(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Wine-making in hot climates"

! BERKELEY 
-IBRARY 
JKNVERSITY OF 

CAIIFORNIA 














v J 




TMEN1 




DEPARTMENT OF AGRICULTURE. 



VITICULTURAL STATION, RUTHEMLEN, VICTORIA, 



WINE-MAKING IN HOT CLIMATES 



L. R O O 8, 

Director of the (Enological Station of the Herault. 



Translated by 
RAYMOND DUBOIS, B.Sc. (Paris), 

Diplome de I'Ecole d' Agriculture de Montpellier, Director of the 

Viticultural Station, Victoria ; 

AXD 

W. PERCY WILKINSON, 

Private Assistant to the Government Analyst, Consulting Analyst to the 
M. and M. Board of Works. 



$B ^uthoritg : 

ROBT. S. BRAIN, GOVERNMENT PRINTER, MELBOURNE. 
1900. 



10649. 



TRANSLATORS' PREFACE. 



Iii presenting this translation of U Industrie Vinicole 
Meridionale* by Professor L. Roos, to Australian wine- 
makers, the sole aim of the translators has been to render 
a thoroughly modern work on wine-making available, 
of a type of which the necessity has been obvious, and 
frequently commented on for some years. 

The selection of the present work for translation was 
guided principally by the fact f that the climate, and 
conditions of wine-making, in the South of France, for 
which the book was expressly written, are practically 
identical with those of Australia. The new methods and 
innovations in vinification adopted there (as also in 
California) should be applied here without hesitation, if 
we are to keep abreast of recent advances, or rather, of 
our competitors in the export wine trade with Great 
Britain, on which the future expansion and success of our 
viticultural industry largely depends. 

We feel convinced, from an intimate knowledge of the 
actual local conditions of wine-making, that the general 
and immediate adoption throughout Victoria of the 
improved methods of vinification so ably advocated by 
Professor Roos, and already extensively applied in practice 
in the South of France, Algiers, and California, will 
prove of the utmost advantage to our wine industry ; 



* Roos, L., V Industrie Vinicole Meridionale, pp. vi. 326. 8vo. Montpellier 
and Paris. 1898. 

f One of us (R. Dubois) studied for several years under Professor Roos 
at Montpellier. 



804 



and should result in greatly diminishing the quantity ot 
wine annually passed through the still, and in increasing 
the production of sound dry wine of good keeping qualities, 
which will be of higher average market value than hitherto. 

Our earnest hope is that Australian wine-makers will 
accord Professor Roos' book the serious attention and 
consideration it merits, as recording the latest definite 
advances in wine-making in hot climates. 

RAYMOND DUBOIS. 

W. PERCY WILKINSON. 

Viticultural Station, 
Rutherglen, 15th February, 1900. 



WIM-IAKIM IN HOT CLIMATES, 



CHAPTER I. 

FERMENTATION. 

Etymologically, the word fermentation (derived from the 

\h\ fervere, to boil) marks the phenomenon by which the 
transformation of a part of the substances constituting a 
given liquid takes place, the phenomenon being accompanied 
by movements similar to those produced by the boiling of 
a liquid. 

The term fermentation seems therefore only applicable to 
cases where chemical transformations are accompanied by 
a kind of boiling. 

As long as the causes of these chemical transformations, 
of which the bubbling is only the corollary, were not known, 
the above definition sufficed ; but since the cause is known, 
since we know that many other chemical transformations 
although not accompanied by bubbling are similar to those 
which gave rise to the word fermentation, it became neces- 
sary to designate phenomena of the same order by different 
words, or, as has been done, apply to all, despite its etymo- 
logical inexactitude, a word which would have a conven- 
tional signification. 

It is scarcely necessary to speak of Pasteur, as his 
numerous works on this question are . universally known. 
It was he who demonstrated, after the unfruitful researches 
of most eminent scientists, that fermentations were the work 
of infinitely small organisms called microbes. 

All fermentations have a point in common, which is that 
a very small weight of organized matter is sufficient to 
transform relatively considerable quantities of material. 

Thus, a few pounds of beer yeast may produce thousands 
of gallons of that liquid, and a few grains of acetic ferment 
are sufficient to transform a cask of excellent wine into 
vinegar. 

A 2 



4 WINE-MAKING IN HOT CLIMATES. 

Non-organized, often very soluble bodies, are known, 
acting in the same way. For instance, pep sine may trans- 
form a considerable weight of insoluble fibrin into soluble 
peptone. 

Fermentations and transformations of this class are some- 
what similar, and, therefore, the general term of fermenta- 
tion has also been applied to transformations brought about 
by soluble ferments. However, to distinguish the two 
phenomena, the fermentation brought about by organised 
ferments has been called true fermentation, while that 
brought about by the soluble ferments or diastases has been 
named pseudo-fermentation or diastasic-fermentation. 

The microbes or agents of true fermentations exist in 
infinite variety, they are subdivided into several species, 
the principal being moulds, yeasts, mycoderma, micrococci, 
bacteria, bacilli, and vibrios. With regard to the diastases 
they are also in great variety, and bear different names in- 
dicating either their origin or behaviour. That known as 
pancreatine (a mixture of soluble ferments) normally exist- 
ing in the pancreas, plays a very important part in digestion ; 
that called amylase renders the starches soluble. 

As a general principle, all fermentation induces in the 
liquid the disappearance of one or several substances, and 
vice versa, the appearance of one or several new products. 

The most important of all is the alcoholic fermentation. 



ALCOHOLIC FERMENTATION. 

This is a true fermentation, and is, in the great majority 
of cases the work of organised microscopical plants, known 
as yeasts (levures). 

It is the transformation of several substances of an 
analogous chemical constitution (glucose and other sugars) 
into alcohol as the principal product, carbonic acid, glycerine, 
succinic acid, and a few other substances, some of which are 
not yet completely known. 

We say intentionally glucose and other sugars, although 
it is well known that alcohol may be obtained from many 
other substances, starch for example, but these substances 
are not capable of being directly transformed into alcohol 
and secondary products. They must first be transformed 
into glucose or fermentable sugar. 



FERMENTATION. 5 

There are, it is true, a few rare exceptions to this rule, 
and though of very great scientific interest, they remain 
unimportant in practice. 

The transformation into glucose, of substances forming 
alcohol, may be brought abont by chemical means, or more 
often by diastasic fermentations preceding the alcoholic 
fermentation. 

Sometimes, as happens in the case of a large number of 
yeasts, the alcoholic ferment secretes a diastase, bringing 
about the transformation into fermentable sugar. Cane 
sugar, for instance, only gives alcohol after having been 
submitted to a diastasic fermentation, which is indirectly 
the work of the yeast itself, for it is by the aid of a soluble 
ferment, invertine, secreted by it, that the preliminary pre- 
paration is accomplished. 

Starting from glucose, the production of alcohol is the 
result of true fermentation ; starting from cane sugar, it is 
the result of a double fermentation, one diastasic, the other 
true. 

The most searching analyses, made on many different 
cepages, have not revealed in grapes, at maturity, the 
presence of cane sugar in noticeable quantities. 

Grape must only contains glucoses, as directly fermentable 
constituents, the two most important being dextrose and 
levulose, existing in about equal proportions at maturity. 
Therefore, the vinous fermentation can only be regarded as 
a true fermentation. 

Alcoholic fermentations are numerous ; the best known in 
our regions are those furnishing wine, ale, or beer, cider, and 
perry. But the alcoholic beverages used in different 
countries, and prepared from very dissimilar substances 
milk, juice of certain roots are also the result of fermenta- 
tions analogous to those already mentioned. 

They are all produced by related organisms, but yet not 
identical. The Characteristic of their common work is the 
production of alcohol, but they differ individually with 
respect to the weight of alcohol produced in relation to the 
weight of sugar consumed, and by the nature and quantity 
of secondary products formed. 

These secondary products are of two kinds : first, those 
depending on the variety of the ferment effecting the trans- 
formation. 



6 WINE-MAKING IN HOT CLIMATES. 

The products of fermentation, principal and secondary, are 
eliminated by the organisms as the result of their work. 

The researches of Pasteur, justly considered unattaekahle 
from a scientific stand-point, brought about the conceptions 
we have just briefly described. 

The alcoholic ferment is a plant cell, nourishing and re- 
producing itself in a suitable liquid, and, as a result of its 
nutrition, producing new substances utilized by it in turn. 

The agents of alcoholic fermentations are called yeasts, 
and belong to the order Saccharomyces. 

The first studied and best known is the Saccharomyces 
Ceremsia, or beer yeast. 

The Saccharomyces Cerevisiae is composed of cells, which 
appear under the microscope in a lenticular more or less 
globular shape, often elliptic, and sometimes circular. They 
measure, on the average, five or six thousandths of a milli- 
metre in diameter, and are surrounded by a thin membrane, 
the composition of which is approximately that' of cellulose. 

The yeast cells, according to their age, have varied aspects; 
when young they appear turgid, full of non-granular highly 
refractive protoplasm ; when old they seem almost empty, 
shrivelled, wrinkled, with the protoplasm full of pigment, 
and more or less opaque. 

The reproduction of these micro-organisms occurs in two 
different ways, but only one is of interest to the fermentation 
industry, the reproduction by budding. 

It consists in the cell swelling at one point of its surface. 
The swelling is full of protQplasm, and, at the beginning, 
is not differentiated from the protoplasm of the mother cell. 
The swelling is at first very wide at the base, but contracts 
gradually until it forms a true ramification on the mother 
cell. Under ordinary circumstances these ramifications very 
soon become detached. The cells, in groups of two or three, 
become separated, and, isolated or not, become new mother 
cells, ready to reproduce by the same process. 

It goes without saying that to vegetate and reproduce 
normally, the yeasts must find in the liquid they live in. 
besides special physical and chemical conditions, elements 
which are necessary to the constitution of their tissues. 

These elements are of two classes, organic and inorganic, 
as has been proved by numerous analyses of yeasts. 



FERMENTATION. 7 

The thin membranous envelope covering the protoplasm 
seems to consist of a substance analogous, if not identical, 
with cellulose. The following analysis, due to Schlossberger, 
shows this striking analogy : 

Envelope of the Yeast. Cellulose. 

Carbon ... 45-50 ... 44-50 

Hydrogen ... 6'90 ... 6-20 

Oxygen ... 47-60 ... 49-30 



100-00 100-00 



The envelope represents one-fifth to one-sixth of the total 
weight of the yeast in a dry state. The protoplasm has a 
much more complex organic and inorganic composition. 
The greater part is formed of nitrogenous matter, similar to 
albumen ; but contains also fatty substances. 

The inorganic matters represent about 6 per cent, of the 
total weight of the dry yeast, they number about one dozen, 
their respective importance is rather varied. 

Phosphoric acid and potash predominate, the phosphoric 
acid represents over 50 per cent, of the weight of the ash, 
the potash about 40 per cent. 

To conclude, the liquid must offer to the yeast, carbon, 
nitrogen, oxygen, hydrogen, phosphoric acid, potash, and 
traces of other mineral matters, to insure its development. 

In the must or juices used by different fermentation 
industries, the sugars furnish carbon, hydrogen, and oxygen. 
As for the other matters, they exist in various more or less 
complex forms in the liquid itself. The nitrogen in the 
form of albumenoid or even ammoniacal compounds. The 
inorganic matters are constituents of the parts of the plants 
which furnish the must. 

The characteristic of the yeast is that it consumes con- 
siderable quantities of carbohydrates (sugars), retaining only 
a very small proportion (-rVth) for the constitution of its own 
substance. All the rest is transformed into alcohol and 
other secondary products already mentioned. 

The work of the yeast is too complex to be expressed by 
a chemical equation. 



8 WINE-MAKING IX HOT CLIMATES. 

The following simple table will show what becomes of 100 
grammes of glucose under the action of beer yeast, in a 
liquid suitably constituted : 

Alcohol ... ... ... 46-56 

Carbonic acid ... ... ... 48- 36 

Glycerine ... ... ... 3"25 

Succinic acid ... ... ... 0'6 1 

Glucose used by the yeast for its 
constitution, and in the formation 

of not clearly defined products ... T26 

100-00 



VINOUS FERMENTATION. 

The vinous fermentation is that by which the must of 
fresh grapes is transformed into wine. 

Under ordinary conditions, it is a spontaneous fermen- 
tation. The must does not require to be sown with yeast, as 
is often done in the manufacture of other fermented drinks. 

At maturity, the grape is covered with micro-organisms, 
which induce the fermentation of the must. 

This fact was clearly established by Pasteur ; and it is 
only at the time of maturity that the exterior of the grape is 
covered with yeast-spores.* 

Grapes protected against outside dust by proper devices, 
furnish musts incapable of spontaneous fermentation, if 
they are prepared with the precautions necessary to preserve 
them from contamination. 

The particles of dust are fixed on the grapes and stalks, 
and even on any other of the vine organs, by a kind of waxy 
matter. This forms the grape-bloom. 

Most diverse matters are found side by side, mineral 
particles, spores of common mildew, germs of wine yeasts, 
and in still greater number, the germs of a yeast, common 
to all sweet fruits, but, as we shall see, of no great import- 
ance in vinification, this is the apiculate yeast. 

The principal factor in vinous fermentation is the elliptic 
yeast (Saccharomyces ellipsoideus). 

* It was believed for a loner time that the ferment or yeast existed in the 
pulp of the grape. This erroneous opinion is even now quoted by certain 
authors. 



PLATE I. 




Wine Yeast (Young). 



Wine Yeast (Old). 




Apiculatus Yeast. 



FERMENTATION. 9 

In spite of its name it is almost circular, of lenticular 
shape, transparent, like the yeast of beer, and full of re- 
fractive liquid when young and active ; more or less full of 
pigment, opaque, and shrivelled when old or living in an 
unfavorable liquid. 

The dimensions of the elliptic yeast are about five thou- 
sandths of a millimetre each way. Its mode of repro- 
duction is the same as that of the beer yeast, but the 
ramified form is less frequent in the Saccharomyces ellip- 
soideus than in the Saccharomyces cerevisice. 

However, if in reality the elliptic yeast is the principal 
agent of vinous fermentation, it is not so exclusively. The 
apiculate yeast (Saccharomyces apiculatus) is one of the 
most widely distributed in nature. Pasteur was the first 
to indicate its existence on acid and sweet fruits generally, 
and grapes in particular. Reitsch and Martinand * also 
indicated the predominance of apiculate yeast on the 
surface of ripe grapes. 

They have shown, further, that it exists in abundance at 
the beginning of any spontaneous vinous fermentation. 

Its action, however, is only partial, for it cannot live in 
must containing more than 3 to 4 per cent, of alcohol. 

Reitsch and Herselin established this fact by a series of 
conclusive laboratory experiments. f 

The elliptic yeast, on the contrary, is able to work in a 
much more alcoholic liquid. It commonly gives up to 16 
per cent, (by volume) of alcohol, t but it really starts work- 
ing in ordinary cases, that is, in unsterilized musts, only 
when the fermentation has been commenced by the apicu- 
late yeasts. 

For vinous fermentation to take place under good con- 
ditions, and for a must to give not only the maximum 
yield in alcohol, but also that harmony of qualities which 
assures its value, the fermentable liquid should realize 
certain chemical and physical conditions, some of which 
are still obscure, but others very distinctly established. 

Later on, when discussing the vintage, and vinification, we 
will study the influence of the chemical and physical con- 
ditions of the must, on the quality of the wine. We desire 



* Comptes Rendus de 1'Acad. des Sciences, 6 April, 1891. Des micro- 
organismes des raisins murs. 

t Reitsch and Herselin. Progres agricole et viticcle, 1895. 
+ 28 per cent, of proof spirit. 



10 WINE-MAKING IN HOT CLIMATES. 

to draw attention here to the relative inferiority in prac- 
tice, now long known, of the wine-making industry as 
compared with other fermentation industries. 

Defects in qualities of wines are of two kinds. Those 
known as organic, depending on the grape, the cepaye, its 
state of maturity, the atmospheric influences which it was 
submitted to, alterations caused by diseases it may have 
been subject to, &c. 

Against some of these defects nothing very effective can 
be done ; against others, resulting from vine diseases, for 
instance, continual care and efficacious treatment are gene- 
rally sufficient to annihilate them. 

The other qualities or defects, which may be termed 
accidental, are the result of different manipulations to 
which the grapes were submitted during their transforma- 
tion into wine, and of the conditions under which the 
transformation was effected. Theoretically, the transfor- 
mation ought to take place under the exclusive influence of 
the yeasts we have just mentioned, but practically it is not 
so. 

The vinous fermentation generally remains the principal 
result, but side by side there are effected a number of other 
fermentations, which are known as secondary fermentations, 
because they usually have less influence on the nature of the 
product. Their action, however, is never nil in practice, 
and the further the must is from its normal state, the 
greater their importance becomes. 

In all the industries of fermentation of sweet musts, what- 
ever the origin of that must is (brewing, distillation, for 
example), manufacturers do not go groping like blind people ; 
the conditions of these fermentations, on the contrary, are 
carefully studied, and care is always taken to realize the 
most favorable conditions. 

In the wine-making industry this is not done, perhaps 
because it is the most important of all. This seems to every- 
body, however, to be a very poor reason. We are more 
inclined to think that it is because tlie wine-grower does 
not know, and will not take the trouble to frankly regard 
himself as a manufacturer during the vintage time. 

We know what objections will be raised against this 
argument. The grape harvest is only made once a year, 
whereas, the operations of other industries are repeated 
every day. We agree that this is a difficulty, but also think 



FERMENTATION. 1 1 

that it does not justify either a complete lack of observation 
or disregard ; it seems, on the contrary, that the necessity of 
observing the conditions is so much more necessary as the 
occasions are more rare. 

Are there many vignerons who are able to recall the 
behaviour of particular vatfuls of the preceding year, the 
diverse phases of their fermentation, or who possess such 
a stock of observations as to enable them to deduce the 
best conditions for the vinous fermentations ? They are 
rarae aves. 

The characteristic failing of vine-growers is to act without 
method, and the result is an exceedingly great diversity of 
processes used in working the raw material, which, after all, 
does not vary much in composition. 



12 WINE-MAKING IN HOT CLIMATES. 



CHAPTER II. 

STUDY OF THE GRAPES. 

MATURATION. 

The phenomenon of the maturation of fruits has been the 
object of numerous studies. Many eminent scientists have 
tried to solve this captivating problem, but we cannot yet 
state that complete light has been thrown on the subject. 

We shall refer here to a study, dating from the last few 
years only, which is interesting from two points of view 
first, because it summarizes the principal works on the 
subject ; secondly, because it is applied to a very important 
cepage of the southern region of France. 

That cepage is the Aramon, and the Aramon grafted on 
American vines in extensive culture. 

The researches mentioned date from 1891. In that year 
the vine which furnished the samples was not submitted to 
any particular care. In the preceding year it had received 
an ordinary fertilizing with farm manure composed of 
arachide shells litter. 

The plot of ground, situated in the commune of Ville- 
veyrac (Herault), is flat, constituted of clay-limestone soil, 
limited to the west by a departmental road and by private 
roads on the other sides. 

The vineyard, planted with Jacquez in 1884, was grafted 
with Aramon in 1886. 

The samples were taken every fortnight, from the 1st of 
May to the 21st of September, 1891. The vintage took 
place on the 28th September. 

The first sample taken on the 1st May represents the 
whole of the buds ; but, from the 15th of May, it was pos- 
sible to separate the three principal aerial organs the 
grape, leaf, and branch and to analyze each separately. 

In this study we will consider more particularly the for- 
mation of sugar in the grape. 



STUDY OF THE GRAPES. 13 

FORMATION OF SUGARS IS THE GRAPE.* 

" Although these experiments were not carried out with 
the exclusive object of throwing light on the controversy as 
to the origin of sugars, we shall see that the results may be 
valued, in presence of the principal hypothesis actually 
existing on the genesis of the sugars in grapes. As happened 
with Fortes and Ruyssen, we found ourselves confronted with 
three theories to explain the essential phenomena of matura- 
tion diminution of acids and augmentation of saccharine 
matters for, as we have seen, these two phenomena occur 
at the same time. 

" 1st. The theory which regards tannin as the generator 
of sugar. 

" 2nd. The theory which considers starch as the principal 
source of almost all the organic principles. 

" 3rd. The theory which accords to the acids the part 
played by starch in the above theory. 

" We have not followed the tannin in the various phases 
of vegetation, and cannot therefore express an opinion on 
the first of these theories. It has been, however, almost 
completely abandoned, 

" With regard to the second, we searched for starch in the 
different organs and succeeded in detecting it under the 
microscope, in small spherical granules, greenish, but not 
coloured blue by iodine, and not luminous in polarized light 
with the Nicols crossed. Only a few granules of an 
irregular shape were coloured blue by iodine. 

" The starch with these two characteristics was only found 
in the seeds of the grape. The granules, however, were 
smaller than those of ordinary starch comparable in dimen- 
sions to those of rice starch. 

a We cannot conclude from these succinct results that 
starch only exists in small quantity, or not at all, in the 
different organs of the vine. Sachs, Cuboni, Schimper, with 
less rudimentary methods, consisting of eliminating the 
chlorophyll by a preliminary treatment, have detected and 
even estimated the starch in vine leaves ; we have no wish 
to depreciate the results obtained by these observers, without 
previously obtaining the support of more convincing experi- 
ments. 

* L. Roos & E. Thomas. Contribution a 1'etude de la vegetation de la 
vigne. (Ann. Agronomiques.) 



14 WINE-MAKING IN HOT CLIMATES. 

" Starch seems, therefore, to exist in the leaves, and, in a 
general way, in all the green parts of the plant ; it may 
therefore be considered as the source of the more or less 
numerous organic products, particularly the saccharine 
matters. 

" But this hypothesis has been contradicted by Buignet, 
who, to begin with, contests the presence of starch in acid 
fruit. 

" In admitting its presence in the plant, he adds that its 
transformation could not in any case furnish the sugar of 
the fruits, as this sugar is Isevogyre, while the glucose 
derived from starch is dextrose, with a rotation of + 53. 
This is an argument which seems to dispose of the opinion 
of Alessandri and Pollacci,* who assert that the sugar is the 
result of the saccharification of the starch in the pips or 
seeds ; and that of Leon Brasse,| who studied the trans- 
formation of starch in a great number of different leaves, 
amongst which, it is true, the vine leaf does not figure, and 
demonstrated that a soluble ferment, amylase, existed in 
all leaves, capable of saccharifying not only the soluble 
starch, but also crude starch. 

" This appears convincing, but to be really so it would be 
necessary to know if the vine starch exists only in one 
modification, and if that modification is that furnishing 
dextrose by saccharification. 

" We know that the sugar resulting from saccharification 
of inuline is Isevogyre, and it is not proved that inuline does 
not exist in the vine. 

" Previous observations due to Deherain established that 
the rotation of fruit sugars, though at first decidedly positive, 
diminishes progressively and passes to minus. Later on, 
Prof. Bouffard, of the School of Agriculture, Montpellier, 
arrived at similar results while studying Aramon must. 
Our results entirely confirm those of the two above authors, 
and allow us to affirm that grape-sugar is composed of an 
admixture of glucoses in which dextrose predominates before 
maturity. 

" Buignet asserts that the sugar of fruits is at first in the 
state of cane sugar, which, later on, by inversion yields 
glucoses. But the argument he advances against the 

* Botanische Zcitung, 1883. 

t Dissolution de 1'amidon dans les feuilles. Ann. Agronom., t. xii. 



STUDY OF THE GEAPES. 15 

amylaceous origin may be turned against him, for if it is 
true that grape-sugar has about the same composition us 
inverted sugar in the fruit at maturity, this is not true if 
it is considered before that epoch, and the inversion giving a 
mixture in equal parts, Isevogyre, of dextrose and levulose, 
could not at any moment produce a sugar of positive 
rotation. 

" To conclude this matter, Boehm has proved that the 
leaves form starch with the aid of sugar, and that, by sub- 
mitting plants normally exempt from starch to the action 
of a saccharine solution, one can, after a while, distinctly 
detect the formation of starch. 

" Schimper, arguing from his own experiments and those 
of Boehm, concludes that the appearance of starch in the 
leaves being always posterior to that of glucose, this 
cannot have an amylaceous origin, at least in the leaves ; 
its accumulation in the fruit would therefore be the result of 
a direct migration in the shape of glucose, or an indirect 
migration of the glucose transformed previously into ordi- 
nary starch, and further into soluble starch, which would 
pass inro the berry to become saccharified. 

"Amylase operates, no doubt, in rendering the starch 
soluble, and subsequently in saccharifying it. 

"It is also to that ferment that the disappearance of 
cane sugar should be attributed. 

" However, it is possible to admit that the inversion of 
the crystallizable sugar furnishes a part of the glucoses 
detected in the fruit, that a part of those glucoses emanates 
from the starch, the dextrose being furnished by the 
ordinary starch, the levulose by a kind of inuline, or, as 
we will see later on, might have a different origin. 

" Let us now examine our results, in comparison with 
the theory which sees in the transformation of the acids 
the genesis of the sugars. 

"From the weights of the grapes, leaves, branches, and 
the number of branches gathered for each experiment, 
we intend to establish the composition of an average 
branch, starting from the 28th June, the date at which 
the blooming is completely achieved ; and . place in 
juxtaposition the absolute quantities of acids expressed as 
sulphuric acid, of saccharine matter as glucose, and of the 
ashes contained in the different organs. 



10 



WINE-MAKING IX HOT CLIMATES. 



g 

53 

B 







^ ^ 


i 

(M 


CC 


1 

CO 


I 


<M 

P 


^ 


<* 
3 

H 


i 


sau^o 


b 


b 


I 
O 


b 


1 

o 


CO 

o 




r-i 


g 

s 

<< 


< 




te ^~- 


! 


1 


I 


: 


CO 


cc 

CO 


33 




- 


Sc ^ 
b 


i 

b 


1 


I 


S 


1 


1 


02 f 

* a 



^ 

a 

o 
*n 




j 


CO 


CC 


^J 


cc 





I 

CO 


! 


UANTITIES 
), AND OF 


Acidity 
sed as Sulphuric 


sa.vBaq 


C & 

b* T 1 
O 

^ 


b 
b 


2 

p 

o 

O5 

b 


1 

o 

T 
CO 

b 


1 

b 

5 

b 


cc 

s 

b 

b 


i 



1 

b 


is 


1 

vS 


,^o 


b 


CO 

0- 

CO 


c? 


1 


1 


CO 


00 
CO 


gs. 


V 


W o, 


*l 


1 


1 

CO 


s 


1 


k 


g 
1 


^ 

H 

K ^ 


J 





CO 

^ s 




b 


1 

b 


b 


b 


b 


b 


M^ : 

H^ 

HH fcH 


1 





^? 


8 

Oi 

b 


I 


! 


I 


cc 

T-l 


CO 


^ S 

tc 3 

K w 


>i- 


,^0 


b 


iH 


1 


o 

CO 


1 


. 1 


1 


^ 

^ 


j< 




6| 


CO 
rr 


I 


p 


CO 


CC 

9 


p 



^ H 
1^ 


j< 


> ^q^ia.w 


p 
Sc 


ff> 


p 


1 


CO 


p 

1 


cc 


C 

M O 

> P 
*** _ 


j< 




^ CQ 


1 


cp 


CO 


- 

1 1 


CO 


CO 

g 


^ a 
5 


u 


[ q^uaq 


"* b 





g 


p 


8 


^ 


s 


" <! 





























2 to 

S CO 

be 


i 


9 


p 


p 


p 


i 


COMPOSIT 


1 

1 

c 


5 
i 

^ 


5 

c 

c 
a 

1-5 


"3 


s 


1 


cc 


3T 

CQ 


= 



STUDY OF THE GRAPES. 



17 



" To enable these results to be readily grasped, we have 
expressed them by a graphic curve indicating the elements 
in absolute value at different epochs. 



ABSOLUTE QUANTITIES. OF SACCHARINE MATTER (AS 
GLUCOSE), OF ACIDITY (AS SULPHURIC ACID), AND ASH 
CONTAINED IN AN AVERAGE CANE. 

Sugar. 



Acids. 



28 June | 12 July | 26 July | 9 Aug. | 23 Aug. | 6 Sept. | 21 Sept. 

" We have seen previously that the percentage strength of 
the sugar in grapes increases at the precise moment that 
the production of acidity diminishes. If we consider the 
absolute value of the grape, and the average branch, it is not 
so any more ; the acidity constantly increases in absolute 
value up to the 23rd August, and the formation of sugar is 
observed at the same time. 

" The augmentation of the sugar is even enormous, from the 
9th to the 23rd August, for it is during that period 25 times 
greater than that observed previously for equal intervals. 

"The variations of the acidity and saccharine matter 
therefore seem independent of each other at least up to the 
23rd August. From that date the saccharine matter 
increases considerably up to maturity, but we observe at the 
same time, a great diminution in the quantity of the acid. 

10649. B 



18 WINE-MAKING IN HOT CLIMATES. 

It seems impossible to admit that the total sugar is derived 
from the acids, for we notice that the absolute quantity of 
each increases simultaneously. At the same time, we cannot 
say that the acids do not furnish their contingent of sac- 
charine matter. 

" Fremy noticed that the acid reaction of fruits 
diminishes with ripening, but he also notes that in a great 
many cases the acids of the fruit do not disappear, but 
become neutralized by combining with the bases circulating 
in the plant. If that reaction really occurs in the vine 
there should be an increase in the weight of the ashes at the 
precise moment that the free acids disappear. 

" In fact, we notice between the 23rd August and the 6th 
of September a marked increase in the weight of the ash 
we cannot say that the totality of the acids disappeared, or 
have become combined with the bases. For in the preced- 
ing intervals the weight of the ash was increasing together 
with the acids. To fix with certainty the destiny of the 
acids, we ought to be able to measure the whole of the acid 
produced during a given time. In other words, to know 
and measure all the acids, at first free, and afterwards 
combined. 

" It seems to us that a part of them at least is utilized 
in the formation of organic salts, the bases of which are 
found in the ashes. 

" What becomes of the remainder ? 

" Although we cannot state that the acidity decreases in 
absolute value when the saccharine matter is augmenting, 
we may at least notice that when the acidity decreases, the 
sugar, composed in greater part of dextrose, changes its 
composition. 

" This change is very distinctly shown by the polarimetric 
deviation, which from slightly plus or nil passes to minus, 
and increases in that direction up to maturity. 

" It will be easily conceived that the necessity for perfect 
washing, and of diluting the matter in a large volume of 
water, prevented us from making precise polarimetric obser- 
vations. We noticed slight plus deviations up to the 
23rd of August, and at that date the must, which contained 
5*3 per cent, of glucose, showed no deviation whatever ; on 
the 6th September the must contained 9 per cent, of glucose, 
and the observed deviation in a 20-centimetre tube was 
-12. 



STUDY OF THE GRAPES. 19 

" The augmentation of sugar may, therefore, be attributed 
for the greater part, to the formation of levulose during that 
period. 

" Prof. Bouffard, already mentioned, concludes in the same 
way. according to experiments made by him on Aramon 
cepage, that the dextrose is first formed, and that the 
levulose appears later on. 

" As the result of our observations, it appears that the 
diminution in absolute value for the acidity, is always accom- 
panied by an augmentation of levulose in the fruit, and one 
is led to think, that if the acids contribute to the fermentation 
of sugar, it is the levulose that originates from them. 

" We certainly do not want to generalize this hypothesis, 
or even to apply it to the Aramon cepage in an absolute 
manner. Our experiments, only conducted during one year, 
and under given conditions as to soil and climate, ought 
to be confirmed by new studies or experiments made under 
different conditions as to soil and climate. 

" We may add that on the 10th August, the acidity of the 
grapes was constituted by more than 50 per cent, of free 
tartaric acid, which progressively diminished, and on the 
21st of September was not detectable." 



COMPOSITION OF RIPE GRAPES OF DIFFERENT CEPAGES IN 
THE SOUTH OF FRANCE. 

The succinct study of the phenomena of ripening which 
we have just considered, is only of theoretical interest to the 
wine-making industry. 

The knowledge of the immediate composition of grapes at 
vintage time is of much more direct interest. 

Until recently no complete study of the subject had been 
made. Girard and Lindet have filled this gap, and we will 
borrow from their very conscientious and complete work, a few 
general ideas on the composition of the different parts of the 
fruit, and figures relating to the principal cepages of the 
South of France.* 

With regard to its apparent structure, the grape is divided 
into two parts. 

The stalk, that is to say, the ligneous and herbaceous parts; 
and, secondly, the berries borne by it. 

* A. Girard and L. Lindet. Composition des raisins des principaux 
cepages de France. Bulletin du Ministere de I' Agriculture, Paris, 1895. 

B 2 



20 WINE-MAKING IN HOT CLIMATES. 

The berry comprises three principal organs : the skin or 
pellich (outside envelope); the pulp, mass of cells filled 
with juice ; the pips or seeds, reproductive organs, generally 
disposed symmetrically around the centre of the berry. 

Each of the four parts composing the fruit the support, 
pellicle, pulp, and seed has a special composition. Each 
brings to the vat special substances exerting a favorable or 
unfavorable influence on the wine, proportional to the abso- 
lute quantity of active substances they may contain. 

As far as vinification is concerned, the grape consists of a 
liquid part the must, and a solid part the marc. 

The must alone contains all the substances necessary to 
the fermentation of white wine, sometimes even of a reddish 
wine, and contains all the substances necessary to the life of 
the vinous yeast. 

These are, placed in their order of importance (water 
excepted) : 

Glucoses : dextrose and levulose. 

Organic compounds, acid or not. 

Salts of organic acids (bitartrate of potash). 

Mineral or inorganic salts, phosphates, sulphates, traces of 
chlorides, &c. 

The mixture of dextrose and levulose is the most important 
part of the must, these sugars constitute its value, deter- 
mining the future alcoholic strength, and give to the wine its 
vinosity through the three principal bodies formed as the 
result of their transformation, alcohol, glycerine, and succinic 
acid. 

The organic acids and the acid salts of the must are of 
secondary importance, but of such relative importance that 
every vine-grower ought to be able to determine the exact 
amount of acidity in must. 

It is this acidity which renders the must more favorable 
to the alcoholic than any other fermentation, when its per- 
centage is sufficient. It may therefore be necessary to in- 
crease in practice the amount of the acidity. This operation 
is often done ; although very frequently in a rather empirical 
manner, sometimes by acidifying musts which would do much 
better without it, and not acidifying musts enough which 
really need the addition. 

AVe shall refer again later on to this operation, as the 
only one we consider useful for the improvement of certain 
defective vintages. 



STUDY OF THE GRAPES. 21 

The other substances contained in the must contribute to 
the formation of extractive and mineral matters, after having 
served to nourish the yeast. 

The must extracted from the interior of a berry without 
coming in contact with the outside of the fruit is sterile, and 
will not ferment. It is through the crushing of the grapes, 
and washing of the skins by the must, that the sowing with 
yeast occurs. 

The marc, constituting the solid part of the grape, includes 
the stalks, skins, ligneous part of the pulp, and seeds. 

The fermentation of red wine takes place in the presence 
of all these organs, unless submitted to special treatment, 
such as stemming or removal of seeds ; each of these may 
impart to the wine defects or qualities which it is well to 
know. Stemming, and removal of the seeds, are opera- 
tions, especially the latter, rarely used in the manufacture of 
common wines. 

The stalks contain a number of substances studied by the 
Italian Professor Comboni. It would not serve any useful 
purpose to describe these in detail, it will suffice to indicate 
the principal effect of the stalks. 

They contain tannin which is dissolved by the wine. This 
is beneficial, but we must not confuse the true tannin exist- 
ing in small amount in the stalks with certain substances of 
a disagreeable, bitter, and astringent taste which may pass 
into the wine. 

These substances, which may all be summed up under the 
heading, organic acids and salts, are detrimental to the 
finesse of the wine, as well as to its preservation and im- 
provement. It is this particular astringent taste of wines 
fermented on the stalks which resulted in erroneously 
attributing to them an excessive richness in tannin. This 
was a mistake ; for Coste-Floret, who advocates with firm 
conviction the operation of stemming, has proved that the 
difference of richness in tannin was very slight between a 
stemmed and non-stemmed vintage. 

On the contrary, Prof. Bouffard asserts that stemming 
sensibly diminishes the richness in tannin in the proportion 
' of 1-15 to 1-60 for the Aramon. 

We are, therefore, confronted with two conflicting state- 
ments. 

In reality, the stalks of ripe grapes contain only a small 
amount of tannin, and even if they did not furnish any to the 



22 WINE-MAKING IN HOT CLIMATES. 

wine, their presence would play a useful part, that of sub- 
dividing the marc and facilitating the penetration of the 
surrounding liquid. 

They may prove inconvenient on account of the detri- 
mental substances already mentioned, and this will certainly 
be so if the proportion of stalks is too great. This is very 
rarely the case for the cepages in the South of France, if the 
length or duration of the maceration is not too prolonged, 
and if the temperature of fermentation does not become too 
high. 

Under the influence of excessive temperature and pro- 
longed contact with the liquid, the cells of the stalks are 
softened and disintegrated, and the matters or bodies they 
contain are directly exposed to the solvent action of the 
surrounding liquid, helped to a great extent by the elevated 
temperature. This inconvenience is considerably diminished, 
or even stopped, if the duration of maceration is reduced and 
the temperature maintained between recognised limits. As 
the stalks introduce into the wine elements which assist in 
the formation of a good foundation, and their presence being 
mechanically useful, we are inclined to think that preliminary 
stemming should not be employed in the case of wines for 
ordinary consumption. We do not find in this practice 
marked economical advantages, especially if we reduce the 
noxious influence of the stalks by well-conducted fermen- 
tation. 

Later on, when discussing stemming, we will go into the 
question more fully, and give precise opinions about this 
practice. 

The pellicle or skin constitutes the most important solid 
organ of the grape in the vinification of red wine. It brings 
with it the colour, most of the tannin, a notable proportion 
of extractive and mineral matter, and the greater part of 
the germs of yeast. 

Armand Gautier* has carried out important researches 
on the colouring matter of the grape, and more successfully 
than previous investigators. From the study of this sub- 
ject he was enabled to establish the formation in the 7 leaf 
of coloured matters, derived from colourless substances 
producing ampelochroic acids, which, migrating from the 
leaf towards the fruit, constitute in the pellicle different 
colouring matters now known as cenolic acids. 

* Comptes rendus, vols. 84 and 114. 



STUDY OF THE GEAPES. 23 

These cenolic acids are all red, but of various shades, 
according to the cepage: They give the colour to the skin 
of the grape, and exist in great variety, their chemical 
composition, although not exactly identical, is close enough 
to allow it to be practically considered so. 

These colouring bodies are distributed in the cells at the 
periphery of the grape under the epidermis, in the majority 
of cepages. 

Quite characteristic is their insolubility in water, except, 
however, in cepages teinturiers, or varieties derived from 
them, such as Bouschet hybrids. 

