR CHEESE-MAKING 201
lowed to go beyond 0.16 to 0.19 of 1 per cent acidity in
the whey by the acid test or TS to J of an inch of acid
on the hot-iron test, before the whey is removed.
199. Hot-iron test. 1 This test is employed to determine
the amount of acid in the curd. A piece of iron, such as
an iron pipe two feet long, is heated in the fire to proper
temperature. If the iron is too hot it will burn the
curd, and if not hot enough the curd will not stick to
the iron. When hot, it is taken from the fire and wiped
clean with a cloth. A handful of curd is taken from the
vat and squeezed dry, either in the hand or in a cloth.
This curd is carefully pressed against the hot iron and
drawn away. If the iron is at the right temperature and
the curd has sufficient acid development, the curd will stick
to the iron and when pulled away will form fine threads.
The length of these threads determines the amount of
acid in the curd. The acid is usually spoken of in
terms of the length of threads, as J inch of acid, J
inch of acid and the like. The curd must have a
slight development of acid before it will stick to the
iron. This test takes advantage of the peculiar
properties 2 of curd which are produced by the action
of the acid on the casein.
200. Firmness of the ctird. The cheese-maker must
be able to judge the firmness of the curd by physical
examination. The particles of curd should have shrunken
to about one-half their original size and should be of
uniform consistency throughout; they should not have
1 S. M. Babcock, Hot iron test of cheese curd, Wis. Exp.
Sta. Kept. 1895, pages 133-134.
2 Van Slyke, L. L., and E. B. Hart, A study of some of the
salts formed by casein and paracasein with acids, their relation
to American Cheddar cheese, N. Y. (Geneva) Exp. Sta. Bui.
214, 1902.
202
THE BOOK OF CHEESE
any soft centers. The curd should be firm and springy.
When a double handful is pressed and suddenly released,
the curd particles should spring apart. The curd should
have a " shotty " feeling when in the whey. If the curd
has attained the proper firmness, and the acid has not
reached the correct stage to remove the whey, it may
be left in the whey until sufficient acid development
has been attained. This is liable to cause the curd to
become too firm and to result in a hard dry cheese. If
there is no evidence of
the presence of undesir-
able organisms, such as
bad odors, or gas holes
in the curd, it is better
to remove the whey and
develop the acid when
the curd is in the "pack."
The pack refers to the
first piling of the curd.
The whey may be re-
moved either by means
of a faucet or gate in the
vat or by a siphon (Fig.
36). With either form
of removal a whey-strainer (Fig. 37) should be used to
prevent loss of curd particles. It requires considerable
time for the whey to escape from a large vat. After the
curd has been heated to the proper temperature, it is
well to remove a portion of the whey. In doing this the
surface of the whey should not be drawn down quite to
the top of the curd. When ready, the remaining whey
can be quickly removed.
If it is decided that the curd is not firm enough, when
FIG. 36. Whey siphon with
strainer.
CHEDDAR CHEESE-MAKING
203
the whey is drawn down to the surface of the curd and
the acid has developed sufficiently, the curd should be
firmed up in the whey by stirring it vigorously by hand
before the remainder of the whey is removed. This is
commonly called "hand stirring." This difficulty results
either from the use of too much
starter or from holding the milk
until too much acid develop-
ment has taken place before
adding the rennet. Hand stir-
ring accomplishes what natural
forces would accomplish if
given sufficient time. If the
curd does not firm naturally
in the whey, there is a large
loss of fat and other solids, be-
cause the pieces of curd will
have to be broken up to allow
the water to escape from the
soft centers of these masses.
This loss can usually be re-
duced by firming the curd in
the whey or adding water
rather than by stirring without
either water or whey. If the
curd is not properly firmed, it
carries extra whey into the
cheese. With the increase in whey, the amount of milk-
sugar carried into the cheese increases. This extra milk-
sugar attacked by bacteria produces an excess of lactic acid,
which results in " sour " cheeses. This explains why the
curd is placed beyond the danger of over-development
of acid by removing so large a portion of the whey.
FIG. 37. Whey strainer with
spout to fit into the gate in
the vat.
204 THE BOOK OF CHEESE
If the curd is properly firmed in the whey and the whey
is removed before too much acid has developed, it is im-
possible to make a sour cheese.
201. Gathering the curd together. Before the last
of the whey has been removed, the curd should be pushed
back from the faucet into the upper two-thirds of the
vat and spread in an even layer. This layer should be
six to eight inches thick. The curd can be pushed back
with the rake or a board which will fit crosswise in the
vat, in which are many holes. As soon as the whey has
been removed so that there is not enough to wash the
curd into the lower part of the vat, the vat should be
tilted and a ditch eight to ten inches wide cut in the curd
through the center. The curd from the ditch should
be removed to either side and spread evenly. As soon
as all the whey has been removed, the pieces of curd scat-
tered about in the vat should be gathered up and placed
with the remainder.
In some factories, instead of matting the curd in the
vat, a curd sink is used. This is a wooden receptacle
about the size of the vat but not so deep, with a slatted
false bottom. It is fitted with castors so that it can be
easily moved about. A cloth is placed in the sink
and the curd and whey are dipped upon the cloth. The
whey escapes very rapidly through the cloth. The curd
sink is an advantage in those cases in which it is de-
sirable to remove the whey from the curd quickly, such
as high acid curds which have to be hand stirred to firm
the curd. The disadvantage lies in the work required
to keep the sink and the large cloth clean.
202. Matting or cheddaring is the distinctive feature
of the Cheddar process. It is the piling and matting
of the curd. Whether the curd is matted in the vat
CHEDDAR CHEESE-MAKING 205
or in the curd sink, the process is practically the same.
The object of cheddaring is three-fold : (1) to control the
incorporation of moisture; (2) to control undesirable
ferments, if present in the curd; (3) to develop the
texture desired in the cheeses.
After the curd in the vat has become matted so that
the particles stick together, the masses on either side of
the central channel are cut crosswise into strips with a
cheese knife (Fig. 38). The width of the strip depends
on the water-content of the curd at this stage. The
more water, the smaller should be the pieces of curd.
This allows the whey to drain away much more rapidly.
As soon as the strips of curd are cut, they should be turned
over or stood on edge. A drain should be left along the
middle line of the
vat and on each
side. This permits
. FIG. 38. A cheese knife.
the whey to run
away freely. If, on the other hand, the outlet is dammed
up, the curd may become " whey-soaked/' This pro-
duces a soft mushy cheese which sometimes is "acidy"
or sour. After the curd is turned each time, all crumbs
of curd broken off should be brushed underneath the
masses of curd so that they will mat with it. They
should never be placed on top of the curd because
they will not unite but will become dry and hard. If
the crumbs are not kept brushed up, they become dry
and will cause an open textured granular cheese and
possibly lumps in the cheese. After the pieces of curd
have been turned several times, and the whey has fairly
completely drained away, they may be piled first two
deep, then three deep and so on, the depth of the piling
being gauged by the softness or amount of water in the
206 THE BOOK OF CHEESE
curd and the temperature. The higher the curd is piled,
the more water it will retain (assimilate), so that the
amount of moisture in the curd is regulated by the size
of the pieces into which it is cut and the rapidity and
depth to which it is piled.
The curd should not be left too long from the time it
is turned until it is turned again. This period is usually
about ten to fifteen minutes. The moister the curd, the
more often it should be turned. In turning, care should
be taken to keep the ends at the same temperature as
the remainder. This can be done by piling them inside,
thereby keeping them warm. There is a tendency for
the ends of the pieces of curd to remain granular and so
cause an open-textured cheese.
During the cheddaring process, the temperature should
be reduced uniformly and gradually. If there is danger
of the curd becoming too cold, the vat should be covered
and a pail of hot water may be placed inside, if it is deemed
necessary. The temperature of the curd should not be
allowed to go below 85 to 90 F. If kept too warm, the
curd will become soft and plastic, and if too cold, it will
not mat together.
While the curd is being turned and piled, its physical
properties are changing. The acid develops. When
the cheddaring process is completed, the curd should be
elastic, smooth and fibrous. The curd should have the
close meaty texture desired in the cheese. If this step
in the process is neglected, defects may appear later in
the body, texture and flavor of the cheese. Attempts
to pile the curd too fast result in a soft, mushy, open-tex-
tured product. Such cheese has mechanical holes, in
which moisture collects, and so is likely to cause rot
while curing.
CHEDDAR CHEESE-MAKING 207
If gas is detected either before or during the cheddaring
process, the curd should be piled until the gas holes are
no longer round but flat. If the gas holes are not flattened
or obliterated during this process, the cheeses will be
very liable to puff on the shelves in the curing-room.
The curd should be handled until the gas holes flatten
out evenly, although this may require considerable time.
At best, gassy curd will never produce the highest grade of
cheese.
Cheddaring or piling the curd is not thoroughly under-
stood by most cheese-makers. Because the moisture
contains the milk-sugar, there is danger of having so much
moisture present in the cheese that it will become sour
from the action of the lactic acid-forming bacteria on the
milk-sugar. A cheese may be sweet when made and later
become sour because it contains too much moisture or
milk-sugar. This is known as "shelf souring." For the
proper cheddaring of a curd, it is necessary that it be
properly firmed in the whey. If the moisture is not evenly
incorporated, the cheese will have a mottled color. The
pieces that have the more moisture will be lighter
colored. If the proper amount of moisture is not incor-
porated, the cheese will be dry and hard, and if too much,
soft and pasty.
203. Milling the curd. The large pieces formed by
the cheddaring process must be cut into small ones before
the curd can be easily put into the hoop. This is called
" milling." Properly milled curd can be salted evenly,
cools more quickly and uniformly and can be distributed
evenly in the hoops.
The proper time to " mill " the curd is determined by
its physical condition. Some curds will cheddar much
more rapidly than others, hence no definite length of time
208 THE BOOK OF CHEESE
can be given. Curd, "when ready to mill, should have a
fibrous texture somewhat like the white meat of a chicken
breast. The pieces of curd should split very easily.
When cut, the curd should show a close, solid, smooth
interior. The amount of lactic acid developed may vary
within rather wide limits. The hot iron may show
IT
FIG. 39. Gosselin curd-mill.
strings | to 1 inch long. The acidity (by titration of the
freshly separating whey) may be 0.45 to 0.65 of 1 per cent.
If the curd has been properly made, that is, firmed up in
the whey with the proper acidity so far, acid develop-
ment during the cheddaring process will take care of itself.
The physical condition remains the principal means of
determining the time when the curd should be milled.
FIG. 40. Barnard curd-mill.
There are many kinds and styles of curd-mills on the
market. Gosselin, Barnard, Pohl, Junker, Victor,
Harris are well-known kinds (Figs. 3942). Some are
hand, others power mills. Some of these tear the curd
into pieces of unequal size, others cut it into uniform
pieces. A mill that will do the work with the least
CHEDDAR CHEESE-MAKING
209
possible pressure on the curd and which will cut it
into small uniform-sized pieces is most desirable.
FIG. 41. Junker curd-mill.
The ideal mill should release the least fat and leave
the curd in the best condition to receive the salt. It
is impossible to run curd through any mill without
FIG. 42. Harris curd-mill.
exposing some fat on the freshly cut surfaces, and if the
curd is put under pressure, more fat will be pressed out
and lost. Cutting in the mill, like cutting the curd after
210 THE BOOK OF CHEESE
coagulation by rennet, may be called a necessary evil.
There is an unavoidable mechanical loss which may be
greater or less according to the mill used. If the curd
has been properly handled so that the water in it has
become thoroughly assimilated (properly incorporated),
this loss will be reduced to the minimum. If the curd
contains free moisture and many of the particles have
soft interiors, a stream of white whey will run down the,
vat as the curd masses are cut. Some samples of such
white whey will test as high as 15 per cent fat. This
not only causes a loss in yield but in quality of cheese,
according to the amount of fat lost. White whey is an
indication of loss of fat. If the proper amount of
moisture is present
and is so thoroughly
incorporated in the
curd that it can be
separated only by
FIG. 43. A curd fork. evaporation, the ideal
condition has been
reached. While milling, the cut curd should be stirred
as fast as milled to prevent matting again and to allow
odors to escape. This stirring is usually performed with
a curd fork (Fig. 43) . At the same time the temperature
will be lowered. The milled curd should be spread evenly
over the upper three-quarters of the bottom of the vat.
The flavor of the curd that has been made from tainted
milk can be very much improved by stirring at this time
so that air can enter.
A gassy curd, which has been held until the holes have
become flattened, should be stirred very frequently during
this stage to allow the gas to escape, thereby improving
the flavor.
CHEDDAR CHEESE-MAKING' 211
204. Salting. Salt is added to Cheddar curd for
several purposes: (1) for its taste; (2) to aid in the
removal of the whey and to harden and shrink the curd ;
(3) to influence the fermentation by slowing down acidi-
fication, checking the growth of unfavorable organisms
and delaying ripening. The salt should be pure.
It should be coarse-grained, because the large grains
dissolve more slowly and permit its absorption to a much
larger extent than the fine-grained salt. Salt that
dissolves slowly is, therefore, to be sought for this purpose.
The following factors must be considered in determin-
ing the amount of salt to be used : (1) the amount of curd
from the milk ; (2) the percentage of water in the curd ;
(3) the acidity of the curd ; (4) the particular market
form of cheese desired. The custom of determining the
quantity of salt by the weight of milk is an inaccurate
practice. The amount of salt should be based on the
amount of curd. If the amount of fat in the milk is
known, a fairly accurate estimate of the amount of curd
can be made. It would be more accurate to weigh the
curd before salting, but this is not practicable or necessary
to insure a good quality of cheese. The amount of salt
varies from 1| to 2j pounds of salt to the curd from each
1000 pounds of milk.
The salt should not be added directly after milling
because, at that time, it would cause a large loss of fat.
After milling there should be time before salting for the
freshly cut surfaces to dry or " heal over." When first
milled the curd has a dry harsh feeling ; when ready to
salt it will feel soft and mellow and some moisture can
usually be squeezed out easily. Fifteen to twenty minutes
from the time of milling are required before the curd is
ready for the salt. When ready, the curd should be
212
THE BOOK OF CHEESE
FIG. 44. Wilson press hoop. A, com-
plete hoop ; B, bottom cover with
wide flange ; C, top cover with narrow
flange ; D, closed body ; E, bandager.
spread evenly over the bottom of the vat. The salt
should be carefully weighed, and then applied, evenly, over
the surface of the curd, in two or three applications. The
curd should be thoroughly stirred after each application
of salt. While the salt
is being dissolved and
absorbed, the curd
should be stirred oc-
casionally to prevent
lumps from forming.
205 ' Hooping the
CUfd. When the salt
i v i i i
has become dissolved
and the curd as soft
and mellow as before the salt was added, it is ready to be
put into the hoop. Various sized hoops may be used,
depending on the desired size of the cheese. Two types
are the Wilson and the Fraser (Figs. 44, 45). With
either type, a dampened press cloth should be cut just
to fit the bottom of the hoop.
A starched circle may or may
not be used ; if used, it should
be placed on top of the press
cloth. The bandage now com-
monly employed is the seamless
one which comes in the form
of a tube of Various sizes for
different sized hoops. The
lengths of bandage cut for each
hoop or cheese depend on the height of the cheese plus
about one and one-half inches' lap on each end. The
bandage, after being cut the desired length, is placed
on the part of the hoop made to hold it, so that it is
FIG. 45. Fraser press hoop.
A, complete hoop ; B, band-
D, fi-
CHEDDAR CHEESE-MAKING 213
suspended about the side of the hoop and laps about
one and one-half inches on the bottom. The band-
age should be free from ravelings and placed squarely in
the hoop.
The hoop is now ready to fill with curd. Enough hoops
should be prepared to hold all the day's curd as fast as
it is ready. In order to have all the cheeses as nearly
as possible of the same size, it is advisable to weigh the
curd into the hoops. The curd may be measured into the
hoops, but this is not so accurate. The curd may be
dipped with a flat-sided curd pail
or a curd scoop into the hoops
(Fig. 46).
206. Pressing the curd. The
natural changes sought in the
curd require a period of at least
five hours between the time of FlG - 46 '"~ c ^ 1 d scoop and
setting (addition of the rennet)
and the pressing of the curd. Less time than this involves
loss in yield and quality of the cheese. In other words,
the time requirement for these changes cannot be ignored.
The object of pressing is not primarily to remove whey
but to produce the physical conditions essential to ripen-
ing the cheese in a mass and put it in convenient form
for handling. The whey should have been removed
during the cooking and cheddaring. When ready for
the press, the temperature of the curd should be about
80 to 85 F. ; it should be brought down to this point
during the milling, salting and hooping processes. If the
curd is put to press too warm or too cold, the following
results may be expected :
Too high temperature during pressing produces several
faults, as :
214
THE BOOK OF CHEESE
(1) Favors the development of undesirable ferments.
(2) Causes excessive loss of fat.
(3) Gives the curd pieces a greasy surface so that they
will not readily pass into a compact cheese. If a cheese
is greasy, the bandages will not stick.
(4) Favors the formation of mechanical holes in the
cheese.
(5) Causes " seamy " color in the cheese by the collec-
tion of fat between pieces of curd.
Too low temperature has its difficulties, such as :
(1) The pieces of curd will not fuse together.
(2) The rind does not form properly.
(3) It appears to cause mottled cheese.
The commonly used gang press may or may not
have an arrangement to cause continuous pressure to be
FIG. 47. Continuous pressure gang cheese-press.
applied to the cheese (Figs. 47, 48). When fresh cheeses
are first placed in the press, the pressure should be
applied very gradually. The curd, after being cut through
CHEDDAR CHEESE-MAKING
215
216 THE BOOK OF CHEESE
the mill, will have many exposed fat globules. A heavy
pressure at first will force out the whey set free by the
extracting power of the salt. The whey will carry away
the exposed fat globules, and therefore reduce the yield.
As soon as white whey starts from the hoops, the
increased application of the pressure should be stopped
until the whey regains the appearance of clear brine.
More pressure can then be gradually applied until full
pressure is reached. The cheeses should remain under
heavy pressure for one-half to one hour, when they should
be removed from the press and dressed.
207. Dressing the cheese. When ready to dress
the cheese, the press is opened and the hoops turned down.
The hoops are opened so that the bandages can be lapped
over the top of the cheeses about 1^ inches. Before
turning a bandage down, it should be carefully pulled up
to remove any wrinkles from the sides of the cheese,
but not hard enough to pull it free from the bottom.
After it is pulled up, the bandage should be lapped over
the top about 1| inches, and if not even should be trimmed
with a sharp knife. It should then be sopped down with
warm water. Plenty of warm water to wet the bandage
and cloths helps to form a good rind. If starched circles
are used, one should be placed on the top of the cheese
and sopped down with warm water. If not, the press cloth
should be wrung out of warm water and put on smoothly,
so there will be no wrinkles. The hoop is then put to-
gether and placed back in the press under heavy pressure
for twelve to eighteen hours. The pressure should be
sufficient to cause the curd particles to unite so that the
surface of the cheese will be smooth. The next day the
cheeses are taken from the hoops and placed in the curing-
room. If they do not come out of the hoop easily, they
CHEDDAR CHEESE-MAKING 217
may be loosened by cutting between the sides of the cheese
and the hoop with a knife. A special thin-bladed knife
for this purpose is called a speed knife (Fig. 49). Care
should be taken not to cut the bandage when trying to
loosen the cheese. If starched circles are used, the press
cloths are removed from the cheese, when they are put
in the curing-room. If neither starched circles nor press
cloth are left on the cheese in the curing-room, the rind
will crack on account
of drying out on the (
exposed surface. This
FIG. 49. Speed knife.
allows mold and in-
sects to enter the cheese. The flavor, body and texture
and color of the cheese are all dependent on the skill of
the cheese-maker and the quality of the milk from which it
is made. The finish is dependent entirely on the skill and
carefulness of the maker. An operator should see that
the cheese press is straight so that there will be no
crocked cheese and that the bandage and press cloths are
properly put on, because the finish or appearance of the
cheese is an index of his ability.
208. Handling over-ripe and gassy milk. Because
it is sometimes necessary to make over-ripe 1 or gassy
milk 2 into cheese, special directions or precautions are
necessary. The best way is to reject this milk. When
it is necessary to make it into cheese, the losses are much
1 Decker, J. W., Cheesemaking from sour milk, Wis. Exp.
Sta. Kept. 1898, pages 42-44.
2 Russell, H. L., Cheese as affected by gas producing bacteria,
Wis. Exp. Sta. Kept. 1895, pages 139-146.
Marshall, C. E., Gassy curd and cheese, Mich. Exp. Sta.
Bui. 183, 1900.
Moore, V. A., and A. R. Ward, Causes of tainted cheese curds,
N. Y. (Cornell) Exp. Sta. Bui. 158, 1899.
218 THE BOOK OF CHEESE
more than with normal milk. It is a question of making
as good a cheese as possible, and the subject of losses
is ignored.
(1) Over-ripe milk. The fact that the milk is over-
ripe shows that there is already too much acid present.
Every effort must be made to get the curd as firm as pos-
sible in the whey with the acid development as low as
possible or before the acid has had time to develop any
more than can be helped. Although the milk is over-ripe,
it is a good plan to add about J of 1 per cent of starter just
before the rennet. This starter will not begin to work until
the curd is being cheddared and it will help the flavor,
especially if any bad fermentation should be present.
The rennet is added at 80 F., as this lower temperature
tends to check the acid development. More rennet is used,
commonly from 4 to 4| ounces to 1000 pounds of milk.
This gives a quicker coagulation. The curd is cut soft,
as this tends to expel the moisture more quickly. The
heat is turned on sooner after cutting. The time to turn
it on and the length of time to heat are determined by
the amount of acid. A curd should not be heated in less
than fifteen minutes. If the curd has enough acid and
has not begun to firm up much, the whey should be drawn
down to the surface of the curd, water the temperature
of the whey and curd put into the vat, and the curd firmed
up in this water. The water washes the acid out of the
curd and because of the lack of milk-sugar checks the
acid development.
If the milk is not so ripe and the curd nearly firm
enough, the whey may be drawn off and the curd firmed
up by hard stirring in the vat or sink. The curd should
not be pushed back enough to be very deep or thick
when ready to cheddar.
CHEDDAR CHEESE-MAKING 219
The curd should be cut into very small pieces to cheddar.
The smaller the pieces, the faster the whey drains away.
Sometimes it is necessary to cut the curd into pieces six
inches square. The pieces should not be piled but should be
turned often and stood on edge to let the whey drain away
and sometimes pressed with the hands to force the whey out.
It is often all one man can do to keep the curd turned.
The curd is not cheddared very long but is milled early
so that the whey can escape. If it is thought that the
cheese will be sour, the curd should be washed in cold
water to remove the acid and milk-sugar. A little more
FIG. 50. At the left is a regular shaped, close, solid textured cheese;
at the right one puffed up with gas.
salt is sometimes used. A product made from over-ripe
milk, no matter how skillful the cheese-maker, will show
traces of a sour cheese.
(2) Gassy milk. If a cheese-maker knows that there
is " gassy " fermentation, he should add more starter
and develop more acid when ripening the milk to try to
overcome this. There are different kinds of gassy fer-
mentation. Some produce acid and some do not. Some
will not show until the cheeses have been on the curing-
room shelves several days. Others will cause the curd
to float in the whey. Usually the gas shows as pin-holes
while the curd is being cheddared.
220
THE BOOK OF CHEESE
The gas causes tiny round holes in the cheese, resulting
in the cheese swelling or puffing out of shape and some-
times breaking open (Figs. 50, 51). The only time to
overcome the gas is during the cheddaring process. The
curd is piled and repiled until the holes flatten out. This
shows that the gas-producing organisms have weakened
and will not cause any more holes. Because the curd has
FIG. 51. This shows the same cheeses as in Fig. 50, cut open to show
the solid and gassy texture.
to be piled so many times and so long, the pieces become
very thin. The curd is ready to mill when most of the
holes have flattened. After milling, the curd should be
stirred and aired for some time before salting to allow the
bad odor to escape.
Because of the high acid development, it often happens
that the cheese will not be gassy but will be sour. At
best a cheese made from milk having gassy fermentation
will have a bad flavor. The quality of the cheese can be
CHEDDAR CHEESE-MAKING 221
no better than that of the milk from which it is made,
plus the skill of the cheese-maker.
209. Qualities of Cheddar cheese. The cheese should
be neat, clean and attractive. If unclean, and the bandage
not put on the cheese properly, it shows that the manu-
facturer is not particular to keep the curing-room shelves
tidy nor careful and painstaking in dressing. The
cheese should not be lopsided or bulged. When cut,
it should have a uniformly colored interior. The prin-
cipal color defects are too high, or too light color,
mottled or seamy. The texture should be solid and close.
A common defect is mechanical holes or openings and
another is gas pockets. The body can be tested by rub-
bing the cheese between the thumb and fingers. It should
be smooth and waxy and free from lumps. It should rub
down like cold butter. The common defects are graini-
ness and lumpiness. Graininess may be caused by too
much acid or too much moisture in the cheese. Lumpi-
ness is due to uneven curing. If too much moisture is
present, the body will be soft and mushy ; if not enough
moisture, the body will be hard and dry.
The cheese should have a pleasant, clean, mild aroma
and the characteristic flavor which is usually somewhat
similar to that of nuts and so is spoken of as a nutty
flavor.
CHAPTER XIII
COMPOSITION AND YIELD OF CHEDDAR
CHEESE
So many factors affect the composition and yield of
Cheddar cheese that no positive or exact statement can
be made unless other facts are definitely known. The
following factors affect both the composition and yield :
1. The chemical composition of the milk.
2. Amount of moisture incorporated into the cheese.
3. The amount of solids lost in cheese-making.
4. The skill of the cheese-maker.
5. The bacterial-content of the milk.
210. Composition of milk, whey and cheese. The
following Tables l VI, VII, VIII, which are the average
of forty-eight factories for the season of 1893, show the
minimum, maximum and average composition :
TABLE VI
AVERAGE COMPOSITION OF THE MILK
MINIMUM
MAXIMUM
AVERAGE
Water
Total solids
86.28
11 70
88.30
13 72
87.28
1272
Fat ... . .
3.30
4.40
3.77
Casein
2.20
2.85
2.48
Albumin
052
081
69
Sugar and ash, etc. . .
5.63
5.89
5.78
1 Van Slyke, L. L., Investigations relating to the manufac-
ture of cheese, N. Y. (Geneva) Exp. Sta. Bui. 68, 1894.
222
COMPOSITION OF CHEDDAR CHEESE 223
TABLE VII
AVERAGE COMPOSITION OF THE WHEY
MINIMUM
MAXIMUM
AVERAGE
Water
92.75
93.28
93.00
Total solids
6 72
725
700
Fat
0.24
0.51
0.38
Casein, albumin . ...
Sugar, ash, etc
0.66
5.63
0.99
5.86
0.86
5.76
TABLE VIII
AVERAGE COMPOSITION OF THE GREEN CHEESE
MINIMUM
MAXIMUM
AVERAGE
Water
33 16
43 89
37 33
Total solids . .
6684
56 11
6267
Fat
Casein
30.00
2080
35.89
2548
33.41
23 39
Sugar, ash, etc
4.86
7.02
5.89
Table VI shows the minimum, maximum and average
composition of the milk and Table VIII the composi-
tion of the cheese made from that milk. The average
composition of the cheese in Table VIII shows that it
contains 37.33 per cent of water. The tendency to-day
seems to be for a softer cheese so that the average would
probably be higher. Table VIII also shows the wide
variation in the composition of the cheese. The moisture
and total solids both vary about 10 per cent. In order to
judge the variation in composition, one must know the
224
THE BOOK OF CHEESE
composition of the milk and the moisture-content of the
cheese and then only a very inaccurate estimate of the
composition of the cheese can be formed.
211. Relation of fat to casein in normal milk. In
order to understand the relation of the composition of the
milk to yield of cheese, one must be familiar with the rela-
tion of the fat to the casein in normal milk. The follow-
ing table 1 shows the relation of fat to casein in normal
milk:
TABLE IX
SUMMARY SHOWING THE RELATION OP FAT TO CASEIN
IN NORMAL MILK
GROUP
PER CENT
OF FAT IN
MILK
NUMBER
OF
SAMPLES
AVERAGE
PER CENT
OF FAT IN
EACH
GROUP
AVERAGE
PER CENT
OF CASEIN
IN EACH
GROUP
AVERAGE
POUNDS OF
CASEIN FOR
EACH POUND
OF FAT IN
MILK
I ...
3.0-3.5
22
3.35
2.20
0.66
II ...
3.5-4.0
112
3.72
2.46
0.66
Ill ...
4.0-4.5
78
4.15
2.70
0.65
IV ...
4.5^5.0
16
4.74
3.05
0.64
V ...
5.0-5.25
7
5.13
3.12
0.61
Table IX shows that the pounds of casein for each
pound of fat are not constant but that the casein does not
increase in proportion to the fat above 4.0 per cent of fat
in the milk.
212. Influence of fat in milk on yield of cheese.
The following table shows the influence which fat in the
milk has on the yield of cheese : 1
1 Van Slyke, L. L., Investigations relating to the manufac-
ture of cheese, N. Y. (Geneva) Exp. Sta. Bui. 62, 1893.
COMPOSITION OF CHEDDAR CHEESE 225
TABLE X
SUMMARY SHOWING RELATION OF FAT IN MILK TO YIELD
OF CHEESE
GROUP
AVERAGE PER
CENT OF FAT IN
MILK
POUNDS OF GREEN CHEESE
MADE FROM 100 LB. OF
MILK
POUNDS OF
GREEN CHEESE
MADE FOR 1 LB.
OF FAT IN MILK
I ...
3.35
9.14
2.73
II .
3.72
10.04
2.73
Ill . . ,
4.15
11.34
2.70
IV ...
4.74
12.85
2.71
V ...
5.13
13.62
2.66
Table X shows that as the fat in the milk increases,
the pounds of cheese made from 100 pounds of that milk
increases ; but the amount of cheese made for each pound
of fat in the milk does not increase. This is due to the
fact pointed out in Table IX, namely, that as the fat in-
creases in the milk the casein does not increase in the rich
milk in proportion to the fat. From Tables IX and X
this conclusion may be drawn : that as the percentage of
fat increases in the milk the more cheese can be made
from 100 pounds of that milk, but after the increase in
fat gets above 4 per cent the amount of cheese that can
be made for each pound of fat in the milk is decreased
because the casein does not increase in proportion to the
fat. No exact statement of yield can be made without
first stating the moisture-content of the cheese. The
losses also must be considered.
Van Slyke 1 in the following Table XI shows the effect
of the fat-content of normal milk on the yield of cheese.
1 Van Slyke, L. L., Methods of paying for milk at cheese
factories, N. Y. (Geneva) Exp. Sta. Bui. 308, 1908.
Q
226
THE BOOK OF CHEESE
The moisture-content of all the cheeses is reduced to a
uniform basis of 37 per cent. (See cut showing yield of
cheese, Fig. 52.)
FIG. 52. The figures represent the relative yield of cheese containing
different percentages of fat, but all have a uniform content of 37 per
cent water.
TABLE XI
TABLE SHOWING THE EFFECT OF THE FAT-CONTENT OF
NORMAL MILK ON THE YIELD OF CHEESE
PER CENT OP FAT
IN THE MILK
PER CENT OF
CASEIN IN
THE MILK
AMOUNT OP
CHEESE MADE
FROM 100 LB.
OF MILK
AMOUNT op CHEESE
MADE FOR EACH
POUND OF FAT
IN THE MILK
3.00
2.10
8.30
2.77
3.25
2.20
8.88
2.73
3.50
2.30
9.45
2.70
3.75
2.40
10.03
2.67
4.00
2.50
10.60
2.65
4.25
2.60
11.17
2.63
4.50
2.70
11.74
2.61
4.75
2.80
12.31
2.59
5.00
2.90
12.90
2.58
213. Fat loss in cheese-making. The amount of
solids lost in the whey also affects the yield. The follow-
COMPOSITION OF CHEDDAR CHEESE 227
ing table gives the amount of fat lost in whey with normal
milk containing different percentages of fat :
TABLE XII
SUMMARY SHOWING AMOUNT OF FAT IN MILK LOST IN
CHEESE-MAKING
GROUP
POUNDS OF FAT IN
100 LB. OF MILK
POUNDS OF FAT LOST
IN WHEY FOB 100
LB. OF MILS
PER CENT OF FAT
IN MILK LOST
IN WHEY
I ...
3 to 3.5
0.32
9.55
II ...
3.5 to 4
0.33
8.33
Ill ...
4 to 4.5
0.32
7.70
IV ...
4.5 to 5
0.28
5.90
V ...
5 to 5.25
0.31
6.00
Table XII shows that the percentage of fat in the whey
is approximately the same for milk high or low in fat.
But the milk low in fat loses a higher percentage of the
total milk-fat in each 100 pounds of whey.
214. Effect of bacterial-content of milk on yield of
cheese. The bacterial-content x of the milk influences
the yield by affecting both the moisture-content and the
losses. If the milk is sour or has bad fermentation, the
losses will be increased because the curd cannot be care-
fully handled, and the moisture cannot be incorporated
to the extent that it can in clean milk, without injury
to the quality. The proper cooling of the milk in one
instance increased the yield 0.3 pound of cheese for each
100 pounds of milk. The more moisture that can be in-
corporated into the cheese up to the legal limit, the greater
the yield.
1 Farm Bur. Exchange, St. Lawrence Co., N. Y., Vol. 1, no.
9, 1915. Cooling milk before delivery at the cheese factory.
228 THE BOOK OF CHEESE
215. Factors affecting the moisture-content of Cheddar.
-The amount of moisture that can be incorporated
in a curd depends on several factors. 1 The following in-
crease the moisture-content control of the cheese :
1. Cutting the curd coarse.
2. High setting temperature.
3. Low acid in the curd at time of removing whey.
4. Not stirring the curd with the hand as the last of
the whey is removed.
5. Slow pressure.
6. High piling of the curd in the cheddaring process.
7. Small amount of salt.
8. Holding the curd at low temperature after the whey
is removed.
9. Large amount of rennet.
10. Cutting the curd hard.
The following factors decrease the moisture-content of
the cheese :
1. Fine cutting.
2. Low setting temperature.
3. High acid in the curd at time of removing the whey.
4. Stirring the curd with the hand as the last of the
whey is removed.
5. Fast pressure.
6. Low piling of the curd in the cheddaring process.
1 Sammis, J. L., et aL, Factors controlling the moisture con-
tent of cheese curds, Wis. Exp. Sta. Research Bui. 7, 1910.
Ont. Agr. College and Exp. Farm Kept. 1909, pages 111-
124, Cheese making experiments.
Ont. Agr. College and Exp. Farm Kept. 1910, pages 111-128,
Cheese making experiments.
Fisk, W. W., A study of some factors influencing the yield
and the moisture content of Cheddar cheese, Cornell Exp. Sta,
Bui. 334, pages 515-537, 1913.
COMPOSITION OF CHEDDAR CHEESE 229
7. Large amount of salt.
8. Holding the curd at high temperature after the
whey is removed.
9. Small amount of rennet.
10. Cutting the curd soft.
From this discussion, it is evident that the yield of
cheese from 100 pounds of milk increases with higher
percentages of fat and casein in the milk, with reduced
losses of solids during manufacture, with the absence of
undesirable fermentations, and with the incorporation of
large amounts of water.
216. Variations of the Cheddar process. The Cheddar
process, as already described, is widely employed in cheese
factories. Many varieties are found, however, and
varietal names are used for such products. A whole
series of these forms are either locally or widely made in
England and taught in the English dairy schools. Some
of these varieties resemble the factory Cheddar product
fairly closely; others are clearly different products. A
typical series of the variations as developed in America
will be considered.
In the commercial trade Cheddar cheese is usually
designated by some name which indicates its size. The
size of the cheese is determined by that of the hoops.
The hoops vary both in diameter and height. The
table on the following page shows the usual sizes of the
hoops and the weight and name applied to the cheese.
217. Cheddar-type cheese from pasteurized milk. -
Sammis and Bruhn l have described a variation of the
Cheddar process to overcome the difficulties of making
1 Sammis, J. L., and A. T. Bruhn, The manufacture of cheese
of the Cheddar type from pasteurized milk, U. S. Dept. Agr.
Bur. An. Ind. Bui. 165, pages 1-95, 1913.
230
THE BOOK OF CHEESE
cheese from pasteurized milk. Such milk curdles in very
unsatisfactory manner unless some chemical is added to
compensate for the salts lost and to offset the other
changes resulting from heat. For this purpose, they
found the use of hydrochloric acid satisfactory.
TABLE XIII
SIZE OF CHEESE HOOPS, WEIGHT, AND TERM APPLIED TO
CHEESED
DIAMETER OP
HOOP
HEIGHT op
CHEESE
WEIGHT OF
CHEESE
POUNDS
TERM APPLIED TO
CHEESE
6-7 in.
7-8 in.
9-11
Young America
Tapers 5-7 in.
10-14 in.
10-16
Long Horn
12-14 in.
3MI in-
18-24
Daisy or Picnic
14-15| in.
4-6 in.
30-40
Twin (two in same box)
14-16 in.
4-7 in.
35-40
Flat
13|-15 in.
10-12 in.
40-50
Cheddar
14-16 in.
12-15 in.
75-90
Export
" The acidulation of milk with hydrochloric acid after
pasteurization is accomplished without difficulty or danger
of curdling by running a small stream of the acid, of normal
concentration, into the cooled milk as it flows from the
continuous pasteurizer into the cheese vat. One pound of
normal-strength acid is sufficient to raise 100 pounds of
milk from 0.16 per cent to 0.25 per cent acidity (calcu-
lated as per cent of lactic acid). The amount of acid
needed each day to bring the milk up to 0.25 per cent
acidity is read from a table or calculated from the weight
of the milk and its acidity, determined by the use of
Manns's acid test (titration with tenth-normal sodium
hydrate and phenolphthalein) . The preparation of stand-
ard-strength acid in carboy lots for this work and the
COMPOSITION OF CHEDDAR CHEESE 231
acidulation of milk present no great difficulty to any one
who is able to handle Manns's acid test correctly.
" After the milk is pasteurized and acidulated three-
fourths per cent of first-class starter is added and the vat
is heated to 85. It is set with rennet, using 2 ounces
of rennet per thousand pounds of milk, so that the milk
begins to curdle in 7 minutes and is cut with three-eighth
inch knives in 25 minutes. All portions of the work
after adding rennet are carried out in an unvarying routine
manner, according to a fixed-time schedule every day.
As soon as the rennet has been added the cheese maker
is able to calculate the exact time of day when each of the
succeeding operations should be performed, and the work
of making the cheese is thus simplified and systematized.
It is possible that the routine process here described may
be varied somewhat with advantage at different factories."
This cheese usually lacks characteristic Cheddar flavor
or contains it in very mild form. It therefore satisfies
only those who seek very mild flavored products. Efforts
are now being made to find a flavor producing substance
or organism which will bring the flavor of this product
more nearly to that of typical Cheddar.
218. Club cheese is known by a variety of trade
names. It is made from Cheddar cheese, so that it is
especially liked by persons who care for strong Cheddar
flavor. It has a soft texture so that it spreads easily,
and is therefore much used for sandwiches. Well-ripened
or old Cheddar cheese is ground in a food chopper. The
older the Cheddar, the stronger will be the flavor of the
club cheese. Cheese of good flavor should be used. In
order to do away with all lumps in the texture, it is some-
times necessary to run the mixed cheese through the food
chopper a second time. While all lumps must be worked
232 THE BOOK OF CHEESE
out, care should be taken not to work the cheese so much
that it will become salvy and sticky.