They are slightly soluble in strong, but not in weak acids. 
This explains the possibility of making white wine from red 
grapes (a great number of cepages at least) as the colouring- 
matter does not find in the must before fermentation a 
proper solvent.* 

The oanolic acids form a chemical group, the properties 
of which closely resemble those of the tannins, as has been 
established by Louis Hugounenq.t We, therefore, see at 
once the importance of the pellicle, for through its oanolic 
acids and pure tannins it furnishes the wine with useful 
tannin-like substances. 

The action of the tannins is very favorable, they are good 
antiseptics and powerful preservatives against the possible 
future deterioration of the wine. On the other hand, they 
communicate to the wine that special flavour called by wine 
tasters charnu, mdcke, grain. 

The pellicle also contains an important odoriferous sub- 
stance which has been carefully studied by Girard and Lindet. 

" One of the most interesting facts, noticed by us during 
the analytic study of the different parts of a grape, is the 
localization in the cellular tissue of the skin of an odorifer- 
ous substance which gives to the wine of each cepage an 
essential and peculiar character this substance is totally 
distinct from the bouquet, which is only formed gradually 
as the wine becomes matured. 

* According to recent experiments made by Rosensthiel, this opinion may 
be disputed, at least as far as the fruit sugars are concerned, if not the water. 
Rosensthiel proved that, when out of contact with air, the colouring matter of 
fruits is dissolved in their juice by prolonged contact, and especially at an 
elevated temperature; this, it is understood, without interference of fermenta- 
tion, in other words, in absence of alcohol. He goes so far as to state that we 
may preserve the must with the colour, flavour, and perfume of the fresh fruit. 
A very easily conducted experiment shows that the colouring matter of the 
grape is not 'soluble in water. It suffices to dilute with water a concentrated 
alcoholic solution of the colouring matter to precipitate it as a powder. 

t JZecherches nouvelles sur le vins. Imp. A. Storck, Lyon. 



24 WINE-MAKING IN HOT CLIMATES. 

" All oenologists know that every wine resulting from the 
fermentation of a particular cepage has, especially while the 
wine is young, a characteristic flavour. The wines made 
from Aramon and Carignane, for instance, from the South 
of France, and those from Pinot and Garnay, from the Bour- 
gogne cepages, differ entirely from each other. 

" Expert tasters can differentiate these odours, which 
must not be confused, as is often done, with the so-called 
earthy taste. It is not the climate nor soil which determines 
it, they are peculiar to each cepage, and are often sufficient 
to characterize it. The influence of climate and soil only 
modifies them. 

" The origin of these odours has not been indicated up to 
the present. Our researches enable us to state that they 
must be sought for in the cellular tissue of the skin, where, 
ready formed, this odorous matter, which imparts the 
character to the wine, exists side by side with the colouring* 
matter, which determines the robe of the wine. 

Vergnette-Lamothe had, it is true, so far back as 1867,* 
originated the idea that certain essential odoriferous oils 
existed in grape skins, but the part played by them, and their 
nature, had not been ascertained so far. 

" It is only in studying the weak alcoholic solutions from 
macerated skins for the estimation of the colouring matter 
and tannin, that we recognise the importance of this obser- 
vation. 

" Each of these solutions after a few days was impregnated 
with a strong odour reminding us of the flavour of young 
wine, and were easily differentiated from one another even 
by non-expert observers." 

The seeds contain a fatty oil which is fairly abundant, and 
a number of substances some of which would be detrimental 
to the wine, if they were dissolved. 

Fortunately, the most useful substance the seeds may yield 
to the wine, tannin, is placed near the periphery in such a 
way that it enters into solution before any of the others are 
appreciably affected. The increase in tannin due to the 
presence of the seeds is not positively proved, although some 
authorities believe that that substance is completely and 
quickly dissolved. 

According to Girard and Lindet, " the seed also contains 
a resinous matter, the formation of which seems to be in direct 



* Le Vin, by Vergnette-Lamothe, p. 335. 



STUDY OF THE GKAPES. 25 

proportion to that of the tannin ; volatile acids are also con- 
tained, which apparently belong to the fatty series. They 
result from the saponification and oxidation of the neutral 
oil contained in the nucleus of the seed. 

" The resinous matter is easily soluble in alcohol, slightly 
soluble in boiling water, and almost insoluble in cold water. 

" By evaporation of these solutions it is deposited in the 
form of a light-brown powder, which tastes harsh when 
recently prepared but gradually becomes sweetish. 

" It may be dissolved in alkaline liquids and precipitated 
from the combination so formed by the addition of an acid. 
It is easily oxidizable, especially in the presence of alkalies, 
and through oxidation loses the above-mentioned properties. 

"To summarize, it is analogous to ordinary resins, but 
more rapidly alterable, and may be placed provisionally on a 
level with the product extracted from the bark of certain 
trees by Hoffstetter and Stahelein, and named by them 
Phlobaphenes. 

" Amongst the properties mentioned above, one of them 
cannot fail to attract the attention of osnologists, namely, 
that the harsh taste is progressively attenuated by time 
that attenuation enables us to account for certain long- 
known changes in the taste of maturing wines. 

" But the presence of volatile acids detected in the seeds 
is still more important they probably play an important 
part in the production of the bouquet." 

We are inclined to think that Girard and Lindet place an 
exaggerated importance on the substances contained in the 
seeds. The analogy of the action of time on those substances, 
compared with its action on wine itself, does not seem to 
be sufficient to credit them with such importance. The 
harshness of young wines is generally recognised ; it exists 
in stemmed red wine, and even red wines fermented without 
the seeds ; and even in white wines, fermented without 
contact with either skins or seeds. 

However, if the seeds are not crushed and they never 
should be their presence is harmless. The epidermis is 
impermeable enough to prevent the solution of the substances 
contained in them, which might exercise a detrimental in- 
fluence on the wine. Besides, they are contained in the 
centre cells, and their solution is not to be feared, provided 
that the epidermis is not softened by too prolonged macera- 
tion. 



26 WINE-MAKING IN HOT CLIMATES. 

In short, in the South of France, all the solid parts of the 
fruit may remain in contact with the must during fermenta- 
tion, in the manufacture of red wine. Their presence pre- 
sents some advantages and very few inconveniences. 

COMPOSITION OF GRAPES OF THE PRINCIPAL 
"CEPAGES" OF THE SOUTH OF FRANCE. 

AKAMOX "CEPAGE." 

Constitution of the bunch. 

1893. 1894. 

Stalks ... ... ... 4-07 ... 3-65 

Berries 95*93 96-35 



100-00 100-00 



Constitution of a berry of average weight 3-69 gr. 

Pulp ... ... ... ... 88-81 

Skin ... ... ... ... 9-45 

Seeds ... ... ... ... 1-74 

100-00 



The 88*81 per cent, of pulp represented 83*4 litres of 
juice per 100 kilos, of berries. 

Chemical composition of the pulp representing 88*81 per cent, 
of the weight of berries. 

1893. 1894. 

Density of juice ... ... 1-064... 1-056 

Water ... ... ... 82-46 ... 

Fermentable sugar... ... 14-09 ... 11-48 

Bitartrate of potassium ... 0*62 ... 0-51 

Free tartaric acid I* n o Q TO- 12 

Malic and other acids / '" \ 0-68 

Nitrogenous matter ... 0-27 ... 

Matters not estimated ... 1*61 ... 

Mineral mattersf ... ... 0*13 ... 

Ligneous insoluble ... 0*43 ... 

100-00 



* Expressed as malic acid. The figure for 1893 appears very small and is 
met with quite rarely. L. R. 

t The potash in combination with tartaric acid deducted. 



STUDY OF THE GEAPES. 27 

Chemical composition of the skin = 9-45 per cent, of the 
weight of the berry. 

1893. 1894. 

Water ... ... ... 76-80 ... 

Tannin ... ... ... 1-27 ... 

Bitartrate of potash ... 

Free acids* ... x 

Ligneous... ... ... 20-10 ... 

Mineral matters ... ... 1-83 ... 

100-00 



Chemical composition of the seeds = 1-74 per cent, of the 
weight of the berry. 

1893. 

Water ... ... ... ... 34-82 

Oil ... ... ... ... 6-92 

Volatile acidsf ... ... ... 0-57 

Tannin ... ... ... ... 2-56 

.Resinous matters ... ... ... 4-45 

Ligneous ... ... ... ... 48-82 

Mineral matters 1-86 



100-00 

Chemical composition of the stalks 3-85 per cent, 
(average) of the grapes. 

1893. 1894. 

Water ... ... ... 79*66 ... 78-91 

Tannin ... ... ... 1-23 ... 2-52 

Resinous matters ... ... 1-07 ... 0-87 

Bitartrate of potash ... ... 0-92 

Free acids J ... ... ... 0*33 

Ligneous ... ... 15-71 ... 14-49 

Mineral matters ... ... 2-33 ... l-96 



100-00 



* Expressed as tartaric acid. 

1* Expressed as sulphuric acid. 

+ Expressed as tartaric acid. 

The potash in combination with tartaric acid deducted. 



28 WINE-MAKING IN HOT CLIMATES. 

CAEIGNAN CEPAGE. 

Constitution of the bunch. 

1893. 1894. 

Stalks ... ... ... 3-00 ... 2-91 

Berries ,.. ... ... 97-00 ... 97-09 

100-00 , 100-00 



Constitution of a berry weighing 2-58 grammes. 

1893. 

Pulp ... ... ... ... 89-40 

Skin ... ... ... ... 7-60 

Seeds ... ... ... ... 3-00 

100-00 

The 89*40 per cent, of pulp represented 83 litres of must 
per 100 kilos, of berries. 



Composition of the pulp=89'4:0 per cent, of the weight 
of berries. 

1893. 1894. 

Density of juice ... ... 1*076 ... 

Water ... ... ... 77*85 ... 

Fermentable sugar ... 16*12 ... 12*64 

Bitartrate of potash ... 0*62 ... 

Free tartar ic acid ... ... 1 n - Q 

Malic and other acids .../ 

Soluble nitrogenous matters ... 0*18 ... 

Matters not estimated ... 3*80 ... 

Mineral matters ... ... 0*17 ... 

Ligneous insoluble 0*68 



100*00 



STUDY OF THE GRAPES. 29 

Chemical composition of the skins=7'6Q per cent, of the 

berry. 

1893. 1894. 

Water ... ... ... 73-76 ... 

Tannin ... ... ... 1-61 ... 

Bitartrate of potash ... ... 1-Q7 

Free acid ... ... ... 0-70 

Ligneous and not estimated ... 22- 73 ... 

Mineral matters ... ... 1-90 ... 

100-00 



Chemical composition of the seeds ;3 per cent, of the weight 
of the berry. 

1893. 

AYater ... ... ... ... 33'28 

Oil 7-81 

Volatile acids ... ... ... 0-81 

Tannin ... ... ... ... 0*31 

Resinous matters ... ... ... 1-35 . 

Ligneous and not estimated ... ... 54-66 

Mineral matters ... ... ... 1-78 

100-00 



Chemical composition of the stalks = 2-41 per cent, of the 
weigh t of the bunch . 

1893. 1894. 

Water ... ... ... 69-50 ... 72-00 

Tannin ... ... ... 1-01 ... 1-02 

Resinous matters ... ... 0-85 ... 1-21 

Bitartrate of potash ... ... 1-10 

Free acids ... ... ... 0-48 

Ligneous and not estimated ... 25-96 ... 22-09 

Mineral matters ... ... 2-68 ... 2-10 

100-00 , 100-00 



30 WINE-MAKING IN HOT CLIMATES. 

PETIT-BO USCHET CEP AGE. 

Constitution oj the hunch. 

1893. 1894. 

Stalks ... ... ... 4-40 3-82 

Berries 95-60 96-18 



100-00 100-00 



Constitution of a berry weighing 1-95 grammes. 

1893. 

Pulp ... ... ... ... 85-80 

Skin ... ... ... ... 11-36 

Seeds ... ... ... ... 2-84 

100-00 



The 85*80 per cent represented 80*8 litres of must per 100 
kilos, of berries. 



Chemical composition of the pulp =85*80 per cent, of th( 
weight of berries. 

1893. 1894. 

Density of juice ... ... 1-061 ... 

Water ... ... ... 82-11 ... 

Fermentable sugar ... 15*74 ... 15'80 

Bitartrate of potash ... 0* 

Free tartaric acid 

Malic and other acids 

Soluble nitrogenous matters... 0-22 

Matters not estimated ... 0-68 

Mineral matters ... ... 0-08 

Ligneous insoluble... ..." 0-33 



... 0-18 ... 0-56 



100-00 



STUDY OF THE GKAPES. 31 

Chemical composition of the skin 1\-^ per cent, of the 
weight of the berry. 

1893. 1894. 

Water ... ... ... 77.94 _ 

Tannin ... ... ... 1-Q6 

Bitartrate of potash ... ... j Q3 

Free acids ... ... 

Ligneous 
Mineral matters 



100-00 



Chemical composition of the seeds 2'84 per cent, of the 
weight of the berry. 

Wato 38 . 02 

011 ... ... ... 4-48 

Volatile acids ... ... ._ 

Tannin .. ... ... .'.'.' 2-26 

Resinous matters ... ... 4.97 

Ligneous and not estimated ... ... 49-41 

Mineral matters ... 1-76 



100-00 



Chemical composition of the stalks 3*82 per cent, of the 
weight of the bunch. 

1893. 1894. 

Water ... ... ... 80-30 ... 76-52 

Tannin ... ... ... (>89 ... 1-05 

Resinous matters ... ... 1-01 ... 1-24 

Bitartrate of potash ... ... 1-26 

Free acids ... ... ... 0-26 

Ligneous and riot estimated ... 15-40 ... 17-63 

Mineral matters 2-40 2-04 



100-00 100-00 



32 WINE-MAKING IN HOT CLIMATES. 

PICQUEPOUL BLANC CEP AGE. 
Constitution of the bunch. 

1893. 1894. 

Stalks ... ... ... 4-15 ... 3-04 

Berries ... ... ... 95-85 ... 96-96 



100-00 , 100-00 



Constitution of a berry weighing 2-62 grammes. 

1893. 

Pulp 91-90 

Skin ... , 5-63 

Seeds ... ... ... ... 2-47 

100-00 

The 91-90 per cent of pulp represented 86*6 litres of must 
per 100 kilos, of berries. 



Composition of pulp = 91-90/>0r cent, of the weight of the 

berries. 

1893. 1894. 

Density of juice ... ... 1*060 

Water ... ... ... 80-67 ... 

Fermentable sugar ... 15-88 ... 16-68 

Bitartrate of potash ... 0-53 ... 

Free tartaric acid { n AA A . Q1 

ii/r v J .LT_ ' ~\ ( v OO ... U ol 

Malic and other acids ) 

Nitrogenous matters ... 0*21 ... 

Matters not estimated ... 1*42 ... 

Mineral matters ... ... 0*30 ... 

Ligneous insoluble ... ... 0*33 ... 

100-00 



STUDY OF THE GEAPES. 33 

Chemical composition of the skin = 5-63 per cent, of the 
weight of the berry. 

1893. 1894. 

Water ... ... ... 73*52 ... 

Tannin ... ... ... O50 ... 

Bitartrate of potash ... ... 0*80 

Free acid ... ... ... O49 

Ligneous and not estimated ... 24-29 ... 

Mineral matters ... ... 1-69 ... 

100-00 

Composition of the seeds = 2-47 per cent, of the weight of 

the berry. 

1893. . 

Water ... ... ... ... 31-31 

Oil ... ... ... ... 8-81 

Volatile acids ... ... ... 0'64 

Tannin ... ... ... ... 0*81 

Resinous matters ... ... ... 1-40 

Ligneous and not estimated ... ... 55*66 

Mineral matters .. ... ... 1-33 

99-96 

Chemical composition of the stalks = 3-50 per cent, (average) 
of the bunch. 

1893. 1894. 

Water ... ... ... 75-48 ... 72-24 

Tannin ... .... ... 1-30 ... 2-33 

Resinous matters ... ... 0-81 ... 1-40 

Bitartrate of potash ... ... 1-15 

Free acids ... ... ... 0-35 

Ligneous and not estimated ... 20-59 ... 21 -14 

Mineral matters 1'82 ... 1-38 



100-00 99-99 



The grapes used for the manufacture of red wine bring 
to the vat soluble and insoluble matters, which co-operate 
in the formation of the wine. The former are submitted to 
a chemical transformation or are simply dissolved in the 
liquid ; the latter play a mechanical part, which cannot be 
disregarded. 

10649. C 



34 



WINE-MAKING IN HOT CLIMATES. 



The soluble matters are far the most important ; in the 
manufacture of white wine they are limited to those con- 
tained in the pulp, the white wines being fermented without 
contact with stalks, skins, or seeds. 

This amply explains the difference in richness of extractive 
matter observed between red and white wine, even in white 
wine made from red grapes. 

However, the substances contained in the must alone are 
sufficient to insure largely the healthy life of the vinous 
ferment whose function it is to transform it into wine. 

We shall see later on in what degree it is useful to modify 
the composition of the must. 

MATTERS BROUGHT TO THE VAT BY 100 KILOS. OF VINTAGE. 

We have already stated that each of the four constituent 
parts of the complete fruit stem, skins, pulp, and seeds- 
bring to the vat special products influencing the wine, either 
favorably or otherwise, proportionally to the absolute 
quantity of active substances they contain. 

We have just been studying the percentage composition of 
each of the four parts of the fruit ; we are now going to 
show in the following tables, borrowed from Girard and 
Lindet's work, what is in absolute value the quantity of 
active or inactive substances brought to the vat by 100 kilos, 
of Aramon, Garignan, and Petit-Bouschet cepages, that is 
to say, the three red cepages most widely cultivated in the 
South of France. 



Name of Product. 


100 kilos, of Entire Bunches bring 
to the Vat 


Total. 


Pulp. Skins. 


Seeds. Stems. 


A 

Fermentable sugar 
Bitartrate of potash ... 
Free tartaric acid 
Malic and other acids 
Tannin 


kil. gr. 

ramon cej 
11-910 
0-434 
0-102+ 
0-579 


kil. gr. 
wge. 

0-079 
j 0-062 
0-114 

0-136 


kil. gr. 

0-043 
0-074 

0-115 
0-009 

O-O*L 


kil. gr. 

0-030 
0-013 

0-097 
0-032 

0-075 


kil. gr. 

11-910 
0-543 

0756 

0-254 
0-106 
0-230 
0115 
0-009 
0-352 


Resinous matters 
Soluble nitrogenous matters 
Oil ... 


; 230 
0110 


Volatile acids * 
Mineral matters t 



NOTE.- For references (*), (f), and (J) see footnotes to next page. 



STUDY OF THE GKAPES. 



35 



Name of Product. 



100 kilos, of Entire Bunches bring 
to the Vat- 


Total. 


Pulp, 
kil. gr. 


Skins. 


Seeds. 


Stems. 


kil. gr. 


kil. gr. 


kil. gr. 


kil. gr. 



Fermentable sugar 

Bitartrate of potash ... 

Free tartaric acid 

Malic and other acids ... 

Tannin 

Resinous matter 

Soluble nitrogenous matters 

Oil 

Volatile acids * 
Mineral matters f 



Carignan cepage. 


... 


13-980 
0-537 
J- 0-502 


0-079 
0-052 
0118 




0156 






0147 


0110 



... 


0-032 




0-017 


0-009 
0-039 


0-029 
0-034 


0-227 
0-023 
0-052 


0-061 



Petit-Bouschet cepage. 



13-980 
0-648 

0-571 

0-156 
0-073 
0-156 
0-227 
0-023 
0-370 



Fermentable sugar 
Bitartrate of potash ... 
Free tartaric acid 
Malic and other acids .. 
Tannin 


12-960 
0-543 

} 0147 


0112 
0-047 
0115 


0-061 


0-040 
0011 
0-042 


12-960 
0-695 

0-205 
0-218 


Resinous matters 
Soluble nitrogenous matters ... 
Oil 


0181 




0110 
0124 


0-050 


0-160 
0181 
0-124 


Volatile acids* 
Mineral matters t 


0-065 


0-073 


not esti- 
mated 

0-048 


0-081 


0-267 



* Expressed as sulphuric acid. 

t The potash in combination with tartaric acid deducted. 
J At complete maturity, we have not noticed free tartaric acid in the 
Aramon grapes, nor in several other cipages. 
The figure given is very small. 



C 2 



36 WINE-MAKING IN HOT CLIMATES. 

CHAPTER III. 

VINTAGE. 

The word vintage has a very wide signification ; it means 
the gathering of the grapes, the result of the gathering, and 
the general cellar operations connected with it. In the fol- 
lowing pages we will mean by the vintage the gathering of 
the grapes and the produce of that operation. 

The choice of the time for the vintage is an important 
question to the vine-grower. 

In the South of France, in the few days preceding perfect 
maturity, the transformation of the berry is so rapid, and the 
crop exposed to so many dangers, that we may easily con- 
ceive the haste with which the vine-grower endeavours to 
place in safety, sheltered against the inclemency of the 
weather, the fruit of the year's hard labour and uninterrupted 
care. 

Logically, for the manufacture of table wine, the vintage 
must be made when the grapes have acquired their maxi- 
mum of saccharine richness and maximum weight. It is 
well, therefore, to know some of the processes enabling us to 
fix the precise moment at which the grapes cannot gain any- 
thing by remaining longer on the vine. 

These processes are of three kinds, empirical, physical, 
and chemical. The first, based on the exterior alterations and 
appearance of the grapes the browning at the base of the 
stem, the increased transparency of the skin, the way in 
which the pedicel can be detached from the berry, with a 
portion of the pulp remaining attached to it, and, above all, 
the Pollacci process, relying on the close observation of the 
phenomena of ripening. 

Pollacci noticed that ripening always commences from the 
outside and works gradually towards the centre of the grape ; 
it suffices, according to him, to taste the pulp in contact with 
the seed, and compare it with the pulp in contact with the 
skin. Complete maturity is indicated at the moment that no 
difference in taste is detected. 

The physical and chemical means, necessitating special 
though fortunately simple apparatus, are preferable and more 
accurate. 



VINTAGE. 37 

DETERMINATION OF SUGAR. 

The method most employed in determining the saccharine 
richness is, according to the density of the must, determined 
by means of a densimetre, known also as glucometre, 
mustimetre, gluco-oenometre, &c. 

If accurately graduated, or even if not, provided that the 
correction is known, they give reliable indications. They 
differ slightly from one another, in some cases the graduations 
read on the instruments can only be transformed into sugar 
by calculation. In other cases the graduation indicates 
directly the quantity of sugar present. 

They all depend on the well-known law of Archimedes 
" All bodies plunged into a liquid are submitted from top to 
bottom to a pressure equal to the volume of liquid dis- 
placed" 

It is clear, therefore, that if an instrument capable of 
floating is plunged into the must, the heavier the must, that 
is to say, the more sugar it contains, the less it will sink. 

The density of a liquid containing a substance in solution 
is submitted to variations almost proportional to the quantity 
of the substance dissolved. Grape must, it is true, contains 
besides sugar a fair proportion of other substances, but their 
total weight compared with the sugar is negligable. 

The glucometre devised by Dr. 'Guyot, and constructed by 
the Salleron firm, is, we think, the most convenient of these 
instruments. It consists of a thin glass tube, widened in 
cylindrical shape for one-third of its length, and provided 
at its base with a small bulb. 

The instrument so constructed is adjusted by placing 
mercury or shot in the bulb, in such a way that when plunged 
into pure water at a fixed temperature it sinks almost to the 
top of the tube at that point the zero is marked. 

If now we allow the instrument to float -in a saccharine 
liquid of which the strength is known, it will sink less, and 
level with the liquid a figure corresponding with the known 
strength is marked. 

To complete the graduating, it suffices to divide into pro- 
portional intervals the space between the zero and the point 
determined by the experiment. cw r - < 

The graduation of these instruments is usually ready 
printed on a piece of paper, fixed inside the tube at the 
required height. 



38 



WINE-MAKING IN HOT CLIMATES. 






The graduation of the Guyot glucometre, 
shown in the drawing, presents the advantage 
of enabling ns to read under three different 
forms from one observation, giving the richness 
in sugar expressed as kilogrammes per hecto- 
litre, the degree Baunie", also called liquor 
degree, and the quantity of alcohol expressed in 
volume per cent., which will result from the 
fermentation of the must, if it is done under 
favorable conditions, and completely.* 

The Salleron mustimetre only indicates the 
density of the must, and by means of a special 
table sold with the instrument we can ascertain 
from one observation : 

First. The corresponding degree Banine". 
Second. The weight of sugar in grammes 

per litre of must. 
Third. The alcoholic strength of the wine 

after fermentation. 

Fourth. The weight of crystallized sugar 
to be added to one litre of must 
for the wine to contain 10 per 
cent, of alcohol by volume. 
Fifth. The density of the resulting wine, 
and therefore the weight of 
one hectolitre the results 
Enabling us to gauge a cask 
without measuring the liquid. 

The very complete indications obtained from 
a single observation, followed by the reading 
of the table, make it a very handy and useful 
instrument. 

The gluco-oanometre simply gives the degree 
Baume\ 

The shape of all these instruments is similar, 
they are simply areometres of constant weight 
and variable volume, which means that the 
volume submerged varies with the density of 
the liquid. 

* A correction, however, must be made. The Guyot scale always indicating 
for the determined sugar the weight and alcoholic volume a little in excess, 
namely, 0*8. This, no doubt, is the result of this scale being calculated on the 
basis of the theoretical chemical equation. 



IS 



VINTAGE. 39 

The different indications given by these areornetres directly 
or indirectly are useful, but not indispensable. It is neces- 
sary in order to determine the moment of perfect maturity 
to . rapidly test for the stationary state of the saccharine 
weight. For this purpose any densimetre, correct or not, 
may be used, provided the same instrument is used for each 
trial. 

The chemical processes for determining sugar are very 
exact, but are too complicated to be usefully recommended 
to vine-growers. 

We only attach secondary importance to the exact 
knowledge of the sugar content of the must. If it is neces- 
sary to operate with precision in scientific researches, it is 
not so when we have to deal with wine-making on a 
large scale, and densimetrical observations are sufficiently 
accurate. 



DETERMINATION OF ACIDITY. 

This is of great importance, and gives a very good indica- 
tion of the state of maturity. 

The acidity of the grapes decreases from the change of 
colour of the berry till maturity, remaining at that time 
almost stationary, and then increases when the grapes are 
drying. 

The increase after maturity is only apparent, and does not 
affect the percentage weight. 

If we measure the absolute quantity of acid in a ripe 
berry, and in a berry of equal size taken at the same 
moment, but left attached to the stalk to dry, we do not 
find a notable diminution in the acids. 

In practice, however, it is easy to detect the above- 
mentioned stationary state. 

We have often mentioned in previous publications and 
lectures the necessity for the wine-maker to be able to 
determine exactly the acidity of the musts, for it is an 
important factor in the future quality of the wine. 

We will explain later on the reasons which lead us to 
attach such importance to the acidity. 

In a laboratory, no doubt, and to any one used to chemical 
manipulations, the determination of acidity is a very simple 
operation. The necessary apparatus for it always exists 
even in the most elementary laboratories. In the vineyard 



40 



WINE-MAKING IN HOT CLIMATES. 



it is complicated to any one unacquainted with the exact 
measurements made on small masses, and with the necessary 
calculations to bring the result to concrete figures. 

The acidimetric apparatus consists essentially of an instru- 
ment measuring a known volume of the liquid to be 
examined, a graduated tube or burette for delivering the 
alkaline solution accurately, and an alkaline solution of 
previously determined strength as compared with a known 
weight of acid. 

The neutral point is rendered easily detectable by the use 
of colouring matters, called in chemistry indicators, which 
have the property of changing colour in the presence of acids 
or alkalies. It suffices to have an extremely slight excess of 
either acidity or alkalinity for these changes of colour to be 
manifested. 

The natural colouring matter of the grape is itself a good 
indicator, red in acid solution, changing to green with 
alkalies. 

For white musts, phenolphthalein dissolved in alcohol is a 
very convenient indicator. It remains colourless in acid 
solutions, and becomes purple red in presence of an infini- 
tesimal quantity of alkali. Agidimetres are numerous and 
varied in arrangement. They do not all render the measure- 
ment of acidity 'easy of performance by the vine-grower. 

One of these, constructed by Dujardin,* 
called Acidimetric tube is the smallest and most 
simple. It consists of a cylindrical glass tube, 
closed at its lower end, and bearing graduated 
marks on the central part. The first division 
from the bottom indicates the volume of wine 
or must to be used ; the divisions over it serve 
to measure the quantity of alkaline liquid ne- 
cessary to obtain the reaction marking the end 
of the operation. 

The modus operandi is simple. 
Pour the must or wine into the tube up to A, 
adjust the liquid to the level of the division by 
means of a pipette, and add, if operating on 
white musts, two or three drops of phenolph- 
thalein solution. 

Pour in carefully, and in small quantity, 






Fig. 3. 
Acidimetric Tube, 



the titrated alkaline solution, a rosy tint 



* J. Dujardin, successeur de Salleron, Paris. 



VINTAGE. 41 

appears, which, however, disappears on shaking. Add the 
alkaline solution in successive small portions till the last 
drop colours the solution a permanent rose tint.* 

The acid strength expressed as tartaric acid per litre is 
given by the figure opposite the level of the liquid in the 
tube. 

It is a very simple operation, but perhaps less simple in 
practice than it seems through reading the description. 

The drawback of most acidimetres is that they are operated 
with small quantities of liquid, and therefore any error in 
measurement becomes greatly increased when calculated to 
one litre. 

When the must is measured by means of a pipette it gives 
good results, but is rather difficult to an inexperienced per- 
son. The operation seems easier when the measurement is 
made in a tube, as in the above acidimetre, but the slightest 
error in agreement between the level of the liquid and the 
division leads to a considerable error. As for the reading 
of the volume of alkaline solution, in a burette or tube it 
always remains uncertain, and leads to errors, and falsifies 
the result, varying more or less the smaller the quantity of 
liquid that is operated upon. 

We must, therefore, if we want the vigneron to get into 
the habit of measuring the acidity of the grape must, devise 
a simple apparatus, facilitating the operation and working 
on a sufficiently large volume of liquid to render the errors of 
reading the divisions negligable ; and giving the acid 
strength of the must per litre from one observation only. 

We may easily make such an acidimetre with the following 
pieces of apparatus : Fig. 4. First, a burette, or cylindrical 
tube, 1 centimetre in diameter, and divided into T Lths from 
to 20 cubic centimetres, B. Second, a graduated flask 
with a narrow neck cut off exactly at 100 c.c.m. to allow the 
measurement of the must to be made simply by filling it, I. 
A large glass beaker holding 400 cubic centimetres, D. A 
titrated alkaline solution (potash or caustic soda), E. 

A solution of phenolphthalein, F, of which two or three 
drops are placed in the must before the operation, and by 
turning red indicate the end of the operation. 

The acidity of the wine is usually expressed in terms of 
sulphuric acid per litre. This is a conventional arrangement 

* In the case of red must a greenish colour marks the completion of the 
reaction. 



42 



WINE-MAKING IN HOT CLIMATES. 



not calling for criticism, bat when we have to deal with 
musts it is preferable to express the acidity as tartaric acid, 
as it is the only acid used to correct the vintage. It would 
suffice to titrate the alkaline solution in such a way that one 
cubic centimetre would neutralize exactly 10 centigrammes 
of tartaric acid, so that the figure read on the burette would 
represent the weight of tartaric acid per litre. 




Fig. 4. Portable Acidhnetre. 

But, however simple the use of an acidimetre of this kind 
may be ? we must draw the attention of the vine-grower to 
a few details as to the method of operating in order to 
obtain exact results. 

MODE OF OPERATING. 

Crush with the hands, about 500 grammes of grapes, and 
squeeze the juice through a cloth. 



VINTAGE. 43 

Fill the flask with the must thus obtained until it 
overflows. 

Pour the contents of the flask into the 400 cubic centi- 
metre beaker ; rinse the flask with an equal quantity of 
water (rain water or distilled, if possible) and add it to the 
must. 

Add to it 4 or 5 drops of phenolphthalein solution. 

Fill the burette to the zero point with the alkaline solu- 
tion ; deliver the alkaline solution gradually from the 
burette into the must until the reddish coloration appears 
permanently. 

When that result is obtained, read on the burette the 
graduation level with the surface of the alkaline solution. 
Let us assume, for the sake of argument, that it is 9- 7 ; this 
means that the must contains 9*70 grammes of tartaric acid 
per litre, or 970 grammes per hectolitre. In this case it 
would be unnecessary to add any acid to the must. 

Under these circumstances, even if placed in unskilful 
hands, this apparatus will give sufficiently exact results, 
especially if care be taken to make previously a rapid trial 
giving the approximate acid strength. 

To do so one operates as above described, adding the 
alkaline solution in fractions of 1 cubic centimetre each. 
At 8 cubic centimetres, for instance, the liquid has not 
yet become red ; at 9 cubic centimetres it is completely 
red, this meaning that the result is between 8 and 9 
grammes per litre. It will, therefore, suffice to commence 
the operation again, adding at once up to 8 cubic centi- 
metres of the alkaline solution, and continuing drop by 
drop till the appearance of the permanent rose tint. 

A little before obtaining the final tint the liquid becomes 
slightly brownish. This renders the determination of the end 
of the reaction rather difficult for beginners. This colour- 
ing occurs with all musts, even when there is no indicator 
added, and should not be taken into account. It is in order 
to diminish it that the must is diluted with water. 

As long as the colour remains brown it need not be 
further considered than as a precursory sign of the end of 
the operation : an additional two drops ( T Vth cubic . centi- 
metre) of alkaline solution added to the must will cause the 
colour to turn from brown to red quite decidedly. 

A final experiment on the range of colours as above will 
render this quite clear. 



44 WINE-MAKING IN HOT CLIMATES. 

The pieces of apparatus required are easily procured from 
commercial houses. With regard to the alkaline solution, 
any scientific pharmacy can supply it to order. The wine- 
maker may, however, rectify the alkaline solution by dis- 
solving a known weight of tartaric acid in an accurately 
measured litre of distilled water (8 grammes, for instance), 
and using that solution in place of the must it should show 
on the burette the figure 8, if the titrated liquid furnished 
by the pharmacist is exact. 

The tartaric acid of commerce is sufficiently pure to be 
used for the trial, and any pharmacist will weigh it 
accurately. 

All non-coloured or slightly reddish musts may be tested 
in the manner above described, but for coloured musts, such 
as those of the Bouschet hybrids, the end reaction is not so 
distinct. It is preferable, in this case, to work on must 
diluted with twice its volume of water, and without an indi- 
cator. The modus operandi would then be as follows : 

Fill the 100 cubic centimetre flask with must, and pour 
the contents into the 400 cubic centimetre beaker ; rinse the 
flask twice with water, filling it each time, and add the 
rinsings to the must. 

Run in, with constant shaking, the alkaline solution from 
the burette. 

The diluted must will pass through the following range 
of colours : Red, violet red, violet, brown, and suddenly 
become deep green. This indicates the end of the reaction. 

The green colour must not be observed by transmitted 
light, the liquid being too deep in colour to allow a clear 
perception of the transition tint, but by rotating the beaker 
it is easy to detect it in the thin film of liquid wetting the 
sides of the beaker. 

The wine-maker, therefore, has at command two means 
quite sufficient to enable him to ascertain the maturity of his 
crop. First, the glucometre shows when the grapes aje 
not increasing in sugar content ; second, the acidimetre 
shows when they are not diminishing in acidity. 

It is desirable for the vintage to be made at that precise 
moment, for then only can the maximum of alcoholic 
strength be obtained, and therefore the maximum of 
pecuniary value, considering, as goes without saying, the 
common wines of the South of France. The . correction of 



VINTAGE. 45 

the acidity, which one is very often obliged to increase, 
is a simple and economical operation considering the gain 
of alcohol it brings abont. 

However, that desideratum is not always easy to realize in 
practice, as the wine-maker is not always able to wait till 
the opportune moment. 

Many circumstances, amongst which we will note the 
necessity of assuring the indispensable labour, restrict the 
desired 6bjects of the large growers; the small grower alone 
remains master of his vintage. 

In the South of France there is a very marked tendency to 
vintage sooner than is necessary. We know there are many 
good reasons to justify this tendency, but we have still better 
reasons to combat it. 



INFLUENCE OF THE TIME OF VINTAGE ON THE QUALITY 
OF WINES, 

General observations have shown that early vintages 
ferment well, and that the resulting wines are judged more 
favorably by expert tasters. 

We will endeavour to explain why this is so. 

For fermentation to take place under favorable condi- 
tions, it is necessary for the yeast, which has to transform 
the sugar into alcohol and secondary products, not to be 
retarded by the composition of the must or its temperature 
during fermentation. We know that the yeast cannot with- 
stand a high temperature, nor too large a proportion of 
alcohol. Moreover, the higher the temperature the smaller 
the quantity of alcohol the yeast can withstand. 

If, in the fermentation of an early vintage, we do not notice 
a slackening in the activity of the ferment, although the 
temperature is often very high, it simply means that the 
alcoholic strength is low. 

In a late vintage, on the contrary, the alcohol being in 
greater abundance, adds its detrimental effect to that of the 
temperature, and the result of the two actions is to paralyze 
the ferment, preventing it from transforming the remaining 
sugar into alcohol. 

The complete disappearance of the sugar will, it is true, 
in many cases, take place through a slow fermentation, but, at 
the same time, other organisms will be at work communicat- 
ing to the wine characteristics which will have the effect of 
diminishing its organoleptic value. 



46 WINE-MAKING IN HOT CLIMATES. 

Even in admitting a complete and rapid fermentation 
(which is often obtained with a late vintage notwithstand- 
ing the unfavorable conditions of temperature, if the wine 
is not to contain more than 10 or 11 percent, of alcohol when 
completely fermented), the wines resulting are more often 
than not less appreciated by expert tasters. 

The tasting is very complex, and exceedingly difficult to 
analyze, especially when we have to judge the pecuniary 
value of a wine. We must apply for the tasting trial to 
wine merchants, who always have a tendency to judge 
more favorably types of wine adapted to their own particular 
trade. All wine merchants have not the same requirements ; 
a wine adapted to an export wine merchant's trade would 
command a higher price than another wine which would 
have been paid for at the same rate by a merchant selling 
locally. 

There is, in this instinctive tendency of the wine taster to 
judge the value of a wine from his own personal stand-point, 
something disconcerting for scientific researches. 

However, these divergences of appreciation are not very 
considerable, and if we sometimes find many wine tasters 
agreeing with each other, to award the same number of marks 
to a wine submitted to their judgment, they often indicate by 
different terms the qualities distinguished by them. It is 
therefore very difficult to determine to what element the 
wine owes its quality or value, and chemists cannot fail to 
recognise that an analysis of wine, however complete it may 
be, cannot give its real organoleptic value 

By comparing these two methods of examination, chemical 
analysis and tasting, we may endeavour to discover if some 
of the results of the analysis, are constant for a comparative 
tasting appreciation, and therefore if we cannot deduce a 
rule from the great number of cases observed and see if that 
rule is absolute and shows no exceptions. 

Indeed, a rule may be deduced from the numerous 
analyses of natural wines of different regions, and to that 
effect we have studied the analyses published : 

By Professors Gayon, Blarez, and Dubourg, of the wines 
of the Gironde, for two successive years (1887 and 1888). 

By Prof. Margottet, Director of the Agronomic Station 
of the Cote-d'Or, of the wines of Bourgogne. 

By Giraud, David, and myself, of the wines of the Herault 
vintages of 1889 and 1890. 



VINTAGE. 47 

The wines of the Giroude and Bourgogne are unques- 
tionably superior, owing- to their origin ; their average 
acidity is 5'21 for the former, and 5'98 for the latter,* acidity 
expressed in terms of sulphuric acid per litre. 

The analyses of the wines of the Herault furnish us 
with still more suggestive results ; the acidity of the wines 
for the 1889 vintage averaged 5-15, for the 1890 vintage 
4-80 ; and everybody knows that the quality of the wines of 
the 1889 vintage was unquestionably superior to that of the 
wines produced the following year. 

To sum up, the conditions under which the samples of the 
1890 crop were taken enable us to deduce conclusive results 
from the analyses made. 

A jury of wine tasters was asked to express their opinion 
of the wines ; before analysis the bottles were specially 
marked, to enable them to be identified later on. The wines 
judged to be the best were those in which the average acidity 
was highest. The average result of the analysis gave 5.44, 
being 0'64 above the average acidity of the other wines of 
the same year, analyzed at the same time. The opinions of 
the expert tasters, therefore, very fortunately corroborate 
what we have been saying respecling the acidity of the must ; 
and this is not a blind judgment, for the appreciation is 
constant with regard to natural acidity. The judgment is 
quite different with regard to artificial acidity ; if we take a 
wine of medium quality with an acidity of 4*00 for instance, 
and if that acidity is brought to 5 or 5-5 by the addition of 
tartaric acid, it will still be declared to be of medium quality 
by the expert wine taster, for the impression perceived by 
his palate will be totally different to that resulting from a 
wine naturally containing 5*5 acidity. 

All wines favorably judged by skilful tasters possess a 
relatively high acidity, which is never below 4*50 grammes, 
expressed in terms of sulphuric acid per litre. 

It does not follow that all acid wines are good. It only 
means that wine cannot be good if deficient in acid. 

We cannot hope, therefore, to make a good wine if the 
average total acidity does not reach 4-50 per litre. f And in 

*Figures given by P. Paul in his work on Vinification, already mentioned. 

t This amount, however, is only sufficient in the case of a wine of high 
alcoholic strength. It is too low, for wines containing 8 per cent, of alcohol. 

To calculate the acidity as tartaric acid, the figures expressing it, as sulphuric 
acid must be multiplied by T53. 



48 WINE -MAKING IN HOT CLIMATES. 

southern regions with our cc'pages, a well-ripened vintage 
does not reach that indispensable acidity, but contains it 
only in under-ripened vintages. 

For these two reasons ; difficult fermentation and lack of 
acidity, the wines of late vintages are often classified as 
inferior when compared with the wines of an early vintage. 

We have tried to discover if by properly correcting the 
acidity of the vintage it is possible to obtain wine of equally 
good flavour, but richer in alcohol, by retarding the time of 
gathering. With this object two lawful means may be used ; 
the addition of tartaric acid extracted directly from the grape, 
seems most simple and practical, on account of the facility 
of estimating it, and its small market price. 

There are also cases where the second crop may be used 
with advantage,* as advocated by eminent oanologists, such 
as Prof. A. Gautier. 

Both of these means lead to the same result, for, as we 
have said in another work,t the acidity of the second green 
crop is mainly due to tartaric acid. 

During two successive years we made laboratory tests, 
the results of which have always been excellent, the tem- 
peratore of fermentation being easily regulated in the 
laboratory. In cellars this is not possible, at least, not yet, 
therefore we cannot expect on the commercial scale such 
satisfactory results, but we have made large scale experi- 
ments, amongst which we quote the two following : 

1st. At Frontignan (Herault). 

Vineyard well sheltered against cryptogamic diseases 
(heavier yield than previous year)J. On the 6th September 
a small vat of 15 hectolitres, was filled with Aramon and 
Carignan, in the proportion of three to one ; the first racking 
took place four days afterwards. 

On the 21st September the same vat was filled in, exactly 
the same way, with the only difference that 60 grammes of 
tartaric acid per hectolitre were added. The racking again 
took place four days later. 

* In the Revue de Viticulture, dated 7th September, 1895, an article 
appeared on this subject. Owing to its importance for local wine-makers, it was 
translated by one of us (W. P. W.). See the Australian Vigneron. Dec., 1895. 
And applied by us at the last vintage at the Yiticultural College, Rutherglen 
(R. D.). 

t Roos and Thomas. Contribution a 1'etude de la vegetation de la vigne. 
Ann- Agronomiques. 

+ The trials were made in 1895, when mildew was very prevalent. 



VINTAGE. 49 

From September to February the two wines were kept in 
25 litre casks, without any special care, or racking or filling 
up, which allows conclusions to be drawn, as to their 
respective power of conservation under unfavorable con- 
ditions. 

The following are the results obtained by the analysis of 
these two wines : 

Early Vintage Late Vintage 

(Frontinnan). (Frontlgnan). 

Alcohol (by volume) ... 8 '6 per cent. 10*5 per cent. 

Dry extract ... ... 16 '0 grammes 18 '90 grammes 

per litre per litre 

Reducing matters (sugars) traces traces 

Acidity (total) ... ... 575 grammes 6 '01 grammes 

per litre per litre 

The wine of the late vintage is of richer colour than that 
of the earlier vintage ; the latter did not keep well, it turned 
and became cloudy. The wine of the late vintage kept in a 
much more satisfactory manner. 

2nd. In the environs of Thuir (Pyrenees Orientales). 

Vineyard well protected against cryptogamic diseases. 
On the 12th September, a 70 hectolitre vat was completely 
filled with Carignan gathered in equal parts from two plots 
of the same soil, one being manured, the other not ; the 
racking took place five days later. 

On the 28th September the same vat was filled with 
Carignan, gathered in the same proportion from the same 
plots, but 70 grammes of tartaric acid per hectolitre were 
added. 

The racking took place five days later, and the two wines 
were afterwards submitted to the same treatment. Here are 
the results of the chemical analysis : 

Early Vintage Late Vintage 

(Thuir). (Thuir). 

Alcohol (by volume) ... 10'50 per cent. 11 '60 per cent. 

Dry extract ... ... 18 "50 grammes 25 '00 grammes 

per litre per litre 

Reducing matters (sugars) traces 1'25 grammes 

per litre 

Acidity (total)... ... 5 '10 grammes 5 '90 grammes 

per litre per litre 

The wine of the late vintage is richer in colour. It is, 
therefore, perfectly certain that the time of vintage has a 
very great influence on the composition of the wine. The 
figures expressing the alcohol and dry extract are notably 
higher for the late vintage wine. 

10649. D 



50 WINE-MAKING IN HOT CLIMATES. 

But are those wines really better, or will the} 7 simply 
bring a higher price when placed on the market ? * 

Personally, we think they are better, if the fermentations 
were not too poor, and if the wines have a sufficient quantity 
of acid. If, in other words, the vintage has been corrected 
in such a manner as to obtain wines of an average acidity of 
4*50 or over, per litre. It is also to be noticed that the 
detrimental influence of high temperatures is diminished by 
high acidity. 

Therefore, this reason alone should be sufficient to induce 
us to increase the acidity of the must before fermentation. 
The temperature appears of greater importance when we 
examine the phenomena accompanying the use of tartaric 
acid in the vintage. 

If the acidity of wine is an important factor for its quality, 
the ratio of acidity is not alone sufficient to constitute that 
factor. It is necessary that the acidity should be due 
exclusively to the acids existing normally in the vintage, 
even if not quite ripe. Amongst these acids the tartaric acid 
alone is of importance. We have frequently tried to increase 
the acidity of a wine deficient in acid (otherwise well consti- 
tuted, but of medium quality only) by adding tartaric acid ; 
and to submit it to the judgment of skilful tasters. In most 
cases the wine was improved, but never enough to be con- 
sidered a good wine. 

The acidity of the wine should never be due to free 
tartaric acid in notable proportion ; the tartaric acid dis- 
appears in the grape as maturity advances, and does not 
exist at all a few days before complete maturity. 

This is a phenomenon noticed by different authorities, one 
of them being Prof. Bouifard. 

From researches undertaken in collaboration with Eugene 
Thomas, in 1891, f it appears that on the lUth of August the 
acidity of the grape, expressed as 19'90 of sulphuric acid per 
litre, was half of it due to free tartaric acid, whereas on the 
21st September the acidity had fallen to 5'60, which was 
exclusively due to fixation of the other acids of the grape. 

* These four wines were presented to the Central Agricultural Society and to 
the Departmental Society for the Advancement of Agriculture of the Herault. 
The wine tasters of the former society called to express an opini n, concluded 
in favour of the early vintage wines from Thuir, and in favour of the late 
vintage wines from Frontignan. The wine taster of the latter society found in 
both cases that the late vintage wines were superior. 

t L. Roos and E. Thomas. Contribution a 1'etude de la vegetation de la 
vigne. Ann. Agron., 1892. 



VINTAGE. 51 

The above figures show the percentage proportion. The 
analysis made on that occasion enable us to establish the 
real disappearance of the tartaric acid, so far as free tartaric 
acid is concerned, but they do not yet show the diminution 
of the acid in actual value. 

This disappearance, however, is certain, as the following 
absolute values drawn from the same researches go to prove. 

On the 10th August, 343-60 grammes of grapes contained 
a total amount of acids equivalent to 6*83 grammes, expressed 
as sulphuric acid, whereas on the 21st of September the same 
grapes weighing 753 grammes contained only 4'21 grammes 
of total acidity. This disappearance affecfs, so far as free 
acids are concerned, the tartaric and other acids of the fruit, 
and it is quite probable that it is simply the result of the 
plant absorbing chemical bases from the soil, converting them 
into neutral salts through combination with the acids. 

There was, in fact, in the 343*60 grammes of grapes on the 
10th August, 1-27 grammes of mineral matters, of which 
0-55 grammes were potash. At the same time, in the 753 
grammes of grapes gathered on the 21st September, there 
were 2*86 grammes of mineral matters, of which 1'20 were 
potash in presence of 4'2 1 grammes of acidity. 

Complete maturity has, therefore, the effect of fixing as 
saline compounds, especially potassic, a part of the acids 
forming the normal acidity of the grape, in such a way that 
if the vintage does not possess at maturity the required 
acidity, it is not that it does not contain the required acids 
for that purpose, but that the excessive amount of potash 
partially neutralizes their properties. 

The addition of tartaric acid to the vintage has the effect 
of immediately entering into combination with the potash, 
and has, therefore, the secondary effect of increasing the 
acidity, by causing the re-appearance in the liquid in a free 
state of the acids pre-existing in neutral combinations. This 
effect is so true, that not only do we fail to find any free tar- 
taric acid in the wines resulting from an acidified vintage, 
but, further, we can by laboratory experiment find the total 
tartaric acid added in the form of a surplus of bitartrate of 
potash. 

This fact has been verified by us frequently, as well as by 
Prof. Bouffard, who established it a few years ago in the 
course of experiments on the vinification of Jacquez. 



D ^ 



52 WINE-MAKING IN HOT CLIMATES. 

These considerations explain why the addition of tartaric 
acid to the vintage produces much more favorable effects 
than the addition of tartaric acid to the wine. 

In the latter case, unless we deal with very small quan- 
tities, a part of the added tartaric acid remains free, and 
imparts to the wine that harsh taste, setting the teeth on 
edge, and contracting the muscles of the mouth in a dis- 
agreeable manner, which is so characteristic of tartaric acid. 

The experiments we have just been considering are no 
doubt incomplete. We should also have made trials on late 
vintage wines non-acidified in order to judge them com- 
paratively. This did not occur to us at that time, but we 
intend to complete these experiments at an early date. 

A most remarkable fact noticed during the above experi- 
ments is that, although we tried to bring the acidity of all 
the late vintage wines up to the same standard of acidity 
as those of the early vintage, the late vintage wines remain 
more acid than those of the early vintage. We expected a 
diminution of the acidity, as the increase of the alcoholic 
strength checks the solvent action of the liquid on the bitar- 
trate of potash. The only possible cause we can see to 
explain the increase of the acid is an increase of succinic 
acid. 

There is another plausible explanation. It is a fact that 
the wines resulting from the above experiments varied con- 
siderably in intensity of colour, the late wines being much 
richer in colour. The colouring matters which play the part 
of acid in the wine are not measured in the must, and it is 
to the increase of colouring matter that the unforeseen 
increase of the acidity may be due. But this yet remains to 
be cleared up. 

The results obtained are, however, of a nature to cause 
new experiments to be made in cellars, in correcting the 
vintage, firstly by acidification, and secondly by regulating 
the temperature. 

We feel convinced that if these two conditions are realized, 
wine of a much higher class will be obtained by vintaging 
later than is usually done. 

M. Coste, Departmental Professor of Agriculture of the 
He"rault, informed us recently that in any vineyard, small 
enough to allow the vintage to be made rapidly, the date of 
vintaging should be postponed as much as possible and the 
musts corrected subsequently. 



VINTAGE. 53 

It is not within the scope of this work to discuss the viti- 
cultural reasons that may interfere with this practice. But 
if the economical advantages of late vintages were well 
established, means might be found to reduce the danger 
there is of leaving grapes too long on the vine. 

We have only aimed at showing by comparative trials 
that it is possible to obtain wines of very different composi- 
tion, taste, and value, according to the time the vintage is 
made. 



IMPROVEMENT OF CERTAIN VINTAGES. 

We have already seen* the quantities of soluble matters 
brought to the vat by 100 kilos, of different ccpages. In 
the great majority of cases the vintage does not require to 
be modified in composition, in order to furnish wines of clean 
taste and good keeping quality. 

There are cases, however, where improvement of the 
vintage is necessary. 

The defects most frequently met with are: 

An imperfect bloom on the berries, caused by heavy 

rains, which also soil the grapes with earth. 
A deficiency in saccharine strength, due either to an 
invasion of cryptogamic diseases or of unfavorable 
climatic conditions. 
A lack of acidity ', always noted during hot and damp 

seasons. 

In the first case the use of cultivated yeasts is indicated. 
Selected pure yeasts may now be obtained in commerce, or 
they may be cultivated by vine-growers, carefully choosing 
only healthy grapes to start with. 

We have had occasion to point out f that some vintages 
resulting from flooded vines, which had yielded under ordi- 
nary conditions a turbid muddy liquid, deserving any name 
except nine, had given, by the use of cultivated yeasts, wines 
of clean taste and excellent keeping qualities. 

It is, therefore, to cultivated yeasts that recourse should be 
had, whenever the skins of the grapes, from whatever cause, 
are deficient in yeast germs, as is often the case in some 
regions of France. 



* Girard and LinHet, loc. cit. 

f Vinif. et lev. cultivees. Progres agncole et viticole. 



54 WINE-MAKING IN HOT CLIMATES. 

The addition of sugar to the must is the remedy for 
deficiency of sugar in the grapes.* 

DEFICIENT ACIDITY. 

This is very frequently noticed in the South of France. 
It is a true defect, for the quantity of acid in the must 
has a very great influence on the development of the yeast. 
We may lay" down as a general principle that the more 
acid a vintage is, the greater difficulty ferments other 
than alcoholic will find in developing. 

The standards of required acidity for a few important 
cepages are : 

8 grammes of tartaric acid per litre for musts of 
Aramon, Carignau, and other varieties used for 
making ordinary wines. 

10 grammes of tartaric acid for Bouschet hybrids. 

12 grammes of tartaric acid for Jacquez. 

Whenever the acid strength is below these standards, it 
should be brought up to them in order to obtain the maxi- 
mum quality. 

The acidification of the vintage with tartaric acid is a 
lawful operation, for it does not add anything to the result- 
ing wine, if the addition to the must be properly made. 

The acidified vintage, as we have just pointed out, does 
not furnish a harsh wine, as in the case of wine acidified 
after fermentation. 

The acidification of the vintage is a common practice in 
the South of France. Very often it is badly conducted, and 
frequently done when not necessary. The explanation 
offered by some vine-growers is that a neighbour did it the 
previous year and made a fairly good wine. 

The measurement of the acidity of the must is not an 
impossible operation for vine-growers. Commerce places at 
their disposal a cheap apparatus reducing the operation to 
its simplest expression. They are thus enabled to know 
when it is necessary to add tartaric acid to the vintage, and 
the figures we have given will enable them to know in 
what proportion the addition of acid should be made. 

* We have omitted the details of this practice as it is rarely necessary in 
Victoria. (Trans.) 



VINTAGE. 55 

When the quantity to be added to a given vat has been 
calculated, the acid is distributed by hand, over the grapes 
in the crusher, as they are passing through. 

We may operate in another way by filling a bucket with 
the crystals of tartaric acid, and washing with a stream of 
must from the vat, by means of a pump, until completely 
dissolved. 

It may sometimes happen, as was frequently observed in 
1896, that, although resulting from well-matured grapes, 
the must shows a percentage of acid higher than the figures 
above mentioned as desirable. This is generally the result 
in dry and warm seasons. L. Mathieu, in a study on the 
improvement of acid wines,* does not advise any special 
process. 

It does not appear that a superabundance of acid is an 
inconvenience. Wines resulting from rather acid vintages, 
but well ripened, are always good. In these not very 
frequent cases, it is to a superabundance of bitartrate of 
potash that the excessive acidity is due. It simply results 
in the lees being richer in cream of tartar. 

It is not so, however, if we consider a badly-ripened 
vintage, as is too often the case in the Centre and East 
of France. 

We have only addressed ourselves to the hot climates in 
what we have said so far, where complete maturity can 
always be obtained. 

* L. Mathieu. Amelioration des vins verts. Heoue cte Viticulture. 



56 WINE-MAKING IN HOT CLIMATES. 



CHAPTER IV. 



VINDICATION. 

We will not describe here the details relating to the 
gathering, or the various methods used to convey the grapes 
to the cellar, but will only study the fermentation proper. 



VINDICATION OF RED WINE. 

The first manipulation the grapes are subjected to is 
the crushing. 

Crushing, with very few exceptions, is recommended by 
all osnologists and practised by all vine-growers. It consists 
in disintegrating the grapes in such a way that the juice 
and pulp are expelled from the skin without the stalk or 
seeds being crushed. The machines used for this purpose 
are called crushers. 



CRUSHERS. 

The most old-fashioned farm, still used in a few small 
vineyards, is a kind of kneading trough, with the opening 
placed above the fermenting vat, in which the grapes are 
squashed by the rosy feet of young farm girls. 

This is an excellent means of crushing, the stalks and 
seeds remaining intact, while the vintage is submitted to 
prolonged contact with the air, for the surface being 
incessantly agitated insures perfect aeration of the must. 

Crushing by the feet is, however, a tedious and expensive 
operation, and can only be used by small proprietors. It 
presents a repugnant feature, however, no matter what 
cleanliness be attributed to the crushers. This reason alone 
amply justifies the progressive abandonment of the old- 
fashioned kneading trough, to the advantage of mechanical 
crushers. 



VINDICATION. 57 

M. Paul, civil engineer, in his work De la vindication* 
classifies crushers into four groups : 

Simple crushers, operating by compression or pro- 
jection. 

Stemmer and crusher combined. 
Extracting crushers, also called continuous presses. 
Extractor and classifier crushers. 

This last group does not seem to us applicable to true 
crushers, but rather to a series of apparatus performing a 
number of operations,- which are not all indispensable. 

The best-known mechanical crusher is that constructed 
with two cylinders. This is the oldest and most used. It 
acts by compression (like a rolling mill), the grapes being 
forced to pass through a limited space, too narrow to allow 
the berry to escape being crushed. 




Fig. 5. Cylinder Crusher fixed above the Vat. 

It is composed of two cylinders. (Fig. 5.) One with 
grooves running parallel to the axis, the other with helicoidal 
grooves. The distance apart of the cylinders is carefully 
regulated. If too close, only a limited amount of the 
work is utilized, and if too far apart the crushing is 
insufficient. The cylinders are rotated at different speeds, in 
the ratio of 1 to 3, the cylinder with helicoidal grooves 
revolving fastest. 

They are worked by hand or mechanical power, the work 
performed corresponding to the regularity of feeding. 

* Paris. J. Fritsch, 1894. 



58 WINE-MAKING IN HOT CLIMATES. 

Those worked by hand are usually mounted on wheels and 
placed above the opening of the vat ; under these conditions 
the aeration of the vintage is imperfect, the contact with 
air being almost nil. 

This is, fortunately, a defect which may easily be remedied, 
as we shall show when discussing aeration. 

One of the greatest inconveniences of the cylinder 
crushers is that the accidental introduction of a hard body 
(a stone, for instance) may break the cylinders and stop the 
work. Attempts have been made to minimize this defect, 
but so far unsuccessfully. 

The working of such a crusher is laborious. The men 
must often be relieved, but this only becomes an incon- 
venience in the case of large cellars. In small cellars, on 
the other hand, this does not apply, the work being inter- 
mittent, on account of the loads of grapes arriving at the 
cellar at intervals. 

A crusher constantly fed and worked by four men, 
relieving each other at intervals, cannot crush more than 
3,000 kilos. (6,600 Ibs.) of vintage per hour. The yield of 
juice for a given cepage is poor with this type of crusher. 
This is only a defect in the case of white wine, especially 
when made from red grapes. 

If the vintage is crushed by means of a double crusher 
(with four cylinders) the yield of juice is notably increased. 

Finally, this type of crusher is good, and will long remain 
the most practical, for small and medium sized cellars. 

The depth of the grooves is of importance ; if too shallow 
the rolls cannot draw the grapes through, and they form 
a, vault over the cylinders or slide over them. 

If too deep they cannot do good work, if the cylinders 
are too far apart ; or crush both stalk and seeds if the 
rolls are too close together. Ihisis an objection raised by 
P. Paul against large grooves. 

In a report on cellar appliances read before the Inter- 
national Viticultural Congress held at Montpellier, in 1893, 
Paul states that grooves geared into one another do not give 
good results. 

This criticism does not seem to be fully justified. 

If we consider the case of grooves sufficiently large to 
allow the grapes by their elasticity to become adapted to the 
shape of the grooves, without being torn to pieces, we may 
hope for satisfactory crushing, without the seeds or stalks 
being ground. 



VILIFICATION. 



59 




This is exactly 
what M. Blaquiere, 
of Beziers, tries to 
realize with his fluted 
cylinder grape com- 
pressor^ which con- 
sists of two cylinders 
with six large longi- 
tudinal flutes, G G, 
geared without 
touching, in such a 
way that all the sur- 
faces during rotation 
are at a constant dis- 
tance apart, and are 
revolved in opposite 
directions by means 
of outside cog-wheels 
worked by hand, 
whim (horse), or 
steam power. 



Fig. 6. -Blaquiere's Crusher (side elevation). G G, crushing 
cylinders ; T, hopper ; V, crank wheel. 



! V 




The fluted 
cylinders of the 
hand model are 
75 cm. (30 inches) 
long, with an ex- 
terior diameter 
of 29 cm. (Hi 
inches). They are 
mounted parallel 
to one another on 
steel shafts, and 
revolved in unison 
by two equal 
pinions. At the 
extremity of one 
of the shafts is 



Fig. 8. Blaquiere's Crusher (front view). G, crushing cylinders ; 
T, hopper; V V, crank wheels. 



60 



WINE-MAKING IN HOT CLIMATES. 



another large cog-wheel, revolved by means of a pinion 
keyed on the same shaft as the crank. 

The ratio between the large cog-wheel and the pinion is 
, which means that one complete revolution of 



or 



the fluted cylinders corresponds to 8J revolutions of the 
crank. The movement is slow enough, and the depth of the 
flutes sufficient to prevent the vintage sliding on the surface 
without being drawn down. 




Fig. 7. Blaquiere's Crusher (top view).- G G, crushing cylinders; 
V V, crank wheels. 

A crusher of this kind performs more work than one with 
ordinary cylinders. 

The crushing which results is satisfactory ; all the grapes 
get squashed, the other parts remaining uninjured. 

Blaquiere's crusher is comparatively novel, and has not 
yet been, to our knowledge, described in detail. We con- 
sider it an excellent machine, but it has the defect common 
to all compression crushers, that of liability to damage 
through the accidental introduction of any hard body 
(stones, &c.). 

This, however, rarely happens, as the hard body generally 
crushes with the rest, but an accident during vintage time 
leads to so many grievous consequences that its occurrence 
should be rendered almost impossible. 

Later on this matter will be considered when studying 
stemmers, as the stemmer attached to this crusher presents 
some interesting details of construction. 



VINDICATION. 



61 



n 



A new, very interesting, 
and original crusher, based 
on a principle which has 
never been applied before to 
grape crushing, has been 
invented by P. Paul, called 
the A ero-crushing-turbine. 

Although only four or five 
years old, the machine has 
been modified in several 
details by the inventor. 



Fig. 9. Aero-crushing-turbine. P. Paul (diagram). 

Fig. 9 shows the outline of the machine, and Fig. 10 its 
elevation. 




Fig. 10. Aero-cruahing-turbine, P. Paul, provided with an elevator feeding stemmer and drainer. 



62 WINE-MAKING IN HOT CLIMATES. 

In the report of the International Viticnltural Congress, 
held at Montpellier,* the following simple and clear descrip- 
tion of this machine is given : 

" P. Paul, constructing engineer of Cette, is the first 
to have applied centrifugal force to the crushing of grapes. 
His system has been described by so many viticultural 
authorities in various reviews, that it will suffice to htate that 
the squashing of the berry and liberation of the must is 
obtained by projecting the grapes against the vertical walls of 
the fixed cylinder of the turbine. With the speed of rotation 
properly controlled we are certain to squash all the berries 
without crushing either the seeds or the stalks, points of 
great practical importance. 

" To break the tissue of the seeds or stalks the speed of 
rotation requires 'to be infinitely greater ; and in this lies the 
original and important point, the perfect selection between 
the matters to be crushed, and those the crushing of which 
would prove useless, or even detrimental. 

" M. Paul's turbine is a crusher, not a compressor. It 
liberates the juice from the berry, and delivers both marc 
and juice together ; to effect their separation various devices 
are required, according to the nature of the wine to be made. 

"The prize (vermeil medal) awarded was the only one 
placed by the Congress at the disposal of the jury to be 
granted for grape crushers. 

" M. Paul exhibited two types of turbine : one worked by 
hand, the other by steam power. The first was tried by the 
jury at the doniaine des Gausses (vineyard owned by Prosper 
Gervais). The grape passed through, was Aramon. Out of 
1,150 kilos. (2,530 Ibs.) of vintage, 708 kilos. (1,557 Ibs.) 
of white must were extracted in twenty minutes. 

"The yield given by the machine was therefore 61 '5 per 
cent. It was worked by four men, two to operate each 
crank. 

" Later on, apart from official trials, it was tried at the 
Chateau de Villeroi (Compagnie des Salins du Midi) with a 
dynamo-metric crank, with the following results : 

" With Terret-Bourrets the force required to crush one 
kilo, of vintage was 27-20 kilogram-metres, of which 3'504 
kilogram-metres was expended in rotating the apparatus. 

* Etienne Gervaise. Congres International Viticole de Montpellier. 



VINDICATION. 63 

u With Aramoii the force, required was 23'10 kilogram- 
metres. 

" Therefore two men are not sufficient to work the 
machine, as they cannot develop more than 12 kilogram- 
metres (Claudel. Formules, &c., p. 14.) 

" It would be interesting for the constructor to try and 
manufacture a machine capable of being worked by two men. 
It is easy to see from what has been said that such a machine, 
might crush 20,000 kilos. (44,000 Ibs.) of vintage per day, 
which is all that is required by the medium proprietor. 

" The Aero-crushing-turbine worked by steam power, was 
seen by the jury working in the domains du Mdle, near 
d'Aiguesmortes, with the vintage in full swing. 

u It was fed by an elevator (Burton system), at the same 
time the must was elevated by a rotary pump, the whole 
being worke,d by a 5 h.p. engine. 

" The yield of must was rather difficult to determine, for 
marc and juice fell together into a tank, from which it was 
conducted to the press. The following are the results 
obtained, taking as liberated must that which flowed naturally 
after the press was charged : 

" From 2,879 kilos. (0,333 Ibs.) of vintage (Aramon) 1,379 
kilos. (3,033 Ibs.) of white must were extracted. The yield 
in must was therefore 47*8 per cent. But it should be 
remembered that the marc still remaining in the press con- 
tained a large quantity of must, liberated from the pulp, 
which further drainage would have removed. 

" The machine is of very simple construction, and we can- 
not see a priori any possibility of its getting out of order. 
We may mention that at the cellar of Yilleroi (Compagnie 
des Salins du Midi), after being used last year on trial, the 
machine was installed permanently this year, and that it 
has worked without a breakdown, and crushed from 180 to 
200 tons per day. Dynamo-metrical tests have not been 
made on this turbine, but it is supposed that it requires a 
motive force of from 4 to 5 h.p. 

" At Villeroi, as well as at Mole, the turbine is fed by two 
elevators. This is a very important item for the success- 
ful working of the machine. But the turbine is not the 
only machine requiring regular feeding, this being a sine 
qua non condition for the proper working of all continuous 
machines. 



64 WINE-MAKING IN HOT CLIMATES. 

" Finally, another important advantage of the turbine is 
that the marc is much easier to press, the cellular tissue 
of the berry being completely destroyed, and with it the 
elasticity which is such a great obstacle in the pressing of 
the fresh vintage." 

Such is the judgment of the Commission of the Inter- 
national Viticultural Congress. It is favorable to the 
machine worked by steam, but perhaps rather vague with 
regard to the turbine worked by hand. 

The report of the Commission ends up with " The Aero- 
crushing-turbine gives excellent results where mechanical 
power is available," but adds it " has not yet received the 
sanction of general usage." 

However, the turbine working on a large scale has been 
installed in a number of cellars long enough to enable us 
to appreciate it. In conclusion, it is an excellent machine 
for large cellars. 

We must add to the advantages expressed in the above 
report the perfect aeration of the vintage. The must 
coming out of the turbine is, so to speak, an emulsion of 
air and must. 

We have not measured the amount of air emulsionized, 
but according to various reports published by the inventor, 
it is 5 per cent, in volume. 

These are, as we shall see later on, very favorable condi- 
tions for a good start in the fermentation. 

The various advantages of this highly original crushing- 
machine justify the as yet uncontradicted success which 
welcomed it from its first appearance. 

As we have already stated, the regularity of the feeding of 
crushers has a great bearing on the perfection of their work. 
The mode of feeding will vary greatly according to local 
conditions, and the various means by which the elevation of 
the vintage to the crusher are obtained. 

In most cases the arrival of the drays to the level of the 
top of the vats by means of a gradient is recommendable ; 
in that case the feeding takes place by pouring the contents 
of the tubs directly into the crusher. 

Chain and cup elevators are good, and comply with various 
required conditions. They are recommendable for large 
cellars, but may also be arranged and worked by hand in 
small places. 



VINDICATION. 65 

These elevators may be used with either fixed or movable 
crushers. In the first case, it is necessary to have means of 
conveying the must from the crusher to the vats (in many 
cases simply by a wooden shute) ; in the latter, the elevator 
being- fixed on a truck running on rails, may be moved 
alongside the cellar ; when established in this manner, even 
if outside the cellar, the elevator may fill two parallel rows 
of vats with a simple shute conveying the crushed vintage 
from the top of the elevator to the fermenting vat. The 
crusher in this case is moved on another truck parallel to 
the elevators. 

We must add that a few vine-growers (though quite 
exceptionally) consider crushing useless, regarding the result 
of the different manipulations the grapes are subjected to, 
before being placed in the vat, as quite sufficient. 

Whether the vintage is elevated -by a cup elevator, or 
thrown into the vat by means of shovels, it acts certainly 
as a partial crushing ; but, the use of crushers is preferable 
and indispensable when making white wine. 

Crushing is praised by the majority of oanologists, and is 
an excellent practice, as it enables the fermentation to get a 
good start, and facilitates the drainage of the marc. 

In uncrushed or badly-crushed vintages, we always find 
grapes remaining attached to their pedicle, intact, and filled 
with unfermented must. When pressed these grapes .burst 
and contaminate the wine with fermentable substances, 
which only have at their disposal old yeast, living with 
difficulty in a liquid *almost completely fermented. The 
work done by the ferment in this case is very slight, 
frequently the sweetish wine resulting becomes the prey of 
noxious ferments, which, except in the case of sterilized 
must, always exist in the wine, awaiting favorable conditions 
to multiply. 

The presence of unfermented sugar fills one of these 
conditions. 

STEMMING. 

-This operation, which consists in separating the grape 
from the stalk, has been known from ancient times, and 
is a necessary practice in some viticultural regions, such 
as Bordeaux. 

In the South and South-west of France, however, it is 
only occasionally practised. 

10649. E 



66 



WINE-MAKING IN HOT CLIMATES. 



In former times it was performed by means of a kind of 
rake, with teeth fixed far enough apart to allow the grapes 
to pass between, but placed close enough to retain the stalks, 
the operation being done over a screen ; it is an expensive 
method and gives very imperfect results. 



STEMMERS. 

Only mechanical stemming is employed nowadays. It is 
done by means of special machines called stemmers, gene- 
rally attached to the crusher, and performing the sorting as 
the crushing is going on. 

The steminer consists of a horizontal perforated cylinder 
or cylindrical envelope, in the axis of which a shaft revolves 
bearing helicoidally mounted boards (Fig. 11) or spikes. 




Fig. 11. - Stemmer fixed above the Vat. 



VIN1FICATION. 



67 



The shaft, studded with spikes, or carrying boards, is 
revolved rather rapidly together with the crasher. 

The crushed vintage falls into the stemming cylinder. It 
is then energetically beaten by the spikes, separating the 
grapes from the stalks. The former, together with the 
juice, fall through the perforations into the collecting trough ; 
the latter gradually work their way to the extremity of the 
cylinder, and are then expelled. 

Blaquiere, the constructor of the crusher previously 
described, has also invented a stemrner, which differs in 
many respects from the ordinary appliance. 

It consists of a per- 
forated cylinder revolving 
round an axle. This 
cylinder is provided inside 
with from three to six 
pieces of wood, projecting 
a few centimetres, and 
placed parallel to the axis. 
The cylinder is inclined 
horizontally and revolves 
slowly. 

The crushed vintage 
falls into the raised end of 
the stemmer, and is then 
caught by the projecting 
pieces of wood and carried 
onwards to the lower end 
by its own weight. 

The shocks resulting 
from the successive falls 
of the bunches completely 
detach the grapes from 
the stalks, . the grapes 
falling through the per- 
forations. The forward 
movement of the stalks 
results from the inclina- 
tion of the cylinder, every 
fall carries the stalks 
towards the outlet, and 

E 2 




68 



WINE-MAKING IN HOT CLIMATES. 



with a machine of this kind it is only after a considerable 
number of falls that the stalks are finally expelled. 




Fig. 13. Blaquiere's Combined Crusher, Drainer, and Stemmer (front view). 

ADVANTAGES OF STEMMING. 

Stemming is not much practised in the southern regions 
of France, and does not seem to be generally called for in the 
manufacture of red wine. It is, however, advocated by many 
authorities, such as Coste-Floret, who has used it for more 
than ten years on his extensive vineyard*, and recommends 
the practice strongly. 

Stemmed wines, according to Coste-Floret, have more 
jinesse, are more alcoholic, and have better keeping qualities, 
than wines from the same vintage made without stemming. 

He admits that wines made from stemmed grapes will have 
to force their way, as the public taste has been always culti- 
vated for wines from unstemmed grapes. 

" The difficulty that the stemmed wines have to encounter is 
due, according to Coste-Floret, to the depraved taste of a 
certain class of consumers who formerly drank our common 
wines from non-stemmed grapes, but who appear to have now 
abandoned us. We must create a new market if we do not 
wish to see our wines discarded and used as raw material for 



* Saint Adrien, near Beziers. 



VINDICATION. 69 

manipulations which do not deserve to be encouraged, and we 
must make wines of good quality, able to be sold directly as 
natural pure wines." 

Indeed, it is truly desirable that our wines should not be 
discarded, and they should certainly be consumed without 
sophistication, but is it not excessive to think, as Coste- 
Floret appears to, that an important class of consumers no 
longer drink our wine, and that it should be necessary to 
stem the grapes to induce them to return to this custom. 

We are not of the same opinion. Wines made from 
stemmed grapes have more finesse and are slightly more 
alcoholic than wines from unstemmed grapes, but, contrary 
to Coste-Floret's opinion, they have poorer keeping qualities, 
and contain less dry extract. 

The greater richness in dry extract of wines from un- 
stemmed grapes is a well-known fact, and we shall presently 
quote some figures to prove this ; but is the excess in dry 
extract due to the stalks ? We do not think so. 

We have previously seen how small the proportion of 
stalks is in our southern regions, and how small also the 
percentage of soluble matters contained in the stalks. It 
is only 'by grammes that we express the soluble matters 
brought to the vat by 100 kilos, of vintage of Aramon, for 
instance, and, even then, the greater proportion consists of 
tartar and tannin. 

The great richness of wine from unstemmed grapes in dry 
extract cannot therefore be attributed to the stalks, but 
simply to the mechanical part played by them in dividing 
the marc and facilitating the penetration of the surrounding 
liquid, and therefore its solvent action. We must reject any 
idea of unfavorable influence of the stalks, on account of their 
small proportion in all our southern cepayes, and of the 
small quantity of soluble matter they contain, provided they 
have not been bruised by the crusher, and that the fermen- 
tation has been well conducted. 

We do not deny the usefulness of stemming in some 
special cases, in that of damaged vintages for instance, but if 
its efficacious action is evident in such a case, it must not be 
attributed to the fermentation of the grapes after separation 
from the stalks, but rather to the more or less perfect 
rejection of damaged from undamaged vintage, which is 
the result of the stemming, owing to all the rotten and 
dried grapes being separated with the stalks. In the case 



70 WINE-MAKING IN HOT CLIMATES. 

of a healthy vintage, and of cepages where the proportion 
between the stalk and the grape is not greater than in our 
cepages in the South of France, we do not see the necessity 
of advocating the general adoption of this operation. 