Usually a little pepper is added, to give the cheese a
biting taste. Some manufacturers add a great variety
of substances, but these are not necessary and destroy
the flavor of the cheese.
Club cheese may be wrapped in tin-foil or put up in
air-tight glass jars. The latter practice, while more
expensive, has the advantage of making the cheese keep
longer; but for local trade tin-foil is just as satisfactory
as glass. In filling the glass, care must be taken not to
leave any air spaces between the cheese and the glass,
as this is likely to permit the cheese to mold. A glass jar
can be filled and air spaces prevented by first smearing
a very thin layer of cheese over the glass.
219. The stirred-curd or granular process. The
original practice as brought from England and followed
in the farm dairies before the development of the factory
system is now known variously as the " stirred-curd "
or " granular curd " process. With the introduction of
the cheese factory, as known to-day, this system was re-
placed by the Cheddar cheese. The old farm process is
still used on some farms and in a few factories. As the
name indicates, the curd for such cheeses is kept stirred
so that it remains in granular condition instead of being
allowed to mat as in the Cheddar process.
The early steps of the two processes are identical. They
diverge at the point at which in the factory Cheddar
process the whey is drawn and the curd is allowed to mat.
In some factories the curd and part of the whey are dipped
into a curd sink. This allows the whey to escape more
easily and quickly. In the stirred-curd process, the
pieces of curd are kept separated by stirring and not
COMPOSITION OF CHEDDAR CHEESE 233
allowed to mat. The whey is drawn off and the stirring
continued by hand. After stirring fifteen to twenty
minutes, the curd becomes so dry as not to mat easily.
As soon as the curd has reached this stage, the salt is
evenly and thoroughly mixed with it. More salt is added
than in the Cheddar process because the curd is more
moist than Cheddar curd at the time of salting. The
whey freely separating carries away much of the salt.
The quantity of salt to use depends on the amount of
whey draining from the curd. After salting, the curd is
allowed to cool, with occasional stirring to prevent the
formation of lumps. The advantage of the stirred-curd
practice lies in the shorter time required for making
cheese and in the greater yield due to increased water-con-
tent. It has several disadvantages, among them being :
(1) lack of control of undesirable fermentation; if gas
organisms are present, the cheeses more frequently huff
than with the Cheddar system; (2) there is more fat
lost while stirring the curd, hence quality and yield suffer ;
(3) the water is not so thoroughly incorporated, which
more frequently results in mottled cheeses; (4) the
body is commonly soft and " weak," shows mechanical
holes, and cures too rapidly. These faults are closely
correlated with the presence of higher percentages of
water than in cheeses made by the Cheddar process. In
other words, the stirred-curd process usually produces a
cheese with higher water-content, hence more subject
to the development of unfavorable fermentation than the
Cheddar cheeses.
220. California Jack cheese 1 is very similar to the
stirred-curd or granular process. This cheese was orig-
inally made in Monterey County on the coast of Cali-
1 New York Prod. Review, Vol. 34, no. 2, page 66.
234 THE BOOK OF CHEESE
fornia, about twenty-five years ago, in small quantities,
but after it was found to sell well other counties started
to manufacture it. As Monterey was the first county
to make this product, it was named " Monterey " cheese.
In order to distinguish the cheese made in other counties
from this, it was suggested that it be given a name and,
consequently, it was called " Jack " cheese. This has
been accepted as its true name. The cheese is made
mostly by Portuguese and Italian-Swiss, although some
of the best of the variety is now manufactured near
Modesto, California.
This cheese is adapted for manufacture on small dairy
farms, where there is inexpensive and scanty equip-
ment. The smaller sizes of cheese are made and ripened
quickly. It has become widely used in California.
The cheese is made every morning, from evening's
and morning's milk. The former is put into the cheese
vat at night, and morning's milk is added as milking is
going on. When the milk is all in the vat, it is immedi-
ately warmed to 86 to 88 F. and rennet extract is added
(when milk has 0.2 to 0.21 of 1 per cent acidity) at the
rate of 6 to 8 ounces to 1000 pounds of milk. No coloring
matter is used. It is ready for the curd-knife in thirty to
thirty-five minutes, its readiness being determined the
same as in making Cheddar cheese. The curd is first cut
lengthwise of the vat with the horizontal curd-knife and
allowed to stand until the whey rises over and partly
covers the curd, when it is cut again with the vertical
curd-knife crosswise of the vat. It is then hand-stirred,
gently at first, and the stirring is finished with the rake.
Either a steam-heating or self-heating vat is used (the
steam-heating vat is preferred) and temperature increased
about one degree in five minutes. The curd is heated to
COMPOSITION OF CHEDDAR CHEESE 235
98F. in winter, and to 105 F. to 1 10 F. in summer. After
temperature is up, it is stirred occasionally with a rake
until the whey is drawn at 0.14 to 0.15 of 1 per cent
acidity.
The curd is hand-stirred as soon as the whey is nearly
drained off, and raked to each side of the vat to drain more
thoroughly, when it is quickly stirred again to keep it
from lumping or matting. Salt is now added at the rate
of ij pounds to 100 pounds of curd, and stirred in thor-
oughly several times. During the salting process, cold
water is allowed to run under the vat, the hot water hav-
ing been run off previously.
Curd is put into cloths at a temperature of 80 to 85 F.
No cheese hoops are used. Two sets of press cloths are
necessary ; one set is ready to use while the other is still
on the cheese in the press. These press cloths are about
one yard square. The press cloths are all laid out evenly
one on top of the other, as many as there are cheeses.
They are then taken together and spread out over the
top of a large, open tin milk-pail, and pushed down in
the center to the bottom of the pail, with the edges hang-
ing over the top. A common one-gallon lard pail is used
to measure the curd into the press cloths. A lard pail
full will make a cheese weighing six and one-half pounds,
which is the popular size. After a pailful has been put
into the press cloth, the four corners are caught up with
the left hand, while with the right hand the curd is formed
round and the press cloth straightened and the other
corners in turn taken up. The press cloth is now taken
up tight over the curd with the left hand, while the
cheese is given a rolling motion on the table with the right
hand, pressing at the same time to expel some of the
whey. This twists the press cloth tight over the curd,
236 THE BOOK OF CHEESE
where it is tied with a stout string. After fixing them
all (as many as there are cheeses) in this way, they are
ready for the press.
The cheeses are pressed between two wooden planks,
12 inches wide, Ij inches thick, by whatever length is
required for the number of cheeses to be pressed. One
plank is nailed on supports at a convenient height from
the floor on a little slant for the whey to drain off better.
The cheeses in the press cloths are placed at the proper
distance apart so they do not touch. Then the other
plank is put squarely over the top of the cheese and levers
about four feet long at an interval of five feet are placed
over this plank, from a cleat in the wall, on the other end
of which is placed a heavy weight of about 100 pounds,
which acts as an automatic pressure. The cheeses are
left in the press until the next morning, when they are
taken out and put on the shelves in the curing-room.
The cheeses have no bandage or covering, and do not
seem to crock, and they form a very good rind.
The cheese is a sweet variety, weighs six and one-half
pounds cured and cures in about three weeks ready to
ship, and sells at 16 to 25 cents a pound wholesale. Most
of the work seems to lie in forming and rolling the curd in
press cloths before pressing. Trouble is experienced by
the makers, especially in warm climates in summer, in
not having the milk at a uniform acidity when rennet is
added. Great improvements could be made in this cheese
by using an acidimeter, paraffining and curing the cheese
in an even temperature, not much over 60 F.
Old and hard Jack cheese is also employed for grat-
ing and cooking, while the fresh is used for the table,
221. The washed-curd process has been developed
in recent years largely in the state of New York. In
COMPOSITION OF CHEDDAR CHEESE 237
this method, a regular Cheddar curd is made up to
the time of milling. This curd is washed or soaked in
cold water during or directly after milling. The theoreti-
cal object of this washing is to carry away bad flavors and
to reduce over-development of acidity by washing away
all traces of whey. However, cheese-makers soon found
that it increased the yield and this led some to carry it
to extremes.
After the curd has been milled, it is covered with cold
water. The temperature of this water ranges from 50 F. to
70 F. The curd is stirred in this water for various lengths
of time according to the judgment of the cheese-maker.
This time varies from five minutes to one hour. Some-
times the vat is partly filled with water and the curd
milled directly into the water. This process has certain
advantages and disadvantages.
The advantages are : if too much acid has developed
in the curd, this washing will reduce it so that the cheese
will not be sour. Sometimes when bad flavors are present
in the curd, washing will tend to overcome or remove
them. Its disadvantages are : the larger yield due to
excessive soaking tempts the makers to soak curd beyond
the time needed to relieve the initially sour condition.
Curd soaked in this way produces cheeses containing
percentages of water so high as to lower their quality.
This increases the yield sometimes as much as 3 to 5
per cent. Such a cheese is very soft in texture and
does not cure like a Cheddar cheese which has not been
washed. Part of the lactic acid, milk-sugar l and the
1 Babcock, S. M., et al., Cheese ripening as influenced by sugar,
Wis. Exp. Sta. Kept. 1901, pages 162-167.
E. G. Hastings, et aZ., Studies on the factors concerned in the
ripening of Cheddar cheese, Wis. Exp. Sta. Research Bui. 25.
238 THE BOOK OF CHEESE
inorganic salts are removed by this washing. A washed-
curd cheese will sometimes rot, due to the activity of the
putrefactive bacteria, and to the lack of the restraining
effect of the lactic acid-forming bacteria. Some washed-
curd cheeses are so soft that they will not retain their
normal shape.
A washed-curd cheese is never sour because the milk-
sugar and lactic acid have been removed by washing.
222. English dairy cheese. In some localities cheeses
are still made on the farms. These are mostly produced
after the stirred-curd process, hence are soft-bodied and
open-textured. They usually weigh ten to twelve pounds
and are three to four inches thick and twelve inches in
diameter.
223. Pineapple cheese. This variety derives its
name from the fact that the cheeses are made in about
the size and shape of a pineapple. The curd is made
after the Cheddar process from either whole milk or
partly skimmed milk. It is pressed in molds shaped
like a pineapple. The cheeses are then hung in nets
to give the checked appearance on the surface. They are
rubbed with linseed oil to prevent the surface cracking,
and finally are shellacked.
224. Ley den. Among specialties, a cheese called Ley-
den originating in Holland is made in Michigan and New
York. This is a part skim cheese heavily spiced with
caraway seed. The ripe cheese is colored red as it goes
to market.
225. Cheddar cheese with pimientos. Recently some
Cheddar cheeses have been made with pimientos
added. This gives a mixture of characteristic Cheddar
and pimiento flavors, which seems to be desired by some
persons. An ordinary Cheddar curd is made and the
COMPOSITION OF CHEDDAR CHEESE 239
pimientos added just before salting. The pimientos are
ground rather coarsely and then added to the curd to-
gether with the liquid which was with the pimientos in the
can. The pimiento should be thoroughly and evenly
mixed with the curd to insure a uniform distribution and
mottled color in the cheese. The salt is then applied.
The remainder of the process is the same as for ordinary
Cheddar cheese.
226. Sage cheese is a product flavored from the
leaves of the ordinary garden sage. It is made by -two
methods : one, in which the sage leaves are used, and the
other, in which a part of the curd is colored to imitate that
given by the sage leaves, and sage oil or tea is used to give
the flavor.
In the leaf method, a regular Cheddar cheese curd is
made up to the time of salting. Just before the salt is
added, sage leaves are mixed with the curd. The leaves
should be dried and freed from stems and other coarse
particles and the leaves themselves broken up rather
finely. The leaves are then added at the rate of 3 ounces
for every 1000 pounds of milk. Care must be exercised
to see that the leaves are evenly mixed through the
curd or an evenly mottled cheese will not result. The
salt is then added. This sequence seems to increase the
absorption of the flavor by the curd.
If these cheeses are consumed as soon as well cured,
no fault can be found. On the other hand, if they are
held for any length of time, yellow areas form about each
piece of sage leaf ; the leaves decay rapidly and spoil
the cheese. This method gives a very true flavored
sage cheese, the only objection being that it cannot be
held in storage for any length of time without a marked
deterioration.
240 THE BOOK OF CHEESE
In the other method of making sage cheese, either a
vat with a movable partition or a large and a small vat
must be used. In many cases the receiving can is used as
the small vat. After the milk is properly ripened and
ready to set, one-sixth to one-seventh of the milk is put
into the small vat. To this small vat, green coloring mat-
ter is added. Juice from the leaves of corn, clover, or
spinach was formerly used as coloring. Consequently the
manufacture of sage cheese by this method was limited
to the seasons of the year when these leaves could be
obtained. Now, however, the dairy supply houses have
a harmless green color paste which is much cheaper and
can be secured at any season of the year. The amount
of color paste to use will vary from 30 to 35 c.c. for every
1000 pounds of total milk. This should be added to the
small vat of milk. It gives a green milk and later a green
curd.
Both vats are worked along together, until the time for
removing the whey. Then the partition in the vat is
removed or the small vat is mixed with the large one.
The green curd should then be evenly mixed with the
white one or an even green mottled cheese will not result.
The curds should not be mixed until they are well firmed
or the white curd will take on a greenish cast and spoil
the appearance of the cheese.
After the whey is removed, the curd is allowed to mat
as in ordinary Cheddar but care must be exercised to pile
the curd so that it cannot spread or " draw " out. If
it does draw out, the small green spots will be stretched
out and large blotches or patches of green will be the
result. The cheese-maker must watch the curd closely
or he may not secure the much desired small green mottles.
When the curd is well matted, it is milled as in Cheddar.
COMPOSITION OF CHEDDAR CHEESE 241
Just before the salt is added, the sage extract is applied
to the curd.
The sage extract can be obtained from dairy supply
houses, or a sage tea can be made by steeping the sage
leaves. In many cases the commercial extract gives the
cheese a strong disagreeable flavor, but not a true sage
flavor. The sage tea gives a flavor more like that of
the leaves themselves. Too much of the extract or the
leaves will give a very rank flavor. The sage extract
can best be put on the curd by means of a sprayer or
atomizer with which it can be evenly sprayed over the
entire surface. The extract should be applied two or
three times and the curd well stirred after each application.
The amount of the extract to use depends altogether on
its strength ; an ounce of the extract or three ounces of
sage tea to 1000 pounds of milk is about the correct
amount. After the extract has been added, the salt is
used at the same rate as with a normal Cheddar curd
and the sage curd is carried along the same as a Cheddar.
This extract method gives a sage cheese mottled with
small green spots which somewhat resemble the green of
sage leaves. A cheese made in this way can be held for
a long time, as nothing has been added which can decay.
The only objection to this method is that the sage extract
may not give a true sage flavor. Therefore, the maker
must try to obtain the best extract possible or make his
own from the sage leaves.
227. Skimmed-milk Cheddar cheese. 1 The process of
making skimmed-milk cheese after the Cheddar process is
varied with the amount of fat left in the milk. Before
attempting to make skimmed-milk Cheddar, one should be-
1 Fisk, W. W., Skim-milk Cheddar cheese, N. Y. (Cornell)
Exp. Sta. Ex. Bui. 18, 1917.
B
242 THE BOOK OF CHEESE
come familiar with the process for whole-milk Cheddar.
Skimmed-milk cheeses are usually highly colored.
When part skimmed-milk cheese is manufactured, there
is often difficulty in getting the milk in the vat to test the
desired percentage of fat. Some cheese-makers skim all
the milk and then put in the desired amount of cream.
This practice seems wasteful, not only because of the cost
of separation, but because the fat will not mix easily
with the milk but will tend to float on the surface. If the
fat floats, there will be a large loss. After a very few
trials an operator can tell about how much of the whole
milk must be skimmed in order to have the mixed skimmed-
milk and whole milk test the desired percentage of fat.
The necessary percentage of fat in the mixed milk to pro-
duce cheese of a certain grade can be determined by
testing the cheese by the Babcock test. (See Chapter
XIX.)
228. Full skimmed-milk Cheddar cheese. In the
summer there is not much demand for full skimmed-milk
cheese, but it is made in large quantity in winter. The
method of manufacture is as follows :
Skimmed-milk as it comes from the separator is at a
temperature of about 88 to 90 F. ; it is ripened and set
at this temperature. It is ripened rather highly on the
acid test, from 0.18 to 0.20 of 1 per cent, and to correspond
on the rennet test which will not be many spaces. In
about twenty-five to thirty minutes it is coagulated ready
for cutting. The curd of skimmed-milk cheese is cut a little
softer than is that of whole-milk cheese. Milk is usually
set at 88 to 90 F. The curd is not ordinarily cooked
above this temperature. If the milk was 84 to 86 F.
when set, then the curd should be raised to 88 to 90 F.
The curd firms in the whey very rapidly. When firm
COMPOSITION OF CHEDDAR CHEESE 243
enough, it should have a slight development of acid.
On the acid test it should show 0.17 to 0.19 per cent, and
on the hot iron | to J of an inch. The milk should
be ripe enough or starter enough should have been used,
so that the acid will continue to develop in the "pack "
very rapidly. During the cheddaring process the curd
is piled more rapidly and in higher piles than is cus-
tomary with whole-milk cheese. This is necessary to
incorporate or assimilate a large percentage of water or
whey in the cheese. Therefore the process of skimmed-milk
Cheddar cheese is much shorter. More acid is developed
with the skimmed-milk than with the whole-milk cheese
because it seems necessary to develop proper texture.
If the acid is not developed sufficiently, the cheese will be
very rubbery and cure very slowly, in which case bad
fermentation and flavor may and often do develop.
The curd is turned, pifed or cheddared in the vat until
it begins to become meaty and fibrous. If there is danger
of too much acid, the curd may be rinsed off with water.
It is then milled and salted at the rate of 1 or Ij pounds
of salt to the curd from each 1000 pounds of milk. The
remainder of the process is the same as that for making
whole-milk cheese.
229. Half skimmed-milk Cheddar cheese. No definite
directions can be given for the manufacture of part skimmed-
milk cheese, because the process varies with the amount
of, fat left in the milk. As the fat is decreased, the pro-
cess becomes more like that for making full skimmed-milk
cheese ; as the fat is increased, the process becomes more
like that for whole-milk cheese. However, the process
of making half skimmed-milk cheese is about midway be-
tween the two. The milk is ripened more than it would be
for whole-milk cheese, usually until it tests from 0.15 to 0.17
244 THE BOOK OF CHEESE
of 1 per cent acid. The curd is coagulated and cut the
same as for the other skimmed-milk cheeses. It is cooked to
a temperature just sufficient to firm the curd, usually from
94 to 96 F. The lower the temperature at which the
curd can be cooked and yet become firm, the better is
the texture of the cheese. When the curd has firmed
enough, or when sufficient acid development, from 0.15
to 0.17 of 1 per cent, has taken place, the whey is removed.
The curd is then turned, piled or cheddared. A skimmed-
milk curd may be piled much more rapidly than a whole-
milk curd without danger of injuring it. When the curd
becomes meaty or fibrous, it is milled. It should be
salted at the rate of 1| to 2 pounds of salt to the curd
from each 1000 pounds of milk. The remainder of the
process is the same as that for making whole-milk cheese.
The cheese-maker should observe the following points
when making skimmed-milk cheese*: (1) Have clean-flavored
sweet milk ; (2) use clean-flavored commercial starter ;
(3) ripen the milk sufficiently, but not too much;
(4) firm the curd at as low a temperature as possible;
(5) have the curd properly firmed when the whey is
drawn; (6) cheddar the curd faster than the curd from
whole milk; (7) make the cheeses all the same size;
(8) keep the cheese neat and clean in the curing-room.