In any case, the action of the stemming is only secondary, 
not direct. The properties distinguishing stemmed from 
non-stemmed wine, are only the result of had fermentations 
due to unfavorable temperature, or of remaining too long on 
the marc. The defect in the case of wine from non-stemmed 
grapes is not to be imputed to the stalks, but to an increased 
maceration of the other parts of the marc, to which the pene- 
tration of the wine is facilitated by the presence of the 
stalks. 

M. Yincens, Professor in the School of Agriculture at 
Ondes, starting from the idea that the market value of 
wine depends on four principal factors the alcoholic 
strength, dry extract, acidity, and coloration studied 
methodically the influence of stemming on these four 
factors. 

The trials were carried out for three cepages Negrette, 
Aramon, Petit-Bouschet an equal quantity of wine being 
made from each, with and without stemming. 

AVe will quote his results.* Noting that the stemming 
was done by hand. 

Composition of Experimental Wines. 

Alcohol T^, Acidity as n . _ . .. 

- " 



Negrette, stemmed 89 16 "5 3 '66 3rd violet red 175 

,, not stemmed 8'7 17'5 3'80 200 

Aramon, stemmed 8 '8 19'5 5 "58 4th - 440 

not stemmed 8 "75 20 '4 5'11 445 

Petit-Bouschet, stemmed 8 '9 19-4 4'37 3rd 80 

not stemmed 8 '9 21 '3 4 '46 65 

" The above trials were made with the usual instruments 
found in trade Salleron's ebulliometre ; Houdart, oano- 
barometre, and Salleron's colorimetre. 

The acidity was determined with a normal potash solution. 

" The observations of temperature, which we consider 
useless for this table, show that in all cases the maximum 
temperature was 1 higher, and took place one day earlier, 
in the non-stemmed than in the stemmed vintages. These 

* Revue Internationale de viticulture ct d'cenologie t. I., No. 4. 



VINDICATION. 71 

results confirm the well-known fact, that the presence of 
stalks in the vat accelerates the fermentation. 

" When examining the composition of the wines, we see 
that the increase in alcoholic strength due to stemming is 
very slight. It is nil for Petit-Bouschet, insignificant for 
Aramori, and reaches two-tenths of a degree for Negrette. 
This difference is evidently due to the fact that during the 
submersion of the marc, which was only done in the case of 
Negrette, the stalks absorbed a greater quantity of alcohol. 

" The differences between the figures for dry extract is 
much more noticeable. It varies from 0*8 to 1*9 grammes 
per litre, and constitutes a disadvantage for the non-stemmed 
wines* which contain less. We noticed, in estimating 
the astringent matters according to the process of Aime" 
Girard, that the difference was almost entirely due, with 
the exception of Aramon, to the ceno-tannin, an excellent 
agent in the preservation of wine. 

" Except for the Aramon, which has a very peculiar com- 
position, the acidity is higher in non-stemmed wine ; although 
the difference is very slight, we must take into consideration, 
in the case of our southern wines, which are generally flat, a 
lack of fresh, cool, acid taste. 

" If we now examine the colour, the figures representing 
its intensity being in inverse proportion, we see that the dif- 
ferences in favour of non-stemmed wines are nil for Aramon, 
one-eighth for Negrette, one-fifth for Petit-Bouschet. t 

" To the taste the .stemmed wines were less harsh or rough 
than the non-stemmed, but these were mOTefruites, corses, 
and they would unquestionably be preferred by wine mer- 
chants. 

" As the stalks always absorb a certain quantity of wine, 
an increase in yield of 2 per cent, is due to the stemming, 
but this augmentation not covering the cost of extra mani- 
pulation we need not take it into consideration. 

" To sum up, in our experiments stemming has always 
furnished inferior wines, less rich in dry extract and 
colouring matter, and only slightly different in alcoholic 
strength. 



* We quote exactly, although it is easy to observe on examining the above 
table that it is stemmed wine that should be read in place of non-stemmed. 

t There is a contradiction between this conclusion and the figures of the 
table, but it is without importance, the result being in both cases very slightly 
different. 



72 WINE-MAKING IN HOT CLIMATES. 

" As the advantage resulting from the aeration of the 
vintage, and the expulsion of foreign matters and germs of 
noxious fermentation, may be realized without stemming, we 
may conclude that for wine made from heavy-bearing kinds 
of the south-west, of which the three experimented upon 
are the most important, that this practice is useless, if not 
actually injurious." 

We concur entirely with the views expressed by Vincens, 
taking exception however to those referring to altered (in- 
jured) vintage, and for special vinifications, such, for in- 
stance, as the vinification of red wine with grapes partly 
drained for white wine. 

Later on we will discuss these exceptional cases when 
describing the manufacture of white wine from red grapes. 

THE VATT1NG. 

The squashed vintage delivered from the crushers is fer- 
mented in vats. For the fermentation to take place in a 
satisfactory manner, so that the resulting wine will possess 
the maximum qualities compatible with the nature of the 
vintage, it is necessary: 

First That the vinous ferment which causes the pheno- 
mena be the only one at work in the must. 

The presence of healthy, vigorous, and abundant yeast is 
indispensable to attain this object. 

The aeration of the crushed vintage is an important factor 
in the multiplication of the ferment. 

Second That the transformation be effected as rapidly as 
possible. The rapidity of the work depends on the life of the 
ferment, which will only furnish its maximum yield if the 
chemical and physical conditions of the liquid are suitable. 

Third That the solid parts of the grape be sufficiently 
in contact with the liquid part to enable it to dissolve the 
necessary substances. This is obtained by various methods 
and special manipulations. 

AERATION OF THE VINTAGE. 

Let us assume the grapes to be introduced into the vat 
without being crushed, and the air in the vat replaced by an 
inert gas, such as nitrogen. If we thea prevent the access 
of any air and crush the grapes in situ, it would be noticed 
that the phenomena following the crushing were not at all 



VILIFICATION. 73 

comparable to what takes place under ordinary circum- 
stances^ The fermentation would be very difficult to start, 
and if it started at all would have no energy and probably 
be the seat of a great many alterations. If this be so it 
means that the germs of the ferments existing on the sur- 
face of the grape have only had at their disposal the small 
quantity of oxygen remaining in the grape, and that it is 
indispensable for the yeasts to have at their disposal a 
quantity of air sufficient for their normal development. It 
is not so for all the micro-organisms existing on the surface 
of the grape, for a number of these find the conditions con- 
genial, and succeed in changing the must into a liquid 
having nothing in common with wine. 

Let us suppose again a vintage crushed in contact with 
the air, but with a limited aeration, such as would result 
from crushing grapes in a bottle almost full, and closed 
before crushing so as to prevent the access of any additional 
air. The fermentation would start and become rather active. 
The activity may be measured by the amount of carbonic 
acid produced in a given time. If we study this fermenta- 
tion we will see that it diminishes rapidly, although there is 
a great quantity of sugar left, showing that the ferment still 
has food left, and that the cells of the ferment require after 
their first work a certain quantity of air to restore them to 
activity and enable them to multiply. 

This statement made by Duclaux, and deduced from 
Pasteur's classical experiments, is easy to verify. 

If the above must is racked in contact with air it will be 
seen that disengagement of gas increases at once. Aeration, 
we therefore maintain, is not only useful but absolutely 
indispensable to enable the germs on the grape skin to 
develop, and it is necessary to restore the ferment while the 
fermentation is proceeding, to enable the complete conversion 
of the sugar to take place. 

The first aeration takes place during the crushing, and it 
is the imperfect aeration in cylinder crushers which causes 
the inferiority so often noticed in wines so made, as compared 
with those from crushing by the feet. In the latter case the 
vintage remains longer in contact with the air, consequently 
the aeration is more perfect. 

In some districts (Bordeaux) they even go further. The 
vintage is thrown up in the air with shovels, before being 
placed in the vat. 



74 WINE-MAKING IN HOT CLIMATES. 

Does this mean that we must place the mechanical 
crushers aside and return to ancient methods ? 

Certainly not. Sufficient aeration may be obtained with 
machines. Some machines, such as the aero-crusher, effect 
the aeration during the crushing, in other cases, especially 
if the grapes have to travel in a long and open shute, it 
produces the same result. The paddles of the stemmers also 
have an aerating effect. We may also, immediately after 
the crushing, pump the must over the head (marc floating 
in the vat), being careful to spread it all over. This practice 
is quite sufficient to introduce into the must the quantity of 
oxygen necessary for a good start. The pumping over of 
the must may be repeated if necessary, and will prolong the 
fermentation until the sugar has entirely disappeared. 

Stemming, as we have seen, has not got a very direct 
influence on the quality of the wine, but it acts indirectly 
through the intense aeration it furnishes, and many think it 
is the only benefit we can get from the adoption of this 
practice in the South of France. 

We cannot do better than support our views by those of 
Pasteur. The following is his opinion, built on the irrefut- 
able experimental methods everybody grants to that scientist, 
taken from his Etudes des Vins: 

u I have noticed that when musts are exposed to contact 
with the air in a shallow vessel for many hours and stirred 
that fermentation is much more active than with non-aerated 
musts. The fact that aeration produces such apparent 
effects even during fermentation, while the liquid is already 
charged with carbonic acid and alcoholic ferments, is worthy 
of attention." 

Pasteur describes experiments which leave no doubt on 
that subject, and which show conclusively that non-aerated 
must produces more acid wines than those aerated. 

To any one who reads between the lines, abnormal increase 
of acidity is not a good sign, but rather a sign of defective 
fermentation, for the increase of acidity is generally due to 
the formation of volatile acids so characteristic of diseased 
wines. 

Apart from this, the aeration of the vat has a very bene- 
ficial influence on the ultimate preservation of the wine. 

We have no experiments to support this fact, as convincing 
as those of Pasteur, but it seems logical, and many authori- 
ties admit it. 



VINDICATION. 75 

Ott, an American scientist, lays down the principle that 
the more abundant the oxygen in the must, the more albu- 
minoid matters the ferment will absorb, and that the wines 
resulting will keep better the presence of albuminoid 
matters in excess in the wine being conducive to diseases. 

Ott's opinion is, we believe, annually confirmed in the 
vineyards of California, where aeration is a common practice. 

It consists in forcing air by means of a pump to the 
bottom of the vat, and discharging it in a fine stream through 
a perforated rose. This operation is repeated each day for 
ten minutes. The forcing of air through the fermenting 
must is no doubt a good thing, and tends to the preservation 
of the resulting wine ; but it has a decided inconvenience in 
the case of wine required in commerce to be brilliant and 
frais. 

According to Ott, aeration matures the wine quickly, and 
gives it that tawny colour so characteristic of old wines. 

We may obtain certain advantages by well-conducted 
aeration, but it must be well conducted, for it may become 
injurious if practised to excess and under bad conditions. 

Aeration before the fermentation starts, can never be too 
thorough or complete. 

When once fermentation has started, we must act with 
caution, for given with circumspection, the oxygen maintains 
the life of the various ferment and enables it to work with 
proper activity. It slightly oxidizes the colouring matter, 
and gives it a greater facility of dissolution, without modify- 
ing its tint. If the oxidation is excessive the colouring matter 
alters and becomes brownish, and loses its fixity in solution. 

This applies specially to fermentation in the South of France 
and Algeria, where very often the temperature is so high that 
the ferment dies. Excessive aeration under these circum- 
stances acts on the colouring matter in a disastrous way. 
Notwithstanding this great inconvenience aeration must not 
be rejected, for it still has a marked utility. It allows the 
complete conversion of the sugar, which is indispensable if we 
wish to avoid making wine which will certainly be of doubt- 
ful keeping qualities. 

Eietsch and Herselin* pointed out these advantages in a 
series of laboratory experiments bearing on apiculatus and 
ellipsoideus yeasts. 



Proyres Ayricole et Viticole, 1895 



76 WINE-MAKING IN HOT CLIMATES. 

They were able to obtain in all the fermentations at high 
temperatures at 36 C. (97 F.) a more rapid and complete 
decomposition of the sugar when aeration was used. 

The vine-grower, therefore, is confronted with an unpleasant 
situation if the temperature of the vat is allowed to rise too 
high. Without aeration he will obtain wine of uncertain 
keeping quality, with aeration better keeping wine but less 
fine will result. 

The maintenance of the temperature of the vat between 
proper limits is the only way of avoiding this embarrassing 
situation. 

The process has also many other advantages. We have 
had an opportunity of making a series of experiments in 
Algerian cellars on this subject, and these have since been 
continued in our laboratory in conjunction with F. Chabert, 
as studies on the different actions of high temperature on 
alcoholic fermentation. These studies are not yet completed, 
but allow us to clear up certain obscure points in the above 
observations. 

We will reproduce, in extenso, these studies, and hope they 
will prove the absolute necessity for controlling the tempera- 
ture during fermentation. 



CONTRIBUTION TO THE STUDY OF VINOUS 
FERMENTATIONS. 

INFLUENCE OF TEMPERATURE. 

(By L. Roos and F. Chabert.) 

The temperature of fermentation plays a part in viuification 
which recent studies have shown to be so important, that 
it is to-day a subject of thought for every cenologist. 

The flavour and keeping qualities of wines, depend to a great 
part on the temperature at which the transformation of the 
must is made. If it is too low the fermentation does not 
start, or starts too slowly, for the ellipsoideus yeast does not 
develop well, and bacterial actions take place which alter 
the value of the product. If it is too high the wine retains 
untransformed sugar, which forms a suitable medium for and 
favours the development of bacteria, which may so alter the. 



VINDICATION. 77 

nature of the liquid as to render it unfit for consumption. The 
natural consequence of this double observation leads us to heat 
our musts in cold climates, a very old practice justified by ex- 
perience, and to keep the temperature between given limits 
in hot regions. 

The study of the various processes of heating or refriger- 
ating musts, does not come within the scope of this paper. 
We have simply tried to discover the temperature preferred by 
the wine yeasts, that is to say, the temperature at which 
they perform a maximum of work in a minimum time. 

High temperature during fermentation has an unfavorable 
influence on the resulting wine. It reduces its alcoholic 
strength, alters its taste, and diminishes its keeping quality. 

The consecutive alterations of fermentations at high tem- 
peratures are well established, but have according to us, been 
too generally attributed to the development of micro- 
organisms, called parasitic, to distinguish them from those 
which transform the sugar into alcohol. 

Our experiments tend to show that, together with the 
bacterial action (an indirect result of the excessive tempera- 
ture) there is another action of the same class, but perhaps 
less important, attributable to the yeast itself, the. evolutions 
of which, and its conditions of work, are profoundly modified. 

Our experiments were made on raisin must, during the 
year, and with fresh grape musts during the vintage of 1896. 
We did not use yeasts of a special character, but simply took 
them from the wine lees of the district, making sure, how- 
ever, that the wine yeasts were self-cultivated. The colonies 
were obtained in solid gelatine and multiplied in sterilized 
must. The lees from which we extracted the yeasts came 
from the environs of Mudaison (Herault) and Saint Laurent 
d'Aigouze (Gard). 

We tried to keep as far as possible within general viti- 
cultural conditions, but do not pretend not to recognise the 
difference there is between laboratory practice and cellar 
operations. This simply means that we cannot give our 
results as the exact expression of what takes place in a cellar, 
but that they are simply land-marks placed on the path of 
this very complex study. 

Before giving our results, and describing the apparatus 
used by us, we will briefly summarize the previous work on 
this subject. 



78 WINE-MAKING IN HOT CLIMATES. 

OPINIONS OF VARIOUS AUTHORITIES AS TO THE 
BEST TEMPERATURE FOR FERMENTATION. 

Chaptal * states that the most favorable temperature is 
15 R. (66 F.) It languishes below that temperature, 
becomes too tumultuous above it, and if the temperature is 
too high or too low does not take place at all. 

According to A. Gautier f the most favorable temperature 
is between 28 and 32 C. In no case should it fall below 
18 C. or exceed 36 C. Once that extreme maximum is 
reached the glucose not only forms .alcohol, but also other 
products, and the rapid disengagement of carbonic acid 
carries away a notable quantity of alcohol. { 

Gautier points out already the formation of " other pro- 
ducts " is a result of fermentation at high temperature. Our 
experiments verify this opinion, for they show in the ferment- 
ing liquid the existence of products, not yet well defined, but 
exerting a distinct action. 

Prof. Bouffard fixes 25 C. as the temperature required 
for a good fermentation. " The temperature of 20 C. which 
sometimes cannot be exceeded in Bourgogne and that of 
35 C. always reached in Algiers are unfavorable. Wines 
made between 20 and 32 C. have more suavity in perfume 
and taste. Those obtained between 30 and 35 C. are flat, 
less perfumed, and possess foreign tastes due to the develop- 
ment of parasitic ferments." 

L. RougierJ in his Manuel Pratique, also studies the 
influence of temperature. Below 8 or 10 C. fermentation 
is impossible. The activity of the ferment increases little by 
little as the temperature rises to 25 or 30 C., above 40 or 
45 C. the fermentation tends to stop before the sugar is 
completely transformed. When the temperature gets over 
30 C. the carbonic acid carries away a certain quantity of 
alcohol and volatile principles constituting the bouquet.lf 

* L'Art de foire le Vin, p. 94, by Count Chaptal. 1819. We must draw 
attention to the correspondence between the Centigrade and Reaumur 15 
Reaumur, 1870 Centigrade. 

t Dictionnaire de Chemie de Wurtz. Art. Vin. 

+ We will see that if a notable quantity of alcohol is carried away it is to be 
attributed to the elevation of the temperature, and not to the rapidity of the 
evolution of gases, which, on the contrary, become slower. 

Role de la Chaleur et du Froid dans la Vinification. Progres Agricole et 
Viticole. 1891. 

|! Manuel Pratique de la Vinijication. L. Rougier, p. 25. 3rd Ed. 1895. 

IF This remark corroborates Prof. Bouffard's opinion above given, that wines 
made at high temperatures are deficient in perfume. 



VINDICATION. 79 

Dr. Frederic Cazalis * quotes the experiments of Miiller- 
Tlmrgau. These experiments show that " the fermentation 
of a must between 9 and 36 C. proceeds so much the more 
rapidly, and with more bubbling, as the temperature is higher, 
but past that point it stops the more rapidly, leaving a part 
of the sugar unconverted, as the temperature is higher." 
Cazalis notes afterwards the considerable influence the tem- 
perature has on the yield in alcohol, quoting the following 
figures : 

Fermentation at 9 C. ... 17-29' alcohol by volume 
18 C. ... 15-09,, 
27 C. ... 12-23,, ,, 
36 C. ... 8-96,, 

These results, exact no doubt under the conditions of the 
experiments of Miiller-Thurgau, cannot be generalized. The 
factor time, is missing from the table, and it is one of the most 
important. If we may admit the accuracy of the results with 
the Rhine yeasts, when treated in laboratories, it is easy to 
oppose against their generalization the fact well known to the 
vignerons of the South of France that we may easily obtain 
up to 10 or 11 per cent, of alcohol at temperatures over 36 C. 

Dr. Fred. Cazalis concludes that the temperature for a good 
fermentation lies between 15 and 25 C. Prof. Miiller- 
Thurgau noticed that fermentation ceases between 25 and 
36 C. before all the sugar is transformed into alcohol, because 
" the alcohol at such a high temperature acts upon the fer- 
ment, and even small amounts can arrest its activity."! We 
admit this action of the alcohol but only as one of the factors 
causing the stoppage of fermentation. 

We will show by experiments that the presence of alcohol 
is not the only cause retarding the work of the ferment. 

If it were possible, it would be sufficient to bring the liquid 
back to a proper temperature to see the yeast regain its 
former activity, but this does not happen. The fermentation 
only proceeds slowly, and is not even sensibly increased by the 
addition of fresh yeast taken from another vat in full activity. 

U. GayonJ gives as a limit 27 to 38 C., which should not 
be exceeded in any case if we do not wish to see the must 

* Traite Pratique de I' Art de faire Ic Vin. Dr. Frederic Cazalis, p. 144. 
Montpellier. 1890. 

f This is only true for quantities of alcohol varying between 8 and 10 per 
cent., and for temperatures exceeding 36 C. (R>os and Chabert.) 

t U. Gayon, Rapport sur la Vinification dans Us Annies Chaudcs. Bordeaux, 
1895. 



80' WIXE-MAKIXG IX HOT CLIMATES. 

attacked by disease ferments, and especially by the mannitic 
ferment.* It is the toxic action of the alcohol, the absence 
of oxygen, and the high temperature of 40 C. which para- 
lyzes the ferments. 

Miintz and Rousseaux f define the " critical point" as the 
temperature the yeast cannot support without suffering ; if 
that temperature is exceeded by a slight degree, its influence 
on the course of the fermentation has an important influence. 
This critical point is characterized by the fact that the yeast, 
still living if that point is just reached, dies directly it is ex- 
ceeded. We can enable the ferment, therefore, to recover by 
refrigeration, provided that the critical point is not exceeded. 
Should it be exceeded and the yeast destroyed, nothing can 
be done. These authors give an instance, the critical point 
being supposed to be between 38 and 40 C. 

We admit with Miintz and Rousseaux a morbid state of the 
yeast at high temperature, increasing as the temperature 
exceeds 35 C., we admit also a kind of critical point: 38 to 
40 C., which should not be exceeded if we wish to bring the 
ferments back to activity by refrigerating ; but we think 
that 38 to 40 C. conduces only to a more accentuated morbid 
state, and not to the death of the ferment, as this only occurs 
at a high temperature, for when sown in fresh must these 
yeasts start fermenting regularly again. 

H. Dessoliers,J in a study on vinification in hot countries, 
explains at length the influence of temperature on fer- 
mentation. " The temperature is a dominant and essential 
element in fermentation. The duration of fermentation will 
be so much the greater that the must has been the longer 
exposed to a high temperature (40 to 42 C.). The duration 
of the action of the high temperature must be taken 
into consideration more than the temperature itself." Des- 
soliers shows that high temperature produces sweetish wines 
liable to alterations, and quotes an observation due to 
Maerker, who asserts that yeasts do not multiply at tempera- 
tures over 28 C. This statement cannot be accepted without 
reserve. At 35 or 40 C. the yeasts multiply, not under 
favorable conditions perhaps, but nevertheless they multiply. 

* Gayon points out that the mannitic ferment starts during the true fermen- 
tation. We have shown that this disease easily develops in a sweet wine at 40 
C. L. Roos, Journal de Pharmacie et de Chimie, 1892. 

t Miintz and Rousseaux. Etudes sur la Vinification dans le Roussillon, 
faites aux Vendanges de 1894. Bulletin du-Ministere de V Agriculture, 1895, 
p. 1208. 

+ H. Dessoliers, Vinification en Pays Chauds. Alger. 1894. 



VERIFICATION. 81 

Dessoliers states that yeast cannot germinate if it has 
been submitted to too high a temperature. We have, 
however, shown above that it can germinate normally if 
placed in new must. 

One of us, taking into consideration numerous experi- 
ments made on yeasts from many different countries, fixed 
the maximum vitality of the vinous ferment, whatever species 
it may belong to, at between 28 and 32 C. At 20 C. the 
activity is very slow. At 40 C. it is nil. At 45 C. it dies, 
or is of no further use.* " The very best temperature is 
30 C., and the must cannot go much above or below this limit 
without becoming liable to bacterial diseases, those made at 
the higher temperature becoming most liable. The vinous 
yeast may be killed at temperatures insufficient to kill other 
ferments. At high temperatures the yeasts eliminate 
products detrimental to the wine, which may even render the 
must sterile, although still containing 'sugar, and the other 
conditions apparently seeming favorable ; or the yeast in 
full activity develops badly, or perhaps not at all."f 

To summarize, different authorities agree that in high 
temperature lies the most important cause of the defects of 
wines made in hot regions. The sugar they often contain, 
through the fermentation not being completed, is a favorable 
ground for the development of bacterial diseases. 

The numerous applications of refrigeration to musts 
confirm this opinion of scientific authorities. 



METHODS AND APPARATUS EMPLOYED. 

Exact estimations of acidity calculated as sulphuric acid 
were made for all the musts experimented upon. 

Reducing Sugar. We used, for the estimation of this, the 
ordinary ciipro-potassic solution, but substituting the elec- 
trolytic determination of the precipitated copper for the 
volumetric method, relying on the disappearance of colour. 
The musts, although diluted, were rich enough for the 
slightest divergency in measurement of the volume of liquid 
in the burette, corresponding to the end of the reaction to 

* L. Roos. Principes generaux de la vinification en rouge. Proyres agricole 
et viticote, 1894. 

t L Roos, Etudes sur la vinification en pays chauds. Revue de Viticulture, 
1894. ' 

10649. F 



82 



WINE-MAKING IN HOT CLIMATES. 



result in notable errors. The musts were examined in 
Laurent's polarimetre. We used Salleron's mustimetre to 
obtain approximate indications. 

Acidity. Determined by titrated lime water. The wines 
resulting were more closely examined. We determined : 

Reducing Matters, always expressed as glucose, estimated 
by the ordinary method, that is, decoloration of a cupro- 
potassic solution by the wine previously treated with sub- 
acetate of lead. 

Alcohol in Volume, per cent, determined by distillation, and 
density by pyknometer, this being the most accurate method. 
Acidity is expressed as sulphuric acid per litre. 
Total Nitrogen (with the exception of nitrogen existing 
in the shape of pyridine compounds) was estimated by the 
Kjeldahl process. 

By the way, we draw attention to an experimental point. 
It is often difficult to obtain a complete decomposition 
without loss, when examining wine rich in sugar. By evapo- 
rating on a water bath from 50 to 100 c. c. of wine in a small 

flask of 200 to 300 c.c., 
and adding to the residue 
a few drops of concen- 
trated sulphuric acid, a 
spongy carbonaceous 
mass is formed well 
adapted to complete 
decomposition, without 
producing the violent 
frothing so liable to oc- 
casion trouble or loss. 

The fermentations 
were conducted at four 
different temperatures, 
including the maximum 
and minimum generally 
observed in our regions, 
25, 30, 35, and 40 V. 
These temperatures 
were maintained constant 
by meansof the apparatus 

Fig. 14. -Flask submerged by a lead ring, con- shown in Fig. 14. The 
taining the must-C, circular gas burner ; L, rCCCptacle COntainS Water 
Liebig bulbs, containing sulphuric acid; R, 
thermo-regulator ; S, tripod ; T, thermometer. 




VINDICATION. 



83 



X 



in which the thermo-regulator is placed. The regulator is 
influenced to a certain extent by the pressure of the gas 
supply. We were, therefore, obliged to interpose between it 
and the gas supply a Moitessier pressure regulator. 

A flask, B, of two litres capacity, containing 1-5 litres of 
must, kept submerged by a lead ring, supported in the tank 
on a wood-lead ring, and closed with a doubly perforated 
cork. Through one hole a thermometer, T, passed, through 
the other an exit tube, connected with a Liebig's absorption 
apparatus, L, where the alcohol and the water vapour 
escaping were caught. 

The quantities of gas disengaged were measured either by 
the balance, or the self-registering gas disengagement machine 
of Houdaille.* In either case the temperature of the must 
inside the flask and of the surrounding water were recorded 

every other hour. 
In the first case the 
weighings were 
made at even inter- 
vals. In the second 
case the carbonic 
acid was measured 
by the Houdaille 
self-registering ap- 
paratus, of which 
we will now give a 
short description, 
Fig. 15. 

It consists of a kind of gasometer, G, with two compart- 
ments, C and C, plunged in water, oscillating on a horizontal 
axis in such a way that, moving round the pivot under the 
pressure of the gas, one of the compartments may empty 
itself while the other is filling. Each oscillation, by means 
of a very simple system of levers, prints a point on the 
cylinder moved by clock-work. 

The cylinder may move normally in the direction of the 
lever; in front -of it is a groove, D, and as it revolves once 
in twelve hours, it suffices for a small lateral displacement 
of the cylinder, to avoid the overlapping or super-position of 
the points, and therefore allows the continuous observation 

* Houdaille. Sur un appareil enregistreur des fermentations alcooliques. 
Annales dt VEcole d* Agriculture dc Montpellier, 18S7- 

F 2 





Fig 1 . 15. G G', compartments of the gasometer, G; D, 
groove ; I, cylinder ; P P l , counterpoise ; R, trough 
containing the water ; T, tube leading gas to register. 



84 WINE-MAKING IN HOT CLIMATES. 

of a few days' fermentation. We used a four-compartment 
register, one being applied to each fermentation. 

This apparatus works very accurately in the case of a gas 
insoluble in water, but is not so satisfactory with carbonic- 
acid. The solubility of carbonic acid in water is an obstacle 
to its perfect action. This might be avoided in using a liquid 
in which carbonic acid is insoluble. 

It is very difficult to find such a liquid ; glycerine is the 
only one not exerting a solvent action, but it has the dis- 
advantage of being too viscous, and diminishing the mobile 
action of the compartment. 

We endeavoured to render the solution of the carbonic acid 
almost nil, by maintaining the water in the trough constantly 
saturated with carbonic acid, by interposing an atmosphere 
of that gas between the water and the atmosphere. 

With this object each of the com- 
partments received a slow current 
of carbonic acid, obtained by a 
regular flow of alkaline carbonate 
into dilute sulphuric acid, the two 
bottles being placed one above the 
other, F F, fitted with a Mariotte 
tube, Fig. 16. 

A board, in which is bored a hole 
to allow the movement of the rod 
connected 'with the compartments, 

shelters the SUrfaCC of the Water 

o K te p againstdraughts which might sweep 
tu P befo7 t ie S 'c2SnTc ; an: wa 7 ^ liberated gas. This slight 
hydride. modification enabled us to obtain 

with the Houdaille apparatus results quite comparable with 
those obtained by weighing. 

We will, later on, describe the device by which we 'tried 
to measure the quantities of alcohol carried over mechani- 
cally by the carbonic acid. 



STUDY OF FERMENTATIONS. 

At 25 G. the start is very slow, the froth only appears on 
the fourth day, although the disengagement of gas shows 
the fermentation to be already well established. The liquid 
is rendered turbid by the yeasts, and the sulphuric acid in 
the Liebig bulbs is coloured brown by the gas. 




VINDICATION. 85 

At 30 0. very rapid start, very regular course, slacking 
down before the sugar is completely transformed, the liquid 
is very turbid, and the sulphuric acid in the bulbs is coloured 
more intensely brown than before. 

At 35 C. the start is also very rapid, and the activity is 
very regularly maintained as long as the alcoholic strength 
is below a certain limit. It slacks off sooner than* the fer- 
mentation at 30 C. and leaves more sugar tin transformed. 
The liquid is very turbid at the beginning, and becomes clear 
after the yeast diminishes its activity, the sulphuric acid in 
the bulbs becoming very intensely coloured. 

At 40 C. the start is not very noticeable, and the fermenta- 
tion is always very slow. The liquid did not get very turbid, 
although there was an abundant deposit of yeast at the 
bottom of the flask. A great part of the sugar remained 
undecomposed. The sulphuric acid in the bulbs becomes 
only slightly coloured. 

The fermentations which are most active at the beginning 
are, in order of rapidity 35, 30 C.; sometimes, however, that 
at 30 C. takes the lead, but in most cases the fermentation 
at 35 C. overtakes it ; this only happens at the commence- 
ment and for a short time, after which they keep at the same 
rate. 

The fermentations at 25 and 40 C. start with more diffi- 
culty, the latter being always slower and less active. 

Between the fermentations at 25 and 30 C., the difference 
of the rate of activity can only be observed at the beginning. 
The start is more difficult at 25 C., but when once the fer- 
mentation has commenced it proceeds very regularly with 
much greater loss of weight than that of the fermentation at 
30 C. In such a way that by prolonging the experiment 
we arrive at the decomposition of the sugar quite equally in 
both flasks. While by that time the flasks at 35 and 40 C. 
have already stopped fermentation. 

A constant and remarkable fact noticed in our experiments 
is that, with the same must, the higher the temperature rises 
the deeper the colour becomes. We can evidently not put 
this down to oxidation of the colouring matter of the must, 
for it is isolated from contact with the air by the Liebig 
bulbs. In the cases where we tried the action of the air 
during fermentation, we observed this modification of colour 
before the introduction of air, and did not observe any 
influence of this kind due to the air in that operation. 



86 WINE-MAKING IN HOT CLIMATES. 

The sulphuric acid in the Liebig bulb becomes differeutly 
coloured, the density of the brown colouring being deeper for 
the fermentation at 35 C., a little less for the fermentation 
at 30 C. This coloration seems to depend on two factors, 
the temperature and the rapidity of the evolution of gas, and 
this explains the coloration of the acid corresponding to the 
flasks fermenting at 40 C., for if in this case the tempera- 
ture is higher, there is only a very slight quantity of car- 
bonic acid passing through the sulphuric acid bulbs. 

The brown coloration turns to a very fine pink on the 
addition of water to the sulphuric acid. We thought that 
the turning to pink was peculiar to dry grape musts (raisin 
must), but fresh grape musts gave the same results. 



INFLUENCE OF TEMPERATURE ON THE YIELD OF 
ALCOHOL. 

Two cases will be considered, the absolute yield of alcohol 
independently of the quantity of sugar decomposed, and the 
relative yield that is to say, the ratio between the alcohol 
obtained and the sugar which has disappeared. 

In both cases the yield in alcohol is less as the tempera- 
ture is higher. In absolute yield this result only holds if we 
consider fermentations lasting more than ten days ; below 
this limit the fermentations at 25 C. furnished less alcohol 
than that at 30 C., but the relative yield always remains 
greater. 

In short, tor a normal duration of eight days the fermenta- 
tion at 30 C. is the best, then follow in order 25, 35, 40 
C., the latter always taking much longer than the others. 
If we allow the fermentation at 40 C. to remain undisturbed, 
it continues to gain in alcohol, but very slowly, and then only 
under the influence of a fermentation, the exterior characters 
of which are very different from those of an ordinary fer- 
mentation. Two of our experiments (on must from fresh 
grapes), which did not contain: One, 4 per cent, of alcohol on 
the seventh day, and the other, 6 per cent, on the tenth day, 
showed for the first 9*5 per cent, two months after, and the 
other 6*4 per cent, after eighteen months. 

We have never obtained 47 per cent, of alcohol per 100 of 
sugar decomposed, considered as a practical yield, although 
we have closely approached it. 



VILIFICATION. 87 

This might be because our temperatures were too high 
even that of 25 C. 

The yield of 47 per cent, which can be obtained in cold 
regions is never obtained to our knowledge in warm regions, 
and we think that the measurement of the sugar, based on 
the transformation of that body by fermentation, must be 
done in order to be exact, when the operation is effected at a 
very low temperature, and during a long time. 

The following tables summarize the analytic results 
obtained on some of our wines, and give the differences 
observed in relative and absolute value : 

RAISIN MUST, No. 1. 

Reducing matters ... ... 174 grammes per litre. 

Mustimetre ... ... 170 

Polarimetric deviation ... 22 (sugar degree) 

25 C. 30 C. 35 C. 40 C. 
Alcohol in volume, per cent. ... 10-1 9'7 9-2 2*1 

Alcohol in weight, per litre .,. 80-8 77'6 736 16'8 
Sugar remaining ... ... 2'0 2*5 4'5 * 

Sugar transformed ... ... 172*1 171-6 169'6 

Ratio of alcohol to sugar trans- 
formed ... ... 46-94 45-22 43'39 

Difference from the practical 

yield of 47 per cent. ... 0-06 178 3-61 

Difference from the theoretical 

yield of 48-5 per cent. ... 1'56 3'28 5-11 

Quantities of alcohol condens- 
able hypothetically, in abso- 
lute volume ... ... 1-57 3-17 4-70 

Quantities of alcohol condensable 
hypothetically, in weight, per 
litre ... ... ... 1-42 2'54 3'76 

RAISIN MUST, No. 5. 

Reducing matters ... ... 174*5 grammes 

Mush'metrc ... ... ... 167 '0 ,, 

Polarimetric deviation ... 32'4 (sugar degree) 





25 C. 


30 C. 


35 C. 


40 C. 


Alcohol in volume, per cent. 


9-9 


9-7 


9-1 


7-3 


Alcohol in weight, per litre 


79-2 


77-6 


72-8 


58-40 


Sugar remaining 


3-0 


3-0 


100 


41-0 



* An accident prevented the determinations being made for the fermenta- 
tion at 40 C. 



8 WINE-MAKING IN HOT CLIMATES. 

RAISIN MUST, No. 5 continued. 

25 C. 30 C. 35 C. 40 C 

Sugar transformed ... l7l'5 171'5 164-5 133-5 

Ratio of alcohol to sugar 

transformed ... ... 46' 17 45-25 44'25 42-24 

Difference from the practical 

yield of 47 per cent. ... 0'83 l'6o 2'65 4-66 

Difference from the theoretical 

yield of 48-5 per cent. ... 2'43 3'25 4'25 6'26 

Quantities of alcohol con- 
densable, hypolhetically, in 
absolute volume ... 2'40 3'27 3*86 4'57 

Quantities of alcohol con- 
densable, hypothetically, in 
weight, per litre ... 1-92 2'62 3'10 3'65 

RAISIN MUST, No. 6. 

Reducing matters ... ... 247 grammes 

Mustimetre ... ... ... 247 

Polarimetric deviation... ... - - 28'2 U (sugar degree) 

25 C. 30 C. 35 C. 40 C. 

Alcohol in volume, per cent. in 10'6 9-3 * 

Alcohol in weight, per litre 88 '8 84'N 74-4 
Sugar remaining ... 56-8 63'2 83'3 

Sugar transformed ... 190-2 183'8 163-7 

Ratio of alcohol to sugar 

transformed ... ... 46*68 46- 13 45'44 

Difference from the practical 

yield ... ... ... 0'32 O87 1-56 

Difference from the theoretical 

yield ... ... ... 1-82 2'37 3'06 

Quantities of alcohol con- 
densable, hypothetically, in 

absolute volume ... 2'02 2'51 2-84 

Quantities of alcohol con- 
densable, hypothetically, in 
weight, per litre ' ... 1*62 2'01 2'28 

After eight days, even when the flask had returned to 
the temperature of the surrounding air, the fermentation 
did not start, which leads us to think that the temperature 
of 40 C. had killed the yeast. We only noticed this in one 
instance. 



* The fermentation at 40 C. did not move appreciably. This was due, no 
doubt, to the great saccharine richness of the must. 



VINDICATION. 



89 



FRESH GRAPE MUST (TERRET- 

JKb. 

Reducing matters 
Mustimetre 
Polarimetric deviation 

Alcohol in volume per cent.* 

Alcohol in weight, per litre ... 

Sugar remaining ... 

Sugar transformed 

Ratio of alcohol to sugar 
transformed 

Difference from the practical 
yield ... 

Difference from the theoretical 
yield ... 

Quantities of alcohol con- 
densable, hypothetically, in 
absolute volume 

Quantities of alcohol con- 
densable, hypothetically, in 
weight, per litre 

FRESH GRAPE MOST 

Reducing matters 
Mustimeire 
Polarimetric deviation 

Alcohol in volume, per cent. 