230. Yield and qualities of skimmed-milk Cheddar
cheese. The results of skimming different percentages of
whole milk containing varying percentages of fat are given
in the following table. As the percentage of fat in the
milk decreases, the yield of cheese also decreases, accord-
ing to the table. As the percentage of fat decreases
in the milk, the percentage of moisture in the cheese
increases, showing that moisture is substituted for fat.
The yield of cheese from 100 pounds of milk is also given
COMPOSITION OF CHEDDAR CHEESE 245
in this table. This yield varies with the amount of mois-
ture incorporated into the cheese, the amount of solids not
fat in the milk, and the solids lost in the whey.
TABLE XIV
TABLE SHOWING THE COMPOSITION AND YIELD OF SKIMMED-
MILK CHEDDAR CHEESE
PERCENT-
COMPOSITION OP THE CHEESE
PER-
PER-
AGE OP FAT
NUMBER
OF POUNDS
CENTAGE
OF FAT
IN THE
MILK
CENTAGE
OP THE
MILK
SKIMMED
IN THE
MILK
IN THE VAT
AFTER
SKIMMING
op CHEESE
PROM 100
POUNDS
OF MILK
Percentage
of Total
Solids
Percentage
of Fat
Percentage
of Water
4.7
50
2.4
9.92
54.75
22.00
45.25
4.7
60
2.0
9.74
52.46
17.50
47.54
4.7
70
1.5
9.26
49.87
13.50
50.13
4.7
80
1.0
8.42
48.26
10.00
51.74
4.0
50
2.0
9.70
53.29
21.00
46.71
4.0
60
1.6
9.50
50.89
17.00
49.11
4.0
70
1.2
9.30
48.06
13.50
51.94
4.0
80
0.9
9.20
45.24
10.50
54.76
3.5
50
1.8
8.54
54.20
19.50
45.80
3.5
60
1.5
8.10
51.10
16.50
48.90
3.5
70
1.1
7.44
52.62
13.00
47.38
3.5
80
0.9
7.00
49.64
9.54
50.36
3.4
50
1.9
8.24 i
54.50
20.00
45.50
3.4
60
1.5
7.82
52.05
16.50
47.95
3.4
70
J1.4
11.2
J7.80
\7.28
/ 49.04
\50.76
/ 14.00
\ 14.00
/ 50.96
\ 49.24
3.4
80
0.9
7.24
47.41
10.50
52.59
In some creameries and cheese factories, the milk is
skimmed and the cream made into butter and the skimmed-
milk into cheese by the Cheddar process. In making
cheese without the milk-fat, it is difficult to standardize
a method that will produce the flavor and body of the
1 Curd was spilled but practically all recovered.
246 THE BOOK OF CHEESE
whole-milk Cheddar cheese. A skimmed-milk cheese lacks
the softness and mellowness of texture of the whole-milk
product. It is very likely to be tough, dry or leathery. It
is attempted to remedy this defect by incorporating more
moisture into the skimmed-milk cheese. The added mois-
ture tends to replace the fat in giving a soft mellow body.
It requires skill on the part of the cheese-maker to incorpo-
rate moisture to take the place of the fat in giving the
cheese mellowness and smoothness of body.
The grades of skimmed-milk cheese vary between rather
wide limits from those made entirely of skimmed-milk
to those made of milk from which only a small amount
of fat has been removed and which are almost like whole-
milk cheese. Because of the gradations of skimmed-milk
cheese, it is difficult to make anything but general state-
ments and to base comparisons with whole-milk cheese.
CHAPTER XIV
CHEDDAR CHEESE RIPENING
FRESHLY made Cheddar cheese is hard, tough and elastic
and lacks characteristic cheese flavor. In this condi-
tion it is called " green/' unripe or not cured. Before
the cheese is ready to be eaten; it passes through a
complex series of changes which are collectively known
as ripening. In the ripening process the texture
becomes soft and mellow and the characteristic cheese
flavors develop. Cheese ripening must be considered
from two view-points, first, the changes taking place in-
side the cheese and secondly the outside conditions neces-
sary for ripening. Some of the chemical changes during
ripening are known, while others are not understood. The
different agents causing ripening, and the constituents of
the milk, will be discussed.
231. Fat. Numerous investigations have been made
to ascertain what chemical changes the fat undergoes
in the ripening process. Suzuki, 1 in studying the fat,
found no enzyme capable of producing lactic acid or
volatile fatty acids. However, these acids were found
in increasing amounts during the ripening process and
after the lactose had disappeared. Acetic and propionic
acids reached a maximum at three months and then
1 Suzuki, S. K., et al., Production of fatty acids and esters in
Cheddar cheese, Wis. Exp. Sta. Research Bui. 11.
247
248 THE BOOK OF CHEESE
decreased, while butyric and caproic acids continually in-
creased during the experimental period covered. Formic
acid was detected in the whole-milk cheese only at the
five and one-half month stage. In the judgment of
the experimenter the principal source of acetic and
propionic acids was probably lactates. Traces of these
acids may have had their origin in protein decomposition
or further fermentation of glycerine. The principal
sources indicated for butyric and caproic acids were fats
and proteins.
The distillate from the experimental cheese was desig-
nated " flavor solution " and contained alcohols and
esters, giving a close resemblance to the cheese aroma.
The " flavor solution " from the mild whole-milk cheese
contained esters made up largely of ethyl alcohol and acetic
acid, while from the more pungent skimmed-milk cheese
the esters were largely compounds of ethyl alcohol and
caproic and butyric acids. The alcohol may have come
from the lactose fermentation. It appears to be an im-
portant factor in flavor production. The agencies opera-
tive in the production of volatile acids and syntheses of
esters are as yet undefined.
232. Milk-sugar. The milk-sugar (lactose) is changed
into lactic acid by the lactic acid-forming organisms,
within the first few days after the cheese is made.
This acid is combined with the other constituents as fast
as it is formed. After a few days, the milk-sugar will
have entirely disappeared from the cheese. 1 The relation
between the milk-sugar and lactic acid is very close. It
is necessary that milk-sugar be present in order later to
have the lactic acid develop.
1 Babcock, S. M., et al., Cheese ripening as influenced by sugar,
Wis. Exp. Sta. Kept. 1901, pages 162-167.
CHEDDAR CHEESE RIPENING 249
233. The salts. Just what changes the salts 1 undergo
or how they combine with the other compounds is not
definitely known. It is supposed that the calcium salts
first combine with the phosphates and later, as the lactic
acid is formed, they combine with the lactic acid, forming
a calcium lactate.
234. Gases. In the process of cheese ripening,
gases are formed, the commonest being carbon dioxide. 2
Exactly how this gas is formed is not known. It may be
due to the formation of lactic acid from the milk-sugar
or to the living organisms in the cheese.
235. Casein or proteins. Complex ripening changes
in the cheese take place in the casein compounds or pro-
teins. Because of the complex chemical nature of the
proteins and the various agents acting on them, it is diffi-
cult to follow these changes. This has led to different
opinions regarding the ripening process. The various
compounds thought to be formed from the casein or pro-
teins are as follows : 3
1 Bosworth, A. W., and M. J. Prucha, Fermentation of citric
acid in milk, N. Y. (Geneva) Exp. Sta. Tech. Bui. 14, 1910.
Van Slyke, L. L., and A. W. Bosworth, Condition of casein
and salts in milk, N. Y. (Geneva) Exp. Sta. Tech. Bui. 39, 1914.
Van Slyke, L. L., and E. B. Hart, A study of some of the salts
formed by casein and paracasein with acids ; their relation to Amer-
ican Cheddar cheese, N. Y. (Geneva) Exp. Sta. Bui. 214, 1902.
Van Slyke, L. L., and E. B. Hart, Some of the relations of
casein and paracasein to bases and acids and their application
to Cheddar cheese, N. Y. (Geneva) Exp. Sta. Bui. 261, 1905.
Van Slyke, L. L., and O. B. Winter, Cheese ripening investi-
gations, N. Y. (Geneva) Exp. Sta. Tech. Bui. 33, 1914.
2 Van Slyke, L. L., and E. B. Hart, The relation of carbon
dioxide to proteolysis in the ripening of Cheddar cheese, N. Y.
(Geneva) Exp. Sta. Bui. 231, 1903.
3 Van Slyke, L. L., and E. B. Hart, Some of the compounds
present in American Cheddar cheese, N. Y. (Geneva) Exp.
Sta. Bui. 219, 1902.
250 THE BOOK 'OF CHEESE
Paracasein (formed by the action of the rennet on the
casein). Insoluble in brine and warm 5 per cent salt brine.
Protein. Soluble in warm 5 per cent salt brine.
Protein. Insoluble in warm salt brine or water.
Paranuclein. A protein soluble in water and precipi-
table by dilute hydrochloric acid.
Caseoses and proteases. Protein derivations soluble in
water and not coagulated by heat.
Peptones. Protein derivations simpler than the pro-
teoses, soluble in water and not coagulated by heat.
Amido acids. Protein derivations soluble in water,
least complex except ammonia.
Ammonia. The simplest protein derivations.
From the discussion of the constituents in the milk
and cheese, it is evident that practically all the prin-
cipal ripening changes are concerned with those taking
place in the proteins.
236. Causes of ripening changes. Authorities dis-
agree as to the exact agents which cause the ripening
changes. Some think they are due to the action of the
enzymes in the rennet and those secreted in the milk.
Others hold that these changes are due entirely to
bacterial action. A combination of the two seems prob-
able. The action of the rennet extract renders the
casein insoluble and in the ripening process the pro-
teins become soluble, the degree depending on the length
of time the cheese is ripened. The amount of water-
soluble proteins and protein derivatives is used as a meas-
ure of the extent of cheese ripening, considered from a
chemical standpoint.
237. Action of the rennet extract. Some authorities
hold that rennet extract contains two enzymes, rennin
and pepsin, while others think it is a single peptic fer-
CHEDDAR CHEESE RIPENING 251
ment. These enzymes produce effects 1 closely related to,
if not identical with, those of pepsin in the following par-
ticulars : neither the rennet enzyme nor pepsin causes
much, if any, proteolytic change except in the presence
of acid; the quantitative results of proteolysis furnished
by the rennet enzyme and pepsin agree closely, when
working on the same material under comparable condi-
tions ; the classes of soluble nitrogen compounds formed
by the two enzymes are the same, both quantitatively and
qualitatively; neither enzyme forms any considerable
amount of amido compounds and neither produces any
ammonia; the soluble nitrogen compounds formed by
both enzymes are confined to the group of compounds
known as paranuclein, caseoses and peptones.
Rennet exerts a digestive effect on the casein 2 which is
intensified by the development of acid in the curd. The
soluble nitrogenous products formed in Cheddar cheese
by the rennet enzymes are the albumoses and the higher
peptones. Experiments show that no flavor develops
until the amido acids and ammonia are formed. When
the rennet enzymes were the only digesting ferments in
the cheese, there was no trace of cheese flavor. This is
probably due to the fact that the rennet enzyme changed
the casein into caseoses and peptones but did not form
amido acids and ammonia. Some authorities 3 think
1 Van Slyke, L. L., et al., Action of rennin or casein, N. Y.
(Geneva) Exp. Sta. Tech. Bui. 31, 1913.
Van Slyke, L. L., et al., Cheese ripening investigations ; rennet
enzyme as a factor in cheese ripening, N. Y. (Geneva) Exp.
Sta. Bui. 233, 1903.
2 Bosworth, A. W., Studies relating to the chemistry of milk
and casein, N. Y. (Geneva) Exp. Sta. Tech. Bui. 37, 1914.
3 Wis. Exp. Sta. Kept. 1898, Distribution of galactase in
milk from different sources, pages 87-97.
Wis. Exp. Sta. Kept. 1903, pages 195-197, 201-205, 222-223,
Action of proteolytic ferments on milk.
252
THE BOOK OF CHEESE
that the enzyme galactase carries the ripening of the
protein from this stage. The question arises whether
these intermediate compounds must be found before other
agents can form the amido acids and ammonia.
TABLE XV 1
SHOWING THE EFFECT OF DIFFERENT AMOUNTS OF RENNET
EXTRACTS ON THE RATE OF FORMATION OF SOLUBLE
NITROGEN COMPOUNDS IN CHEESE RIPENING
QUANTITY OP
RENNET ADDED PER
1000 LB. OP MILK
PER CENT OP WATER SOLUBLE NITROGEN COMPOUNDS IN
THE CHEESE
Initial
32 days
80 days
270 days
2 oz.
0.14
0.47
0.68
1.30
4 oz.
0.16
0.75
1.13
1.74
8 oz.
0.16
0.90
1.50
1.97
16 oz.
0.14
1.26
1.70
2.04
The above table shows that the more rennet extract
used the faster the cheese cures, measured by the
amount of water-soluble nitrogen compounds formed in
the cheese.
238. The action of the bacteria. Authorities 2 dis-
agree as to the groups of bacteria found in Cheddar
cheese. This may be due to lack of proper classification.
Some of the groups are : Bacterium lactis acidi, B.
coli communis, B. lactis aerogenes, B. casei, Streptococci,
B? Bulgaricum and Micrococci. Authorities agree that
the B. lactis acidi group is the most prominent. This
group makes up 90 per cent or more of the total bacteria
1 Wis. Exp. Sta. Rept. 1900, pages 102-122.
2 Harding, H. A., and M. J. Prucha, The bacterial flora of
Cheddar cheese, N. Y. (Geneva) Exp. Sta. Tech. Bui. 8.
3 Bacterium, Bacillus and Lactobacillus are preferred by dif-
ferent authors as generic placing of the Bulgarian sour milk species.
CHEDDAR CHEESE RIPENING
253
flora of the cheese in the early stages of ripening. In the
course of a few weeks, however, this group is largely
replaced by the #. casei group. 1
TABLE XVI
SHOWING THE NUMBER OP BACTERIA TO A GRAM IN CHEDDAR
CHEESE AS DETERMINED BY LACTOSE-AGAR PLATE CUL-
TURES
TIME OP
PLATING
CHEESE NUMBER
580
581
582
683
Milk . .
8,000,000
500,000
700,000
500,000
Curd at
salting
time .
160,000,000
326,000,000
912,000,000
839,000,000
12 hours
332,000,000
1,048,000,000
623,000,000
965,000,000
1 day
586,000,000
736,000,000
709,000,000
. 569,000,000
2 days .
235,000,000
405,000,000
848,000,000
580,000,000
4 days .
145,000,000
684,000,000
522,000,000
1,025,000,000
6 days .
165,000,000
184,000,000
853,000,000
184,000,000
14 days .
51,000,000
211,000,000
369,000,000
401,000,000
21 days .
284,000,000
290,000,000
348,000,000
319,000,000
28 days .
285,000,000
453,000,000
314,000,000
144,000,000
35 days .
104,000,000
261,000,000
326,000,000
504,000,000
49 days .
132,000,000
228,000,000
436,000,000
661,000,000
70 days .
128,000,000
291,000,000
193,000,000
168,000,000
98 days .
114,000,000
212,000,000
45,000,000
55,000,000
From Wis. Bui. 150.
1 Hastings, E. G., Alice C. Evans and E. B. Hart, The bac-
teriology of Cheddar cheese, Wis. Exp. Sta. Bui. 150, pages 1-52,
1912.
254 THE BOOK OF CHEESE
The large number of bacteria in the cheese is very
striking. The number as given in the accompanying table
is not that actually in the cheese, as it is very difficult to
obtain the sample in suitable condition for plating. 1
The principal action of the lactic acid-forming bacteria
in the cheese ripening is the changing of the milk-sugar
or lactose into lactic acid and the formation of small
amounts of other substances, such as acetic, succinic
and formic acids, alcohol, aldehydes and esters and some
gases, carbon dioxide and hydrogen. While the amount
of these substances other than lactic acid is small, it is
thought that the effect of these on the cheese may be im-
portant. Heinemann shows 2 that lactic acid exists in
two optical modifications, the levorotatory and dextroro-
tary acids. In cheese they are usually found in the inac-
tive or racemic form, the levorotatory and dextrorotary
acids being present in equal amounts. What impor-
tance the question of optical activity of the lactic acid
may assume is not definitely known. Just as some groups
of bacteria have a specific effect on the lactose, producing
only one modification of lactic acid, so bacteria attacking
lactic acid may exercise a selective action and use only
one or the other optically active modification. In other
words, the early flora of cheese-ripening bacteria may
determine the later flora by the production of a form of
lactic acid attacked by one group of bacteria and not by
another, and the effect on the flavor will differ accordingly.
The amount of lactic acid in the cheese increases for a
time, then decreases.
1 Harding, H. A., The r61e of the lactic acid bacteria in the
manufacture and in the early stages of ripening of Cheddar
cheese, N. Y. (Geneva) Exp. Sta. Bui. 237, 1903.
2 Heinemann, P. G., The kinds of lactic acid produced by
lactic acid bacteria, Jour. Biol. Chem., Vol. 2, pages 603-608.
CHEDDAR CHEESE RIPENING 255
The errors in determining lactic acid are considerable.
It seems that the tendency is toward an increase of lactic
acid in the cheese long after the lactose has disappeared.
Two explanations are offered : one, that in the lactic acid
fermentation an intermediate compound or compounds are
formed which exist for some time, the conversion into
lactic acid being complete at about three months; the
other is that lactic acid is formed as a product of para-
casein proteolysis.
The lactic acid formed in cheese ripening does not
exist in a free state but reacts with the calcium salts
in the cheese and forms calcium lactates. It is thought
that there is sufficient of these salts to neutralize all the
acid formed, and therefore the acid does not enter into
combination with the paracasein salts. It has been
found that lactates are the principal source of acetic and
propionic acids. These are supposed to have some effect
on the flavor of the cheese.
The effect of lactic acid as a determinant of bacterial
and enzymic changes is very important. Early in the
ripening process, lactic acid suppresses the growth of un-
desirable micro-organisms. It also furnishes the acid
medium necessary for the best action of both the coagulat-
ing and peptic enzymes.
The importance of the lactic acid bacteria in cheese
ripening has been summed up by Hastings 1 as follows :
" The functions of this group of bacteria in Cheddar cheese
are through their by-product lactic acid as follows : (a)
To favor the curdling of milk by rennet, (b) The bacteria
of the milk are held in great part in the curd. Through
the acid they influence the shrinkage of the curd and
1 Hastings, E. G., et aL, The bacteriology of Cheddar cheese,
U. S. Dept. Agr. Bur. An. Ind. Bui. 150, 1912.
256 THE BOOK OF CHEESE
expulsion of the whey, (c) The acid so changes the nature
of the curd as to cause ' matting/ or ' cheddaring '
of the curd, (d) The acid activates the pepsin of the
rennet extract, (e) The acid prevents the growth of
putrefactive bacteria in the cheese. (/) It has been shown
that Bacterium lactis acidi is able to form acid in the ab-
sence of the living cell, (g) The development of Bacterium
lactis acidi is followed by the growth of another group of
acid-forming bacteria, the Bacillus Bulgaricus group.
They reach numbers comparable with those of the first
group, reaching their maximum number within the first
month of ripening. Since they develop after the fermenta-
tion of the milk-sugar, they must have some other source
of carbon and of energy than milk-sugar." It is also prob-
able that other groups constantly present contribute to
the changes.
From the preceding discussion it is evident that each
of the ripening agents has its important part to play in
the ripening process and a normal ripening of the cheese
is a composite result of these various agencies.
239. Conditions affecting the rate of cheese ripening.
-The rate at which these agents cause ripening of the
cheese depends on several factors. 1 Most of these factors
are within the control of man. They are as follows : the
length of time ; temperature of the curing-room ; moisture-
content of the cheese ; size of the cheese ; the quantity of
salt used ; the amount of rennet ; the influence of acid.
240. The length of time. The water-soluble nitro-
gen compounds increase as the cheese ages, other
conditions being uniform. The rate of increase is not
1 Van Slyke, L. L., and E. B. Hart, Conditions affecting
chemical changes in cheese ripening, N. Y. (Geneva) Exp. Sta.
Bui. 236, 1903.
CHEDDAR CHEESE RIPENING 257
uniform; it is much more rapid in the early than in
the succeeding stages of ripening.
241. The temperature of the curing-room. Very few
cheese factories have made any provision for regulat-
ing the temperature of the curing-room. Without such
provision the temperature follows closely that of the out-
side air. In some cases the curing-room is located over
the boiler-room and hence becomes very hot. In the
cheese warehouses, provision has been made to control
the temperature very closely. Experiments show that
the soluble nitrogen compounds increase, on the average,
closely in proportion to an increase of temperature, when
the other conditions are uniform.
The temperature of the curing-room has a material
effect on the quality of the cheese. Cheese made from the
same day's milk, and part cured at 40 F., part at 50 F.,
part at 60 F. show considerable differences, the great-
est seeming to be in the flavor and texture. Those kept
at the low temperature cure more slowly and develop a
milder flavor, those at the higher temperature cure faster
and develop undesirable flavors. At the higher tempera-
ture the undesirable organisms seem to be more active.
Some very skillful makers and judges of cheese have
always contended that if Cheddar is properly made,
firmed to the body and texture of a high-class cheese, ripen-
ing at 55 to 60 F. gives a higher quality. Such a cheese
must be low in moisture, perhaps 3 to 5 per cent lower
than one cured successfully by the cold process.
The following tables 1 XVII, XVIII show the effect
of different temperatures of curing cheese on the total
score and on the points of the flavor, body and texture :
1 Van Slyke, L. L., et al., Cheese ripening at low tempera-
tures, N. Y. (Geneva) Exp. Sta. Bui. 234, 1903.
258
THE BOOK OF CHEESE
TABLE XVII
TABLE SHOWING THE RELATION OF TEMPERATURE OF CURING
TO TOTAL SCORE
TEMPERATURE OF CURING
TOTAL SCORE
40
50
60
95.7
94.2
91.7
TABLE XVIII
TABLE SHOWING THE RELATION OF TEMPERATURE OF CURING
TO SCORE OF BODY AND TEXTURE, AND FLAVOR
TEMPERATURE OP CURING
40 F.
50 F.
60 F.
Body and texture . . .
Flavor
23.4
47 4
32.0
464
22.2
44 8
Of the three temperatures of curing, the lowest gave
a higher total score and a higher score for flavor, body
and texture.
The curing temperature should not go low enough to
freeze the cheese, as this lowers the quality. The cheese
will cure very slowly and have a mealy texture.
242. Moisture-content of the cheese. Other condi-
tions being equal, there is a larger amount of water-
soluble nitrogen compounds in cheese containing more
moisture than in that containing less moisture. There-
fore, a high moisture-content of the cheese causes it to
cure faster. The presence of moisture also serves to
dilute the fermentation products which otherwise would
accumulate and thus check the action of the ripening
agents.
CHEDDAR CHEESE RIPENING 259
243. The size of the cheese. Cheeses of large size
usually cure faster than smaller ones, under the same
conditions. This is due to the fact that the large cheeses
lose their moisture less rapidly by evaporation and there-
fore after the early period of ripening have a higher water-
content.
244. The amount of salt. The relation of salt
to the rate of ripening is more or less directly associated
with the moisture-content of the cheese, since an in-
crease in the amount of salt decreases the moisture.
Thus, cheese containing more salt forms water-soluble
nitrogen compounds more slowly than that containing
less salt. The salt also has a direct effect in retarding
one or more of the ripening agents.
245. The amount of rennet extract. The use of in-
creased amounts of rennet extract in cheese-making,
other conditions being uniform, results in the production
of increased quantities of soluble nitrogen compounds
in a given period of time, especially such compounds as
paranuclein, caseoses and peptones.
246. The influence of acid. It is necessary that
acid be present but the exact relation of varying quanti-
ties of acid to the chemical changes of the ripening pro-
cess is not fully known. If too much acid is present, it
imparts a sour taste to the cheese. It also causes the
texture of the cheese to be mealy or sandy instead of
smooth and waxy.
Conditions that may increase the rate of ripening :
1. Increase of temperature.
2. Larger amounts of rennet.
3. More moisture in the cheese.
4. Less salt.
260 THE BOOK OF CHEESE
5. Large size of the cheese.
6. Moderate amount of acid.
Conditions that may retard ripening :
1. Decrease of temperature.
2. Smaller amounts of rennet.
3. Less moisture in the cheese.
4. More salt.
5. Small size of the cheese.
6. No acid or an excess of acid.
247. Care of the cheese in the curing-room. The
cheeses need daily attention while in the curing-room
(Fig. 53). They should be turned every day to prevent
sticking and molding to the shelf and to secure an even
evaporation of moisture. If not turned, the moisture
will not evaporate evenly from all surfaces and will result
in an uneven distribution in the cheese, which causes
uneven curing, and usually gives the product an uneven
color.
The surface of the cheese should be watched to see that
the cloths stick. If they do not, the surface will crack,
due to the evaporation of the moisture. If the cloths
are loosened, they should be removed and the surface
of the cheese greased with butter. The grease will tend
to prevent the rind from cracking. If the surface of the
cheese is not smooth, due to wrinkles in the bandage,
or if it cracks, due to the lack of cloths, it furnishes the
opportunity for insects to lay their eggs and the larvae
to develop within the cheese. Molds also lodge and
grow in such cracks.
The cheese should be kept clean while in the curing-
room. This means that the hands of the person handling
the cheese must be clean. The shelves should be washed
CHEDDAR CHEESE RIPENING
261
262 THE BOOK OF CHEESE
with good cleaning solution and scalded with hot water
whenever they become greasy or moldy.
Some means should be provided for regulating the
temperature and humidity of the curing-room. In most
factories this is accomplished by opening the doors and
windows at night to admit the cool air and closing
them in the morning to keep out the hot air. Care
should be taken to keep the doors and windows closely
secured. The windows should have shades to keep out
the sun. If the room becomes too dry, the floor may be
dampened with cold water.
The length of time in the curing-room depends on how
often shipment is made to some central warehouse or to
the market. This usually varies from two to six weeks.
When the surface of the cheese becomes dry and the
rind is well formed, the cheese may be paraffined. It
usually requires four to six days after cheeses are taken
from the hoop before they are ready for this process.
The object of paraffining is to prevent the escape of mois-
ture and to keep the cheese from molding.
248. Evaporation of moisture from the cheese during
ripening. The losses due to evaporation while the
cheeses are curing are a considerable item. The rate of
evaporation depends on the temperature and humidity
of the curing-room, the size of the cheese, the moisture-
content and protection to the surface.
Table XIX 1 shows the effect of size of cheese and
temperature of the curing-room, on losses while curing.
This table shows that the evaporation of moisture is
more as the size of the cheese decreases and the tempera-
ture is increased. This is probably due to the fact that
1 Van Slyke, L. L M et al., Cheese ripening at low temperatures,
N. Y. (Geneva) Exp. Sta." Bui. 234, 1903.
CHEDDAR CHEESE RIPENING
263
the smaller cheese has more surface to a pound than a
large cheese. The evaporation increases with tempera-
ture, probably because of lowered relative humidity. The
humidity can be tested with an hygrometer.
TABLE XIX
SHOWING THE VARIATION OF LOSSES IN WEIGHT OF CHEDDAR
CHEESE WHILE CURING, DUE TO SIZE OF CHEESE AND TEM-
PERATURE OF CURING-ROOM
WEIGHT OF CHEESE
IN POUNDS
WEIGHT LOST PER 100 POUNDS OF CHEESE IN 20
WEEKS AT
40 F.
50 F.
60 F.
70
2.5
2.4
4.2
45
2.7
3.7
5.1
35
3.9
5.9
8.5
m
4.6
8.1
12.0
The higher the moisture-content of the cheese, usually
the more rapid is the evaporation. This is due to several
causes : there is more moisture to evaporate ; the mois-
ture is not so well incorporated ; a moist cheese does not
form so good a rind.
249. Paraffining 1 consists of dipping the cheese in
melted paraffin at a temperature of about 220 F. for
six seconds. Fig. 54 shows an apparatus for paraffining.
This leaves a very thin coat of paraffin on the cheese ;
at a lower temperature, a thicker coat would be left.
The thicker coating is more liable to crack and peel off.
If the cheese is not perfectly dry before it is treated,
the paraffin will blister and crack off.
1 Doane, C. F., Methods and results of paraffining cheese,
U. S. Dept. Agr. Bur. An. Ind. Circ. 181, pages 1-16, 1911.
264
THE BOOK OF CHEESE
Before a cheese is paraffined, the press cloth is removed
and also the starched circles, if loose. After a cheese has
been paraffined, if the coating is not broken, the loss
due to evaporation is greatly reduced. The amount
of paraffin to coat a 35-pound cheese will depend on the
temperature of the paraffin and the length of time the cheese
is immersed. Usually at 220 F. it requires about 0.15
^^^-A of a pound for each 35-pound
f^** cheese. After the cheeses have
been paraffined, they may be
left on the curing-room shelves
or boxed ready to ship.
250. Shipping. When ready
to ship, each cheese should be
carefully and accurately
weighed and boxed. Usually
these cheeses are boxed after
being paraffined. If press
cloths are left on the cheese in
the curing-room, they should
be removed just before weigh-
ing. These cloths should not
be left in a pile in the factory
after being removed as they
have been known to heat and sometimes cause fires.
They should be washed clean and dried ready for use
again. If starched circles are used, they should be left
on the cheese. A scale board should be placed on each
end of the cheese to prevent its sticking to the box and
also to keep the box from wearing the surface of the cheese.
The box should be a trifle larger in diameter than the
cheese so that the latter can be easily placed in it. The
sides of the box should be the same height as the cheese.
FIG. 54. A paraffiner for
cheese.
CHEDDAR CHEESE RIPENING 265
The weight of each cheese should be neatly and accu-
rately marked on each box. Care should be exercised to
keep the boxes clean.
DEFECTS IN CHEDDAR CHEESE
A great number of defects may occur in Cheddar
cheese. Certain of these are due to known causes and
proper remedies are definable, while neither cause nor
remedy has been found for other defects. Some of the
common defects and their causes and remedies are
discussed under different headings of the score-card as :
defects in flavor, their causes and remedies; defects in
body and texture, their causes and remedies; defects in
color, their causes and remedies; defects in finish and
their causes and remedies.
251. Defects in flavor. Any flavor differing from the
characteristic Cheddar cheese is a defect. Certain of
these defective flavors can be recognized and causes
and remedies given for them, while others may be distin-
guished as such but no cause or remedy can be given.
252. Feedy flavors. Flavors may be characteristic
of certain feeding stuffs. Feeding strong-flavored foods,
such as turnips, cabbage, decayed silage, certain weeds
and sometimes rank green feed, give their peculiar flavors
to both milk and cheese. Freshly drawn milk usually
absorbs these odors from the air in barns filled with such
foods. Certain of these materials may be fed just after
milking in moderate amounts without affecting the milk
drawn at the next milking. Others should not be used.
Milk should not be exposed to strong volatile odors.
Some of the objectionable odors may be removed by
airing the curd for a longer time after milling before
the salt is applied.
266 THE BOOK OF CHEESE
253. Acid flavors. A cheese with an acid flavor has
a pronounced sour smell and taste. This is caused by
the over-development of acid which may be due to any
of the following causes : (a) receiving milk at the factory
which is sour or has too high development of acid; (6)
using too much starter; (c) ripening the milk too much
before adding rennet ; (d) not firming the curd sufficiently
in the whey before removing the latter; (e) developing
too much acid in the whey before it is removed ; (/) re-
taining too much moisture in the curd.
The trouble can be reduced or eliminated by one
or more of the following precautions : (a) receiving
only clean, sweet milk at the cheese factory; (6) main-
taining the proper relation between the moisture and
acidity; (c) adding the rennet at the proper acidity;
(d) using less starter; (e) adding the rennet extract so
that there will be sufficient time to firm the curd before
the acid has developed to such a stage that it will be
necessary to draw the whey; (/) producing the proper
final water-content in the newly made cheese.
254. Sweet or fruity flavors. These are the sweet
flavors characteristic of strawberry, raspberry and the
like. Such flavors are very objectionable and usually
increase with the age of the cheese. They appear to
be caused by : (a) carrying both milk and whey in the
same cans without properly cleaning them ; (b) expos-
ing milk near hog-pens where whey is fed; (c) dirty
whey tanks at the cheese factory; (d) micro-organisms
which get into the milk through any unclean conditions.
These troubles can be controlled : (a) if milk and whey
must be carried in the same cans, the cans should be
emptied immediately on arrival at the farm and thor-
oughly washed and scalded; (6) the whey vat at the
CHEDDAR CHEESE RIPENING 267
factory should be kept clean and sweet; (c) the starter
must have the proper clean flavor.
Other defects may be classed as " off flavors," " dirty
flavors," " bitter flavors " and the like. These are un-
doubtedly due to unsanitary conditions whereby undesir-
able organisms get into the milk, even though the particular
organism is often not determined. The flavors may be
improved by the use, of a clean-flavored commercial starter
and by airing the curd after milling before salting. The
best remedy is to remove the source of the difficulty.
255. Defects in body and texture. The body and
texture should be close. A sample rubbed between the
thumb and fingers should be smooth and waxy. Any
condition which causes a body and texture other than this
is to be avoided.
256. Loose or open texture. A cheese with this
defect is full of irregularly shaped holes and usually soft or
weak-bodied. This is serious if the cheese is to be held
for some time. Moisture and fat are likely to collect in
these holes and cause the cheese to deteriorate, thereby
shortening its commercial life.
Several causes may bring about this condition : (a)
insufficient cheddaring ; (b) pressing at too high a temper-
ature; (c) inadequate pressing; (d) development of too
little acid.
The corresponding remedies are : (a) cheddar the curd
until the holes are closed and the curd is solid ; (6) cool
the curd to 80 F. before putting to press ; (c) press the
curd longer, possibly twenty-four to twenty-six hours;
(d) develop a little higher acid in the whey before re-
moving the curd.
257. Dry body. A cheese with this defect is usually
firm, hard and dry, sometimes rubbery or corky. This
268 THE BOOK OF CHEESE
may result from lack of moisture, fat or both, and may be
due to the following causes : (a) making the cheese from
partly skimmed-milk ; (6) heating the curd in the whey
for too long a time; (c) heating the curd too high; (d)
stirring the curd too much in the whey or as the last of
the whey is removed ; (e) using too much salt ; (/) develop-
ing of too much acid in the whey ; (g) curing the cheese
in too hot or too dry a curing-room; (h) not piling the
curd high or fast enough in the cheddaring process.
The cause should be located and the corresponding
remedy found, as follows: (a) make cheese only from
whole milk ; (6) draw the whey sooner ; (c) firm the curd
at as low temperature as possible in the whey ; (d) stir
the curd in the whey only enough to keep the curd par-
ticles separated but do not hand-stir it ; (e) use less salt ;
(/) develop less acid in the whey ; (g) cure the cheese in
a cool moist curing-room ; (h) pile the curd sooner and
higher during the cheddaring process.
. The number of causes which may singly or in combina-
tion produce dry cheese demands experience and technical
skill that calls for the development of a high degree of
judgment.
258. Gassy textured cheese. Gassy cheese has large
numbers of very small round or slightly flattened holes.
When round these are called " pin-holes," and when
slightly flattened " fish eye " openings. These are due
to the formation of gas by the micro-organisms in the
cheese. When a cheese is gassy, it usually puffs up
from gas pressure as in the rising of bread. If enough
gas is formed, it will cause the cheese to break or crack
open. Instead of being flat on the ends, such a cheese
becomes so nearly spherical as to roll from the shelf
at times.
CHEDDAR CHEESE RIPENING 269
The gas-producing organisms enter because of unclean
conditions somewhere in the handling of the milk and
the making of the cheese. Some of the common sources
of gas organisms are: (a) unclean milkers; (6) dirty
cows ; (c) aerating the milk in impure air, especially air
from hog-pens where the whey is fed ; (d) allowing the
cows to wade in stagnant water or in mud or in filthy'
barnyards and then not thoroughly cleaning the cows
before milking; (e) exposing the milk to the dust from
hay and feed ; (/) dirty whey tanks ; (g) drawing milk
and whey in the same cans without afterward thoroughly
washing them; (h) unclean utensils in the factory;
(i) using gassy starter; (j) ripening cheese at high
temperatures.
Some of these causes are within the control of the
cheese-maker after the making process is begun. Many
of them are avoided only by eternal vigilance. Among
the recommendations for meeting gassy curd are the
following : use only milk produced under clean sanitary
conditions ; use a clean commercial starter.
If gas is suspected in the milk, a larger percentage
of commercial starter should be used. More acid must
be developed before the whey is removed. If the gas
shows while cheddaring, the curd should be piled and
repiled until the holes flatten out before milling.
The curd should be kept warm during the piling or
cheddaring process. This may be accomplished by cover-
ing the vat and setting a pail or two of hot water in it.
After milling, the curd should be stirred and aired for a
considerable length of time before salting. This will
aerate the curd and allow it to cool. The cheese should
then be placed in a cool curing-room. (See handling of
gassy milk.)
270 THE BOOK OF CHEESE
259. Acidy, pasty or soft body and texture. A
cheese with acidy body may be either hard and dry
or soft and moist. It has a mealy or sandy feeling
when rubbed between the fingers. The causes and
remedies are the same as for cheeses with acid flavors.
When rubbed between the fingers, it is pasty and sticks
to the fingers. It is caused by the cheese containing
too much water. (See control of moisture.)
260. Defects in color. Any color which is not uni-
form is a defect. The proper color depends on the market
requirement. Some markets prefer a white and others
a yellow cheese ; however, if the color is uniform, it is
not defective.
Mottled color is a spotted or variegated marking of the
cheese. Several causes may give the same general effect :
(a) uneven distribution of moisture, the curd having extra
moisture being lighter in color; (6) neglecting to strain
the starter ; (c) adding the starter after the cheese color
has been added ; (d) mixing the curd from different vats.
Remedies for this mottled color are : (a) to maintain a
uniform assimilation of moisture (see discussion of mois-
ture) ; (6) to strain the starter to break up the lumps be-
fore adding to the milk ; (c) to add all of the starter be-
fore adding the cheese color ; (d) not to mix curds from
different vats.
Seamy color. In " seamy " colored cheese, the out-
line of each piece of curd may be seen. There is usually
a line where the surfaces of the curd come together. It
may be caused by the pieces of curd becoming greasy
or so cold that they will not cement. This may be
remedied by having the curd at a temperature of 80
to 85 F. when put to press. If it is greasy, this may
be removed by washing the curd in cold water.
CHEDDAR CHEESE RIPENING 271
Acid color. This is a bleached or faded color and is
caused by the development of too much acid. (See acid
flavor for causes and remedies, page 266.)
261. Defects in finish. Defects of this class differ
from those previously mentioned in being entirely
within the control of the cheese-maker. All are due to
carelessness or lack of skill in manipulation. Anything
which detracts from the neat, clean, workmanlike appear-
ance of the cheese is a defect that may interfere with the
sale of an article intrinsically good. Some of the common
defects are : (a) unclean surfaces or dirty cheese ; (b) cracked
rinds ; (c) moldy surfaces ; (d) uneven sizes ; (e) cracked
cheese; (/) wrinkled bandages; (g) uneven edges.
CHEDDAR CHEESE JUDGING
Judging of cheese is the comparison of the qualities of
one product with those of another. To make this easier
it is customary to reduce the qualities of the cheese to a
numerical basis. This is accomplished by the use of a
score-card, which recognizes certain qualities and gives
to each a numerical value. Each of these score-cards
gives a perfect cheese a numerical score of 100. Two
score-cards are used to judge cheese, one for export and
the other for home-trade product. The latter is more
commonly used.