Alcohol in weight, per litre ... 

Sugar remaining ... 

Sugar transformed ... 

Ratio of alcohol to sugar 
transformed 

Difference from the practical 
yield ... 

Difference from the theoretical 
yield ... 

Quantities of alcohol con- 
densable, hypoihetically, in 
absolute volume 

Quantities of alcohol con- 
densable, hypothetically, in 
weight, per litre 



BOURRET AND PlCQUKPOUL), 

8. 

190 grammes. 

190 

40 (sugar degree). 

25 C. 30 C. 35 C. 40 C. 

10-9 10-9 9-6 9-3 

87-20 87-20 76-80 74'4 

2-50 2-00 22-90 27'0 

187-50 188-00 167-10 163-0 

46-5 46-38 45-96 45*64 

0-50 0-62 1-08 1-36 

2-00 2-12 2=58 2-86 

2-18 2-31 2-48 2-66 

1-04 1-85 1-98 2-1 

(ARAMON), No. 11. 

203-40 grammes. 
200-00 

37 (sugar degree). 

25 C. 30 C. 35 C. 40 C. 

9-6 7-2 6-1 

76-80 57-60 51-2 

39-15 76-90 86-9 

... 164-25 126-50 110-5 

46-75 45-50 43-9 

0-25 1-50 3-1 

1-75 3-00 4-6 

1-68 2-15 2-94 

1-34 1-72 2-35 



* The analyses of these wines were made three months after the start of the 
fermentation. 



90 WINE-MAKING IN HOT CLIMATES. 

In this trial the experiment at 25 0. was not made, the 
analyses were only made one month and a half after the 
start. 

We see that fermentation left for a few days at a high 
temperature can only be completed after a long time four 
months at least, for fermentations that have been submitted 
to a temperature of 40 C. during ten days. This excessive 
duration of slow fermentation, seems to depend on the time 
during which the flask has been submitted to the high 
temperature ; however, we repeat, one may obtain complete 
fermentations, giving sound wines, but that result can only 
be obtained in the laboratory, that is to say, in must 
previously sterilized and sown with pure yeast. 



INFLUENCE OF THE TEMPERATURE ON THE WORK OF 
DIFFERENT YEASTS. 

High temperatures, therefore, have a retarding action 
on the yeasts of the He"rault, which were used in these 
experiments. 

We tried to ascertain if, as suggested by Marchand, 
Director of the Experimental Cellar at Mascara, in Algeria, 
the yeasts suffer more or less at high temperatures, accord- 
ing to the cold or hot regions they originate from. 

Marchand having studied the working of two yeasts taken 
from the same cepage, but from different regions, and work- 
ing in the same musts, noticed that these yeasts could stand 
very different temperatures, the one originating from the hot 
district suffering less than the other. 

This observation led us to think that the most favorable 
temperature found by us for the yeasts of the Herault 
(30 C.) might be high for yeasts originating from cold 
climates, and low for those from hot climates. 

To verify this idea, we have made a series of experiments 
with yeasts from the Rhine, Burgogne, and Herault. But 
we only obtained the divergent results given in the following 
table : 

25 C. 30 C. 35 C. 40 C. 

Mudaison yeast ... 105 20 164-00 109-00 85-20 

Bourgogne yeast ... 95-40 140-00 131-20 106-50 

Wolbrath yeast ... 130-98 112-00 112-90 90-00 

These figures do not seem sufficient for rejecting 
Marchand's theory, for the Rhine and Burgogne yeasts we 



VINDICATION. 



91 



used had been reproduced many times in the laboratory, at 
somewhat high temperatures, which may have enabled them 
to acquire special resistance. 

If this were so, we may foresee the possibility of creating 
a race of yeasts capable of withstanding without difficulty 
the temperature of the South of France, but this is only an 
hypothesis. 




INFLUENCE OF TEMPERATURE ON THE LOSS OF ALCOHOL. 

We used, to collect the alcohol, the 
following device, Fig. 17 : The exit 
tube, the Liebig bulbs having been 
removed, leads to a bottle, F, containing 
a small quantity of water ; the vapours 
not caught by this, pass through a con- 
denser surrounded by ice. 

The results obtained by this means 
are not accurate, and not comparable, 
for there is a condensation of alcohol 
taking place on the portion of the flask 
Fig. iv. -F, bottle contain^ projecting above the water bath, and 

the water; R, condenser; 7r <? i i m i i_ J.T 

s, worm ; T, tube carrying therefore cold. Ilie higher the tem- 

fne e nfation lvedduringfer " perature of the liquid, the greater the 
condensation. 

The quantity of alcohol carried over is subordinate to the 
rapidity of the disengagement of gas, and the gaseous dis- 
engagement being equal, is so much the greater as the 
temperature is higher, for the tension of the vapour of 
alcohol increases rapidly with the temperature. 

In all our experiments the disengagement of carbonic 
acid did not differ much between the 25, 30, and 35 
fermentations, but was very slow at 40 C. As the strengths 
of alcohol are always greater in the three first fermentations 
than in the last, we should expect to find more alcohol 
carried away from the fermentations at 25, 30, and 35 C. 
than that at 40 C., even considering the high tension of 
alcohol at 40 C. The following figures calculated for one 
litre confirm our expectations : 

25 C. 30 C. 35 C. 40 C. 



Raisin must 

Fresh grape must... 



C.C. 

1-3 

1-8 



C.C. 

2-0 
2-1 



C.C. 

2-1 

2-85 



C.C. 

traces 
1-5 



Raisin 
must. 
2-5 


Raisin Terret-Bourret 
must. Picquepoul. 
23 3-8 


Aramon. 


2-6 


2-4 


3-8 


4-1 


27 


2-8 


4-1 


4-8 


2-8 


3-0 


4-9 


5-1 



92 WINE-MAKING IX HOT CLIMATES. 

These figures are quite sufficient to show that there is a 
loss of alcohol through mechanical means. We do not 
think, however, that this loss is the only cause of the diminu- 
tion of the yield, but, on the contrary, that the most important 
cause resides in the incomplete utilization of the sugar. 



INFLUENCE OF TEMPERATURE ON THE TOTAL ACIDITY 
OF WINE. 

The temperature has a marked influence on the total acidity 
of wine. Experiments have shown us that the acidity always 
increases with the temperature. Here are several of our 
results : 



25 C. . 

30 C. . 

35 C. . 

40 C. . 

We cannot blame for this increase of acidity, parasitic 
fermentations which are the cause of it in ordinary wines, 
as our experiments were made with sterilized must, sown 
with pure yeast ; the only reason we can see, therefore, is that 
the yeast modifies its work with the temperature, and pro- 
duces acid substances, as the precipitation of a part of the 
bitartrate of potash, always greater at low temperature, is 
insufficient to explain the differences observed. 

ACTION OF TEMPERATURE ON THE YEAST. 

One of us has already shown that it is possible to recog- 
nise, by microscopical observation, if the yeast has worked 
at a proper temperature.* 

The morphological differences of yeasts worked at different 
temperatures are very noticeable. The yeast at 25 C. is 
turgid, with hyaline and homogeneous protoplasm, and 
spherical. That at 40 C. is elongated, less regular shaped, 
and coloured, its membrane seems thick, generally wrinkled, 
sometimes star-like, a few cells only remaining refractive. 

In a chemically neutral liquid (distilled water), for in- 
stance, the deformations are still more marked, the wrinkles 
distorted and pigmented. an appearance common with yeast 

* L. Roos. Vinification en pays chauds. 



PLATE II. 




Wine Yeast of the Herault working at 25 C. 




Wine Yeast of the Herault working at 40 C. 



VINDICATION. 93 

fermented at 40 C. If after being washed, the yeast is 
placed in distilled water, after having been submitted for 
eight days to a temperature of 40 or even 25 C., there is also, 
apart from the special action of the temperature, that of the 
complete lack of nutritive substances in the liquid ; the yeast 
produces endogenous spores (Rees spores) at both 25 and 
40 G. 

Therefore, the temperature has an action on the shape of 
the yeast in the must, sufficient to be detected under the 
microscope. It is rational to think that these morphological 
appearances are the exterior manifestations of a morbid 
state, the limit of which causes the death of the yeast. 

Riestch and Herselin state that in two series of experi- 
ments made with Musigny yeast, the yeast, died, after nine 
clays' fermentation, at 36 C. 

Miintz, who we have already quoted, asserts that the 
morbid state is at 37*5 C., which he calls the critical point. 

Our experiments lead us to a different opinion. Our 
yeasts did not die at 40 C., even after remaining ten days in 
the must at that temperature. Some have even been kept 
at 42 C. without dying. 

It is evident that if we consider as the death of the 
ferment, the fact that the must brought down to a proper 
temperature cannot start fermentation again, we agree 
with the above authorities, for it is a fact that over- 
heated fermentations brought down to lower temperatures 
will not start again. This is not due to the death of 
the ferment, but to the impossibility of developing in the 
liquid in which it is. 

To strengthen this opinion, we may mention that we have 
always obtained active yeast cultures by sowing them in 
new must, even after they had reached the temperature ot 
40 C. It does not seem possible to us to fix a limit to the 
temperature at which yeast is killed, for the composition of 
the liquid itself is an important factor advancing or 
retarding this limit. 

INFLUENCE OF THE TEMPERATURE ON THE QUANTITY OF 

NITROGEN. 

Under ordinary circumstances fermentation does not take 
place without the yeast, which absorbs from the liquid the 
nitrogenous principles necessary to its constitution, elimi- 
nating nitrogenous products. It is a general observation of 



94 



WINE-MAKING IN HOT CLIMATES. 



Schutzenberger that the elimination of nitrogenous matters 
increases when the yeast is under unfavorable conditions, 

It appeared to us that the influence of high temperature, 
which determines the morbidity of the yeast, might also 
determine a greater elimination of nitrogen, for we noticed 
in our fermentations that, generally speaking, starting from 
the same must, the wine obtained is so much the richer in 
nitrogen as it has been fermented at a higher temperature. 



Nitrogen, per Litre 



25 C. 



30 C. 



35 C. 



40 C. 





. 




Raisiu must ... 


0-265 


0-322 


0-490 


Terret-Bourrot and Pic- 








quepoul 
Araraon 


0-11,5 0-115 
0-112 


0-120 
0-193 


0-135 
0-183 


Carignan 


0-187 


... 


0-205 



Experiments made by Miintz on this subject have attracted 
scientists' attention. He noticed that wines obtained at 40 C. 
contain more ammouiacal salts than those made at tempera- 
tures below 37 G. But there is this great difference between 
the experiments made by Miintz and ours, that his bear only 
on ammoniacal salts, and ours on more complex compounds ; 
and, what is more, he attributes the increase of ammoniacal 
salts to the destruction of. the nitrogenous molecules by 
the yeast, and that the yeasts themselves can become the 
prey of micro-organisms. 

In our experiments nothing of the kind could happen, 
for, we repeat, we used must sown with pure yeast ; the 
yeast, far from producing ammoni.i, would, on the contrary, 
have used all the ammonia that might have been -in the 
must. 

We have found traces of ammonia only in wine fermented 
at high temperatures, while Miiiitz found it in wines ferment- 
ing at a normal temperature. 

It is therefore a fact, not before stated, that high 
temperatures produce wines rich in complex soluble nitro- 
genous compounds. 

What is the nature of this nitrogenous matter ? We can 
only offer a suggestion. We think that the sterility 



VINDICATION. 95 

acquired by the must ought to be attributed, partially at 
least, to these nitrogenous bodies. 

The result of practical observations made in Algeria 
shows that fermentations, languishing at 40 and 42 C., 
completely stop and cannot start again, when brought back 
to a low temperature. 

Two explanations may be advanced first, the death of 
the yeast ; second, the liquid has become toxic, and there- 
fore either unfer men table or only fermentable with difficulty. 

We have already seen that at 40 C. the yeast was still 
living. We have sown new must, previously sterilized, with 
yeast that had remained ten days at 40 C., the fermentation 
having stopped. This yeast became prolific. 

This experiment has been repeated often, and has always 
given concordant results. 

Our laboratory experiments confirm the second hypothesis, 
which is supported by H. Dessolier's practical observations 
in Algeria. 

From a filled and fermenting vat, six hogsheads of wine 
were racked when the temperature reached 25 C., then 
successively six others, each at temperatures of 30, 35, 40, 
and 42 C., the rest of the vatful was refrigerated, andifresh 
hogsheads taken from it when the temperatures were falling, 
passing 35, 30, and 25 C. The following table shows the 
number of days required to completely transform the sugar 
in each of these series : 

Time required 

Hogsheads. for complete 

fermentation. 

25 C ... ... ... ... 10 days 

30 C ... ... ... ... 10 

35 C ... ... ... ... 10 

40 C ... ... ... 20 

42 C more than ... ... 225 

35 C ... ... -... ... 80 

30 C ... 50 

25 C 36 

The maximum temperature reached only lasted a few 

hours ; its influence, however, was sufficient to more than 

treble the normal duration of fermentation. 

Our results are still more definite, but we prolonged the 

action of the temperature from eight to ten days, and thus 

observed fermentation not completed after four months, in 

the flask, at 40 C. brought down to 25 C. 



96 WIXE-MAKIXG IN HOT CLIMATES. 

To verify the toxicity towards the yeast, of a liquid fer- 
mented at 40 C., we tried it by adding a certain proportion 
of fresh must, and sowing the mixture with active yeast. 

With this object, eight volumes of wine at 25 C. and eight 
volumes of wine at 40 C. were respectively mixed with two 
volumes of fresh must. The quantity of sugar and alcohol 
was rendered uniform in the two mixtures by additions of 
alcohol and pure glucose. They were both sown with yeast 
from the same culture, and both kept at a temperature of 
28 C. 

Regular weighings showed that the course of fermentation 
was much more satisfactory in the flask containing the initial 
wine at 25 G. than in that at 40 C. The loss of sugar was 
twice as great in the first mixture, and was complete in nine 
days, while in the mixture of the wine at 4U C., the fer- 
mentation proceeded slowly, and a month after the start 
the liquid still contained 16 grammes of sugar per litre. 

Our experiments show, therefore, that a liquid previously 
sterilized, and sown with pure yeast, may become unferment- 
able under the sole action of a high and prolonged tempera- 
ture. We must put aside the hypothesis of the toxicity 
brought about by secondary fermentation, and only attribute 
it to the action of the products eliminated by the yeast. We 
do not deny the intervention of parasitic fermentation in 
that sense. We simply desire to point out that the same 
phenomena take place without it. 

We intend to try and show that it is, without doubt, due 
to the presence of albuminoid matters eliminated by the 
yeasts. 

The yeast eliminates volatile acids, mainly acetic and 
propionic acids, but these exist in any fermentation, even 
normal, and do not seem to have any action on the work of 
the yeast, provided that they do not exceed a limit above 
that normally given by the yeast. 

Kayser has observed that the temperature of fermentation 
has no influence on the quantity of volatile acids produced. 

Volatile Acids calculated as Acetic Acid. 
25 C. 35 C. 



Yeast 2 ... ... 0-979 ... 0-780 

8 ... ... M12 ... 1-504 

9 0-862 0-828 



VINDICATION. 97 

U. Gayon has recently pointed out* that whenever the 
proportion of volatile acids increased, that phenomenon 
coincided with the presence of micro-organisms other than 
yeasts, which is in accord with the observations of Kayser. 

As regards the production of higher alcohols and the 
alkaloids which accompany them, it is very small, and these 
substances have not a very energetic action on the yeasts. 
The same may be said of substances such as leucine and 
tyrosine, which are produced in such small quantities, that it 
is necessary to operate on large volumes of liquid to detect 
them. As also for pyridine and collidine, noticed by 
Ordonneau, and proteine matters as yet undetermined which 
we merely mention, and classify with the toxalbumens, 
according to Roussy, who observed them in beer yeast. 

To ascertain if these substances have an'analogy with those 
observed by Roussy, we injected rabbits with liquids obtained 
by macerating wine yeast previously washed for eight days 
in distilled water at 25 and 40 C. We noticed rises of 
temperature, in the animals which were given a few centi- 
metres of the solution from the maceration at 40 C. after 
filtration through a Chamberland candle. 

The infusion at 25 C. does not give any apparent results, 
but the injection of an equal volume of a yeast culture, that 
had not been submitted to an abnormal temperature, also 
produced hyperthermy. As the filtrate from the maceration 
at 25 C. does not produce any effect, we may infer that the 
active substances liable to be developed by the yeast are 
elaborated in the organs of the animal, the temperature of 
which is too high for the yeast. 

It is therefore to these albumenoid substances, which we 
consider analogous to those of Roussy, that we attribute the 
sterility acquired by must, when left for a few days at a too 
elevated temperature. 

This sterility, however, is not permanent. According to 
our experiments we cannot say that fresh yeast will not 
develop at all in the liquid. It works there, but very slowly 
at the commencement, and, what is very remarkable, more 
actively later on, although the contrary would have been 
expected, the activity of the yeast diminishing as the 
alcoholic strength increases. If such a result takes place, 

* U. Gayon. Sur les ucides contenus dans des vins. Revue de Viticulture, 
April 24, 1889. 

10649. G 



93 WINE-MAKING IN HOT CLIMATES. 

it is due, no doubt, as Schutzenberger observed, to diastases, 
amongst which are classified the toxalbumens, the diastase 
being submitted to a progressive alteration, the effect of 
which is the diminution, and even the complete loss, of the 
specific power of the yeasts. 

CONCLUSIONS. 

First. For indigenous yeasts (South of France) the most 
suitable temperature for fermentation is 30 C. (86 F.). We 
think winemakers will with advantage keep their vats about 
that temperature. 

Second. The rise of temperature above 35 C. causes a 
noticeable diminution in the final alcoholic strength. 

Third. The qualities of a* wine, its organoleptic, and 
perhaps pecuniary value, are in inverse proportion to the 
temperature at which it fermented. 

Fourth. The difficulty noticed in completely fermenting 
a wine remaining sweet on account of excessive temperature, 
is due to the liquid containing substances eliminated by the 
yeast, and exerting a toxic action on it. 

Fifth. Fermentations at high temperature give wines 
richer in albuminoids, than those fermented at normal tem- 
peratures. 

Sixth. In our experiments, the greater amount of nitrogen 
yielded cannot be attributed to parasitic ferments, for we 
experimented with sterilized musts. 

INFLUENCE OF THE TEMPERATURE OF 
FERMENTATION ON THE YIELD IN ALCOHOL. 

A fact which has attracted the attention of a few oanolo- 
gists for some time, and which we have often observed, is the 
enormous disproportion between the alcoholic strength and 
the initial sugar contents of Algerian wines. The musts are 
very rich in sugar, but the wines from them relatively 
deficient in alcohol. This is so frequent that an incorrect 
opinion is held by many Algerian vignerons. They consider 
the mustimetre as an inaccurate instrument, always giving 
exaggerated results. In many cases the differences are 
even much greater than they think. 

The observations with the mustimetre are generally made 
without taking the temperature into account, and without 
making any correction, and as in Algeria the temperature is 



VINDICATION. 90 

always above 15 C., this faulty method of observation always 
gives results below the normal. On the other hand, it is the 
rule in Algeria to put into the fermenting vat grapes dried by 
the hot winds blowing from the desert (the Great Sahara). 
These grapes are rich in sugar, and increase the percentage 
of sugar in the vintage without its being shown by the musti- 
metre, as the sugar only dissolves slowly from the mass. 

It is inadmissible that an instrument giving accurate in- 
dications in France should give inaccurate indications in 
Algeria. We must therefore acknowledge a loss, and we 
have ascertained that the loss is considerable. We tried to 
measure it in fermentations resulting from leaving the must 
to itself after crushing, as is generally done in Algeria. 

After having, as far as possible, rendered the must homo- 
geneous in a vat of 250 hectolitres (5,500 gallons), samples 
were drawn at different depths, and carefully tried with the 
mustimetre, applying corrections for temperature. The in- 
dications obtained from the samples were concordant. They 
were also checked by determination of the sugar witli 
Fehling's solution. The differences found were inconsider- 
able. The must tried contained 243 grammes of sugar per 
litre. According to Pasteur's experiments, inverted sugar 
(identical with grape sugar) gives after fermentation 48*5 
per cent, of its weight in alcohol ; in practice, however, this 
yield is not reached. A yield of 47 per cent, may be con- 
sidered as normal, corresponding to 1 per cent, of alcohol in 
volume for 17 grammes of sugar transformed. The above- 
mentioned must should therefore have furnished 

243 

pr = 14*3 per cent, alcohol. 

Here are, in its main lines, the course of the fermen- 
tation : 

It started eight hours after filling the vat, which was 
filled on the 3rd of September. During the whole day 
on the 4th and first half of the 5th September the fermen- 
tation remained very active. On the 5th of September, at 
two p.m., there were only 83 grammes of sugar left 
untransforined, but the fermentation was visibly slackening ; 
the temperature taken at that moment in the vat was 
At 50 centimetres below the head, 38 C. 

1 metre 40. 

the bottom of the vat 39'5. 

G 2 



100 WINE-MAKING IN HOT CLIMATES. 

On the same day, at six p.m., the maximum temperature 
was 41*5 C., and the fermentation seemed to have 
stopped, a determination of the sugar gave 78 grammes. 
Twenty hours after the sugar strength had not varied, the 
fermentation had stuck. 

Racking was advised and took place the day after. The 
wine tested after racking, contained 7*9 per cent, in volume 
of alcohol, and 78 grammes per litre of untransformed 
sugar. A few days afterwards the fermentation started 
again, and continued at a low temperature (25 to 28 (.V) 
outside, in casks of 550 to 600 litres (130 gallons). The 
wine, when completely finished, showed 12*5 pet cent, alcohol, 
and only traces of sugar.* 

There has been, therefore, 14-3-12-5 1-8 per cent, of 
alcohol less than the amount calculated. The yield in this 
case has only been 87*3 per cent, of the normal, that is to 
say, a net loss of 12-7 per cent. 

This observation is not exceptional, it has been given with 
details, because it was followed up with concordant results, 
but we consider it as expressing the minimum loss that takes 
place, as the fermentations last year in Algiers took place 
under most favorable circumstances. 

With regard to the vat studied, the temperature of the 
grapes was not excessive, 22 C. The hot winds (Sirocco), it 
is true, had blown during the night of the 1st and 2nd Sep- 
tember, but the temperature had fallen on the evening of the 
2nd, and remained relatively low during the remaining 
period of fermentation. 

There are, therefore, in this particular, case, favorable cir- 
cumstances, tending to render it comparable with our fer- 
mentations in the South of France. What can we expect, 
then, when fermentation takes place under less favorable 
conditions, such as those, for instance, the result of which we 
have seen at Relizane, and which took place at temperatures 
varying from 40 to 44 C. in the shade ? 

From information gathered from several vine-growers, the 
difference between the indications of the mustimetre and the 
final alcoholic strength reached in some cases the extreme 
figure of 3. 

* We must draw attention to the fact that the sugar remaining after the 
principal fermentation, was ultimately transformed, furnishing the normal 
yield of alcohol. 



VINDICATION. 101 

We can only see one cause, for these small yields, having 
a direct action of a physical nature, and, perhaps, also 
of a physiological order.' This cause is the excessive 
elevation of temperature. This we may easily ascertain, 
and we have done so ; the presence of notable quantities 
of alcohol in the gases evolved during fermentation when 
the temperature exceeds 36 C. being readily detected. 
The alcohol may also be carried away mechanically at 
lower temperatures, but in much smaller amount, and to 
measure it, we need to use more effective means than 
those employed above. It is, probably, to the alcohol 
carried away, that the difference between the theoretical 
yield obtained in the laboratory (48 '5 per cent . of the weight 
of sugar), and that which we may call normal (47 per cent, 
which results from wine-making practice in France), is due. 

There is therefore always a loss which seems inevitable, 
but we must try not to increase it. 

To estimate the alcohol in the gases from the fermentation 
we used Miintz's accurate process, which consists in trans- 
forming the alcohol into iodoform, by means of iodine and 
carbonate of soda, at moderate temperatures. If we plunge 
into the gases escaping a cold body, such as the carefully 
cleaned outside of a cold bottle, it will become immediately 
covered with a condensed film, in which alcohol exists in 
considerable proportion. It suffices, in order to detect it, to 
wipe it with a brush into a test tube, and to apply to the 
liquid thus obtained Miintz's test. One generally perceives 
the odour of iodoform. If the test is made when the tem- 
perature of the vat is approaching 40 C., not only does the 
odour appear stronger, but the liquid contains numerous 
crystals, which, when shaken, appear to the eye to have a 
silky appearance, and deposit in a mass varying in size as 
the experiment is continued longer, and as the surface of 
condensation is colder, or as the temperature of the vat is 
high. 

If we rack into a recipient some of the wine while at a 
high temperature, the presence of alcohol is still more 
accentuated, the odour being easily noticed. 

In the experiments we were able to make, the surface of 
condensation was about 4 or 5 C. above zero, as there was 
alcohol condensed at that temperature, the , tension of the 
alcoholic vapours in the gaseous mass must at least have 
been equal to that corresponding to the temperature of the 



102 WINE-MAKING IN HOT CLIMATES. 

condensing surface. The tension at 4 or 5 C. is represented 
by about 18mm. of mercury, and we may easily conceive 
that the loss of alcohol through being mechanically carried 
away may be considerable, if we consider the enormous 
volume of gas resulting from the phenomena of fermentation. 

The quantitative determination of the loss under given 
circumstances could only be experimentally determined, but 
we feel sure that it is very considerable in Algeria, far more 
so than is generally thought to be the case, and this is ex- 
plained by the comparison of the tension of vapour of al- 
cohol at the average temperatures of 30 C. in France and 
40 C. in Algeria. 

The tensions in mm. of mercury are 78' at 30 C. and 1 34* 
at 40 C. 

In what has been said so far, we mean by yield the 
amount* of alcohol obtained, as compared with the sugar 
transformed, and not in relation to the total amount of 
sugar. For it would be a very different thing if we meant by 
yield the alcohol obtained, without taking into account the 
quantity of untransformed sugar. Another important action 
of the temperature is to completely arrest the fermentation 
at 40 C. ; if the liquid remains in that state, the natural de- 
crease of temperature is not complete or rapid enough to 
allow the yeast to recover its activity, and a part of the 
sugar remains untransformed, which contributes to the 
diminution of the yield in alcohol, and constitutes a cause of 
future alterations. 

If the temperature of the fermenting must is carefully 
maintained below 32 C., in Algeria or anywhere else, the 
resulting wine shows a normal yield of 47 per cent, of 
alcohol per 100 of sugar transformed in weight, and the 
whole of the sugar is transformed, even in the case of wine 
of high alcoholic strength. We have been able to verify 
this fact in the most positive manner, in a cellar, where two 
fermentations only differed in their temperatures. 

By applying to the fermenting must a slight refrigeration, 
the losses are simply diminished, and we obtain a medium 
yield. 

If we represent the normal yield as 100, the yield of a vat 
allowed to rise to 40 C. would be 87'3, that of the same vat 
refrigerated would be 92, and that of the vat not allowed to 
exceed 32 C. would be 100. 



VILIFICATION. 103 

To sum up, ice consider that any elevation of tempera- 
ture above 30 C. is an important cause in the diminution 
of the alcoholic strength, and that the installation of re- 
frigerating plant is necessary in every cellar exposed to 
high temperatures. 

Whatever expense is incurred by this improvement of the 
process of vinijication will be amply repaid by the superior 
value of the wines made by this method. They will be more 
alcoholic, brighter, and, above all, possess better keeping 
qualities than wines made in the ordinary way. 

INFLUENCE OF THE TEMPERATURE OF VINOUS FERMENTA- 
TION ON THE QUALITIES OF WINE. 

As has been already said, the excessive temperature in- 
fluences the yield of alcohol in two ways one physical the 
other physiological. It is necessary to study the physio- 
logical or indirect influence, for it results, not only in the 
diminution of the alcoholic yield, but also constitutes the 
principal cause of the poor quality of wines. 

The activity of the wine ferment is considerably slackened 
down when the temperature gets over a certain limit. The 
curve described above allows us to see easily the slackening 
of the fermentation, and the stoppage of its action. The 
functions of the alcoholic ferment are destroyed, and in 
many cases noxious ferments take its place, consuming the 
sugar without producing alcohol, and introducing into the 
wine new products altering its organoleptic properties. 

This is not the only alteration. The alcoholic ferment 
is not dead, for sown again in new must, and under favor- 
able conditions, it will regain its activity ; but it is mor- 
bid, and shows morphological differences, detectable by the 
microscope, so definitely, that by simply observing it under 
the instrument we are able to say if the temperature has 
risen above 36 C. 

We are inclined to think that the products of elimination 
of a living organism sufficiently diseased, for its shape to be 
altered, must differ from those eliminated normally. In 
confirmation of this opinion, we have, by means of the 
microscope, classified many wines made from the same 
cepages under similar conditions, containing foreign bacteria 
in notable numbers. At M. Debonno's well-known vine- 
yard at Boufarick we were able to control this classification 
with the microscope, assisted by two expert wine-tasters 
MM. Aury and Vielle, of Algiers. 



104 WINE-MAKING IN HOT CLIMATES. 

Among the wines tasted were four samples of white wine, 
racked a few days previously, and still cloudy but quite 
dry, that is to say, containing- only traces of sugar. The 
absence of sugar was a sign that the temperature had not 
risen enough to completely paralyze the ferment. The 
microscopical examination disclosed that all the fermenta- 
tions had not taken place at equal temperatures, as some of 
the yeasts appeared to have suffered. Methodical refrigera- 
tion is used in M. Debonno's cellar, but the instalment is 
insufficient to refrigerate effectively the huge quantities of 
vintage manipulated each day. By microscopical observa- 
tion the wines numbered 1, 2, 3, and 4 were classified 
according to their value, 1, 3, 4, 2. MM. Aury and Vielle, 
simply by tasting, classified them in exactly the same way. 
This test has been repeated frequently, and always with 
success, and with wines completely turbid, in which condition 
it was not possible to make any conjecture as to their future 
quality. 

The same observations were carried out on two white 
wines made from the Cinsaut cepage, the grapes having 
been gathered the same day, and fermented, some in a 
metallic vat (Toutee system), and some in a wooden vat of 
125 hectolitres capacity; the temperature did not exceed 
29 in the metallic vat and was 38*5 C. in the wooden one. 
The fermentations started on the 15th September, and they 
were both almost finished on the 18th. 

Microscopical observation showed that the wine made 
in the metallic vat contained only vigorous turgid yeasts, 
highly refractive; in the wine from the wooden vat, the yeasts 
were unhealthy, shrivelled, and wrinkled ; they did not in 
either case contain bacteria, but to the taste the wine made 
in the metallic vat was much superior. 

These facts certainly support the opinion we have already 
given the wine yeast eliminates at high temperatures pro- 
ducts injurious to the wine. The elimination of abnormal 
products, by the ferment in a visibly morbid state, is one of 
the principal reasons of the inferior yield of alcohol, in wine 
fermented at a high temperature. But we are far from 
denying the analogous action of foreign injurious bacteria 
often developing at a temperature detrimental to the alco- 
holic yeast itself. 

These foreign fermentations happen very frequently. Des- 
soliers, in a very thorough study on " Vinification in Hot 
Climates," published in the Algerie Agricole, mentions this, 



VINDICATION. 105 

but we maintain that the predominant effect is due to the 
wine yeast itself. In the wines just mentioned there were no 
foreign organisms in appreciable quantity, the alteration of 
the organoleptic qualities cannot therefore be attributed to 
the secondary fermentation, but to defective vinous fermenta- 
tion. 

When the fermentation rises to a temperature high enough 
to prevent the transformation of the sugar, the damage is 
still more serious, especially if it remains for some time at 
this temperature. 

We think, without being able to positively assert it, that 
the yeast accumulates morbid products in the ust in suffi- 
cient quantity to render the must sterile. It is from this 
sterility that the sweetish acid taste of incompletely fermented 
wine arises. The must is then invaded with a host of 
organisms, amongst which may be found germs of all the wine 
diseases, which develop with extreme rapidity, living no 
doubt at the expense of the sugar, and converting the wine 
into an undrinkable liquid, only fit for the still, which even 
then only produces spirit of inferior quality. 

We have observed a great number of these wines in the 
Chelif plain, when travelling from Oran to Algiers, where 
the conditions for the vintage were not found this year 
to be as favorable as in other viticultural centres in Algeria. 
Several days after the first racking, and even on the marc, 
these wines contained a great quantity of sugar, and only a 
few wrinkled yeast cells could be detected under the micro- 
scope. On the other hand, they were real breeding grounds 
for a great variety of bacteria. We only found exceptions 
to this fact in cellars where wine was fermented in small 
quantities, and therefore could not reach a high temperature. 

The excessive temperature acts in a third manner in 
diminishing the value of wine. White wines, fermented 
without contact with the marc, are not submitted to this 
action in the same way, or to the same extent, as red wines 
fermented on the marc. Wine tasters are unanimous in 
recognising the relative inferiority of red wines which have 
fermented at a high temperature. They find that they taste 
of the -marc, and that they terroitent, to use the expression 
employed locally. We are, therefore, led to suppose that the 
products dissolved by the wine from the marc, at least at 
different temperatiires, are not the same quantitatively. 
Chemical analysis does not reveal positive differences. We 



106 WINE-MAKING IN HOT CLIMATES. 

can only note as a constant fact that the reduced dry extract 
of wine, made at a high temperature, is in excess of normal 
wines made from the same cepage. In fact, if we examine 
the marcs from fermentations made at 30 and 40 C., the 
tissues of the latter are found to be much more disorganized. 
To conclude, we consider that the elevation of the temperature 
above a certain limit (32 C.) diminishes the quality of the 
resulting wines. It is therefore necessary, in order to improve 
our wines, to check elevation of temperature by the use of 
refrigerating appliances. 

INFLUENCE OF THE TEMPERATURE OF FERMENTATION ON 
THE KEEPING QUALITIES OF WL\E. 

After what has been said about the influence of the tem- 
perature of fermentation on the quality of wine, it is almost 
superfluous to speak of its action on the keeping quality of 
wine, for the two terms quality and keeping quality are 
almost synonymous when applied to wines having the same 
origin. However, we consider it advisable to dwell a little 
longer on this subject, to show the detrimental effects of high 
temperatures. 

Wine is a liquid composed of different parts, which can be 
divided into two groups. The first includes alterable sub- 
stances such as albumenoid matters, sugar, acid-tartrate of 
potash, &c.; the other comprises antiseptic matters pro- 
tecting the first group against possible alterations. These 
are alcohol, glycerine, tannin, and various acids. In the 
manufacture of wine, therefore, we should try and diminish 
the quantity of alterable matters, and increase the quantity 
of natural antiseptic substances. 

In fermentations made at 30 C. the quantities of these 
various substances seem to exist in proper proportion : 
experience has proved that wines obtained at that tem- 
perature, even if only submitted to summary care subse- 
quently, are able to keep well. 

Experience has also proved that fermentations made above 
that temperature, which we will call the optima for the yeast, 
yield wines much more liable to alteration, this liability to 
change varying in proportion as the temperature rises or 
falls from that optima, and being greater for high tempera- 
tures. It is to this that Algerian wines owe their reputation 
for bad keeping qualities. An opportunity occurred in 1892 
of noticing a disease in Algeria which seemed peculiar to 



VINDICATION. 107 

Algerian wines, but which has since been found more general; 
this is known as mannitic fermentation. We were able to 
show in 1892,* from experiments made in the laboratory, 
and in Algeria during the vintage, that the disease was due 
to bacteria, and that it was simply the result of the extreme 
temperature, which had killed the yeast without killing the 
bacteria, which always exist in great quantities even in 
healthy vintages. Gayon and Dubourg have recently isolated 
the mannitic ferment, and confirmed these observations, and 
proved, as a result of their study, that the mannitic fermenta- 
tion can only take place after an incomplete alcoholic 
fermentation. This disease is very frequent in wines made 
at a high temperature, for there undecomposed sugar is 
always left, but if the temperature of the fermenting wine is 
brought down it will not occur. There will be no sugar 
left, and consequently no fermentation is possible. 

Other wine diseases, it is true, may develop even in com- 
pletely fermented wines, but their development is infinitely 
more frequent if the fermentation has been defective. 

High temperature is therefore injurious to the keeping 
quality of wine. It leaves in the wine a large proportion 
of alterable substances, and is the cause of the diminution 
in the alcohol as also of the glycerine, both of ivhich are 
excellent preservative substances. 

REFRIGERATION OF MUSTS DURING FERMENTATION. 
The refrigeration of musts during fermentation has not 
yet obtained the sanction of being an old practice, but trials 
made since 1892 in our Africanf colony, and considerably 
increasing every year in various parts of Algeria, have shown 
decisively that the solution of the problem of wine making in 
hot countries depends entirely on this operation. 

* Journ. de Pharm. et de C/iimie, 1893. 

+ In connexion with the recent extensive application of the system of 
refrigerating musts during fermentation, in the South of France and Algeria, 
it is interesting to refer to an Australian work by Dr. A. C. Kelly, The Vine 

T- ' -fXT- r*-* ft- _ __1_1" 1 1 "_ -1 Ot?1 TVT-11 *^J O.-.K,, ,- TM tl.i.- 



sive and convincing, but were greatly in advance of the times, for, although 
written some 40 years since for the immediate benefit of Australian wine- 
makers, it is well-known that they are even now only tardily availing them- 
selves of the advantages to be derived from fermenting their musts under proper 
conditions. 

The paragraphs of Dr. Kelly's work dealing with the importance of the 
temperature during fermentation are, on account of their present interest, 
reproduced completely in the Appendix to this work. (Trans.) 



108 



WINE-MAKING IN HOT CLIMATES. 



In the South of France, the difficulties met with in Algeria 
exist to a lesser extent, and if refrigeration there is not 
indispensable it is nevertheless so useful that results obtained 
in different vineyards during the last two or three years 
enable us to predict the general adoption of this system at 
an early date. 

How should the fermentation be conducted ? 

Two systems have been proposed : the first consists in 
cooling the must in the vat, the second in cooling it 
outside. 

The first system may be applied in two ways : one as used 
at Jaffa, by Ermens, consists in a long pipe (coiled spirally) 
fixed in the vat itself, and through which cold water circulates 
during the fermentation. (Fig. 18.) The application of 



B 




Scale. 



Fig-. 18 Ermens arrangement for refrigerating inside the Vat. 



VILIFICATION. 109 

this system is so very expensive, and according to the 
inventor necessitates the use of such large quantities of cool 
water to give good results, that it cannot be advocated. 

The second method of refrigeration of the must inside the 
vat is more tempting, because it is more simple. It con- 
sists in .facilitating the exterior radiation of the heat of the 
must, by the use of vats made of material of great con- 
ductivity. These are the metallic vats of Toute"e. 

We had an opportunity of watching two fermentations, 
one in a wooden vat of 125 hectolitres capacity, the other 
in a metallic vat of the same size. The maximum tem- 
perature in the wooden vat was reached at 38-5, and in 
the metallic vat at 29, a difference in favour of the 
metallic vat of 9-5 C. 

This decrease of temperature was ample, but we must 
take into account that it was white grape must, in which 
the homogeneity of the temperature is greater than in 
red must. In the latter the head, or mass of marc, is a 
danger zone, and ought to be refrigerated first. It forms 
a compact felted block, which does not partake much 
of the diminution of the temperature produced by 
the conductivity of the walls of the vat. It would 
be necessary in order to obtain in the fermentation of 
red musts a result equivalent to those of white must fermen- 
tations, to establish continuous circulation of the liquid 
pumped from the bottom of the vat to the top of the head. 
This manipulation already used to a great extent with any 
system, of fermentation would not be very complicated, the 
only question to be considered is the monetary outlay, the 
adoption of the Touted system meaning the integral renewal 
of all the vats. 

Refrigeration of the must by circulation outside the vat may 
be effected in two different ways, sometimes it is spread in 
contact with the air over a great surface. This leads to evapo- 
ration and therefore refrigeration, increased if necessary by 
a strong air blast, or else the must circulates in a closed 
space refrigerated outside by a current of cool water, by 
damp cloths, or sometimes by the air itself, for it is only a 
question of surface. This latter system, we consider, should 
be preferred. 

The refrigeration of musts in contact with the air creates 
energetic oxidation of the wine. 



110 WINE-MAKING IN HOT CLIMATES. 

The oxidation is an advantage, if done before the start 
of the fermentation, but it is not so in the case of wine 
partly or completely fermented. When the fermentation is 
started the aeration may be useful, but it should be sparing if 
we desire to protect the wine against the disadvantages 
which it leads to. 

Fermenting wine, if kept too long in contact with the air, 
becomes flat and insipid. 

It is therefore better to adopt the system of refrigeration 
without contact with the air, and aerate afterwards if judged 
necessary. 

It is by no means difficult to obtain simple and very 
effective cooling apparatus. It is not necessary, as in the 
case of a brewery, to reduce the temperature very low, but 
simply to keep the fermentation about 30 C. 

Water and air are the only two refrigerators that can 
be used economically. 

The air at vintage time in the South of France is 
generally below 30 C., and is always at the disposal of the 
vine-grower in unlimited quantity, and might be used. 

Water, unfortunately existing in too limited supply, is 
much more convenient, as it is generally at a lower tem- 
perature than the air, and even if it were at the same tem- 
perature, it produces an equal cooling effect from a smaller 
surface of contact. 

Water therefore should always be the refrigerating means, 
whenever sufficiently plentiful. 

A simple tube, more or less long, wetted outside by a current 
of water, constitutes the machine, and is connected with 
the bottom and top of the vat. Tinned copper tubes are 
all that is required to make a wine refrigerator when water 
is at disposal. The pipes may be joined by pieces of rubber 
hose and placed in a suitable trough, in one length or in 
a tank zigzaging, divided by partitions to regulate the 
circulation of the water. This form presents the advantage 
of being easily pulled to pieces and used afterwards as 
ordinary conducting pipes. 

The decrease of the temperature of the wine induces a con- 
siderable deposit of tartar, which necessitates the use of 
tubes of large diameter, easily dismantled for cleaning. 

An apparatus of this kind may be fixed without much 
expense in a cellar having water available, and can if neces- 
sary, even be placed outside the cellar. 



VINDICATION. Ill 

If only a limited supply of water is available this device 
can still be adapted, if the water is collected to be used 
over again when its temperature has decreased, OF, prefer- 
ably, another system may be used utilizing more completely 
the cooling power of the water, with or without the inter- 
vention of air. 

The cooling effect of the air may take place directly, simply 
by exchange of temperature, the surrounding air being 
generally cooler than the wine, or indirectly by evaporation 
of part of the water used for refrigerating. This physical 
phenomenon being always accompanied by a decrease of 
temperature. In the latter case it is not indispensable for 
the air to be colder than the wine. 

The metallic vats of Toutee only utilize, when bare, the 
refrigerating effect of the air, but if covered with cloth kept 
wet they utilize the refrigerating effect of the evaporation 
also. It goes without saying that in this case the cooling 
effect is greater. 

We have seen by the figures quoted relative to fermenta- 
tion in metallic vats, that these are quite sufficiently effective 
for white and red wines, if in the case of the latter the must 
is pumped over the head. 

The adoption of the Tout6e system is therefore indicated 
for a cellar with limited water supply, but it would be too 
expensive to establish in a cellar already furnished with 
vats. 

When the water supply is limited, we must try to use the 
same water again, or develop surfaces large enough to act 
with air alone, or adopt a mixed system in which air and 
water act together, as in the Toutee vat covered with cloth. 

Whatever be the ingenuity of apparatus utilizing water 
alone, its consumption will always be large, more than half 
the volume of wine cooled, but if the water supply is suffi- 
cient for one day's operation, the night cooling will be ample. 
With arrangements easily devised we may bring back the 
water to a suitable temperature, ready to be used again the 
next day. 

But there are cases where the cooling of the water must 
be done at the same time as it is employed. 

Dessoliers proposed to rapidly reduce the temperature of 
the heated water with a kind of refrigerator, submitting it 
to a great surface for evaporation, aided with a strong blast, 
and devised for that purpose an apparatus called cheminee 



112 



WINE-MAKING IN HOT CLIMATES. 



climagene (Fig. 19), which consists of a chimney more or 
less high, according to the quantity of water to he treated, in 




Fig. 19.--Climagene chimney of Dessoliers A, Distributing tank for the hot 
water; B, cellular bricks ; C, receiving tank for the cooled water ; d, pump; b, ven- 
tilating fan ; a, e, level indicator. 

the centre of which cellular 
bricks are piled up to the 
top, overlapping each other. 
The water poured on the top 
descends to the bottom, 
spreading completely over 
the surfaces of the bricks 
(Fig. ^0). A strong venti- 
lating fan sends an air blast 
from bottom to top, creating 
active 1 evaporation, with 
consequent cooling of the 
water. 




Fig. 20. Olirnagene Chimney of Dessoliers 
Arangement of the cellular bricks. 



VILIFICATION. 113 

With the cheminee climag<me, the results are excellent, but 
the same result can be reached without going to the expense 
of such a building. 

There are different materials easily procurable every- 
where, such as coke, already employed for similar purposes 
by other industries, which present a larger surface than 
cellular bricks. We feel certain that a cylinder made of 
double hogsheads, with the bottoms knocked out, and filled 
with coke, would afford a better solution of the problem 
than Dessolier's chimney. 

It is rational to utilize evaporation, as it is so active in 
hot climates, but apparatus based on that principle only, 
that is to say, in which the outside surface is just maintained 
moist, cannot have a constant refrigerating action. 

The refrigeration in this case depends on the hygrornetric 
state of the air, and on the rapidity of the air current. 

Theoretically, the cooling produced by evaporation is pro- 
portional to the difference existing between the maximum 
tension of water vapour at the temperature at which the 
work is being done, and the tension existing in the air at the 
same moment. 

If we suppose the air to be completely dry the refrigerating 
power seems unlimited, for if the air is constantly renewed 
it will continuously vapourize the water, and therefore reduce 
the temperature. In reality, equilibrium takes place at the 
moment that the heat lost by the water by radiation and 
evaporation becomes exactly equal to that received from the 
surrounding air. 

These states of equilibrium were experimentally deter- 
mined by Gay-Lussac, who determined them for temperatures 
between and 25 C. by the figures indicating the maximum 
decrease of temperature that can be obtained. The figures 
interesting to us are those corresponding to the temperatures 
of 15, 20, 25 0., and they are respectively 10-8, 12'7, 
and 14-7. 

These experiments were repeated by Regnault, and appeared 
to him to be incomplete, as the influence of the rapidity of 
the current of air on the decrease of temperature was not 
studied. This decrease increases with the rate of movement 
of the air current, when it is higher than 8 metres per 
second, which corresponds to a strong wind, but is easily 
obtainable with a ventilating fan. 

10649. H 



114 WINE-MAKING IN HOT CLIMATES. 

All the results apply to dry air, if the air is damp they 
will be lower, although remaining in the same proportion, 
and become nil if the air is saturated with moisture. 

There are therefore in the utilization of evaporation two 
factors, one of which can be modified the speed of the 
current of air ; the other, which is not controllable, being 
the hygrometric state of the atmosphere ; but the action of 
the latter is so pronounced that it would be imprudent to 
depend on a system based on evaporation alone, in certain 
regions where the hygrometric state is very variable. 

The effect with such a machine would, however, never be 
nil, notwithstanding what has been said ; even if working 
in a saturated atmosphere the effect will always be greater 
than we could have expected from the exact measurement of 
the quantity of water evaporated. 

It seems at first sight that the decrease of temperature 
obtained can only be constituted by the sum of the calories 
given to the water, and that necessary to evaporate the 
weight of water which disappears during the experiment. 
If we represent by A the first of these numbers, by B 
the second, and by C the number of calories lost by the 
wine, it should be possible to write A + B C. In practice 
this is not so. Not only is A + B less than C, but 
experience proves that often A + B is only half of C. 

The heat lost cannot be equal to the heat gained, we must, 
therefore, conclude that there are undetermined elements in 
the calculation, which intervene to a large extent, and which 
cannot be measured directly. They are the exchanges with 
the surrounding; air. These .are so much the greater as the 
temperature of the wine varies from the surrounding air, 
assuming that the surface of evaporation is of constant 
conductivity. 

We have experimented on a cooler constructed purposely 
with a view of utilizing the evaporation effect only. It 
gave insufficient results under rather good atmospheric con- 
ditions. The surface of evaporation acted upon was rather 
small, it is true. The apparatus consisted of six very flat 
lenses made of tinned copper, mounted horizontally on a 
vertical tube, and of a diameter of 40 centimetres. The 
decrease of temperature observed in wine at 38 to 40 C. 
was from 3'5 to 5*5 C., varying according to the strength of 
the current of air, the surrounding temperature, the hygro- 
metric state of the air, and the rate of flow of the wine, 



VINDICATION. 115 

which was between twelve and fifteen hectolitres per hour. 
Although not perfectly satisfactory, an improvement in the 
yield of alcohol resulted, which reached 4'7 per cent, more 
than that of the non-refrigerated wine (92 against 87*3, 100 
being the normal yield). 

No doubt larger decreases of temperature could be 
obtained by using larger surfaces, but there will always be 
an uncertainty of success in countries where the hygrometric 
state varies, as it does in the South of France, during the 
vintage time. 

The problem of refrigerating musts is not very complex. 
There are no insurmountable difficulties, for it is not 
necessary to get a very low temperature as in the case of 
beer ; but only to reduce to 27 or 28 C. a vatful which has 
overreached 32 C. 

It is advisable to go slowly and maintain an average 
temperature in the vat rather than to cool suddenly, for we 
imagine that a sudden large decrease of temperature can 
only be injurious to an organized plant such as yeast. If, 
on the second day after the start, the fermentation has not 
exceeded 28 C. we can without fear let it go on naturally. 
The temperature will not become excessive, for by that time 
the reaction producing the heat is almost all over. 



STUDY OF VARIOUS MUST REFRIGERATORS. 

The expense of refrigeration of the vintage consists of the 
sum representing the sinking fund of the machine 10 per 
cent, of its value the labour necessary for pumping the 
water, which varies with local conditions, and the labour for 
pumping the wine. 

The labour is, of course, proportional to the volume 
treated. It can, therefore, be expressed by a fixed sum per 
hectolitre. This is very small, but the sinking fund for the 
machine is so much the greater as the volume of wine 
treated is smaller. 

Suppose, for instance, a cooler costing 1,500 francs 
(62 10s.) applied to a vintage of 1,000 hectolitres (22,000 
gallons) the operation will be over-estimated from the sinking 
fund by 15 centimes per hectolitre, while if the instrument 
is applied to a vintage of 10,000 hectolitres (220,000 gallons) 
the over-estimation will diminish to 1J centimes per hecto- 
litre. 



H 2 



116 



WINE-MAKING IN HOT CLIMATES. 



In no case, however, will the expense reach the increased 
value acquired by the refrigerated wine. But it would 
always be better in dealing with small vintages to buy 
smaller machines, as these are less complicated and less 
expensive. 

The apparatus of Miintz and Eousseaux is an excellent 
modification, for vinifieation, of a device used in other indus- 
tries, and is actually adopted in many important cellars.* 

It is composed 
JL of two parallel 

series of nineteen 
tubes superposed. 
Fig. 21. Each 
tube is open at 
both ends and 
fixed to a vertical 
plate. A water- 
tight obturator is 
fixed on each plate 
in such a way as to 
be easily detach- 
able. Communi- 
cation is estab- 
lished between the 
tubes in such a 
manner that the 
liquid introduced 
at the bottom 
passes succes- 
sively through all 

Fig. 21. -Miintz and Rousseaux Refrigerating Apparatus. the tubes before 

reaching the top. 

A tube joins the top of one series to the bottom of the other. 
A trough with a row of small holes spreads water over the 
tubes, which are covered with canvas, the water drips over 
the tubes and falls to the bottom trough. 

This apparatus successfully utilizes the cooling effect of 
the water, as the wine is exposed to a large surface before 




* An important work by Miintz and Rousseaux, Etudes sur la Vinification 
et sur la Refrigeration des Mouts, appeared in 1896, and was translated and dis- 
tributed in pamphlet form amongst Victorian vine-growers in the same year 
by one of us.-(W.P.W.) 



VINDICATION. 



11' 



returning to the vat, Each tube measures 4 metres (13 feet) 
in length and has a diameter of 40 millimetres (1J. inches). 

It is an expensive machine, which does not seem to be 
altogether suitable for small growers, but it is in its proper 
place in large cellars. 

We made some experiments on other coolers which 
seem simpler in construction, and of more reasonable price, 
for the use of small and medium cellars. It goes without 
saying that we only considered machines capable of being 
easily cleaned, owing to their shape, and the facility with 
which they could be taken to pieces. 

We tried three systems one constructed by P. Paul on 
ideas we exchanged together ; one invented by Rouviere- 
Huc, and described in the Proyres Agricole ; and the 
third simply composed of concentric communicating vessels, 
invented by P. Andrieu. 

The machine designed by Paul and Roos is composed essen- 
tially of two concentric tubes, 4 metres in length, of 2 or 3 
centimetres in diameter, plunging into a trough of small 
capacity. Each sheaf of concentric tubes forming an element 
of the system, the number of the elements varying according 
to requirements. Fig. 22. 




Fig. 22. P. Paul's Refrigerating Apparatus. Forecarriage, B, exit of the cold wine. 

The wine circulates in the annular space between the 
inside surface of "the outer tube and the outside surface of 
the inner tube. The water travels in an opposite direction 



118 



WINE-MAKING IN HOT CLIMATES. 



to the wine, first of all passing in the inside tube, acting 
through the inside surface of the annular space, then in the 
trough continuing its action on the outside surface. 

In a machine composed of several divisions the wine rises 
from one division to another, while the water descends from 
one trough to another to be emptied at the last one. 

The interior tubes are fixed to the extremities of the 
exterior tubes by screened discs, fixed in the same way as an 
ordinary pipe coupling. Tightening the screws at one end 
of the tubes makes the whole system watertight by com- 
pression on rubber rings. The dismantling of the machine 
for cleaning purposes is simple, and the cleansing is very 
easily done, as the tubes are straight. 

The annular spaces of the two divisions are joined together 
with flexible rubber hose and fixed by means of a coupling. 

Finally, with the view of utilizing ice, which can now be 
obtained at very small cost, low enough to permit its use, 
the system has a box attached to the top to contain the ice, 
over which the heated water is spread and cooled before 
being used. Fig. 23 and Fig. 24. 




Fig. 23. P. Paul's Refrigerating Apparatus. - A, entrance of wine to be treated ; 
C, annular space in which the wine circulates ; D, water supply ; E, entrance of cold 
water ; F, exit of warm water. 



VILIFICATION. 



119 




Fig. 24. Paul's Refrigerating 1 Apparatus. Section view. 

The first tests were made at the petroleum refinery, at 
Balaruc-les-Bains, and we owe to the kindness of M. Durrand, 
Director of this important establishment, the opportunity 
given to make these tests under the most desirable 
conditions. 

The tanks used for the condensation of the petroleum con- 
sumed daily 1,000 cubicmetres of water, which, entering 
cold, flowed out at a temperature of about 50 C. If the 
water is carefully collected at various distances descending 
from the surface, we obtain all the temperatures com- 
prised between the entering and exit temperatures of the 
water. 

The tanks are of considerable dimensions, and receive the 
vapours from enormous boilers. It is possible therefore 
when distillation is in full swing to remove 20 or 25 hecto- 
litres of water per hour during many hours without the 
temperature varying 0'5 C., if it is drawn from a constant 
depth. 

These are very favorable conditions for a test of this 
kind. 



1'20 WINE-MAKING IN HOT CLIMATES. 

The cooler we have just described gave, with water trials, 



the following results : 



EXPERIMENTS MADE ON THE 22xD AUGUST, 1S96. 

1. Quantity of wine (represented by 

warm water) ... ... 2O5 hectolitres per hour 

Quantity of cold water... ... lo'O 

Temperature of wine at entrance (warm water) 35'9 C. 
Temperature of wine at exit 28 C. 

Temperature of water at entrance ... ... 19 C. 

Temperature of water at exit .. ... 27 C. 

2. Quantity of wine (represented by 

warm water) ... ... 20 hectolitres per hour 

Quantity of cold water... ... 14*50 

Temperature of wine at entrance (warm water) 31'7o C. 
Temperature of wine at exit ,, ,, 26-3 C. 

Temperature of water at entrance ... ... 19-0 C. 

Temperature of water at exit ... ... 2-5-,'i C. 

(Results obtained after two hours' work.) 

A trial was made the following day, starting (as an 
experiment) with a higher temperature for the wine 
entering. 

The quantity delivered was in one case 20-50 hectolitres 
for the wine and 1 4-50 hectolitres for the water. 

1. Temperature of wine at entrance (warm water) 35'G C. 
Temperature of wine at exit ... ... 28-0 ('. 

Temperature of water at entrance ... ... 18'2.C. 

Temperature of water at exit ... ... 28'2 C. 

2. Temperature of wine at entrance (warm water) 39-5 C. 
Temperature of wine at exit ... .. 31'0 C. 

Temperature of water at entrance ... ... 18'o C. 

Temperature of water at exit ... ... 31-0 C. 

(Results obtained after two hours' work.) 

In all these trials the quantity of warm water used, 
representing the wine, was measured with great exactitude. 
The machine was fed from a tank the level of which was 
constant. The syphon supplying the refrigerator yielded 
less than the tank received. 



VILIFICATION. 121 

It was, unfortunately, not possible to measure so exactly 
the water used for refrigerating, as it was drawn from a tap 
branching from a pipe feeding other taps at the same tirne> 
so that although the tap was maintained at a constant 
aperture, fluctuations in the delivery of water may have 
occurred, small, no doubt, but sufficient however to pre- 
vent us from trying to estimate the refrigerating action 
attributable to the air. 

The measurements for water given in the above tables 
were made at the maximum, that is to say, when the pipe 
only fed the tap used. 

When tried in a cellar with the vintage fermenting in 
wooden vats, this refrigerator gave similar results. We 
must draw attention, however, to a special feature of this 
machine. 

On account of the thickness of the layer of wine circulating 
in the annular space being very small there is great danger 
of obstruction. 

The refrigerator or cooler used had tubes, whose radius 
differed only by one centimetre. Although the machine 
worked well for a few hours we consider this difference is too 
small and should be doubled. 

It is necessary to introduce into the cooler must free from 
solid suspended matters, such as skins, &c. 

It should be used as follows : 

The must coming from the vat to be refrigerated, falls 
into a tub divided into two compartments by a vertical 
partition of wire gauze. 

In the compartment opposite to that receiving the must 
from the vat, a tube is plunged connected with the bottom 
of the refrigerator, the suction tube of the pump being con- 
nected with the exit at the top of the refrigerator forcing 
the cool must into the vat again. Worked in this way no 
obstruction can take place, and the machine may work from 
250 to 300 hectolitres of must without being cleaned. 

The work done by this cooler is naturally a function of 
the number of divisions of which it consists. Six divisions 
will suffice for a delivery of 40 hectolitres per hour, with 
a decrease of temperature similar to that observed in the 
above experiments. 



122 



WINE-MAKING IN HOT CLIMATES. 



The second cooler experimented with is due to Rouviere 
Hue, a well-known vine-grower of the environs of Mont- 
pellier. It is especially suitable for small growers, is cheap, 
and may be constructed by any plumber. These are ap- 
preciable advantages. 





Apparatus opened out. 



-^^^ 




Fig. 25. Rouviere-Huc's Refrigerating 1 Apparatus. 

The refrigeration is effected by forcing the wine through 
an annular space, limited by the metallic walls of two con- 
centric cylinders. The whole system is immersed in a tank, 
traversed by a constantly circulating current of cold water. 

The annular space is partitioned by projecting metallic 
plates, alternately overlapping, and forcing the wine to 
travel alternately from the top to the bottom of the 
machine. 

The model tried at Balaruc-les-Bains did not give good 
results, the installation was defective, and did not allow 



VINDICATION. 123 

an equitable judgment ; however, the trial enabled us to 
point out a few weak points of the machine which enabled 
llouviere-Huc to make additional improvements before the 
vintage. These, although imperfect, permitted him to carry 
on further trials in 1896. 

He has been kind enough to communicate the figures 
obtained, which are very satisfactory. 

f Temperature of wine entering ... 32-0 C. 

1st hour < P ., fc n~ nc,^, 

( lemperature or wine at exit ... 2o'0C. 

9 ,, J Temperature of wine entering ... 30-5C. 

( Temperature of wine at exit ... 25 C. 

01, (Temperature of wine entering ... 29-5 C. 

I Temperature of wine at exit ... 24-5 C. 

. , i I Temperature of wine entering ... 28*5 C. 

( Temperature of wine at exit ... 24-0 C. 

These are for deliveries of wine and water respectively 
of 18 and 8 hectolitres only, operating on a fermenting vat 
of 150 hectolitres. 

During the fifth hour, the must at entry being below 
28 C., the operation was stopped. 

The water pumped from a deep well, had a temperature 
of 15-5 C. at entrance, and an average of 24 C. at the 
exit. 

Thirty-two hectolitres of water were used during the four 
hours, and absorbed about 27,000 calories from the wine 
in the vat. 

The wine in the vat was reduced after the four hours' 
circulation to 28 C., which is a most satisfactory tem- 
perature. 

These are very good results, and no doubt Bouviere's 
cooler will become a practical machine, when a few addi- 
tional improvements in its construction render its working 
more convenient. 

In spite of the results observed one should use the water 
in a more systematic way, as the working of the machine 
could only be improved thereby. 

The third cooler experimented upon is due to Andrieu. 
The principle it is based on differs from the above in this, 
that it utilizes the refrigerating power of both air and water. 



124 



WINK-MAKING IN HOT CLIMATES. 



The machine has a surface of action much more consider- 
able than the preceding. The wine circulates, as shown in 
Fig. 26, in an annular space, limited by two vertical 
cylindrical metallic walls, one in contact with water the 
other in contact with air. 




Fig. 26. Andrieux Refrigerating Apparatus. A, entrance of wine to be treated ; 
B, exit of cold wine ; D, entrance of cold water ; C, exit of warm water ; E, annular 
space in which the wine circulates. 

It is composed of concentric vats similar to the Toute'e 
metallic vats, the inside vat containing water, and that on 
the outside the wine to be cooled. The circulation of the 
liquids is in opposite directions both from bottom to top. 

In this particular instance the outside vats were made 
of sheet iron covered inside with a varnish unaffected by 
the wine. They measured 1-18 metres in height and 0*82 
metres in diameter ; the inside tank was made of tin, T20 
metre high and 0*63 metre diameter. 

The inside vessel is arranged in such a way that its 
surface is at a constant distance of 9J centimetres from 
that of the outside vessel, both at the sides and bottom. 

It is evident that this machine has a very large surface 
for action, for each division has about 3J square metres of 
available cooling surface, or 16^ square metres for the three 
divisions, while the three divisions of Paul's cooler have 
only 3^ square metres. Again, one should add, to Andrieu's 
machine, the surfaces at the bottom which also bring their 
contingent of cooling effect. 

The results obtained with this device were very satis- 
factory. The decreases of temperature observed were con- 
fined between 4 and 10 C., according to the initial 
temperature of the wine entering (between 28 and 37 C.) 
for deliveries of wine and water comparable to those of 
Paul's cooler, that is to say, 1^ hectolitres of water for 2 
hectolitres of wine. 



VINDICATION. 125 

Here are the figures relating to the two experiments 

1. Quantity of wine ... ... 16*6 hectolitres per hour. 

Quantity of water ... 13*6 

Temperature of wine at ^ 

entrance ... ... 28'2 C. | Temperature of 

Temperature of wine at exit 23'7 C. [^ the air during 
Temperature of water at j the experi- 

entranee ... ... 18-2 C. | ment, 20 C. 

Temperature of water at exit 22 C.J 

2. Quantity of wine ... ... 13'5 hectolitres per hour. 

Quantity of water ... 8*64 

Temperature of wine at "] 

entrance ... 38-8 C. j Temperature of 

Temperature of wine at exit 28'0 C. ) the air during 
Temperature of water at j the experi- 

entrance ... ... 18-5 C. ] ment, 20 C. 

Temperature of water at exit 28*5 C. J 

(Results obtained after two hours' work.) 

Considering the dimensions of the machine the delivery is 
small. We would have preferred making experiments with 
larger quantities, but this was not possible, as the section of 
the exit tubes did not allow a delivery exceeding 16 or 1? 
hectolitres. 

The results are excellent, the only drawback being that 
the machine is cumbersome. 

It has the advantage of not being liable to b'ecome 
obstructed, and the divisions or tanks maybe used when 
the vintage is over in various useful ways storage of 
wine, &c. 

The outside vessels hold about 600 litres, the inside ones 
about 360 litres. 

Vine-growers, therefore, are only embarrassed in choosing 
a cooler, for apart from those we have described, rather at 
length, there are a great many others in existence which 
might prove useful in a number of special cases. Vine- 
growers should convince themselves of the fact, uncontrover- 
tible at present, that the maintenance oj 'fermentation at a 
temperature near 30 C. is a powerful factor in improving 
the quality of the resulting wines, and they must, therefore, 
make every ejfort to attain that desirable result. 



126 WINE-MAKING IN HOT CLIMATES. 

METHOD OF TAKING THE TEMPERATURE OF A 
FERMENTING VAT. 

With or without refrigeration, it is always of great interest 
to the wine-maker, to know the temperature of the vats 
during fermentation, even if only to follow it and make the 
wine systematically. This is done by the use of ther- 
mometers, arranged in a more or less convenient manner. 

It is well to know, to start with, that the temperature 
varies in different parts of the vat when it is full of vintage 
in fermentation. It is generally low at the bottom and 
high at the top, the average temperature being found 
towards the middle of the liquid zone, below the head or 
mass of floating marc. It is, therefore, at that point that 
the temperature should be taken if we desire to know the. 
average. 

The simplest way is to use an ordinary hand thermometer, 
graduated on the stem, placed in a groove made at the end 
of a piece of wood pointed at the end. The piece of wood 
with the attached thermometer is pushed below the marc to 
the required depth, and kept submerged in the liquid for a 
length of time sufficient to allow the thermometer to reach 
the temperature of the surrounding liquid. 

This method is simple, but the observations are difficult, 
and not very exact. When an ordinary thermometer, 
arranged as described above, is used, and the thermometer 
is drawn out, it passes through cooler surroundings, which 
reduce 1 the reading on the thermometer too quickly to allow 
an accurate reading being obtained. 

It is preferable, when an ordinary thermometer is used, 
to choose one riot too sensitive, that is to say, with a large 
bulb and large bore. It will be necessary to leave it for 
some time in contact with the liquid to attain its tem- 
perature, but it will keep that temperature longer after 
removal and facilitate the reading. 

Alcohol thermometers are, all things being equal, better 
than mercurial thermometers for this operation. 

Maximum thermometers, that is to say, those recording 
the indication of the highest temperature to which they 
have been submitted, are preferable. Very accurate and 
sensitive thermometers of this kind are made of the same 
shape as an ordinary thermometer. 

A process much in vogue, allowing the use of any ther- 
mometer, consists in drawing from the vat a bucketful of 



VINDICATION. 



12' 



the must to be examined ; the temperature remains constant 
long enough to allow an accurate reading to be taken. 
This would be an excellent method if the liquid was taken 
from the centre of the vat, but being drawn from the bottom, 
it more often than not indicates too low a temperature. 
Thermometers with stems 
bent at right angles may 
be found in commerce ; the 
bulb is introduced into the 
the vat or cask at the re- 
quired height, the stem 
standing vertically against 
the outside wall. Fig. 27. 
The indications are good in 
this case if the bulb pene- 
trates far enough into the 
vat. Unfortunately, the 
bulb does not generally 
protrude very far into the 
vat, so as to provide against 
breakage, likely to occur 
through the mass of marc 
moving suddenly under 
the influence of the liber- 
ated carbonic acid gas. 

However, the taking of the temperature in any case is a 
very delicate operation, and for this reason Houdaille and 
myself have invented an instrument which is easy to use, 
and automatically registers the results. 

Self-registering Thermometer of Houdaille and Roos 
In devising, in conjunction with Houdaille, the self- 
registering thermometer, which we will now describe, we 
aimed at placing in the hands of wine-makers an instrument 
for observation and control, which dispenses with the taking 
of temperatures, and gives for each fermentation a record, 
the importance of which will soon be appreciated. 

The object is to have an instrument recording automati- 
cally, at any hour of the day or night, exact indications in 
a convenient form for observation. It should be of suffi- 
ciently strong construction to be handled by workmen in 
the cellar without danger of breaking, and capable of being 
introduced or removed from the vat without difficulty ; of 




128 



WINE-MAKING IX HOT CLIMATES. 



simple manipulation, and requiring no special knowledge ; 
not inconveniencing the operations connected with wine- 
making ; and, finally, not too costly. 

To our knowledge, no thermometers answering all these 
conditions were in existence previously, and we think that 
our invention will give satisfaction in each of these respects. 

Our self-registering thermometer consists essentially of 
a metallic reservoir rilled with alcohol and communicating 
by a capillary tube with an elastic reservoir filled also with 
alcohol, altering in shape under the influence of the change 
in the volume of alcohol, according to the temperature it is 
submitted to. These deformations are amplified by a lever 
with a pen attached to one end, used for registering the 
temperatures. 

It consists of a projecting cylindrical tube, with a conical 
base of strong tinned copper, of a diameter of 30 m.m., 
and a length varying from 1^ to 2 metres, according to the 
depth of the vat,* 

This protecting tube can 
be dismounted in two parts, 
joined by a coupling to facili- 
tate cleaning ; it contains 
the bulb and capillary tube 
joining it to the receiver 
(Fig. 28), fixed on a solid 
wooden support. The re- 
ceiver is composed of two 
discs with concentric un- 
dulations, soldered on their 
outside edge, slightly 
dished, and communicating 
with the thermometer bulb 
through the capillary tube. 

The whole system is 
filled with alcohol, air or 
gas being carefully ex- 
cluded. 

The discs, on account of their elasticity, swell under the 
influence of the increase in the volume of alcohol when the 




Fig. 28. Self-registering Thermometer of 
Houdaille and Roos. 



* It is desirable that the length of the thermometer be such as to allow the 
bulb to go underneath the head (of marc), that is to say, about half the depth 
of the vat. 



VINDICATION. 129 

temperature rises, and contract when the temperature falls, 
on account of their own elasticity as well as the atmospheric 
pressure. 

The cylindrical thermometer bulb is made of thin copper, 
and contains about 200 cubic centimetres of alcohol. Jts 
length is 60 centimetres ; it presents, therefore, a sufficiently 
large surface for exchange of temperature, to insure sensi- 
tiveness. 

The sine qua non of effectiveness consists in the perfect 
filling of the instrument, as the slightest bubble of air or 
gas would falsify the indications. 

Near the receiver a support for the lever is fixed, con- 
nected by one end to the discs, and provided at the other 
with a pen for registering and amplifying the expansions or 
contractions of the discs. 

The registration is made on a sheet ad hoc, which is dis- 
placed before the pen by clock-work. 

Contrary to what is generally adopted in self-registering 
instruments, we have preferred to register the indications of 
the instrument on a plane, instead of a cylindrical surface. 

This arrangement allows the reading of the complete 
record to be made at a glance, and facilitates the changing 
of the recording sheets. We have simply transformed the 
circular movement of a pinion to a rectilinear movement, by 
engaging it with a toothed rack, instead of a cog-wheel. 

This toothed rack is fixed in the front part of the brass 
plate supporting the recording sheet. 

The clock-work is sufficient for one week's continuous 
record, and insures, therefore, the working of the apparatus 
during the whole time of an ordinary fermentation. The 
anchor, or cylindrical escapement, allows its working in any 
position, and does not necessitate the apparatus being fixed 
vertically. 

The instrument, as above described, is easily handled, and 
transportable. It has been carried great distances without 
special care, and without damage. It may be carried on the 
shoulder (like a gun), but weighs much less. 

We have no doubt that this instrument will render great 
service to those who desire to follow or supervise their 
fermentations, and keep them between recognised limits. 

The form of the curve will show at a glance if the tem- 
perature rises too quickly, and if it is necessary to 
refrigerate. The reading of the curve recorded during the 

10649. * 



130 WINE-MAKING IN HOT CLIMATES. 

hours when direct supervising might have been defective, 
will give the course of fermentation during that time, and 
the proprietor may readily control with it the execution ot 
his orders, and by ultimately comparing the records of each 
vat, and the wines resulting from them, get valuable docu- 
ments on the influence of temperature on fermentations and 
qualities of wines. 

This self-registering thermometer, although very recently 
invented, has been improved in many details, rendering it 
stronger and more symmetrical. 

FERMENTING HOUSE. 

The vintage coming from the crusher reaches directly, 
after travelling a variable distance, the vessels where 
fermentation is to be effected. 

The building in which the fermentation is effected is called 

the fermenting house. There is nowadays a great tendency 

, to isolate the fermenting house from the storage or maturing 

cellar. . This arrangement exists in all newly-built cellars, 

but is not an indispensable condition for success. 

Contrary to general opinion, the fermenting house 
must be very well ventilated, open freely to all winds, and 
constantly swept by draughts. 

Many think that it is better to use underground cellars for 
fermenting because they are always cool during hot days. 

This is an error pointed out by Toutee, the inventor of 
the metallic vat, in the following humorous story 

" I saw the cellar of a large grower, in a hot climate, in 
course of construction. This grower desired to neglect 
nothing in order to make it a success, addressing an architect 
in the following way : ' I want to make wine in - 
where the temperature is rather troublesome, how can I 
protect the vats from that temperature ? ' ' Very simply,' 
answered the architect ; ' begin by sheltering the ground 
against the solar rays by means of a shed, then excavate 
the shaded ground, and cover the excavation with masonry 
vaults, one metre thick, throw over the arches Iwo metres 
thick of soil, and I guarantee the interior will remain 
unaffected by exterior temperatures. My charge is so much 
per square metre excavation, and so much per cubic metre 
masonry.' ' : 



VINDICATION. ]31 

" The question is put in the same terms and solved in quite 
as smart a way by the vat maker, who says ' To shelter 
your musts against the sun and hot wind, isolate them in a 
non-conducting envelope.' 

" Walls of oak (heart wood) 7 to 9 centimetres thick, 
that is how I make vats, they are sold by weight. 

" Premises and vessels cost the bagatelle of 50,000. 

" Well, imagine the stupefaction of our friend, when, enter- 
ing his cellar with me, he noticed that the average tempera- 
ture in Algeria being 29 C. on the 1st of September the 
thermometer showed 41 C. in his cellar. 

" And I say in his cellar, for his musts were at a much 
higher temperature. When the poor man made up his mind 
to take the temperature of his musts by an original method, 
he found the testing glass in the laboratory recorded 49 C. 
after ten minutes waiting and various transversations which 
had made it lose some 4 or 5. 

" It is that the source of the greater heat is not at the 
exterior of the cellar, but rather in the interior of the vats, 
and he had obtained a result all the more worthy of compas- 
sion, inasmuch as he had taken every precaution to prevent 
all exchange of temperature between the interior and the 
exterior. Thanks to the 50,000 spent, the must was keeping 
all the heat developed by the fermentation." 

Under this pleasant form the above account shows per- 
fectly the inconvenience and dangers of a badly ventilated 
fermenting house. We advise, therefore, especially small 
growers, having cellars in town or village, too frequently 
poorly ventilated, to give up fermenting in cellars. Let the 
musts ferment outside under a tree or shed, just sufficient to 
protect the vat from the direct rays of the sun. Let them 
try only, and the results obtained will convince them better 
than any argument of the benefit they will gain by adopting 
this modification. 



FERMENTING VESSELS. 

The vinous fermentation, already briefly described in the 
first part of this work, is a complex phenomenon capable of 
being influenced by numerous causes. Some even assert that 

* Hipp. Lecq. De la Fermentation des mouts de Vin A Temperature basse 
par VEmploi des Cuves Metalliques. Alger. Imprimerie Orientale, Pierre 
Fontana et Cie, 29 rue d'Orleans, 1894. 

I 2 



132 WINE-MAKING IN HOT CLIMATES. 

it is influenced by the shape of the vessel or the nature of the 
materials the vessels are made of. 

In fact, this influence as well as that of the mass is rather 
indirect. There are a number of conditions to be realized for 
fermentation to start well and continue in a satisfactory 
manner, guarded against alterations liable to occur from 
parasitic fermentations ; but, those conditions once realized, it 
is unimportant whether it takes place in wood, stone, brick, 
cement, wrought or cast iron. 

The vessels usually used for fermenting are 

Wooden vats, conic frustrum shape, open or not at the top. 

Stone vats, generally cubic in shape, open or not, coated or 
otherwise, with varnish or glazed tiles. 

Brick vats, generally cylindrical in shape, much used in 
Algeria under the name of anaphoras. 

The vats recently devised, but already much used, of sidero- 
cement ; that is to say, built of a network of interlacing round 
iron, about \ inch in diameter, with a mesh of about 2 inches, 
sunk into a thickness of 2 or 3 inches of cement. They vary 
greatly in shape. 

Toutee strongly advocates the use of iron vats, usually 
cylindrical, for hot regions. 

Finally, ordinary casks used generally in all viticultural 
regions for storage. 

The capacity of the fermenting vessels varies considerably. 

Whatever their shape is, and whatever material they are 
made of, the vat will suit for fermenting purposes, provided 
its interior surface be inert, or incapable of producing altera- 
tions in the taste or chemical composition of the must. 