EXPORT SCORE-CARD HOME-TRADE SCORE-CARD
Flavor 45 Flavor 50
Body and texture . . 30 Body and texture ... 25
Color 15 Color 15
Finish 10 Finish 10
Total 100 Total 100
The same qualities are recognized in each score-card,
but different numerical values are given them.
272 THE BOOK OF CHEESE
262. Securing the sample. The sample of cheese to
be examined is best obtained by means of a cheese-trier
(Fig. 55). This is a piece of steel about five or six inches
long fitted with a suitable handle. It is semicircular
in shape, about J to f of an inch in diameter. The
edges and end
are sharpened
to aid in cut-
ting. This is
FIG. 55. - A cheese-trier. inserted into
the cheese and turned around and then drawn out. It
removes a long cylinder of cheese, commonly called
a " plug." This plug should be drawn from the top
rather than from the side of the cheese, because when
the bandage is cut it often splits, due to the pressure
against it and so exposes the cheese.
263. How to determine quality. As soon as the plug
has been removed, it should be passed quickly under
the nose to detect any volatile odors which are liable
to leave the cheese quickly. Next, the compactness of
the plug should be noticed and the color carefully ex-
amined. Then the outer end of the plug should be
broken off and placed back in the cheese in the hole
made by the trier. It should be about an inch long and
pushed in so that the surface of the cheese is smooth.
This prevents mold and insects entering the cheese.
Usually the cheese will mold after a short time where
the plug has been removed. The remainder of the plug
should be saved for determining the flavor and the body
and texture.
The flavor can be determined by the first odor obtained
from the cheese on the trier and by mixing or crushing a
piece of the plug between the thumb and fore-finger and
CHEDDAR CHEESE RIPENING 273
then noting the odor. Mixing and thoroughly warming
causes the odor to be much more pronounced. The
cheese should seldom be tasted to determine the flavor,
for when many are to be judged, they all taste alike
after the first five or six. This is probably due to the
cheese adhering to the teeth, tongue and other parts of
the mouth, making it difficult to cleanse the mouth
sufficiently. The body and texture can be determined
by the appearance and the feeling of the cheese when
rubbed between the thumb and fingers. The body
and texture are distinct, yet they are more or less inter-
changed. The body refers to the cheese as a whole and
the texture to the arrangement of the parts of the whole.
The openness of texture or the holes can be noted when
the plug is first removed. The firmness of body and
smoothness of texture can be determined when the
cheese is rubbed between the thumb and fingers. The
color can be judged when the plug is first removed.
The finish or appearance may be noted either before
or after the other qualities by carefully examining the
cheese.
Cheddar cheese should have a neat, clean, attractive
appearance; when cut it should show a close, solid, uni-
formly colored interior. It should have ,a clear, pleasant,
mild aroma and a nutty flavor. It should possess a
mellow, silky, meaty texture and when rubbed between
the thumb and fore-finger should be smooth and free from
hard particles.
264. Causes of variations in score. It is very seldom,
if ever, that a cheese is given a perfect score, for it usually
has one or more defects which may be hardly noticeable
or very pronounced. The seriousness of the defect is de-
termined by the individual tastes of the judges and the
274
THE BOOK OF CHEESE
Sample...
CHEESE SCORE-CARD
Date....
SCORE
REMARKS
Flavor
50
Body and
Texture
25
Color
15
Finish
10
Total.. . .
100
Recommendations.
Name of Judge...
SUGGESTIVE TERMS
FLAVOR
Desirable
Clean Pleasant Aroma Nutty Flavor
Undesirable
Due to Farm Conditions
Weedy Feedy Cowy Old Milk Bitter
Due to Factory Conditions
Too much acid Too little acid
Due to either Farm or Factory Conditions
Yeasty Fruity Fishy Rancid
Sour Bitter Sweet Tainted
BODY AND TEXTURE
Desirable
Smooth Waxy Silky Close
Undesirable
Pasty Greasy Curdy Mealy Lumpy
Corky Loose Gassy Yeasty
Acidy Sweet Watery Too dry
COLOR
Desirable
Uniform
Undesirable
Streaked Mottled Acid cut
White specks Wavy Too high
Seamy Rust spots Too light
FINISH
Desirable
Clean surfaces Neat bandage Attractive
Undesirable
Wrinkled bandage Greasy
Unclean surfaces No end caps
Cracked rinds Uneven edges
Undesirable size
CHEDDAR CHEESE RIPENING 275
market requirements. It is customary for the judge to
pick out several samples and score them in order to
fix the standard and if there are several judges this serves
to unify their standard. Ordinarily judges will vary
because of their individual tastes, unless they begin with
a uniform standard.
Certain markets require cheese with given qualities
which on other markets would be considered defects.
For example, the Boston market requires a very soft,
pasty cheese which other markets would consider un-
desirable.
The cheese is constantly undergoing changes due to the
ripening agents so that it may not always be scored the
same. For example, a cheese may have little or no flavor
and after several weeks a very considerable flavor may
have developed. This is probably due to the action of
the ripening agents, and therefore the second time it
would be scored differently.
265. The score-card. When judging several samples
of cheese, the type of score-card on the opposite page is
used for each one.
This gives the date of judging and the sample number,
the judge's name and reasons for cutting the score and
recommendations to avoid these troubles.
CHAPTER XV
THE SWISS AND ITALIAN GROUPS
CERTAIN varieties of hard cheese of foreign origin are
now made to some extent in this country. If not
manufactured in sufficient quantities to supply the
demand, the remainder is imported. These hard cheeses
are now considered.
SWISS CHEESE
Swiss cheese, variously known as Gruyere, Emmenthal,
Schweitzer and Swiss, had its origin in the Alpine cantons
of Switzerland. From this region its manufacture has
been carried by Swiss dairy-men and emigrant farmers
into widely separate lands. The Swiss colonies settled
in the United States in the Mohawk Valley and in Catta-
raugus County, New York; in Wayne, Stark, Summit,
Columbiana and Tuscarawas counties of Ohio, and in
Green and Dodge counties in Wisconsin. Of all these,
the Wisconsin colonies have become the most extensive.
Similar colonies have developed the making of this type
of cheese in Sweden and Finland.
266. The Swiss factory. Swiss cheese cannot be
made in a vat like other types for reasons that will be
explained later. In place of the vat is used a kettle,
generally of copper, and it may or may not be jacketed
for steam or for hot water (Fig. 56). These kettles vary
in capacity from 600 to 3000 pounds of milk. The cheese-
276
THE SWISS AND ITALIAN GROUPS 277
maker takes the best care possible of his kettle, for an
unclean utensil is one of the easiest sources of contamina-
tion of the milk. When the kettle is not jacketed, and
it is only in recent years that this has been done, it is
suspended in a fireplace by
means of a crane arrange-
ment.
This fireplace uses wood,
and is built of brick or stone,
so that the kettle rests on the
edge and is provided with a
door which swings upon
another crane, and can be
closed while the fire is going.
When the kettle is swung on _
& FIG. 56. Swiss-cheese kettle.
a crane, it is possible to
swing it under the weigh-stand for filling. This requires
a lid to swing down over the fire, and keep the room
free from smoke. The chimney generally has a rather
high stack to secure a good draft. This kettle is
fastened to the crane by a large iron band passing around
the neck, to which a bail or handle is attached. The
kettle may be raised or lowered by means of a simple
screw on this beam. The crane consists of a heavy beam
working in sockets in the floor and a beam or cross brace,
which has another and shorter beam braced to it, to take
the weight of the kettle.
The weigh-stand, and its efficient location, is a matter
of extreme importance. It is elevated a little above
the remainder of the floor to allow gravity to do the
work. The next most important equipment is the
press and draining table. The table is made of wood or
stone, and has a slight slope to allow the whey to drain
278 THE BOOK OF CHEESE
off. The press is generally a jack screw which, braced
against a beam, will exert an enormous pressure on the
table below.
Swiss cheeses are made in two styles, the " round "
or drum and the "block" or rectangular forms, each of
which has its advantages. For the round style, which
is most commonly made, the forms for hooping are of
metal or of elm wood, and consist of strips of a given
width, generally six inches, but of an undetermined length.
These strips are then made into a circle and held by a
cord, which is easily lengthened or shortened, thus vary-
ing the diameter of the hoop.
Besides these hoops, cheese boards or followers are
needed. These are heavy circular boards, of a size to
fit that of the cheese generally made, and are banded with
iron around the edge and cross-braced on the bottom
for rigidity. The small tools of the factory consist of
knives to cut the curd, and of a " Swiss harp " or other
similar tool to stir the curd. Many clean bandages are
also needed, and a kettle brake.
267. The milk. Swiss cheese requires clean sweet
milk. Dirt, high acid and infections with undesirable
bacteria involve difficulties of manufacture and frequent
losses of cheese. One common practice rejects milk if
it shows acidity above 0.15 per cent. To secure milk
in this condition, factories are small and located so close
to the producing farms as to secure 1000 to 3000 pounds
of milk delivered warm from the cow twice a day. The
cheese is made twice daily from this fresh milk. If,
however, milk is properly cared for, it is possible to mix
night's and morning's milk without bad results. In fact,
in working experimentally with high grade milk and
taking precautions against loss of fat, it has been
THE SWISS AND ITALIAN GROUPS 279
necessary to skim (separate) part of the milk, thus re-
ducing the ratio of fat to casein. Analysis of good Swiss
cheeses shows that the desired texture is more uniformly
obtained with milk in which the fat is less than the normal
ratio. This assumes that the manufacturing loss is kept
down so that the fat removed offsets the extra loss from
curd-breaking.
268. Rennet extract. Most Swiss cheese-makers pre-
fer to make their own rennet extract from the stomach.
This results in a product which is not uniform in strength
and so requires good judgment to secure the desired coagu-
lation in the allotted time. Some cheese-makers roll
fifteen to twenty well salted calves' stomachs together
and dry them. From this they cut off a definite amount
each day to be soaked for twenty-four hours in two to
five quarts of whey at 86 F. Four quarts of this
solution added to 2000 pounds of milk at 90 F. should
produce a curd ready for cutting in twenty to thirty
minutes.
269. Starter. Makers do not agree as to the use of
" starters " for Swiss cheese. Those opposed to such
use say that a starter will give the cheese a decided
Cheddar flavor, while those in favor of it state that it
will control undesirable fermentations, and that, with
the use of a starter, it is possible to make Swiss cheese
throughout the year, and have uniform success.
Doane, 1 working with Bacillus Bulgarians as a starter,
found that these starters did not always overcome the
undesirable fermentations. If a cheese-maker is having
difficulty to develop the holes or " eyes," this may be
1 Doane, C. F., and E. E. Eldredge, The use of Bacillus Bul-
garicus in starters for making Swiss or Emmenthal cheese, Dept
of Agr. Bur. An. Ind. Bui. 148, 1915.
280 THE BOOK OF CHEESE
overcome by making a starter 1 as follows from good
cheese and whey or milk : Select a cheese which has the
desirable " eyes " or holes and a good flavor. . Grind up
some of this and add about J of a pound to one gallon of
milk or whey. Hold this for twenty-four hours at a warm
temperature (85 to 90 F.). Strain it into the vat of
milk just before the rennet is added.
270. The making process. The milk is delivered
twice a day without cooling. It usually reaches the
factory at a temperature of 92 to 96 F. It is strained
into the kettle, and starter and rennet added at the same
temperature as received. (For method of adding rennet,
see Chapter V.) Enough rennet should be used to give
a coagulation ready for cutting in twenty to thirty minutes.
The firmness of the curd is tested by inserting the index
finger in an oblique position, then raising it slightly and
with the thumb of the same hand starting the curd to
break or crack. When the curd is coagulated ready for
cutting, it will give a clear break over the finger.
It is important to keep the temperature uniform while
coagulation is in process, and this is best accomplished
by the use of a little pan arrangement which fits into
the top of the kettle. When this is full of water at 100
F., the temperature of the air above the milk will be about
90 F. When the curd is ready for cutting, a scoop
may be used and the top layer carefully turned under to
equalize the temperature more closely.
Cutting the curd. In some cheese factories, knives
resembling Cheddar cheese knives are employed to cut
the curd. In other factories, a " Swiss harp " is used
to break the curd. The curd is usually cut or broken
1 N. Y. Produce Rev. and Am. Creamery, Vol. 37, no. 25,
page 1112, Starter for Swiss cheese.
THE SWISS AND ITALIAN GROUPS 281
into pieces about the size of kernels of corn. The
practice of " breaking " curd instead of cutting it with
sharp curd-knives produces excessive loss at times.
Experimental study has shown that the loss of fat
may be kept as low as 0.3 per cent if modern curd-
knives are substituted for the breaking tool formerly
used. Study of Swiss cheeses of all grades supports
the opinion that the removal of a small part of fat
from usual grades of factory milk produces a better
quality of product than the use of rich whole milk. This
may be accomplished through the escape of fat in the whey
on account of breaking the curd and stirring it vigorously,
or by skimming a part of the milk which is then curdled,
cut and stirred under such conditions as to minimize
the loss of fat.
Cooking the curd. After cutting, the curd is stirred
in the whey for about twenty minutes before the steam
is turned on and is then heated to 128 to 135 F. While
this heating is in progress, constant stirring must be
given to avoid matting. This excessive stirring breaks
the curd up into pieces about the size of wheat kernels,
and accounts for the large fat loss, which is one of the
main sources of loss in making Swiss cheese. This stir-
ring is accomplished by a rotary motion, and the use of
a brake, which is a piece of wood closely fitting the side
of the kettle. This creates an eddy in the current at that
point and gives a more uniform distribution of tempera-
ture. The process of cooking takes from thirty to forty
minutes, and at the end of that time the degree of tough-
ness may be determined by making a roll of curd
in the hand, and noticing the break when it is given a
quick 'flip. A short sharp break indicates the desired
toughness.
282 THE BOOK OF CHEESE
Draining and hooping. In this process, the cheese-
makers 1 skill is displayed. With the hoop prepared, and
the curd at the correct stage of toughness, the operator
takes a press cloth, wets it in whey, slips it over a flexible
iron ring which can be made to fit the shape of the kettle,
gives the contents of the kettle a few swift revolutions,
then suddenly reverses the motion, with the result that
the contents form into a cone, and the ring and bandage
are dexterously slipped under this cone, and drawn up to
the surface of the whey with a rope or chain and pulley.
This part of the process is the most important, as a cheese
must have a smooth firm rind, else it will quickly crack.
With too large a batch of milk, the curd can be cut into
two pieces and hooped separately. With the mass of
curd at the top of the whey, the piece of perforated iron
plate just the size of the hoop is slipped under the mass,
and attached to the pulley by four chains. Then the
top of the mass is carefully leveled off, because while still
in the whey, it cannot mat badly and so tend to develop
a rind crack. Now the mass is raised clear of the whey,
and run along a short track to the drain table, where it is
put in the press.
Pressing. The mass of curd is dropped into the
hoop, the edges of the cloth carefully folded under,
and the cloth laid on top, then the pressure is ap-
plied, gradually at first, but increasing until the final
pressure is about fifteen to twenty pounds to a pound
of cheese.
During the first few hours the cloths must be changed
frequently, and the cheese carefully turned over each
time, to secure a more uniform rind. After a time the
changes are less frequent, and at the end of twenty-four
hours the cheese is taken to the salting-room.
THE SWISS AND ITALIAN GROUPS 283
Salting may be done by either the brine or dry method.
To prepare a brine bath, add salt to a tank of water
until it will float an egg, and add a pailful or more of salt
every few days thereafter to keep up the strength. The
cheese is then placed in this bath and left for three to five
days, depending on the saltiness desired. As the cheese
floats with a little of the rind above the surface, it should
be turned a few times to insure uniformity of salting.
With dry salting, the salt is rubbed on the cheese by hand
or with a stiff brush, and any excess carefully wiped off,
leaving only a slight sprinkle on the surface to work into
the cheese.
271. Curing Swiss. From the salting-room, the cheese
goes to the first one of two curing-rooms, where the unique
process of the development of the characteristic eyes
takes place.
During the curing period of either round or block
Swiss, constant attention must be paid to the cheese.
They must be turned every day at first, and then every
second or third day toward the end of the curing period.
Also, great care must be taken that no mold starts
growing, as it will soon work into the cheese, and
spoil its flavor. The best way of preventing mold is
by washing the cheese, in either clean or slightly salted
water, as often as possible. A stiff brush is mostly
used for this.
The development of the " eyes " or holes is the diffi-
cult part of the whole process. It is not known exactly
what causes the development, but it is attributed to
micro-organisms or enzymes. The gas in these eyes has
been examined and found to be carbon dioxide and free
nitrogen. Sometimes hydrogen is found. This comes
from the original fermentation of the milk-sugar and
284 THE BOOK OF CHEESE
remains to contaminate the normal eye. The nitrogen 1
is included from the original air. Propionic acid is
formed at the same time as the eyes, and they are
said to be the result of a propionic ferment of lactic
acid. The interior of the cheese is anaerobic, due to
low permeability and high oxygen-absorbing quality.
This propionic bacterium cannot, however, account for
all the carbon dioxide produced.
After the eyes have started, their further development
depends on temperature and humidity of the air, and on
the moisture of the cheese, as regulated by the amount
of salt used. The first room has a temperature of 70 F.
to start the eyes, which is later lowered in the second
curing-room to about 60 to check the development.
When any local fermentive action starts, it may be
checked by rubbing salt on the affected part. The
humidity of the room is very important, because a
cheese will quickly dry out in a dry room, due to evap-
oration from the surface. To prevent this, it is well
to spray the floor with water, or to have a steam jet in
the room.
If the curd has been cooked too long the cheese may
be too dry. Such cheeses may be piled two or more deep
1 Clark, W. M., On the formation of "eyes" in Emmenthal
cheese, Jour. Dairy Sci. 1 (1917), no. 2, pages 91-113.
Among important studies of Swiss cheese ripening are the
following: Freudenreich, E. v., and Orla Jensen, Ueber die in
Emmentalerkase stattfindende Proprionsauregarung, Centralb. f .
Bakt. etc. 2 Abt. 17, page 529.
Jensen, Orla, Biologische Studien iiber den Kasereifungs-
prozess unter spezieller Berucksichtigung der fltichtigen Fett-
sauren, Centralb. f. Bakt. etc. 2 Abt. 13 (1904), page 161.
Eldredge, E. E., and L. A. Rogers, The bacteriology of cheese
of the Emmenthal type, Centralb. f. Bakt. 2 Abt. 40 (1914), no.
1/8, pages 5-21.
THE SWISS AND ITALIAN GROUPS 285
in the curing-room. It is held by some cheese-makers
that this process causes them to absorb more moisture.
Probably this is due to the checking of evaporation.
The development of the " eyes " may be watched by
trying the following test : Place the middle finger on the
cheese and let the first finger slip from it, striking the
cheese smartly; a dull sound indicates solidity, while a
ring indicates a hole, and an expert maker can tell the
size of the holes by the sound. This requires long
practice for the operator to become proficient.
After a cheese has remained in the first room for about
two weeks and the holes are well started, it is removed
to the second curing-room, which is held at a cooler
temperature and slightly drier atmosphere. The cheeses
are held in this room from three to ten months, depend-
ing on market conditions, and capacity of the curing-
rooms. In Switzerland, it is customary to hold cheese
to secure a well ripened product, while in America most
of the cheeses are shipped comparatively green, hence
do not bring so high a price.
272. Block Swiss. In making block Swiss, the same
procedure is followed through the cooking stage. Then
the curd is pressed in a square form or in one large piece,
each form six inches square on the ends and twenty inches
long, and later cut into sections. These are then pressed,
salted and cured in the same way as round forms. In
this type of cheese there is a much smaller cross-section;
therefore the development of holes is much more easily
controlled on account of the ease with which the salt
can work into the cheese and control undesirable fer-
ments. As it is easy to control, this variety is made in
the fall and winter when the ferments are especially
hard to keep in check. However, this cheese has the
286 THE BOOK OF CHEESE
disadvantage of cutting eye-development short by the
rapid entrance of salt.
The curing consists of the developing of the flavor and
eyes and the changing in body and texture. Just what
causes these changes is not known.
273. Shipment. When ready for shipment, the drum
cheeses of the same general diameter are sorted out and
packed four to six in a cask. Care must be taken to put
boards between them to prevent sticking. These are
called scale-boards, and are made of thin sections of wood
fiber. The cheeses are crowded into the cask to make a
snug fit, and the head carefully fastened.
274. Qualities of Swiss cheese. The peculiar Swiss
cheese flavor may be characterized as a hazel-nut taste.
It is a trifle sweet and very tempting. The " eyes " or
holes should be about the size of a cherry with a dull
shine to the inner lining. The " eyes " usually contain
a small amount of a briny tasting liquid. These
eyes should be uniformly distributed. The color should
be uniform. The cheese should have a neat, clean,
attractive appearance, and the rind should not be
cracked or broken.
There are several common defects in Swiss cheese.
If the milk is not clean-flavored, the cheese will have
the same flavor as the milk. The greatest difficulty is
to produce the eyes or holes. A cheese which does
not have these is called " blind." A product which has
many small pin-holes due to gassy fermentations is
called a " niszler " ; this means a cheese with a thousand
eyes. If gas forms in the cheese and causes cracks, it
is called " glaesler." If the cheese contains too much
moisture, it will be soft and pasty. Such a cheese does
not readily form eyes.
THE SWISS AND ITALIAN GROUPS 287
275. Composition and yield. A large number of analy-
ses of Swiss cheese have been made but there is wide
variation. This is due to the fact that the composition
and yield are both dependent on the following factors:
composition of the milk, losses during manufacture,
amount of moisture in the cheese. The losses in Swiss
cheese are much larger than with some of the other hard
cheeses, such as Cheddar. This is because more fat is
lost in the whey, due to breaking instead of cutting
the curd and the subsequent hard stirring. The pos-
sibility of reducing these excessive losses has already
been indicated.
Swiss cheeses of high grade show about the following
range of composition:
Water ...... 30-34 per cent
Fat 30-34 per cent
Protein 26-30 per cent
Ash 3-5 per cent
Salt (NaCl) .... 1-1.4 per cent
The water-content of this type of cheese is low and the
protein-content is proportionately high. Both condi-
tions lead to firm textures, long ripening and long keeping
periods.
The following score-card is used to judge both block
and drum Swiss cheese :
Flavor 35
Appearance on trier holes ... 30
Texture 20
Salt . . 10
Style 5
100
288 THE BOOK OF CHEESE
The yield of Swiss cheese varies from 8 to 11 pounds
to 100 pounds of milk. The more solids in the milk, the
more moisture incorporated in the cheese; the smaller
the loss of solids in the manufacturing process, the
larger will be the yield from a given amount of milk.
THE ITALIAN GROUP 1
A group of varieties, best known in America by Parme-
san, are made in Italy with related forms in Greece and
European Turkey. These forms are very hard, usually
uncolored, with small eyes or holes. They are made in
large cheeses which ripen very slowly. Cow's milk is
regularly used for Parmesan and Grana in northern
Italy ; other varieties contain goat or sheep milk or vari-
ous mixtures. Aside from Parmesan, few of the other
forms are known outside the place of origin except as
they are exported in a small way to satisfy the demand
of emigrants from these regions.
276. Parmesan. One type of Italian cheese, how-
ever, the Parmesan, has become very widely known. In
general the consuming trade does not discriminate be-
tween Parmesan, Grana and closely related forms. Par-
mesan is made in large cheeses which require one to three
years for proper ripening ; in texture it is very hard with
small eyes or holes formed by very slow fermentation.
Such cheeses are ripened in large storehouses in which
1 Gorini, C., Studi sulla fabricatione razionale del fromaggi
Grana, Boll. uff. del Ministero Agr. Ind. e Comm. Anno X,
serie C, Fasc. 10, pages 1-7, Roma, 1911.
Gorini, C., On the distribution of bacteria in Grana cheese,
Centralb. f. Bakt. etc. 2 Abt. 12 (1904), pages 78-81.
Fascetti, G., The technological chemistry of the manufacture
of Grana cheese in Reggio, Staz. Sper. Agr. Ital. 47 (1914),
no. 8, pages 541-568.
THE SWISS AND ITALIAN GROUPS 289
hundreds and even thousands are brought together
and cared for by experts. The surfaces of these cheeses
are kept clean and free from insects by rubbing with
linseed oil. So hard are these forms that the cheese-
trier is not used in testing, but the texture of the surface
is tested by pricking with an awl-like tool and the stage
of eye-formation and associated ripening is determined
by the sound given out when the cheeses are tapped with
a hammer.
When ripe, the cheeses of this group are used in cooking
principally. The broken cheese is grated and added to
macaroni, spaghetti and other cooked cheese dishes.
Parmesan is usually made from partly skimmed-milk ;
the ratio of fat to protein in analysis runs from 1 : 2 to 3 : 4
in contrast to the normal relation of about 4 : 3 in whole-
milk cheese. In water-content much variation is found,
but ripe Parmesan is usually about 30 per cent water.
Other members of the group are made with different
amounts of skimming, some of them from whole milk.
The group in general represents the requirements of cheese
for the trade of warmer regions (see Mayo and Elling) :
(1) a low fat-content so incorporated that the cheese does
not become greasy or oily in hot weather ; (2) a water-
content low enough to prevent rapid spoilage during the
necessary exposure of handling under warm conditions.
The equipment for Parmesan manufacture has more
resemblance to that of the Swiss factory than the
English and American cheeses. The milk is curdled in
deep copper kettles (Fig. 57), below which there is com-
monly a provision for direct heating by fire which is
sometimes carried on a truck, and therefore can be with-
drawn when heating is sufficient. The steam-jacketed
kettle has replaced this earlier form to a large measure.
290 THE BOOK OF CHEESE
The general character of the manufacturing process is
indicated in the following abstract of one of the methods.
Many variations are to be found. The milk for
Parmesan is allowed to stand overnight. Some acidity
is, therefore, developed in contrast to the absolutely
fresh condition of the milk used in Swiss and the
acidification developed during the making of Cheddar
(Fascetti). It is then skimmed, heated to 72 to 75 F.
Rennet is added in amount sufficient to produce firm
curd in one hour or slightly less. When the curd is firm,
FIG. 57. Parmesan cheese kettles.
a wood fire is made under the kettle and the curd is
broken with a special implement into small particles.
After breaking, four grains of powdered sulfur to twenty-
two gallons of milk are added. The curd is stirred with
a rake. By the time the temperature rises to 77 F.,
the curd should be in very small pieces. Stirring and
heating continue until the temperature reaches 131 F.
At this temperature, it stands fifteen minutes, after which
it is removed from the fire (or the fire is drawn). Nine-
tenths of the whey is then drawn. The cheese-maker
then collects the curd into a compact lump under which
THE SWISS AND ITALIAN GROUPS
291
he slips a cheese cloth. With the aid of an assistant he
removes the mass to a perforated vessel for draining.
After this the curd goes into large wooden hoops, lined
with cloth, which stand upon a slanting draining table
until evening. No pressure is used. Before night they
are taken to the cellar. The cloths are removed next
FIG. 58. A typical cheese-market in France.
day. After standing four days, they are salted by cover-
ing the upper surface with coarse salt. This is repeated
with daily turning for twenty days, then salted on alter-
nate days for another period of twenty days. At the
end of the forty days' salting, the cheese is removed from
the hoop, scraped, sprinkled with whey and the rind
rubbed smooth. A dressing of linseed oil either with or
without bone black is applied.
The cheeses are kept in special ripening rooms,
292 THE BOOK OF CHEESE
and rubbed frequently with linseed oil to keep the surfaces
free from molds and vermin. Careful grading as to qual-
ity of product and consequent response to ripening con-
ditions produce cheeses of many degrees of excellence.
Those in which a ripening of three to four years is possible
are most highly esteemed.
277. Regianito. A cheese of the Italian group is
now made in Argentina and imported to the United States
under the name Regianito.
CHAPTER XVI
MISCELLANEOUS VARIETIES AND BY-
PRODUCTS
As already discussed in Chapter VI, there are a large
number of varieties of cheese. Very many are entirely
unknown in America. A considerable number of forms
are occasionally imported and may be found by visiting
the markets and delicatessen stores in the foreign dis-
tricts of our large cities. Certain forms not widely known
are made in America in a few factories or are imported
in sufficient quantity to call for brief discussion. Some
of these are brought together here.
The importance of the by-products of cheese-making
has not been sufficiently recognized, for manufacture on
a large scale is only beginning to be appreciated in America.
Certain cheese names, such as Mysost, are applied to whey
products. In addition, milk-sugar is extensively made
and whey-butter has been carefully studied and found
to be practicable under some conditions.
278. Caciocavallo originated in Italy, but is now made
in certain factories of New York and Ohio. Some factories
in Lombardy 1 use whole milk, others use half-skimmed
milk. The latter practice is probably the more common.
In making this cheese, the milk is coagulated with rennet,
cut and firmed in the whey, allowed to settle and the whey
1 Cornalba, G., Caciocavallo in Lombardy, L'Industria del
Latte 3, page 105, Abs. in Jahresb. f. Tierchemie 36 (1906),
page 250.
293
294 THE 'BOOK OF CHEESE
drawn. The curd is then piled on the draining table
and allowed to mat or fuse into fairly solid masses. After
several hours of draining and matting, the curd is cut
into strips and placed in a vat of hot water. In the hot
water, the blocks of solid curd melt into taffy-like masses
which are worked and molded by hand into more or less
standard shapes. Indian club or ten-pin forms are
most commonly produced. When the proper shape has
been gained, each mass is thrown into cold water which
solidifies it in that form. Cheese masses heat and cool
slowly; several hours of cooling are required to insure
a firm cheese. The newly made cheeses are salted in a
brine bath, then hung by a string to ripen. Sometimes
these cheeses are eaten fresh, again they are ripened several
months. They vary in size from one to six pounds.
Cornalba gives the composition of Italian caciocavallo
made from whole milk as water 32 to 34 per cent, fat 34
to 36 per cent, protein 28.5 to 29.5 per cent, salt 1.7 to
1.8 per cent; when made from half skimmed-milk, water
28 per cent, fat 27 to 28 per cent, protein 35 to 40 per cent,
salt 2.2 per cent. Other analyses vary widely from these
figures on account of the differing fat-content of the milk.
No standardized practice has been established in America.
Provolono resembles Caciocavallo in method of manu-
facture and composition, the main difference being in
the shape of the cheese. It is more or less round and
is held by a coarse net made of small rope. The cheeses
are treated while curing the same as Caciocavallo.
279. Sap sago. This hard green cheese imported
from Switzerland is made in cakes, tapering from perhaps
two inches in diameter to a rounded top with a height
of about two inches. These are made from skimmed-milk
curd, partially ripened then mixed with powdered leaves
MISCELLANEOUS VARIETIES, BY-PRODUCTS 295
of Melilotus cceruleus, a clover-like plant. The mixture
is then pressed into the market form and dried until very
hard. It is handled without special care since the water-
content is so low that fermentations are exceedingly
slow. This low-priced cheese may be used in cooking.
280. Albumin cheese. 1 In the rennet cheeses, the
albumin, which constitutes about 0.7 per cent of the
milk, passes off in the whey. This albumin is not curdled
by rennet. It is, however, coagulated by heating. The
presence of acid hastens such coagulation but does not
cause it when used alone. When the whey is heated to
about 200 F., the albumin rises and may be skimmed off.
In this form it is recovered and used. It may be shaped
is hoops under pressure, as Ricotte, an Italian form.
This cheese is pressed firmly and dried. Such albumin
is frequently prepared as a poultry feed.
281. Mysost, Norwegian whey cheese. The whey
contains nearly 5 per cent of milk-sugar which can be
recovered by boiling. The Norwegian process which
produces Mysost consists in raising the whey to the boil-
ing point, skimming off the albumin as it rises, then con-
centrating the remainder of the whey. As it reaches
sufficient concentration, the albumin is thoroughly stirred
back into the mass and the mass finally cooled into forms.
Mysost is a brown, hard brittle mass consisting principally
of caramelized milk-sugar. Analysis shows such percentage
composition as follows : water 10 to 20 per cent, protein
10 to 15 per cent, milk-sugar 30 to 55 per cent. Mysost
is found in the larger markets of the United States.
Primost is an albumin cheese somewhat similar to
Ricotte and Mysost. It is made by precipitating the
1 Babcock, S. M., Albumin cheese, Wis. Exp. Sta. Kept. .12
(1895), page 134.
296 THE BOOK OF CHEESE
albumin by acid and heat. The main difference is in
the firmness of the cheese. This is regulated by drying.
282. Whey butter. 1 The loss of a percentage of fat,
rarely less than 0.3 per cent and in some cheeses very
much greater, has led to the making of whey butter.
For this purpose a separator is introduced and all whey
is separated daily. The fat recovered in the form of
cream is then ripened and churned. Whey butter is not
rated as equal to butter made from whole milk but a fair
market can usually be found for the product. The recov-
ery of 0.25 per cent fat means two and one-half pounds
of fat to 1000 pounds of whey. This will make about
three pounds of butter.
Whether whey butter shall be made depends on the
volume of business, the extra equipment required, the
extra help necessary and the market for the product.
As a rule, whey butter is economically recoverable
only in large factories. It is not considered advisable
to attempt to make it unless one has the whey from
10,000 pounds of milk. In some instances, the com-
bination of small cheese factories with one churning
plant has proved to be economical. The objection to
the making of whey butter is, that it stimulates careless-
ness on the part of the cheese-maker because he thinks that
the fat will be recovered by skimming. He does not realize
that the other milk solids are being reduced in the same
proportion as the fat, to the great loss in yield of cheese.
1 Doane, C. F., Whey butter, U. S. Dept. Agr. Bur. An. Ind.
Circ. 161, pages 1-7, 1910.
Sammis, J. L., Making whey butter at Cheddar cheese fac-
tories, Wis. Exp. Sta. Bui. 246, 1915.
Ellenberrger, H. B., and M. R. Tolstrup, Skimming whey at
Vermont cheese factories, Vt. Dept. Agr. Bui. 26, 1916.
CHAPTER XVII
CHEESE FACTORY CONSTRUCTION,
EQUIPMENT, ORGANIZATION
THE principal factor in determining the location of a
cheese factory is the available supply of milk. This
is usually ascertained by making a canvass, and finding
out the number of cows whose milk would be brought
to the factory. The quantity of milk or the number
of cows necessary to insure sufficient milk for the suc-
cessful operation of the factory, depends on the variety
of cheese to be made. When making types of cheese
for which very sweet milk is necessary, the milk must
be delivered twice a day. This demand limits the area
from which the factory can secure its supply. The
length of time the cheeses are held in the curing-room and
the work necessary to care for them also limits the area
which the factory can serve, because a very large amount
of milk cannot be handled when the cheese must be given
considerable attention in the curing-rooms. Swiss, Lim-
burger and Brick cheese factories usually do not require a
large supply of milk ; therefore the factories may be built
close together. The size of the Cheddar cheese factories
varies but it is generally considered unprofitable to make
Cheddar cheese unless there are 5000 pounds of milk
available daily. Conditions have changed so that at
present different kinds of cheese are made from the
297
298 THE BOOK OF CHEESE
surplus milk in market milk plants. In such cases a uni-
form supply is not absolutely necessary. The climate
must also be suitable for the industry.
283. Locating the site. In a farming community,
several factory sites are usually available. It is best
to consider carefully the desirable features of each before
trying to make a definite choice. Many of the present
cheese factories were located in hollows because it was
easy to secure a supply of water, but no thought or
attention was given to the disposal of the sewage. The
following points should be considered in choosing a site :
(1) Drainage. A factory should be so located that it
has good drainage. Ground that slopes away from the
factory makes the disposal of sewage easy. Sewage
should not be allowed to run out on the ground and left
to decay, thus forming a breeding place for flies, but
should run into a cesspool or septic tank. 1 Even in a
porous soil, a cesspool frequently clogs and gives trouble.
The septic tank seems to be the best method to dispose
of the sewage unless the factory is so located that con-
nection can be made with a city sewage system.
(2) Water. An abundant supply of pure water is
essential to a factory. This may come either from deep
wells or springs. The value of a never-failing water supply
cannot be overestimated.
(3) Exposure. The factory should be so located that
the receiving room is away from the prevailing winds.
This prevents dust being blown into the factory. The
curing-room should be on the side not exposed to the sun
as this will keep it cool. Fig. 59 shows a clean cheese
factory of the ordinary type. When it is desirable to cure
1 Farrington, E. H., and G. J. Davis, The disposal of creamery
sewage, Wis. Exp. Sta. Bui. 245, 1915.
CHEESE FACTORY CONSTRUCTION, ETC. 299
the cheese in a cellar, it is better to locate the factory on
the side of a hill. Then the receiving and manufacturing
room may be on the ground level and the curing-room,
a cellar, back of the manufacturing room and yet all on
the same level. This saves carrying the cheese up and
down stairs.
(4) Accessibility to market should not be overlooked.
Often the quality of the cheese is injured by long hauls.
FIG. 59. A cheese factory of neat appearance.
An important item in marketing both milk and cheese is
the use of the automobile. By its use the products are
not so long in transit, and losses from exposure in delivery
are reduced. Both milk and cheese, when exposed to
the heat of the sun for any length of time, become warm.
This gives undesirable organisms chance to develop.
284. The building. Details of construction or esti-
mates of cost will be omitted in the present discussion.
A local contractor can do this satisfactorily and also the
300 . THE BOOK OF CHEESE
cost of materials is constantly changing. Only general
considerations as they apply to the manufacture of the
product will be taken up.
The building may be constructed of wood, stone, various
bricks or concrete. The kind of material will depend on
the relative cost of materials in the local market and
on the amount of money available for building.
285. Heating plant. Many of the older factories
have no heating plants and some are so poorly constructed
that they cannot be warmed. Means of heating should
be provided, either by steam or a stove. The loss due
to freezing is an item which is entirely avoided in factories
properly heated.
286. Curing-rooms. The size of the curing-rooms
will depend on the amount of cheese to be handled and
its location on the variety of cheese to be manufactured.
In every case, some provision should be made to control
humidity and temperature. If the room becomes hot
and dry, evaporation from the cheese will be much more
rapid. In a hot curing-room, undesirable types of fer-
ments are more likely to develop and to injure the quality
of the cheese.
287. Light. The importance of light should be
emphasized. ,It acts as a stimulant to keep things clean.
It also makes the factory more cheerful. There should
be numerous windows to give plenty of light. A skylight
may often serve both as a source of light and ventilation.
288. Ventilation. Plenty of ventilation should be
provided. This may be accomplished by means of the
windows or skylight. However, it is a good precaution
to have at least one ventilator to carry off the steam and
control the circulation of air.' All openings should be
carefully screened to keep out flies.
CHEESE FACTORY CONSTRUCTION, ETC. 301
289. Boiler-room. The boiler-room should be easily
accessible from the manufacturing rooms. A gauge
located in the latter should tell the steam pressure. Win-
dows or doors should be so located that the flues of the
boiler can be cleaned. The coal supply should be handy.
Great care should be exercised to keep the boiler-room
clean for otherwise the dirt will be tracked all over the
factory.
290. Whey tanks should be kept clean. Daily wash-
ing is absolutely necessary to prevent offensive odors.
Pasteurization of whey has been found requisite to
prevent the spread of disease if raw milk is used. 1
This is required by law in some states. It is some-
times accomplished by heat with steam coils; in other
cases by running live steam directly into the whey.