The vats of masonry or sidero-cement cannot be used 
without preliminary preparation, but must be purified, with 
the object of preventing the possibility of their acting on the 
must. 

The various lime compounds, which always exist in mortar 
or cement, have an unfavorable influence on wine, and must 
therefore be eliminated. 

This result is easily attained by washing the inside walls 
with a solution of sulphuric acid, followed by a coating of 
silicate of potash, which,* when once dry, is quite unattacked 
by wine, and has the advantage also of rendering the walls 
impermeable. 

* Sulphuric acid of 10 per cent, strength and two coatings of a 25 or 30 per 
cent, solution of silicate of potash. 



VINDICATION. 133 

The iron, too, remaining in contact with th.e wine would 
give it a styptic very disagreeable taste, and even modify the 
wine so much as to render its conservation impossible. It 
is absolutely necessary that the whole of the internal surface 
of the vats should be covered with an impervious coating 
without action on the wine. 

FERMENTATION. 

If we assume that the physical and chemical conditions of 
the vintage are suitable, those remaining to be fulfilled for 
fermentation to take place under good conditions and for the 
wine to possess its maximum of quality are : 

First Management of the vintage so that the marc be not 
submitted to alterations through contact with the air. 

Second The drainage of the solid parts of the berry and 
the marc, obtained by special distribution of the marc in the 
midst of the liquid or by its lixiviation. 

If fermentation is left to itself without preliminary pre- 
cautions, the stalks and skins forming the marc, although 
at first sunk in the midst of the liquid, agglomerate little by 
little, and being lifted by the carbonic acid gas rise to the 
surface. 

It is this agglomeration of the solid parts of the grapes 
which constitutes the head, and a fermentation is said to 
have a floating head when no special arrangement is made 
to maintain the marc below the surface, and is said to have a 
submerged hecid in the opposite case. They are called mul- 
tiple submerged heads when the marc is subdivided into 
several parts. 

Generally speaking, the floating head is inferior to the 
submerged head method, the reasons for the superiority of 
the latter are of two kinds the marc of submerged head 
fermentations is always perfectly protected from contact with 
the atmosphere, and by its arrangement becomes thoroughly 
extracted by the liquid, while that of a floating head fer- 
mentation is, so to speak, completely in contact with the air 
in open vats, and is only partly exhausted by the liquid. 

The action of air on the marc is injurious, even if a quantity 
of carbonic acid is present. In fermentations where the 
marc is not at all in contact with the air, volatile acids, 
especially acetic acid, which characterize defective fermenta- 
tion, are never produced, while they are always found in the 
opposite case. 



134 



WINE-MAKING IN HOT CLIMATES. 



Pollacci determined these facts by experiments, which 
consisted in following day by day, and hour by hour, two fer- 
mentations conducted side by side, according to each method. 
To strengthen what has been already said we will quote the 
results of Pollacci's experiments. 



POLLACCFS EXPERIMENTS. 



Fermentations made in glass cylindrical vessels, closed by 
means of a glass plate, slightly lifted by a cardboard band 
supported on the edge of the vessels. 



Fermentation withjtoatiny 
head. 



Fermentation 
merged head. 



with sul- 



Second Day Evening. 



Fermentation has begun, 
the space above the head 
still contains air, for a candle 
burns in it. The head shows 
a few moulds, and smell of 
acetic acid is noticeable. 

Third Day- 
Lighted candle still burns. 
More moulds, and acetic 
acid smell more pronounced. 

Third Day 

Lighted candle ex- 
tinguished. 

Moulds still increasing. 

Acetic acid can be detected 
by analysis in the liquid 
surrounding the marc. The 
head was rammed down. 



Fermentation in full ac- 
tivity. 

No trace of moulds or 
acetic acid. 



-Morning. 

A lighted candle extin- 
guished when placed in space 
above head. 

No moulds, no acetic acid. 

-Evening. 

Candle still becomes ex- 
tinguished. 

No moulds, no acetic acid. 



Fourth Day. 



Same as last. The liquid 
still contains 140 grammes 
of sugar per litre. Acetic 
acid smell not noticed after 
ramming the head. 



Same as last. The liquid 
contains only 40 grammes 
of sugar per litre. 



VINIFI CATION. 135 

Fifth Day. 



Same as last. Head 



rammed. 



Same as last. 



Same as last. 



Fermentation continues 



active. 



Sixth Day. 



Fermentation diminish- 



ing. 



Seventh Day. 



Fermentation almost 
finished. 



. Eighth Day. 
Fermentation continues. I Fermentation ended. The 



The liquid still contains 35 
grammes of sugar per litre. 



liquid is clear, cold, and only 
contains 0*80 grammes of 
sugar per litre. 

As has been already mentioned, the opening at the top of 
the glass vessel was very small. It was, however, sufficient 
to allow the access of air in such proportion as to permit 
the development of germs, such as mycoderma aceti. 

With the method of keeping the marc out of direct contact 
with the air, the fermentation is healthier, quicker, and more 
complete. With a submerged head, even with the must in 
contact with the air, the moulds and mycoderma aceti germs 
do not develop, as they do not find a suitable resting place, 
or because the movements of the liquid constantly wet 
them, and prevent the direct action of the air. 

Is there not an evident benefit in submerging the head ? 
For, as has been already said, the suppression of secondary 
fermentation corresponds to the improvement of the vinous 
fermentation. 

The interference of the air is not always injurious, being 
sometimes very useful ; but, as far as the marc is concerned, 
it is always dangerous, except, however, before the start of 
the fermentation after crushing. 



136 



WINE-MAKING IN HOT CLIMATES. 




Fig. 29. Fermentation with Submerged Hea'J. 




Fig. 3 J. -Fermentation with Multiple Submerged Heads. 



The distinction is 
therefore well estab- 
lished in favour 
of fermentations in 
which the marc is 
completely out of 
contact with the air. 

The immersion, or 
submersion of the 
marc, in single or 
multiple heads is ob- 
tained by simple de- 
vices, the following 
(Figs. 29 and 30) 
show plainly how the 
problem can be solved. 
The arrangement of 
multiple heads as pro- 
posed by Michel Per- 
ret dispenses with the 
racking of the must 
for the establishment 
of the false head, but 
the results given are 
not better than those 
obtained with a single 
head. The applica- 
tion of the Ferret 
method is very 
tedious. It is neces- 
sary to place several 
false heads in posi- 
tion, and the waste of 
time is greater than 
the simple racking as 
in the previous case. 

We will quote as 
an ingenious modifi- 
cation of the sub- 
merged head system 
that devised by Coste- 
Floret, which con- 
of two vertical 



VINDICATION. 



137 



partitions dividing the vat. 
Fig. 31 very clearly and 
intelligibly shows it, and 
dispenses with a detailed 
description. 

With the Coste-Floret 
method important advan- 
tages are evident, but we 
also notice some slight de- 
fects the marc will always 
rise up a little and float, and 
will always be, though on a 
very small surface, in con- 
tact with the air. This is a 
defect, but it may easily be 
remedied by fixing a small 
false head horizontally of 
the same size as the marc 
chamber, preventing the 
marc from rising above the 
liquid. 

We do not agree with 
Coste-Floret, that lixivia- 
tion of the marc results from 
forcing the must to pass 
through from one compart- 
ment to the other. 

In fact, even if the marc 
can be prevented from rising, 
it is not possible to prevent 
a certain free space forming 

between the marc and the bottom of the vat. Therefore, 
when the must is made to pass from one side to the other, 
the liquid will naturally travel along the line of least 
resistance, and consequently pass below the marc without 
percolating through it. 

We do not see the necessity for lixiviation in the case of 
submerged fermentation, and a fortiori in the Coste-Floret 
system. In both cases the surfaces of contact of the must 
and marc are quite sufficient to allow the latter to give to 
the wine all the useful principles it contains. 




Fig. 31. Coste- Floret's arrangement. 



138 WINE-MAKING IN HOT CLIMATES. 

The advantages of submerged head fermentation lie 
mainly in the suppression of the injurious action of the air, 
and the fuller utilization of the solid parts of the grape. 

If we manage to place the marc (although floating) out 
of contact with the air, and lixiviate it with the must 
several times, the results will be quite as good, and will dis- 
pense with the tedious manipulations connected with the 
immersion of the marc, and we will always be able to stop the 
extracting action of the must when necessary, by shortening 
or prolonging the lixiviation. 

In this respect the use of large casks is preferable to any 
other vessel, on account of their special shape, narrower on 
the top, preventing the excessive rising of the marc, so that 
the greater part is kept submerged. 

By taking the precaution of covering the top opening 
with a board, all access of air is prevented, and the marc 
surrounded with carbonic acid gas is not liable to the 
alterations observed in open vats. 

The lixiviation is obtained by pumping the must from the 
bottom part of the cask or vat to the top, spreading it over 
the head. 

This distribution of the must over the whole surface of the 
head is very important. If it is not done carefully a small 
part of the marc is too strongly extracted, while the rest 
remains unutilized. 

With a strong jet falling on the head always in the same 
place, a kind of channel is formed in the marc, through 
which the must reaches the bottom of the head without 
distributing through it, and therefore without exerting a 
solvent action in its passage. 

The proper distribution of the must is easily effected by 
the use of several little devices, amongst which may be 
mentioned the hydraulic swivel, and the break jet, which are 
now used by many wine-makers. 

The hydraulic swivel consists ,of a box around which tubes 
are arranged horizontally like the spokes of a wheel, and 
bent almost to right angles in the same direction. The box 
revolves on a pivot when filled with liquid, on account of 
the hydrostatic thrust exerted by the jets of liquid. The 



VINDICATION. 



139 



adaption of the swivel to the distribution of the must pre- 
sented several difficulties. These have been successfully 
overcome by P. Paul. 

Much more simple is the break jet, which we have in- 
vented for use with a machine automatically distributing the 
must over the head, and which will be described later on ; 
although simple, it works perfectly, without inconveniences 
of any kind. 

The principle consists in placing under the jet, normally 
to it, and at a small distance from the opening of the tap a 
disc (Fig. 32) on which the jet breaks, and is transformed 
into a circle of a diameter varying according to the form of 
the jet. 




Fig. 32. Break Jet. 

The jet from a pump is not quite continuous, or does not 
possess the same force constantly, whatever pump is used. 
The result is, that the breaking of the vertical jet on the 
horizontal disc will spread in a very large rose while the 
pump is forcing, and in a small one when the pump is suck- 
ing, and therefore the whole of the marc will be sprayed. 

The operation of spreading the must over the head is 
generally done with a pump any pump may be used- 
coupled on the valve of the cask, if it is not desired to 
aerate at the same time. If it is considered necessary to 



140 WINE-MAKING IN HOT CLIMATES. 

aerate the must before pumping it over the head, it is neces- 
sary to allow it to fall into a tub placed under the vat, so 
that it conies in contact with the air. 

To facilitate the aeration Trabut invented a tap (Fig. 33) 
by which air is introduced into the liquid jet in any quantity 
required. 




Fig. 33. Trabut's Tap for Aeration of the Must, 
a. Tube to regulate admission of air. 

Trabut's tap works very satisfactorily, and may be used as 
an ordinary tap, for the air tube can be completely closed. 

The frequent necessity of pumping the must up for lixivia- 
tion and aeration, induced several persons to try and obtain 
the ascension of the must automatically, using the pressure 
of the carbonic acid gas disengaged during the fermentation 
for the motive power. The first to try and put the idea into 
practice was Victor Cambon. The machine he devised has 
been described in the Pr ogres Agricole* from which we 
take the following extract : 

" The machine invented avoids the inconveniences of 
floating head fermentation. 

" It may be arranged in various ways, but the vat requires 
to be hermetically closed. 

" In the top a manhole is placed for the introduction of 
the vintage, which should be easily closed hermetically. 

* Progres Agricole et Viticolt- 2nd August, 1891. 



VINDICATION. 



141 



If 



" This being arranged, the following is one of the methods 
that may be adopted : 

"On the top of 
the vat (Fig. 34) 
is placed a small 
wooden tank R 
of a capacity of 
about one-twen- 
tieth that of the 
vat. A tube T 
is placed in the 
bottom of the 
tank, communi- 
cating with the 
top of the vat, 
and closed by a 
valve S, the stem 
of which is con- 
nected with a 
lever .oscillating 
round a point 0,' 
and bearing a 
floater F at the 
other extremity. 
A long tube U 

Starting from the Fig " ^-Cambou's Arrangement. 

bung-hole at the bottom of the vat throws the liquid into 
the tank R, a sieve P prevents any skins, &c., getting into 
the tube U, the vat being filled with the vintage through the 
manhole H. It is then closed, and fermentation starts, the 
carbonic acid gas not being able to escape compresses upon 
the must and marc and forces it upwards through the tube 
V into the tank R. When the liquid reaches the height of 
the floater F the floater lifts the valve S, the 'must in the 
tank falls into the vat, and the carbonic acid gas escapes 
and bubbles through it. At the same time the tube U 
ceases to run, the floater sinks and closes the valve, and the 
same operation goes on again." 

Cambon obtained good results with this apparatus, but 
it has several defects which we have tried to overcome and 
will now point out. 

In such a machine the orifice through which the gas is 
liberated should be independent of that through which the 







142 



WINE-MAKING IN HOT CLIMATES. 



liquid enters the vat. We must also determine a sudden 
and complete opening of the two orifices, which should be 
effected by the movement of the liquid in the tank, but which, 
when once started, must continue, without the liquid inter- 
fering. It should happen in the same way for the closing 
of the valve. 

There are other machines aiming at the same object, but 
they do not realize the above conditions, and present the 
same drawbacks as that of Cambon. 

We have tried to solve the problem by means of a simple 
and strong machine, which has been named fermentation 
auto-regulator, arranged as shown in Fig. 35. It consists of 
a brass cylinder tinned inside, on the top of which rest two 
angle-irons, supporting the whole mechanism. 

A 



E 




Fig. 35. Fermentation Auto-regulator. 

This simple mechanism consists of 
First A straight lever A B, which is called the principal 
lever, revolving round a horizontal axis A. 



VINDICATION. 



143 



Second A lever bent at a right angle C D E, revolving 
round a horizontal axle D and having two notches, on the 
vertical arm D E, we will call this piece double catch. 

Third A small straight lever F G revolving round a hori- 
zontal axis A which we will call auxiliary lever. Three 
tubes open into the cylinder, one H is constantly open. It 
starts from the bottom of the vat and opens into the top of 
the cylinder. This tube may have any shape that of a worm 
surrounded with cold water, or of any other system of cooler 
if it is desired to refrigerate at the same time. 

The other two tubes provided with taps start one I I 1 from 
the top of the cylinder, the other J J 1 from the bottom. To 
reach one directly, the other after forming an elbow, the 
opening of the vat U. They are adjusted in the wooden 
door, tightly fitting the opening of the vat. 

Fig. 36 shows the 
arrangement of the 
three tubes and the 
machine on the plat- 
form above the vat. 
The tube H being too 
long has been passed 
around a hogshead. 

A glance at the two 
figures will enable us 
to see readily the work- 
ing of the machine. 

The principal lever 
is connected at its ex- 
tremity A, by means 
of chains to the taps K, 
and a weight P, suffi- 
cient to overcome the 
resistance of the open- AX&&S&&&X 
ing. At the other 

CXtremitV B Of the Fig. 36. Arrangement of Auto-regulator on the Vat. 

lever, is a counterpoise P, calculated to overcome at the right 
moment double the resistance of the weight suspended to the 
taps, and the friction. All the different parts of the machine 
are worked at definite intervals by the displacement of a 
floater L, along a vertical rod, in the following manner : 
The machine being placed over a vat, as shown in Fig. 35, 
and the vat being hermetically closed, except at the bottom 




144 WINE-MAKING IN HOT CLIMATES. 

tap, which is always kept open, the pressure of the carbonic 
acid gas forces the must through the tube into the cylinder. 
The result of this effusion of must is to raise the floater L. As 
follows from Fig. 34, when the floater reaches the weight P it 
will stop a moment, and as it has an upward pressure greater 
than the weight P the floater continues to rise until equili- 
brium is established, releasing the principal lever from the 
weight P. 

However, the lever will not move for it is kept in position 
by the lower notch of the double lever ODE. 

The ascent of the floater and the weight P continues till 
the release R touches the horizontal bar C D of the double 
lever, displacing it around its axis D, freeing the principal 
lever, which rocks and is drawn down by the weight P sus- 
pended to the taps. 

The result of this rocking is the complete and simultaneous 
opening of the two taps, the pressure in the vat is imme- 
diately reduced to zero, the delivery of liquid into the 
cylinder ceases at once, and the tube returning the liquid to 
the vat starts working as a syphon J J 1 , while the gas con- 
tinues to be liberated through the tube I I 1 . 

Let us now study the descending movement of the floater. 

The floater with the weight P descends from the moment 
the tubes are open till the chain to which the weight P is 
suspended is taut, then the principal lever is in an inverse 
position to that shown in Fig. 34, and would be drawn 
down by the weight P if it were not' held up by the upper 
notch of the double lever ODE, on which its extremity B 
rests. The weight P is, therefore, only suspended to the 
principal lever while the floater descends. It is only when 
the latter, reaching its lowest limit, acts by its weight on the 
chain of the auxiliary lever, that the notch will move from 
its position, releasing the principal lever, which is then drawn 
down, the weight P assumes its original position and closes 
the taps. We have returned to the starting point, and the 
movement will continue regularly as above described until 
the end of the fermentation. 

We may add, to complete this description, that the special 
break-jet which spreads the must in a circular sheet at the 
end of the return tube may also, if rendered movable, act 
as a valve, preventing the carbonic acid gas from escaping 
through the return tube when the taps are open, as the escape 
of carbonic acid gas bubbling through the must might cause 
a loss of liquid. 



VINIFICATIOX. 145 

The circulation resulting from the use of this machine 
renders the mass homogeneous in temperature and composi- 
tion. It allows the use of refrigeration by interposing a 
cooler between the vat and the auto-regulator. As for 
aeration, it may be done by spreading the must delivered 
in the cylinder, and may be easily suppressed by simply 
covering the cylinder. The carbonic acid gas remains in it 
on account of its density. 

^^fermentation auto-regulator works very satisfactorily. 
It is excellent if used for cement vats, but we do not advise 
its use with wooden vats without previously ascertaining the 
resistance of the vat to the pressure required. 

The increase of pressure brought about is not very great, 
depending on the height of the auto-regulator above the 
level of the liquid in the must. But wooden vats often do 
not stand even that slight increase in pressure. When well 
built of solid wood, they may support double or treble the 
pressure required, but it is better to test them previously. 

Masonry, or sidero-cement vats, are always strong enough 
to allow the use of the auto-regulator without danger of 
bursting. 

DURATION OF VATTING. 

This means the time during which the must remains in 
contact with the marc in the fermenting vats. 

It is impossible, a priori, to fix a stated time for this, as 
it varies according to the nature of the wine it is proposed 
to make, to the cepage used, to the method of fermentation 
adopted, the temperature of the vat, and the manipulations 
the must undergoes during fermentation. 

If fermentation is studied, three distinct phases will be 
observed, corresponding to the activity of the ferments. 
The first phase, without external manifestation, corresponds 
to the multiplication of the ferments. During this period, 
which is always very short, the sugar is only slightly de- 
composed, and the production of carbonic acid gas is so 
small that it remains in solution in the liquid. The second 
phase, called tumultuous fermentation, corresponds to the 
maximum activity of the ferments. The decomposition of 
the sugar is rapid, and the disengagement of carbonic acid 
gas gives rise to violent bubbling of the liquid. 

The elevation of temperature, which is a function of the 
quantity of sugar transformed in a unit of time, takes 
place suddenly, alcohol accumulates rapidly in the liquid, 

10649. K 



146 WINE-MAKING IN HOT CLIMATES. 

which gradually becomes less favorable to the work of the 
yeast. This brings about the third phase characterized by 
still active but relatively quiet fermentation. 

Each of these phases is of greater or less duration, 
according to the state in which the grapes arrive at the 
cellar, and the perfection of the crushing and aeration of the 
vintage before being placed in the vat. 

As a general principle, the must should be racked and 
separated from the marc, when the total sugar has been 
transformed into alcohol. This corresponds approximately 
to the zero degree of the mustimetre. It is then only that 
the wine has extracted from the marc all the useful mat- 
ters, and acquired its maximum quality. This is only true, 
if all the conditions of fermentation, and especially that of 
temperature are suitable. 

We may lay down, as a rule, that the higher the tem- 
perature is the shorter should be the time in the vat. 

Up to 35 C., and for wines of an alcoholic strength 
not exceeding 10 per cent, by volume, the fermentation 
starts quickly and is soon finished. If the temperature 
exceeds 35 C., or even if it does not exceed 35 in the case 
of wines containing 12 per cent, and over of alcohol, the 
fermentation becomes retarded, and even stops altogether 
if the temperature exceeds 35 C. Under these circum- 
stances, if the means are not at hand for reducing the 
temperature of the fermentation to 30, it is necessary to 
rack, whatever degree is indicated by the mustimetre or 
sweetness remains in the wine. 

Fermentations between 32 and 35 C. are only possible 
in the case of light wines. These are the only kinds that 
are not much damaged, because the fermentation goes 
quickly for two or three days at most, and during the 
short maceration, the marc cannot affect the surrounding 
liquid prejudicially. 

In any case, directly the fermentation exceeds 35 C., if 
refrigeratiou cannot be effected, the wine must be racked. 
No doubt poor wines result from the latter procedure. 
They are superior, however, to those obtained by leaving 
them longer in contact with the marc. They will yield as 
much alcohol, and have the same freshness andjinesse, and 
will, after all, command a higher price than the heavy 
astringent wines of abnormal taste always resulting from 
prolonged contact with the marc at a high temperature. 




VILIFICATION. 147 

The wines called maceration wines are only made 
successfully in cold countries. The wine may acquire 
by prolonged contact with the marc at a normal tempera- 
ture certain qualities demanded by the trade, but at 'high 
temperatures it only acquires defects. In the South of 
France the duration of vatting is generally three or four 
days, but lasts eight days when the temperature does not 
exceed 30 C. In the latter case the wine is coarser, the 
dry extract is higher, and the wine produced is richer in 
colour. The qualities of the colour remain good, without 
any leaden yellow, depressed, undefinable shades of colour, 
which always create a bad impression when examined in 
the tasse* (Fig. 38.) An eight days' 
vatting, if well conducted gives with 
Aramon (even if grown on flat land) 
a wine which many expert tasters would 
not believe to have been made from 
Fig. 3B.-Tasse. Aramon exclusively. 

We will not deal at length with the wines called one-night 
wine. By this expression is meant wines of very short 
vatting. They have generally more finesse, and are richer in 
alcohol than the longer fermented wines, but are after all 
only intermediate between red and white. 



VARIOUS ADDITIONS TO THE VAT. 

ACIDIFICATION. 

We have seen (page 47) the importance attached to the 
acidity of the vintage, and have shown the amount desirable 
completed if necessary by means of tartaric acid in order 
to obtain fine solid wines of good robe (colour, &c.) 

The necessary or useful quantity of tartaric acid to add is 
calculated from a few determinations of the acidity of the 
must, and it is placed with the grapes in the crusher, or 
spread over the vat while it is being filled. Tartaric acid is 
the only acid that can be recommended for practical use, as 
it is the only acid capable of fixing the excess of potash as 
an insoluble combination and liberating the normal acids of 
the grape neutralized by the potash. 

* A shallow silver or electro-plate cup, the interior bossed in opposite direc- 
tions, always used by wine judges in examining the colour of wine. See Fig. 38. 

K 2 



148 WIXE-MAKING Iff HOT CLIMATES. 

PLASTERING 

Is an indirect means of acidifying the vintage, and consists 
in spreading over the grapes in the crusher ordinary plaster 
of Paris (calcium sulphate). This is a very unreliable means 
of increasing the acidity. The plaster acts on the bitartrate 
of potash in the must, liberating half the tartaric acid in 
combination ; but generally the plaster is calcareous, that is 
to say, containing frequently a large amount of calcium car- 
bonate which partly, if not entirely, neutralizes the excess of 
acid resulting from the reaction. 

The reactions of plaster in wine are rather complex. We 
have shown, in conjunction with Eug. Thomas, that in pre- 
sence of Jbitartrate of potash, the plaster (calcium sulphate) 
forms calcium tartrate and acid sulphate of potash, and that, 
contrary to what is generally admitted, the acid sulphate of 
potash does not remain as such in the wine. In turn it 
reacts on the different organo-potassic compounds which 
always exist in wine side. by side with the bitartrate of 
potash, and transforms them into neutral sulphates, 
liberating a part of the acids previously combined as 
organo-potassic compounds. 

Plastering hastens 4he clearing of wine, and increases its 
brightness and keeping qualities ; but unfortunately this does 
not take place without the liquid acquiring a special rough- 
ness due to the presence of sulphate of potash in solution. 

For plastering to be efficacious it should be done freely. 
The maximum limit allowed by law (in France), 2 grammes 
of sulphate of potash per litre, is not. sufficient to enable the 
method to give decided advantages ; it is extremely difficult 
to fix a priori the quantity of plaster to be used for the 
resulting wine to conform to the legal limits. 

It is better to completely reject this method condemned by 
law, and all the more reasonably, as in commerce plastered 
wipe is regarded unfavorably. 

PHOSPHATING. 

This practice, due to Hugounenq, is free from some of the 
adverse criticisms applied to plastering. 

No law prohibits its use. It is recommended by many 
oenologists, and, as a matter of fact, does not destroy the 
finesse of the wine. 

Phosphating consists in adding to the vintage pure di-basic 
calcium phosphate. 



VINDICATION. 149 

The chemical reactions taking place after phosphating are 
of the same class as those occurring in the case of plastering. 
Tartrate of calcium is formed by the action of the phosphate 
of calcium on the acid tartrate of potash contained in the 
must, but it is not yet known which phosphate of potash 
remains in solution ; however, it cannot be injurious, and the 
phosphoric acid it contains cannot but have a favorable action 
on the fermentation. 

The effects of phosphating are the same as those of plaster- 
ing, with the difference already noted that phosphated wines 
retain their 'Jinesse, and the phosphate of potash in solution 
does not affect the taste of the wine to the same extent as 
sulphate of potash. 

The colour, however, does not seem to be influenced to the 
same extent in phosphating as in plastering. 

SELECTED YEASTS. 

The addition to the vat of selected yeasts, that is to say, 
yeasts taken from the lees from grand 'crus, is nowadays 
practised by a large number of wine-makers. 

The technical science of micro-biology enables us now to 
take a single cell of good yeast, to cultivate it, guarded from 
all possible means of contamination, and by using culture 
mediums specially adapted to their development, to get in 
a very small volume a number of active cells, infinitely 
greater than are contained in a large bulk of vintage. 

The object is to insure the rapid predominance of a special 
vinous fermentation, which will more or less check the work 
of the ferments natural to the vintage. 

It is the substitution of the work of a special yeast in 
place of that of the natural yeast. 

The advocates of selected yeasts have greatly exaggerated 
the advantages resulting from their use, still their use 
presents some real advantages. 

In fact, well-conducted fermentation with selected yeasts 
generally gives a slightly superior wine to that obtained 
from a spontaneous fermentation with the same grapes con- 
ducted under the same conditions. This is generally admitted, 
and is certainly important. 

This superiority, however, . is only observed in the case of 
a well-conducted fermentation, especially as far as tempera- 
ture is concerned. . 

In short, a more regular and rapid fermentation is 
obtained, a quicker clearing of the wine, and more highly 



150 WINE-MAKING IN HOT CLIMATES. 

developed qualities of preservation. These are results granted 
by observers to follow from the use of well-selected yeasts. 
But there is another point, their influence on the bouquet of 
the wine, which is much debated. 

Many authors, who have studied the question of the use of 
selected yeasts, have pointed out the action on the bouquet, 
which is regarded by them as the principal effect. It is 
presumably even so real, and so developed, that one of them 
has not been afraid to assert that wort fermented with 
Chablis yeast had been taken by wine judges for true 
Chablis. 

We need not point out the evident exaggeration of such a 
statement. 

The aroma or bouquet of wine must be regarded as the 
product of numerous factors of two classes. 

The first cannot be modified for a given vintage. They 
are the cepage, the soil, the subsoil, and the climate. The 
others depend, perhaps, on the variety of yeast, but more 
positively on the care and attention given to the vintage, and 
ultimately to the wine. These may be modified. 

The perfect cleanliness of all the wine-making material, 
well conducted fermentations, and, later on, opportune 
rackings have more effect than is generally credited on the 
final bouquet of wine. 

The study of the action of the different races of wine 
yeasts is much more complex than that of the various 
races of beer yeasts. In the latter case we work on musts, 
which may always be reproduced identically, and even by 
sterilization cleared from any organisms which might dis- 
turb the result of the fermentation. These conditions 
cannot be realized in vinification. We grant that the varia- 
tions existing between different vintages are slight, but 
they exist, and in the actual state of our knowledge, how- 
ever slight these variations may be, no one can say if it is 
not to them that should be imputed the great dissimiliarity 
observed between the products of their fermentation. 

If we introduce into the must one of the factors influencing 
the bouquet, as already explained, we will improve it slightly, 
but that is all. By using yeast of a particular cru, we 
certainly make a slight advance, but the advance made will 
be so much the greater as the grapes used more closely 
resemble those of that particular cru. This is quite suffi- 
cient, we consider, to show that it must not be thought 
possible to make Bourgogne wine with Aramon grapes. 



VINDICATION. 151 

We are inclined to think that cultivated yeasts, develop 
in the wines they produce, an aroma peculiar to each of them, 
-and which certainly enters in part into the constitution of 
the bouquet of the wines, issued from the same cms as the 
yeasts ; but, we emphasize, the aroma given by the yeasts is 
more often than not a very poor reflection of the bouquet of 
the grand cms. 

The Champagne yeasts, however, have in this respect a 
decided effect, the characteristic flavour of champagne (the 
sugar excepted) is met with in the white wines made in 
districts remote from Champagne, but fermented with yeasts 
originating there. There is in this case an undeniable action 
with regard to the specific flavour which the yeast may com- 
municate to the wine, and it is to be presumed that Champagne 
yeast is not an exception, but that all yeasts, to a greater or 
less extent, act in the same way. 

Whatever this action may be, when it is desired to make 
wines for immediate consumption (like ours in the South of 
France), it is not of much importance whether the yeast 
modifies the future attitude to acquire bouquet or not. 

Selected yeasts seem to furnish straighter, finer wines, of 
good keeping qualities, and this is quite sufficient to justify 
their judicious use. 

The study of wine yeasts and of the advantages that may 
be derived from their application to the different methods of 
vinification is far from being exhausted. Kayser, Director 
of the (Enological Station at Mmes, has tried for a longtime 
to throw light on this obscure question alone or in collabora- 
tion with Barba. He has already obtained results important 
enough to justify the hope that by means of selected yeasts 
(the conditions of life of each race being fixed) still better 
results than those given to-day may be obtained. 



DE-VATTING (DECUVAGE). 

This operation consists in separating the fermented wine 
from the marc. 

The de-vatting is very easily done, when the casks are not 
too far apart, by placing the cask to be racked in con- 
nexion with the empty cask, and letting the liquid run in 
by gravitation until it is at the same level in both, and 
then finishing the operation by pumping. 

The casks which are to receive the newly fermented wine 
must be thoroughly clean, and washed with an abundance of 



152 WINE-MAKIXG IX HOT CLIMATES. 

water, till quite freed from lees. They should not be sul- 
phured, or if they have been, sulphurous fumes should be 
completely removed by a current of air. 

The new wine after racking still continues fermenting 
for a few days, and this must not be checked in any way. 
The sulphurous fumes act as a decided check on the fer- 
mentation, and this is so much the greater as the liquid is 
impoverished as regards its ability to nourish the ferment. 

Contrary to what is usually done, the newly racked wine 
must not remain more than a week or fortnight in the vessel 
it has been racked into. After that time, when the 
fermentation has been well conducted, the wines have 
deposited, and are ready to be racked into another cask, 
which should be slightly sulphured. 

It is a common prejudice that sulphuring should not 
intervene in the fermentation of red wine. This will be dis- 
cussed later on, but we will state now that this prejudice 
is without foundation. The practice of sulphuring cannot 
but have advantages in the case of both red and white 
wines. It is simply a question of the quantity used. 

EXHAUSTION OF THE MARC. 

The de-vatting leaves in the vat the marc from the vintage 
it contained. 

The marc still contains after natural drainage a consider- 
able quantity of wine which should not be lost. It is 
submitted to pressure. This drains it more or less, and 
furnishes what is known as." press wine," as compared with 
the other racked portion known as " taste wine." 

PRESSES. 

The machines used for the extraction of the wine contained 
in the marc are called presses. They are intermittent and 
continuous, depending on the method of feeding adopted. 

INTERMITTENT PRESSES. 

In ancient times planks and heavy stones were all that was 
used, but a very insufficient pressure was the result. It is 
mainly in the direction of presses that mechanical skill has 
been directed during centuries in the cellar, and the ancient 
type, with a few modifications, in detail, is still the most 
widely used. 

The press actually used consists essentially of three parts. 
A vertical screw, a horizontal table or base supporting the 



VINDICATION. 



153 



screw in the centre, and a nnt travelling on the s crew con- 
stituting the compressing part. (Fig. 39.) 




-- The marc to be pressed is 
spread over the table, some- 
times supported at the sides 
by a screen surmounted by a 
cap, and a number of cross 
pieces called the load, which 
transmits to the mass, distri- 
buting it evenly, the pressure 
obtained by tightening the 
travelling nnt. 

The compression is obtained by means of levers varying 
in shape, some worked in one direction only ; others, the most 
commonly used, -worked with an alternating movement, but 
forcing the travelling nut to revolve always in one direction 
by means of a ratchet reversing the movement. 
The table is made of wood, iron, or cement. 



Io4 



WINE-MAKING IN HOT CLIMATES. 



Those made of wood would be excellent if it were not 
rather difficult to make them staunch and impervious. Those 
made of iron are very good, but should be coated to prevent 
the wine acquiring a bad taste by contact with the metal ; 
those of cement built on strong concrete are practically ever- 
lasting. 

The load of the press should always have a certain elas- 
ticity, as it constitutes a pressure accumulator. 

If we consider the marc surmounted by a non-elastic load, 
when once the pressure limit of the machine is reached we 
would have to continue applying pressure unceasingly to 
obtain good results. With an elastic load the press may be 
left to itself, for the pressure continues to act through the 
restitution of the force accumulated in the elastic load. The 
time that the press can be left to act alone is proportionate to 
the deformation of the load under the given pressure. With 
regard to this, wooden loads are superior to those of iron. 

The substitution of powerful steel springs placed between 
the cap and the nut is a decided improvement in intermit- 
tent presses, this suggestion is due to Crassous (Fig. 40).* 




Fig. 40. - Press with spring load. Crassous Arrangement. 



* This idea was first realized in practice by P. Paul, who manufactures these 
presses. 



VINDICATION. 155 

The load is dispensed with but not its useful effect, which 
on the contrary is amplified; the cap is fastened to the bolt 
by a very simple device and they travel together. This 
greatly simplifies the working. But where the main advan- 
tage comes in, is in the action of the springs. These are of 
the same type as those used for railway-carriage buffers. 
Their normal limit of compression is 20,000 kilos, for a 14 
or 15 centimetre stroke. 

The height of the marc on the table diminishes under the 
pressure till its resistance equals the compressing resistance 
of the springs, if from that moment the tightening is con- 
tinued the pressure is accumulated in the springs, which 
become more and more compressed, and is restituted by them 
when the tightening ceases, the cap continuing to descend 
till the springs liave expanded to their normal length. 

The stroke is about 14 or 15 centimetres, and this allows 
a long enough interval for workmen to attend to other 
operations in the cellar. 

While an ordinary press with a wooden load requires re- 
tightening every quarter of an hour, presses fitted with 
-accumulating springs continue acting from two to six hours, 
according to the pressure and the state of the marc. 

The number of springs varies with the surface to be 
pressed, and the surface itself varies according to the pres- 
sure we desire to obtain. 

Generally the marc is cut afresh at the sides to a dis- 
tance of about 30 or 40 centimetres in from the circum- 
ference, as the case may be, and thrown over the cake 
again, and the pressing continued. The pressure is the 
same, but as it is distributed on a small surface it is much 
greater per unit of surface. 

All presses dry the marc to about the same extent, the 
perfection of work depends much more on the way it is 
done than on the type of press employed. 

The opinions of many specialists have led wine-makers 
to try and obtain unnecessarily high pressures. 

The yield of juice from a given quantity of marc depends 
on two factors the pressure and the time during which it 
acts. The second of these factors can in no way be substi- 
tuted for the first. It is better to leave the marc longer in 
the press, submitting it to a moderate pressure, than sub- 
mitting it to a powerful pressure for a short time. 



156 WINE-MAKING IN HOT CLIMATES. 

This method of operating requires the use of a number of 
small presses, or of a lesser number of presses capable of 
receiving a large volume of marc. 

Both large and small presses have their advocates, the 
superiority of either type is far from being admitted; generally 
from comparative observations we consider that large surface 
presses are preferable. Their working is simpler and the 
marc quite as dry as that worked with machines of smaller 
surface. We know many cellars where the presses are large 
enough to receive the marc from a 4oO-hectolitre (9,900- 
gallon) vat, each dries that quantity of marc without cutting 
the cake in 24 hours. Therefore, without any work beyond 
the filling, tightening, and emptying, the draining of the 
marc is quite as satisfactory as that obtained in less time, 
with one or two cuttings. 

CONTINUOUS PRESSES. 

Ordinary presses, such as those above described, give medium 
results, even the best of them, that is if there are any better 
than others. The drainage of the marc is far from being com- 
plete, as it always retains at the end of the operation about 
60 per cent, of liquid. Is it desirable to go to any further 
trouble, and will we not by an increase of pressure augment 
the yield at the expense of the wine ? We do not think it is 
desirable, but the advocates of continuous presses are of this 
opinion, for they quote amongst the advantages of these 
machines a more perfect exhaustion or drainage of the marc. 

In short, continuous presses have been invented with the 
objects 

First To reduce labour. 

Second To reduce the stock of machinery by dispensing 
with the use of ordinary presses, which, to treat an equal 
quantity of vintage, are more numerous and expensive, and 
above all more cumbersome than continuous presses. 

Third To reduce the time of pressing. 

Fourth To increase the yield of press wine. 

We must at once state that the increased yield aimed at 
is not yet proved to be attained. All the continuous presses 
known (with a few rare exceptions), although widely different 
in shape, depend on the same principle. 

They are composed of two or more cylinders, worked as 
crushers if fresh vintage is to be treated, or as light compres- 
sors if fermented vintage is to be dealt with. 



VERIFICATION. 