Whey tanks may be made of wood or steel. The acid
of the whey seems to eat and decompose concrete.
291. Store-room. There should be a separate room
or a place in the attic where the supplies can be kept.
This saves much waste and keeps the factory cleaner
and more tidy.
292. The floors. The floor is the most . important
part of the building. It should be of non-absorbent ma-
terial, which can be easily cleaned, and it should not leak.
Concrete makes the best floor of any material used at
present. It should slope very gently to the drain.
The corners between the floor and side walls should be
rounding to make cleaning easy. The drain should be
provided with bell traps to prevent the entrance of
sewer gas into the factory. If the traps and floor about
them are slightly depressed, it will help to make the
1 Dotterrer, W. D., and R. S. Breed, Why and how pasteurize
dairy by-products, N. Y. (Geneva) Exp. Sta. Bui. 412, 1915.
302
THE BOOK OF CHEESE
floor drain more quickly. A catch-basin should be
provided just outside the factory for all solid material
which might clog the sewer pipe. This should be
cleaned three or four times a year.
293. Arrangement of machinery and rooms. The
rooms and machinery should be arranged so that the work
FIG. 60. A well arranged Cheddar cheese factory, including the
equipment for the manufacture of whey butter.
will follow the natural sequence of the process with as
little inconvenience as possible. Some of the points to
be observed in this connection are : vats should be near
CHEESE FACTORY CONSTRUCTION, ETC. 303
the weigh-can ; boiler-room near the work room ; cheese
presses near the vats; cheese presses near the curing-
rooms and the like.
Fig. 60 shows a well arranged Cheddar cheese factory.
The necessary machinery and rooms for the manufacture
of whey butter are included. In this plan, the attic
contains the store-room and the whey tanks. The whey
is forced from the vats into the tanks with a steam jet
and then runs by gravity to the separator. Slides are
provided in the walls of the ice storage to regulate the
flow of air into the curing-room and butter refrigerator.
In order to have a smaller boiler, a gasolene engine is used
to run the separator, churn and curd-mill. The plan can
be modified to use the upstairs for a curing-room so that
the size of the factory may be reduced. The whey butter
could be shifted to a small room where the curing-room now
is and the boiler-room added as a " lean-to " at one side
of the building. This would materially reduce the size
of the main building.
Another plan (Fig. 61) shows the arrangement of a
Cheddar cheese factory without the whey butter appara-
tus. The location of the drain between the vats might
be criticized. In Fig. 62 is shown the arrangement of a
combined butter and cheese factory. Fig. 63 shows the
possible arrangement of a Limburger factory. The size
of this factory could be reduced by having the salting
tables closer together.
In a Cheddar cheese factory, the curing-room may
be over the manufacturing room. This makes consid-
erable work in carrying the cheese up and down. A
small elevator may be used for this purpose. The same
principle holds in cheese factories in which other varieties
of cheese are made ; the floors should be on one level so
304
THE BOOK OF CHEESE
CHEESE FACTORY CONSTRUCTION, ETC. 305
far as possible. There is danger of the overhead curing-
room becoming too hot and causing the cheese to leak
fat. Shelves or tables should be provided on which to
1, Boiler; 2, engine; 3, water
pump; 4, work bench; 5, wash
sink; 6, press; 7, elevator; 8,
cheese vats; 9, separator; 10,
milk heater; 11, milk receiv-
ing vat; 12, press; 13, shelf;
14, Babcock tester; 15, weigh-
can; 16, churn; 17, starter;
18, cream ripener and pasteur-
izer; 19, refrigerator; 20, milk
sheet and sample jar; 21, milk
pump.
SCAJL& 1M F-EET
FIG. 62. Combined Cheddar cheese and butter factory.
put and keep the utensils. The utensils should never be
placed on the floor.
294. Arrangements for cleanliness. A sink for wash-
ing the utensils should be provided and boiling water
to scald them after washing. After being scalded, tin
utensils dry quickly without rusting. The boiling water
306
THE BOOK OF CHEESE
pa
zi
5?
may be obtained by
placing a steam pipe
in a barrel of water
and turning on the
steam. The utensils
can then be washed
clean, dipped in this
barrel of boiling water
and put in their place.
Too much emphasis
cannot be laid on keep-
ing the factory itself,
the utensils and the
surroundings clean.
This will prevent the
development of mold.
Cases are known in
which the cheese fac-
tory was allowed to
become very dirty, so
that a red mold devel-
oped. This eventually
got into the cheese and
caused red spots. 1
They are called rust
spots. All doors and
windows should be
screened to keep out
flies.
295. Equipment and
supplies list. The
1 Harding, H. A., and G. A. Smith, Control of rust spots in
cheese, N. Y. (Geneva) Exp. Sta. Bui. 225, 1902.
CHEESE FACTORY CONSTRUCTION, ETC. 307
following utensils will be needed in a Cheddar cheese fac-
tory to handle 10,000 pounds of milk daily : 1 5-H. P.
boiler; 160-gallonweigh-can; 1 conductor head and trough;
1 platform scale ; 1 Babcock tester, glassware and sample
bottles ; 2 700-gallon cheese vats ; 2 gang cheese presses ;
1 curd-mill; 2 curd-knives; 30 cheese hoops; 1 whey
strainer ; 1 curd scoop ; 1 long-handled dipper ; 1 strainer
dipper; 1 siphon; 1 cheese knife; 1 glass graduate;
1 cheese-trier ; 1 speed knife ; 1 paraffine tank ; 1 Marschall
rennet test; 1 lactometer; 1 milk can hoist; 1 acid
test ; 1 sink ; 1 40-quart milk can ; 3 pails ; 3 shot-gun
cans for starter; 3 thermometers; brushes and brooms;
1 Wisconsin curd test or fruit jars for same ; 1 set counter
scales ; 2 curd rakes.
If whey butter is made, the equipment should include :
Tanks to hold the whey ; separator ; cream ripening vat ;
churn; butter-worker; butter refrigerator; large boiler
and steam engine or gasolene engine.
The following supplies will be needed for the making
of the cheese : Bandages ; boxes ; scale boards ; starched
circles ; rennet extract or pepsin ; cheese color ; press cloths ;
paraffine ; formalde-
hyde ; alkali ; indi-
cator ; sulfuric acid.
When choosing the
utensils, the ease of
cleaning and sanitary FlG ' w.-A sanite^dipper with a solid
construction should
not be overlooked. One of the most unsanitary utensils
in a factory is a dipper with a hollow handle. Fig. 64
shows a dipper with a solid handle which any tinsmith
can make. The seams of all utensils should be flushed
full of solder, to make cleaning easy. When ready to
308 THE BOOK OF CHEESE
clean or wash any utensils which have come in contact
with milk or its products, the steps are as follows : rinse
in cold water, wash in warm water in which some wash-
ing-soda has been dissolved, rinse clean, scald in boiling
water. Never use a cloth to wash utensils ; a brush is
more sanitary.
296. Factory organization. There are two general
classes of organizations 1 to operate cheese factories, one
the proprietary and the other the cooperative. Un-
less the kind of organization is what the dairy-men desire,
dissatisfaction is sure to result.
(1) Proprietary organization. Under this form of
organization, one person owns and operates the fac-
tory. The dairy-men are paid a stated price for milk,
or the milk is made into cheese for a stated price a
pound. The proprietor receives all profits and assumes
all losses.
So far as the dairy-man is concerned, the stock com-
pany is a proprietary organization. The gains and
losses are shared by each member according to the
amount of money invested.
(2) Cooperative organization. In a true cooperative
cheese factory each patron is an owner, as the name
indicates. The object of this organization is to reduce
the cost of manufacture rather than pay large dividends,
so that the dairy-man with a large herd and small capital
invested in the factory obtains more returns than the
one who owns considerable capital and has a small herd.
Many cheese factories are cooperative in name only and
1 Elliott, W. J., Creameries and cheese factories, Mont. Exp.
Sta. Bui. 53, 1904.
Farrington, E. H., and E. H. Benkendorf, Origination and
construction of cheese factories and creameries, Wis. Exp. Sta.
Bui. 244, 1915.
CHEESE FACTORY CONSTRUCTION, ETC. 309
proprietary in operation. The state of Wisconsin has
a law which tends to stop this defect and defines what
organizations may use the term or name, cooperative.
The constitution of a cooperative organization should
state: 1, Name; 2, object; 3, officers and duties of
officers; 4, manager or other person to run business;
5, capital stock; 6, meetings; 7, voting power; 8,
amendments.
Some of the most important statements which should
appear in the constitution are mentioned in the following
sentences. A statement should show what persons are
eligible to membership in the organization. It is a
careless plan simply to say that the duties of the officers
are those usually defined in such an organization. This
may lead to confusion and neglect, or both. Direct
statements should be made 'explaining the exact duties
of each officer. The limits of the authority of the manager
or person who runs the business should be explicitly
stated. The manager then knows just what his duties
are and what matters or parts of the business must be
considered by other officers or committees. The amount
of capital stock and the number and value of each share
should be exactly stated. The constitution should state
when arid where the regular meetings must be held and
by whom and when special meetings may be called.
This gives every member ample notice of the regular
meetings. Some method or means should be provided to
notify each member of the special meetings.
The voting power should be definitely stated, whether
it is limited to shares of capital stock or by members or
by number of cows owned by each member. It is neces-
sary to indicate just how amendments to the constitution
may be made. Each member should know before the
310 THE BOOK OF CHEESE
final vote just what changes are being proposed. Types
of constitutions may be found in the following references :
ELLIOTT, W. J., Creameries and cheese factories; organization,
building and equipment, Mont. Exp. Sta. Bui. 53, 1904.
FARRINGTON, E. H., and G. H. BENKENDORF, Organization and
construction of creameries and cheese factories, Wis. Exp.
Sta. Bui. 244, 1915.
VAN SLYKE, L. L., and C. A. PUBLOW, The science and practice
of cheese making, pages 447-453, 1909.
Iowa Exp. Sta. Bui. 139, 1913. Creamery organization and
construction.
CHAPTER XVIII
HISTORY AND DEVELOPMENT OF THE
CHEESE INDUSTRY IN AMERICA
JUST when the first cheese was made is not known.
By the time the first immigrants came to America,
cheese-making was rather generally known in Europe,
so that the early settlers brought with them and practiced
established methods. The countries of Europe developed
different kinds of cheese and have since become noted for
such particular varieties, for example : France, Camem-
bert and Roquefort ; Switzerland, .Swiss cheese ; England,
Stilton and Cheddar; Germany, Limburger; Holland,
Edam and Gouda; Italy, Parmesan and its allies,
also Gorgonzola cheese. The manufacture of these
various cheeses has been attempted in this country.
Because of the difference in climatic conditions and
in some cases the use of milk of sheep or goats, it was
and still is difficult to manufacture some of the European
cheeses in America. Since the climatic conditions of this
country and certain parts of England are somewhat similar,
the manufacture of the cheeses of England predominated,
and there was also more information on their manufacture.
These are probably the reasons why the United States and
Canada have become famous for Cheddar cheese.
The first cheeses of the Cheddar group were made on
the farms. The work was usually performed by women,
and the process was very simple. The methods were crude,
311
312 THE BOOK OF CHEESE
and the cheeses were made in a more or less haphazard
way. The milk of the evening was placed in a cheese
tub in the dairy room and cooled to a temperature that
would prevent souring. In most cases the cream that
had raised to the surface of the night's milk was removed
in the morning. This was considered an act of economy,
for it was thought that in the process of manufacture
it would all pass off in the whey and be lost. The morn-
ing's milk was then mixed with that of the evening and
warmed to the setting temperature by placing a portion
in a tin pail and suspending it in a kettle of hot water.
When hot, it was emptied into the tub of cold milk.
By transferring back and forth, the setting temperature
was finally reached. Few of these settlers owned ther-
mometers. Consequently, cheese-makers were obliged
to depend on the sense of feeling to determine temperature.
One of the serious difficulties of the early manufac-
ture was the production of rennet of a uniform strength.
After the addition of the rennet and as soon as the coagu-
lated milk became firm enough, it was broken into as
small pieces as could be conveniently made, a wooden
knife being used for the purpose. After standing ten
minutes it was stirred by hand, breaking the pieces finer,
and the temperature was gradually brought to 98 F.,
aiming as near blood heat as could be judged by the
sense of feeling. It was kept at this temperature until
the moisture was out of the curd and it would squeak
between the teeth. The whey was drawn off and the
curd stirred until dry, salted and put to press. All the
curd of one day was made into a cheese. This resulted
in small uneven-sized cheese. Since such cheeses were
made from the milk of single dairies with all the surround-
ings clean, the flavor was usually good but the texture
THE CHEESE INDUSTRY IN AMERICA 313
was open and soft. The method of caring for the cheese
and marketing was entirely different from that practiced
at the present time. All the cheeses made during the
entire season were held until fall and marketed at one
time. They were packed in casks four to six in a package,
one on top of the other. The earliest date when single
boxed cheeses were on the market was 1841.
Between 1820 and 1840, a small export trade in cheese
was started. As this demand for cheese increased, partic-
ularly in England, it became necessary to change the
methods employed in manufacture. The farm dairy
cheese was rather an open-textured sweet curd product.
If not, it was due more to accident than to any intention
of the cheese-maker to improve the quality. One of the
early complaints from England was that the cheeses were
too small and uneven in size. The practice of making
on the farm continued until about 1851, when the factory
system was started, although home manufactures con-
tinued after that time. Following are the reasons for the
change from the farm to factory system : (1) England
demanded larger cheese; (2) the farm product was not
uniform ; (3) the quality of the farm cheese did not suit
the English trade ; (4) factories saved much labor on the
farms ; and (5) could secure higher prices.
297. The factory system. Where and by whom the
first Cheddar cheese factory in America was started is
not definitely known. Jesse Williams of Oneida County,
New York, is supposed by many to have been the first to
build and operate under the factory system, in 1851.
Cheese factories were opened in Ohio and Wisconsin about
1860. In the period 1860 to 1870, a large number of
cheese factories were built in the various states, especially
New York, Ohio and Wisconsin.
314 THE BOOK OF CHEESE
298. Introduction of factory system in Canada.
In 1863, Harvey Farrington of Herkimer, New York,
was so impressed with the opportunity of developing the
cheese factory system in Canada that he sold out his
business in New York and established the first Canadian
cheese factory in the town of Norwich, Ontario. It was
accepted at once by Canadian farmers, and factory cheese-
making increased rapidly. In 1866, a small quantity of
cheese was exported and from that time the export trade
of Canada has been large and growing. Ontario and
Quebec are now the leading provinces in the production
of cheese.
299. Introduction of cheddaring. The factories at
first used the same process as the farms, namely the stirred-
curd process. In 1867, Robert McAdam introduced the
English Cheddar system in a factory near Herkimer,
New York. This is the Cheddar system as known to-day.
It produces the closer bodied cheese demanded by the
export trade. This introduction made Herkimer County
famous for its cheese.
300. Introduction of Swiss and Limburger. In 1870,
factories for Limburger, Swiss and Brick cheese were
started and have gradually increased. In New York
such plants are located around Boonville in Oneida
County, and Theresa, in Jefferson County. In Wis-
consin, Swiss cheese-making was begun by a colony of
Swiss who came to New Glarus, Green County. It is
now made in Green, Lafayette, Iowa, Grant, Dane and
Rock counties. Limburger and Brick are manufactured
in Dodge, Fond du Lac, Winnebago, Marathon, La Crosse,
Buffalo, Trempealeau, Clark, Washington, Dunn, Barron
and Lincoln counties. In the southeastern part of Ohio
Swiss cheese is produced. Ohio and Wisconsin have
THE CHEESE INDUSTRY IN AMERICA 315
manufactured more of these cheeses, especially Swiss,
than any other states. This is probably due to the fact
that the conditions are more nearly like those of Switzer-
land.
When the cities in New York began to grow, an
increased demand for market milk was felt. The result
was that the dairy-men could not supply both the cities
and the cheese factories with milk. A large part of
the cheese was being exported and most of it had al-
ways been partly skimmed. The amount of skimming,
therefore, was largely increased. Then other animal
fats were substituted for the milk-fat. This product
was known as " filled " cheese. The delay in con-
trolling the practice of making skimmed-milk and filled
cheese ruined the export trade. In Canada laws
prohibited the making of filled cheese and as a con-
sequence Canadian Cheddar cheese is still very popular
in England. However, with the control of skimmed-milk
cheese-making and the elimination of filled cheese, the
volume continued to grow and to find outlet in local
consumption. New York probably exported more
cheese than any other state. Wisconsin shipped cheese
into other regions, especially the southern states in which
no cheeses were made. Some Wisconsin cheeses were
shipped to the New York market from time to time,
but in October, 1913, the first quotations 1 were made
in New York City for Wisconsin products.
301. Number and distribution of cheese factories. -
The following list and maps (Figs. 65, 66) compiled in 1914
by the United States Department of Agriculture Dairy
Division, show the number of cheese factories in the dif-
ferent states and their location :
1 From N. Y. price current.
316
THE BOOK OF CHEESE
THE CHEESE INDUSTRY IN AMERICA 317
Arizona 3 New Hampshire ... 2
California ..... 93 New York 995
Colorado 8 North Dakota. .... 3
Connecticut 2 Ohio Ill
Delaware 1 Oklahoma 1
Illinois 50 Oregon 42
Indiana 13 Pennsylvania . . . 106
Iowa 25 South Dakota ... 1
Kansas 1 Utah 8
Maine ....... 5 Vermont 35
Michigan 196 Virginia 3
Minnesota 74 Washington .... 15
Missouri ...... 4 West Virginia ... 1
Montana 1 Wisconsin 1720
Nebraska 1 3520
302. Total production of cheese in the United States.
The following figures (Table XX) compiled by the
United States Census show the total production of cheese
and the amount made on, farms and in factories in the
United States by ten-year periods :
TABLE XX
SHOWING THE TOTAL PRODUCTION OF CHEESE AND PART
MADE ON FARMS AND IN FACTORIES IN THE UNITED
STATES BY TEN-YEAR PERIODS
1849 Total 105,535,893 pounds
1859 Total 103,663,927 pounds
1869 Total 162,927,382 pounds
1879 Total 243,157,850 pounds
1889 On farms 18,726,818 pounds
In factories 238,035,065 pounds
Total 256,761,883 pounds
1899 On farms 16,372,330 pounds
In factories 281,972,324 pounds
Total 298,344,654 pounds
1909 On farms 9,405,864 pounds
In factories 311,126,317 pounds
Total 320,532,181 pounds
318
THE BOOK OF CHEESE
Comparing the figures of 1899 with those of 1909, it is
seen that the total production of cheese in the United
States increased 22,187,539
pounds, or an increase of 7.4
per cent in 1909 over 1899.
During the same years the
amount made on the farms
decreased 6,966,454 pounds,
or a decrease of 42.6 per
cent, while the amount
made in factories increased
29,153,933 pounds or 10.3
per cent.
303. Rank of the leading
cheese-producing states.
The rank of the leading
cheese states according to
the number of factories in
1914 was : Wisconsin 1720,
New York 995, Michigan
196, Ohio 111, Pennsylvania
106.
The table on the opposite
page (Table XXI) shows
the amount of cheese pro-
duced by the five states
with the largest number of
factories. This table indi-
cates that New York led in
the production of cheese
until some time between 1899 and 1909. This is proba-
bly because, New York having so many cities, the demand
for market milk is so large that it is sold as such instead
FIG. 66. Showing the cheese fac-
tories in the Pacific coast states.
THE CHEESE INDUSTRY IN AMERICA 319
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THE BOOK OF CHEESE
of being manufactured into cheese. There is about the
same number of milch cows in New York and Wisconsin.
However, Wisconsin is credited with more cheese in 1909
than New York ever produced and this output probably
will increase, as there are considerable areas of undeveloped
agricultural land in Wisconsin. It is also 