157 



After passing through these cylinders the vintage is carried 
on by an Archimedean screw, accumulating it in a perforated 
horizontal cylinder, the diameter of which decreases towards 
the exit, and is terminated hy an orifice small enough for the 
marc to form a compact cake or stopper, which can only be 
expelled under considerable pressure. A fresh quantity of 
marc replacing that expelled acts in turn as a stopper, and 
so on as long as the machine is fed. (Figs. 41 to 45.) 




158 



WINE-MAKING IN HOT CLIMATES. 




VINDICATION. 



159 




160 



WINE-MAKIXG IN HOT CLIMATES. 



' ' ' ' 




VINDICATION. 1(51 




Fig;. 45. Self-acting Carrier of Pepin's Press. 

The cylinder may be of conical shape and composed of steel 
blades, allowing the diameter of the exit from the cone to be 
increased or diminished by means of a movable iron collar, or 
it may be as in the Debonno press (the first invented) a tube 
of rectangular section, with the angles rounded off, closed 
at its extremity by an adjustable roller, the axis of which is 
horizontal and perpendicular to the axis of the Archimedean 
screw, rising under the pressure of the marc, and offering a 
resistance, which may be varied by means of weights carried 
on one or two levers connected with the roller. 

The use of continuous presses is particularly tempting in 
the manufacture of white wine, for it is necessary in this case 
to obtain in the shortest time, a separation of the liquid and 
solid parts of the fruit, as completely as possible. 

There is unfortunately in the working a notable defect the 
yield in juice is apparently greater than that furnished by 
an ordinary intermittent press, but the must furnished is 
infinitely more turbid, owing to the greater disintegration of 
the vintage, to such an extent that if we want to know the 
true yield of grape juice, it is necessary to separate from the 
liquid obtained from the continuous press, a quantity of solid 
matters in suspension, which cannot be regarded as juice. 
This quantity is great enough to reduce the true yield of juice 
to even less than that obtained by means of an ordinary inter- 
mittent press. 

And what is more, the pressure on the marc being equal, 
the wine obtained by the continuous press has less finesse 
than that obtained from the use of an intermittent press. 

Whatever be the mode of action of a continuous press, 
while travelling from the entrance to the exit the marc is 



10649. 



162 WINE-MAKING IN HOT CLIMATES. 

submitted to an energetic friction against the internal sur- 
faces of the machine ; disintegration of the stalks, seeds, and 
skins, often very pronounced, results from this friction. 
The organic juices contained in the cells of those organs 
pass entirely into the wine, and, as we have shown, when 
describing the crushers, it is important to leave two elements 
of the grapes (stalk and seeds) intact. The continuous presses 
at present known do not overcome these inconveniences. 

If we are dealing with white wine, this inconvenience is 
still more apparent. We do not know any continuous press 
capable of extracting from red grapes a quantity of white 
must equal to that obtained by an ordinary crushing, followed 
by the usual pressing, without the must 'in the former case 
being more coloured than the latter. This fact is quite 
unexpected, for it is generally admitted that the most im- 
portant factor of the non-colouration of the must depends 
on the rapidity with which the grapes are treated. 

It is a factor, it is true, but not the only one to be con- 
sidered. It is generally admitted that the colouring matter 
of the berry is only soluble in concentrated or diluted alcohol, 
and that if we avoid fermentation the colouring will not 
occur. The colouring matter contained in the cells does not 
pass through the membrane while they are surrounded by 
non-alcoholic must, but if we place in the white must broken 
cells full of colouring matter, the colouring matter, although 
completely insoluble in the must, will diffuse through it in 
very minute particles, which it will be impossible to sepa- 
rate ; but, what is more, if the insolubility of the colouring 
matter is admitted as long as it is protected by the cellular 
membrane, it is not so when the colouring matter is bare 
and exposed to the action of the must. Duclaux has estab- 
lished, by a few experiments, that the colouring matter can- 
not be considered as insoluble in the must, but that this 
liquid has not got the power of dissolving it through the 
cellular envelope. 

These various inconveniences delay the general adoption 
of continuous presses in the viticultural industry. We hope 
that constructors will be able in the future to .overcome 
them. Continuous presses will then, and only then, become 
machines for general use, owing to their advantages, hence- 
forth irrefutable. 



VINDICATION. 163 

EXHAUSTION OF THE MARC WITHOUT PRESSES. 

Presses are far from giving every satisfaction, and the 
marc treated by them has to be submitted to new manipu- 
lations to make piquettes, or marc spirit, if it is desired to 
utilize the wine they still contain. 

AVe studied in collaboration with M. Semichon, Director 
of the QEnological Station of the Aude, various means of 
increasing the yield of pure wine from fermented marc, and 
cannot do better than quote the following extract sum- 
marizing our researches on this subject : 

" Under ordinary conditions, in the vinification of red wine, 
the marc remaining in the vat after the racking of the 
wine, is placed in the press and submitted to a more or 
less greater pressure, during a varying period. 

" It is thought that by this operation, all, or at least a 
greater part of the wine contained in the marc is extracted. 

"Pressure, however, does not give as complete an ex- 
traction as is generally thought, for if we determine the 
quantity of the wine left in the marc after the operation as 
conducted under ordinary circumstances we always find a 
minimum of 50 per cent, of the weight of the marc. Dis- 
tillers know that they generally extract from 100 kilos, of 
compressed marc a number of litres of alcohol equal to a 
little more than half the alcoholic degree of the wine fur- 
nished by that marc. 

"It is therefore an important fraction of the total yield 
that might be used as wine, for if we admit that the pro- 
duction of one hectolitre corresponds to a quantity of 15 to 
20 kilos, of compressed marc, it is (taking the minimum of 
50 per cent, of wine remaining) a volume of 7 or 10 litres of 
wine which may be used for making piquette or marc spirit. 

" This is an important loss, which shows that presses are 
not perfect instruments as far as yield is concerned. They 
are not perfect either with regard to the quality of the wine 
they yield. Every wine-maker knows the defects of press 
wines in regard to their organoleptic value and keeping 
qualities. 

" The improvements made in recent years in the manu- 
facture of piquettes induced us to apply to the exhaustion of 
impressed marc the method which actually gives the best 
results for piquettes, and which consists in methodically 
displacing the liquid impregnating the marc by an ascending 
current of water. 

L ^ 



164 



WINE-MAKING IN HOT CLIMATES. 



" By causing the liquid piston of ascending water to 
displace the wine, we thought that the yield would be 
greater than that of any press. 

u An almost integral 
mechanical displacement is 
possible, and can be demon- 
strated by a simple laboratory 
experiment. 

" If in a flask full of wine 
we allow a current of water 
to slowly flow in to the lowest 
part, the wine is lifted by the 
water, while the line of de- 
marcation of the two liquids 
remains sharply defined if the 
experiment does not last too 
long. If the wine is collected, 
we notice that the diffusion 
zone is very narrow, and that 
the alcoholic strength of the 
liquid experimented upon 
becomes only appreciably 
lower in the last portion col- 
lected. In an experiment 
made with a flask of three 
litres capacity (Fig. 46) filled 
with wine of 1O4 per cent. 




I 



46. 



alcohol, we gathered : 
1 litre, containing 1O4 per cent, of alcohol. 



1 

500 c.c. 
300 

400 . 



10-5 
10-3 
10-05 

3-51 per cent., average of 
eight trials of 50 c.c. each. 



" The three litres of wine experimented upon contained 
312 c.c. of pure alcohol, and the displacement gave 

104 c c. of pure alcohol with the 1st litre. 



105 
51;5 
31-5 
14-04 



2nd 

500 c.c. following. 

300 

400 



VILIFICATION. 165 

" A total of 306-05 c.c., which shows a loss of 2 per cent, 
only. 

" 95'5 per cent, of the alcohol has been extracted in the 
shape of pure wine equal to that experimented upon, that is 
to say, of 10'4 per cent, alcohol. 

" It will be noticed that in this experiment the second 
litre is of higher alcoholic strength. This difference is small 
enough to be attributed to an error of determination. We 
do not believe it, however, for we have always noticed this 
slight increase of the strength in the numerous experiments 
made. We are unable to explain this constant fact, and 
can only record it, pointing out that its constancy cannot 
be explained as a mere coincidence. 

" This shows, when dealing with liquids alone, that it is 
possible to displace, without mixing, and without any other 
help than water, more than 95 per cent, of the wine con- 
tained in the vessel. Will the experiment be as simple if 
the wine to be displaced impregnates a spongy more or less 
continuous mass such as marc ? 

" Evidently not, for new factors come into play. We must 
differentiate between the wine simply wetting the exterior 
of the tissues, and that contained in the tissues. 

u The former is displaced almost as easily as in the case of 
liquids, the latter can only slowly come out of the tissue by 
a kind of dialysis through the membrane of the cells, or 
even through the skins, if we have to deal with badly- 
crushed vintage. 

" We made several displacement experiments with solid 
matters, porous or otherwise, such as broken glass, cotton, 
sponge, pumice stone, &c., saturated with wine, which showed 
very quickly that we could not hope for as good results as 
in the case of liquids alone. 

"We merely quote the results of these experiments as 
references, and did not stop to study them completely, as the 
marc alone interested us. 

" The causes which prevent us obtaining an integral 
yield in the displacement method applied to grape marc, 
are 

1st, The diffusion or mixing of the wine and water. 
2nd. The difficulty the wine encounters in traversing 
the walls of the tissues by a kind of dialysis. 



166 WINE-MAKING IN HOT CLIMATES. 

" We determined by numerous experiments, under varying 
conditions, the rapidity of the diffusion of wine in water. 
We will not insist on the results obtained, but draw the two 
following conclusions : 

1st. There is an advantage in having a rapid displace- 
ment, that is to say, an ascensional rapidity of 
the liquid piston amounting from 8 to 10 centi- 
metres per hour. 

2nd. There is an advantage in operating on the marc of 
well-crushed vintage. 

" In the laboratory we obtained, on small quantities of 
marc it is true, a yield of pure wine notably higher than 
that given by the presses. 

" In current practice, however, the marc cannot be treated 
with the same care that is possible in a laboratory experi- 
ment, but by modifying the arrangement, and by increasing 
the number of displacement tanks and arranging them in 
batteries as is already done for the diffusers in certain 
industries, we may expect a satisfactory enough yield for the 
process to remain applicable. 

" The experiments were made on a large scale, but not, 
however, large enough,* and it will not be possible to do this 
till next vintage. 

"With four displacing tanks, each holding 100 kilos, of 
marc, we obtained results comparable with those of the 
presses. (44*4 litres of pure wine per 100 kilos, of drained 
marc, while 45 litres were obtained with the presses, that 
is to say, about 65 per cent, of the wine contained in the 
marc.) 

" We think that these results would already be ad- 
vantageous, for they dispense with the labour of pressing, 
and give an equal yield ; but the course of the operation 
enables us to foresee that by doubling the number of tanks, 
or even by taking six only, the yield in pure wine would be 
increased, and reach that of the laboratory experiments made 
on the marc, that is to say, about 85 per cent, of the total 
wine contained in the rnarc. 

" We must add that the quality of the wine so obtained 
is superior to that of press wine. It has not the same 

* With a sufficient number of tanks (eight or ten) we might greatly increase 
the ascensional speed of the water. 



VILIFICATION. 167 

harshness resulting from the crushing of the organic tissues, 
neither its defects of preservation resulting from the im- 
purities in suspension in the liquid. 

"The quantity of wine to be utilized in the shape of 
piquette or spirit, will be reduced to 3 per cent, in place of 
7 or 10 per cent. 

" We used in our experiments the following arrangement: 
Four tanks made from casks with the heads knocked out, of 
about 120 litres capacity, provided with a screen forming a 
false bottom, were placed in communication in such a way 
that the liquid entering in the bottom and centre of the first 
one, overflowed by a side aperture in the upper part, to 
pass into the second tank, where it penetrates into the 
middle of the bottom, and so on. 

" The four tanks so arranged were charged with marc, and 
the displacing commences ; at the third we might have 
already drawn pure wine, but we only did this at the fourth 
at the rate of 45 litres per 100 kilos, of vintage. The first 
tank is then considered as exhausted, the slightly pink- 
coloured water it contains is racked and sent back to the 
water tank, while the feeding is made directly on the second 
tank, which now becomes the first ; charged with fresh marc 
the vat we have just finished with becomes the fourth, and 
so on, each cask becoming in turn the first and last of the 
system. 

" The limited quantity of water which remains at the end 
of the operation in the shape of piquette may serve to 
extract the wine from an unlimited quantity of marc. 

" We consider that a battery of eight tanks would give 
much better results, the working would be the same as that 
described ; it might be facilitated, however, by adding a 
ninth tank, for the charging and discharging to be made 
without stopping the displacement operations. 

" The zone of diffusion of wine and water is spread over 
the first two or three tanks, and is preceded by a volume of 
pure wine, sufficiently extended to allow it to be collected 
without any admixture of water. 

" This diffusion zone is so much the greater as the vintage 
is less crushed, we even think that this factor (perfection 
of crushing) is so important that the method would be in- 
applicable in the case of an uncrushed vintage. 

" We tried to obtain a more rapid and better displace- 
ment by the use of a liquid denser than water, and with 



168 WINE-MAKING IN HOT CLIMATES. 

that object worked with solutions of common salt of strength 
varying between 1 and 10 per cent. The yield in wine is 
not increased, and it has the inconvenience of leaving tails, 
that is to say, portions of piquette too salty to be of any 
use. 

" We do not pretend to have made conclusive experi- 
ments on the subject, and we propose to complete them 
during next vintage, out such as they are they enable us 
to lay down the principles of a method of exhaustion of 
marcs more satisfactory than that depending on compres- 
sion." 

Since the publication of this work, M. Semichon and my- 
self have secured the co-operation of several vine-growers 
desirous of experimenting with a method which, while 
dispensing with the work of the presses, would give a 
better result in yield of pure wine, We hope after the 
next vintage (1898) to be able to definitely establish the 
superiority of diffusion over pressing by the figures obtained 
in operating on large quantities. 



VINDICATION OF WHITE WINE. 169 

CHAPTER V. 

VINDICATION OF WHITE WINE. 

^ viuification of white wine differs essentially from that 
of red wine, in the fact that the transformation of the must 
into wine takes place without contact with the solid parts 
of the grape. 

There are two cases to be considered 

Vinifi cation of the grapes of white cepages. 
Vinification of the grapes of coloured cepages. 

The white cepages, most commonly cultivated for the 
manufacture of white wine in the south of France, are the 
Picpoul, Terret-Bourret, and Clairette. 

All red grapes are eligible for making white wine, except- 
ing ^ the Tinto varieties and Bouschet hybrids (having red 
coloured juices). 

VINIFICATION OF WHITE VARIETIES. 

Is much simpler than the vinification of red cepages. It 
consists in crushing the grapes, draining them, placing the 
drained marc in the press, and leaving the juice from both 
the above operations to ferment. However, there are certain 
operations that may improve the finesse and keeping 
qualities of the wine, and therefore increase its value. 
One of these operations is the debourbage (settling). 

This consists in separating the suspended impurities. 
Various methods have been proposed for the debourbage 
simple filtration, the application of which is much too 
expensive, the must offering great resistance to filtration ; 
centrifugating, the effectiveness of which has not yet been 
sufficiently proved ; and the simple separation by deposition 
and consecutive packings, the best, most practical, and least 
expensive of all. 

It is necessary, in order to obtain complete deposition, to 
maintain the liquid perfectly still during a sufficient time, 
that is to say, to prevent the liquid from starting to fer- 
ment. 

Low temperature would be a good means of resolving 
this 'question or problem, but would be rather costly. E. 
Thomas and myself studied a scheme applicable to a daily 
quantity of 500 hectolitres, and we arrived at the conclusion 



170 WINE-MAKING IN HOT CLIMATES. 

that the required result could only be obtained at an extra 
expense of 2 francs per hectolitre, evidently incompatible 
with the value of the product to be made. 

There is fortunately an excellent and cheap means of sus- 
pending the fermentation during the required time. This 
is by sulphuring. 

The gas produced by the combustion of sulphur (sulphur- 
ous anhydride, S0 2 ) is very soluble in water and must, 
and has the property of arresting the reproduction of the 
yeast and rendering it inactive during a certain time with- 
out killing it, if the amount used is not too great. 

It is the exact gauging of the sulphurous acid absorbed 
which is the important point in the application of the 
debourbage. 

We must use sufficient sulphurous acid for the deposition 
to be complete, and yet a small enough amount for the 
inactivity of the yeast to cease directly the separation, of 
the lees has taken place. 

Experiments have shown that an amount of sulphurous 
acid corresponding to O01 per litre of must does not greatly 
retard the commencement of fermentation. A quantity of 
O03 retards the fermentation for 10 or 12 hours. With 
O'Oo it is retarded for 18 to 24 hours, and with 0*075 it 
is retarded from 48 to 60 hours. With O'lO the fermentation 
only starts five or six days after treatment. We can, there- 
fore, retard at will the start of the fermentation by simply 
introducing into the must the above-mentioned quantities. 

It is not very easy to gauge the absorption of the exact 
quantity of sulphurous acid resulting from the combustion of 
sulphur. This is why we are often liable when using imperfect 
apparatus to sulphur too strongly, which retards the fermen- 
tation indefinitely, and therefore the selling of the wine, or 
not enough, in wliich case the fermentation starts before the 
debourbage is completed. One or other of these defects is 
frequently observed when the operation is simply performed 
in a previously sulphured cask. 

We studied some years ago the application of various 
definite compounds to replace sulphuring the alkaline sul- 
phites, the alkaline earthy sulphites capable of being decom- 
posed by the must, and yielding for a given weight, a constant 
quantity of sulphurous acid. The results were excellent, but 
it is difficult to obtain in commerce at reasonable cost, suffi- 
ciently pure chemicals to be used in vinification, and in 



VINDICATION OF WHITE WINE. 



171 



practice the homogeneous admixture of a small quantity of 
matter with large quantities of liquid is always difficult to 
realize. 

Sulphurous acid diffuses more easily in the must than 
the solid sulphites, therefore we have preferred to use it and 
to find practical means of charging the liquid with the 
desired quantity only. 

The application of sulphurous acid to the must is called 
mutage (numbing), a name originating from the effect it 
produces, rendering the must muet (numb). 

The machines used for this operation are called muteuses, 
mutoises, mutoirs. 

The mutage, in view of obtaining dry white wines, is only 
temporary, and requires much less sulphurous acid than in 
the case of the must being required to remain sweet, for 
making ultimately concentrated must, grape syrup, or ports. 

The ordinary muteuse Consists of a vessel in which the 
must travels in one direction, and air charged with sulphurous 
acid in the opposite direction. 

Such for instance is the muteuse of Coste-Floret (Fig. 47). 
The must arrives by the tube a, falling in a spray in the 
muteuse C, through the perforated plates A B, and absorbs 
during its passage the vapours generated by the stove E. 




. 47. - Coste-Floret's Muteuse. 



172 



WINE-MAKING IN HOT CLIMATES. 



The must itself forms a liquid joint in the bottom of the 
tub D, it is then taken by the suction tub b of the pump F, 
and pumped back by the tube c (b.e.). 

The muteuse of P. Paul shown in Fig. 48 is almost as 
simple. It consists of a box 1 metre 30 c.m. high and 
40 c.m. wide. The must arrives at the upper part and falls 
on oblique superposed partitions. It is therefore exposed 
on a large surface to contact with the vapours charged with 
sulphurous acid coming from the stove. 



ENTRANCE OF MUST TO BE TREATED 




Fig. 48. Paul's Muteuse 



VINDICATION OF WHITE WINE. 



173 



These two machines may insure the complete dissolution 
of the sulphurous acid furnished by them, but cannot be 
considered as capable of gauging- the absorption of the sul- 
phurous acid with precision, for it is very difficult, not to 
say impossible, to furnish them with exactly the required 
q uantity of sulphurous acid. 

The weight of sulphur burnt in a given time is a function 
of the speed of the current of air, and the speed for the same 
aperture of the valve varies greatly from one operation to 
another, even at different times during one operation. 

The sulphuring cylinders used at Villeroy by the Com- 
pagnie des Salins du Midi, which work in a similar way to 
the two muteuses described above, have the same defects. 
At their vineyards at Bosquet the Compagnie des Salins du 
Midi use a different apparatus allowing more exact measure- 
ment. 

The muteuse used at Bosquet consists of a sidero-cenient 
chamber d (Fig. 49) in which the necessary weight of 




EcKeYle 



Fig. 49. Bosquet's Muteuse. 



174 



WINE-MAKING IN HOT CLIMATES. 



sulphur is burnt (half the weight of the sulphurous acid 
required) in the shape of sulphured cloth suspended to the 
cloth carrier S, which can be raised or lowered. The cham- 
ber is then filled with must, and when the gas is absorbed 
the valve V is lifted and allows the must to flow into the 
debourbage tank below. 

With this apparatus fairly accurate measurement and 
absorption can be effected, but it is very complicated. 

With the exception of the Bosquet muteuse, which cannot 
be used in small cellars, the machines above described only 
give, an illusory measurement. 

Eugene Thomas attempted to substitute an apparatus 
allowing the measurement and absorption, by direct sul- 
phuring of the vat to be filled with must, the idea being to 
prevent the air which is driven out when filling the vat 
from carrying away with it any sulphurous acid. 




N 







B 



A 

Fig. 51. 



Fig. 50. 

This was realized simply by using 
a kind of funnel, forming a liquid 
joint by means of two systems of 
tubes, one for the entry of the must, 
the other for the air exit. The dia- 
grams (Figs. 50 and 51) give an 
idea of the arrangement of the 
machine. 

It works fairly well, but not per- 
fectly. The washing of the gas is 
done rather spasmodically, which 
leads us to fear it operates imper- 
fectly. For this reason we tried, in 
conjunction with Thomas, to improve 
the apparatus. 



VILIFICATION OF WHITE WINE. 



175 



The modified apparatus consists of three parts, capable 
of being dismounted and fitting together (see Fig. 52).* It 
consists of 

A. A cylindrical vessel of the same diameter as the 

manhole ; the cylinder carries at its top a hori- 
zontal flange resting on the edge of the man- 
hole, to which it is luted with plaster. The 
annular part at the bottom has a space of 8 to 10 
centimetres between the concentric rings. 

B. A cylindrical cover B, the sides of which drop in 

the annular space, about 14 to 16 centimetres 
high. 




Fig. 52. Thomas and Roos Mutoir. 

The vertical walls of this cover are cut in embrasures at 
the lower edge, to allow the passage of the must, and rise 
2 centimetres above the horizontal part, the centre of which 
carries an escape chimney 3 centimetres in height. 

A second lid or cover C, 4 centimetres in height, with 
walls perforated with numerous small holes to divide the 
gases and facilitate the washing. This cover is provided at 
the upper part with a handle, and inside with a hook E to 
suspend the sulphur cloths from. This cover extends over 
the walls of the first cover. The diameter of the cylinder C, 

* This apparatus is constr acted by Vidal. 



176 



WINE-MAKING IN HOT CLIMATES. 



should be 1 centimetre greater than that of the cylinder D, 
and 1 or 2 centimetres less than that of the cylinder B. 

The total depth of the apparatus may vary. We have 
adopted 50 centimetres, which is sufficient to prevent the 
must from splashing out, even during rapid filling. 

The following is the method of operating : The appara- 
tus is placed in the manhole and the upper flange carefully 
luted. It is then filled with must till it overflows inside 
over D. The required quantity of sulphur is then suspended 
to the hook E in the shape of sulphured cloth, or sticks, 
placed in a suitable recipient. The sulphur is lighted and 
introduced into the vat through D, the cone C resting over 
the cylinder D then forming a liquid joint during the com- 
bustion of the sulphur. The end of the combustion is shown 
by the cessation of bubbling. The sulphur is then removed, 
and the pieces B and C placed in position. It only remains 
then to start filling with must. 

The liquid falls over the cover C, and partly passes 
through the horizontal perforated parts, filling the liquid 
joint between D and C. The excess flows over the sides 
of the cover C, forming a thin sheet conducing to effective 
washing. It passes into D through the embrasures at the 
base of B, and falls into the vat in a thin layer, offering a 
large surface for the absorption of the gases. 

Whatever be the quantity of 
sulphur burnt in the vat, the absorp- 
tion of the sulphurous acid is com- 
plete, for no smell can be detected 
above the apparatus. The same 
arrangement may be used for bumj- 
holes. In this" case the piece A is 
modified, as shown in Fig. 53. It 
is prolonged by a conical tube, in 
the side of which a small tube is 
placed for the exit of the gas evolved 
during the filling. 

It goes without saying that in this 
case, unless the cask be small, the 
introduction and combustion of the 
sulphur must be done through the 
bottom manhole. 




Fig. 53. Arrangement for 
Bung-hole. 



VILIFICATION OF WHITE WINE. 177 

Through the fact that the sulphurous fumes contained in 
the vessel are completely absorbed by the must, this appara- 
tus may be considered as a measuring and absorption 
apparatus. 

We know that when sulphur is burnt it produces double 
of its weight in gas ; if, therefore, we wish to charge the 
must with TI grammes of sulphurous acid per hectolitre we 

must burn before filling-- grammes of sulphur, the air con- 
tained in the vessel is more than sufficient to produce the 
required quantity of sulphurous acid. 

Under ordinary conditions of temperature air contains at 
least 20 grammes per hectolitre of oxygen, which can burn 
20 grammes of sulphur to form 40 grammes of sulphurous 
anhydride. This quantity is four times greater than that 
required for perfect debourbage, if completely absorbed by 
the liquid. 

But during the combustion of the sulphur the gas in the 
vessel increases in volume through the heat developed by 
the combustion. It is, therefore, necessary, in order to 
avoid loss and preserve the exactitude of the measurement 
and absorption, that the vessel be closed in such a way 
that the gas can only escape after having yielded the 
sulphurous acid to the must. 

At M. Thomas' cellar the arrangement of the vats facili- 
tates the introduction of a cast-iron pot filled with sulphur, 
which is suspended to the top of the vat at a certain distance 
from the manhole, in such a position that the must does not 
touch it. 

The sulphur is lighted, the apparatus immediately placed 
in position, luted with plaster, and filled with must, taking 
care to fill up two or three times till the combustion 
is over. This is easily noticed by the cessation of bubbling, 
the filling of the vat then begins. 

When it is necessary to deal with a large wooden cask we 
begin by fixing the apparatus. The sulphur is introduced 
and lighted at the bottom opening, when the combustion is 
finished and the equilibrium established for a column of 
5 millimetres of water, the height of the liquid joint, it is 
possible without difficulty to open the bottom manhole and 

10649. M 



178 WINE-MAKING IN HOT CLIMATES. 

remove the sulphur recipient, and close the opening. If 
this operation is done quickly the loss of gas is negligible. 

At this moment the difference of pressure between the gas 
in the vat, and the atmosphere, is sufficiently small to be out 
of consideration. 

To avoid luting with plaster, F. Crassous, Director of the 
Compagnie des Salins du Midi, proposed placing under the 
flange of the apparatus an india-rubber tube, which, when 
compressed by the weight of the apparatus, will insure an 
air-tight joint. 

We think that the air chamber of the pneumatic bicycle 
tire would answer perfectly for this purpose. It could be 
inflated to the required amount, and the thin rubber they 
are made of would insure the exact adaptation of the tube 
to all the irregularities of the wood o.r masonry. We have 
not yet seen this idea applied in practice, and, therefore, can 
offer no positive advice about it ; but it would certainly 
facilitate greatly the handling of the apparatus.* 

To finish the various processes of the application of 
sulphur, we will describe a method called pump sulphuring. 
This idea is due to M. Senac, Viticulturist of the Departe- 
ment of the Gard, which while allowing an exact measure- 
ment dispenses with the use of special apparatus. 

The principle consists in forcing into the must by means 
of a pump all the gas produced by the combustion of a 
given weight of sulphur ; in this particular case the pump 
not only serves to force the sulphurous fumes into the must, 
but also acts as a regulator of the introduction of air, in 
such a way that the combustion of the sulphur is propor- 
tional to the rate of pumping. 

A 120-gallon cask with the head knocked out makes an 
excellent sulphur stove, by placing on the ground an iron 
pot containing the lighted sulphur, and covering the pot with 
the cask, the lower edge of which is slightly raised to allow 
the passage of air. The suction tube of the pump is fixed to 
the bung-hole, the forcing tube being connected with the vat 

* It would be, however, necessary for the rubber tube not to be placed in 
contact with the iron hoops, and to fit on the wood only. This case is rather 
exceptional, as the centre hoops pass very close to the top manhole. 



VILIFICATION OF WHITE WINE. 



179 



(Fig. 54), the gas resulting from the combustion forced into the 
vat is completely absorbed by the must, during the operation 
no sulphurous smell can be detected around the stove, nor at 




Fig. 54. Pump Sulphuring. 

the top hole of the vat. This is an evident proof of the com- 
plete absorption of the gas and of a rigorous measurement, for 
it suffices to weigh the sulphur to be burnt. To apply this 
method to the debourbage of white wine, we begin to force the 
gas when the vat contains a few hectolitres of must, the filling 
up and the sulphuring continuing simultaneously, the latter 
requiring less time than the former. . The pump is stopped 
as soon as the vat is sufficiently full, and we can then as an 
extra precaution give a few strokes of the pump to complete 
the stirring of the mass, and insure the perfect mixing of the 
sulphured must with that added subsequently. 



FERMENTATION. 

When, after sufficient lapse of time the previously opaque 
must has become opalescent, the moment has arrived to 
separate it from the deposit, and to remove it to the vat where 
fermentation is to take place. 

During this operation the must should be very energetically 
aerated to allow the last traces of sulphurous acid to be trans- 
formed by the oxygen of the air, and to enable the oxygen to 

M 2 



180 WINE-MAKING IN HOT CLIMATES. 

remain in solution in the must, so as to assist the multiplica- 
tion of the yeast. When placed in the fermenting vat the 
white must may be left to itself without any danger, through 
the debourbage it has been submitted to, the fermentation 
starts slowly, and is less active than in the case of red wines. 

The time necessary for the complete transformation of the 
sugar into alcohol is much longer, and one of the consequences 
of this slow transformation is a much smaller elevation of 
temperature. 

It is only necessary in rare cases to refrigerate white wines 
after debourbage, even in the hottest regions of Algeria, for 
independently of the retarding causes we have already ex- 
plained, the debourbage has also an advantage in allowing the 
must to cool down during the two or three days rest in the 
vat, which is always below the outside temperature. 

As soon as the fermentation is finished, which is shown by 
the cessation of the evolution of gases, the white wines should 
be racked and placed in slightly sulphured casks until per- 
fectlv cleared. 



MANUFACTURE OF WHITE WINE FROM RED GRAPES. 

The only difference resides in the precautions taken to 
insure the non-dissolution of the colour, it is essential : 

First To avoid incipient fermentation before the separa- 
tion of the must, carefully avoiding squashing the grapes 
before they are brought to the crusher, and proceeding rapidly 
with the operations of crushing and pressing. 

Second To crush the grapes without disintegrating the 
skins, so as not to liberate the colouring matter contained in 
their cells. 

Third To destroy as completely as possible the colouring 
matter which may have been dissolved in the must, and 
separate by debourbage the fragments of coloured skin in 
suspension. 

Therefore, to make white wine from red grapes we must 
lightly crush the grapes, separate the juice by drainage, and 
then by pressing, reserving the juice to be fermented to red 
wine as soon as it becomes too strongly coloured, then pro- 
ceed to the debourbage, and finally leave to ferment. 

This is the process most generally used, but always fur- 
nishes wine too pink to be called white, and not enough 
coloured to be called red. 



VINDICATION OF WHITE WINE. 181 

It is necessary after fermentation to sulphur strongly 
several times, to reduce the colour, and it is not possible to 
make really white wine without altering the character of the 
taste through the frequent sulphuring. 

To obtain fine white wine from red cepages, such as Aramon 
for instance, the first condition is not to expect too much. 

We think it is preferable, when it is desired to make 100 
hectolitres of wine from red grapes, to use for the purpose, a 
quantity of grapes sufficient to make 150 or 200 hectolitres, 
the 50 or 100 hectolitres remaining being made into red wine. 

By working in this way we obtain white wine as good as 
it is possible to make it, considering its origin, and red 
wine of excellent quality, if we slightly modify in the 
latter case the method of vinification described in the pre- 
ceding chapter. We are of opinion that white wine should 
not alone be made from red grapes, but both, so that we 
cannot exclusively study the vinification of white wine here, 
but rather mixed red and white vinification. 

It is evident that, if we take from Aramon vintage a more 
or less greater proportion of the must it can furnish, the 
proportion of marc and juice in the remaining part will be 
very different to what it would have been normally. We 
should, therefore, apply to the remaining part a method only 
allowing in a lesser degree, the solution of the substances 
contained in the marc. By limiting the extraction to 40 per 
cent, we obtain from Aramon a colourless juice which may 
furnish a good type of white wine made from red grapes. 
There is no special rule for the vinification of this must, it is 
submitted to exactly the same operations as in the vinification 
of white grapes above described, and the same quantity of 
sulphur used for the debourbage. 

In the vinification as red wine of the remainder of the 
juice, not used for making white wine, stemming plays an 
important part. We have seen already that the unfavorable 
action of the stalks is due to a greater extent to the physical 
part played by them in facilitating the penetration of the 
marc by the must, than to the substances yielded by them to 
the wine. 

The solvent power of the must may be considered constant, 
but the quantity of soluble matters it extracts from the 
marc depends on the surface in contact and the time the con- 
tact lasts. It is evident that the surfaces in contact will be 
increased in this case, it is therefore necessary to render the 



182 



WINE-MAKING IN HOT CLIMATES. 



marc as impenetrable as 
possible, and to shorten by 
half the period of macera- 
tion. Blaquiere's machine 
(Fig. 55), constructed for 
the manufacture of white 
? wine from red grapes, 
; crushes, drains, and stems 
J at the same time. It does 
good work, but in our 
I opinion the proportion of 
I must separated is too great . 
| Probably, by diminishing 
the length of the drainer so 
| as to obtain only 40 per 
cent of white juice, the 
| results would be better. 

Fermentation starts 
g very rapidly in marcs in- 
J completely drained for 
| white wines, the tempera- 
g ture rises quickly and 
| reaches on the second <l;iy 
jf the limit above which the 
" yeast works imperfectly. 
This elevation of tem- 
g perature is one of the prin- 
cipal causes of the failures 
in the manufacture of these 
wines, the inherent defects 
of high temperatures are 
still increased in this case 
by the greater quantity of 

marc in contact with the must. We cannot therefore 
expect to obtain red wine with fine colour, and clean taste, 
if we do not maintain the vat between the limits of tempera- 
ture shown as most favorable, i.e., 28 to 30 C. 

This method of mixed vinification the only one giving 
good bright wines up to the present time might be replaced 
with advantage by that which L. Sernichon,* Director of the 
(Enological Station of the Aude, studied and perfected last 
vintage. 

* Li. JSemichon. Revue de Viticulture, 1897. 




VINDICATION OF WHITE WINE. 183 

The experiments of Semichon on this subject possess an 
undeniable importance for the South of France. We will 
quote in extenso this communication, trusting- it will be 
applied in practice by the viticulturists of the South. 



NEW METHOD FOR THE VINDICATION OF WHITE WINES. 

" The consumption of white wines has greatly increased 
in latter years, raising as a consequence the market value 
of this product. For this reason viticulturists have tried 
to render practical the manufacture of white wine from 
red grapes ; in this direction the efforts of all tended to 
obtain the greatest possible yield of pink must from a 
given quantity of vintage, but have invariably depended on 
the old process of manufacture based on decolouration 
with sulphurous fumes. 

This process, however, is very defective, the enormous 
difference in the bouquet and flavour between pink and 
white wines made from the same grapes, already shows 
that the sulphurous acid deprives the wine of many of its 
qualities, and leaves a disagreeable taste. It acts as a 
reducing agent, and decomposes the colouring matters by 
removal of oxygen. When the wine comes in contact with 
air through the various manipulations it is submitted to, it 
absorbs oxygen, the colouring matter re-appears and the 
wine becomes pink.* 

" If, therefore, the white wine made in this way is truly 
white and neutral in taste, we may assert that it is in a state 
of unstable equilibrium, between two situations equally 
defective, the excess of sulphurous acid which gives it a bad 
taste, and its inherent defect which renders it pink. 

" These two defects are serious obstacles in commerce, and 
of such importance that many merchants have given up 
buying or making white wine from red grapes ; we are 
almost obliged now to obtain good table wine to have 
recourse to wines made from white grapes. 

* As far as the unfavorable action of the sulphurous acid is concerned, we 
do not share the opinion of our colleague, for here, as anywhere else, it is a 
question of exact measurement of the sulphur used. We have noticed that 
the sulphurous acid produced by the combustion of sulphured cloth remains 
more evident in the wine than that produced by the combustion of pure sulphur. 
This is caused, no doubt, by the formation of sulphuretted bodies, due to the 
combustion of the organic matter of the cloth. L.R. 



184 WINE-MAKING IN HOT CLIMATES. 

" In 1895, Martinand* studied a more rational method for 
the, decoloration of must, which seems destined to have, 
in practice, a great future. It consists in oxidizing the 
colouring matter and precipitating it, instead of simply 
masking it by reduction. 

" The method of vinification he advocates includes five 
different phases : 

1. Extraction of the must without taking the colour 

into account. 

2. Cooling below 15 C. to prevent fermentation 

starting. 

3. Aeration of the must and oxidation to precipitate the 

colouring matter. 

4. Filtering under pressure. 

5. Fermentation. 

" This method presents, in practice, many difficulties for 
instance, the refrigeration to below 15 C., which requires 
special machines, and is difficult to apply on a large scale: 
and the filtration under pressure, which is tedious and 
delicate, requiring expensive apparatus. 

" We have been able to modify this method, so as to 
render it simpler and more advantageous than the sulphur- 
ous acid method. It suffices to dispense with refrigeration, 
and proceed to aerate rapidly by causing the must to fall in 
a shower in contact with the air, immediately after crushing 
or pressing. 

" The colour changes to brown, through the oxidation of 
the colouring matter, which remains suspended in the 
liquid. 

" The essential point is that the oxidation be sufficient 
for the colour to remain insoluble, in the mixture of water, 
alcohol, and acids, constituting the made wine ; the fermen- 
tation proceeds in the usual way, and when completed, the 
particles in suspension subside slowly. We may, however, 
increase the rate of subsidence by a slight fining, for the 
oxidized colouring matter plays the part of tannin. 

" It is indispensable in Martinand's method to separate 
the colouring matter before any formation of alcohol, how- 
ever slight, and that is why he advised the refrigeration of 
the musts so as to retard the fermentation, and to aerate 
and filter before it started. 

* Revue de Viticulture, vol. iv., 1895, and Comptes rendus de I' Academic des 
Sciences, 1895. 



VINDICATION OF WHITE WINE. 185 

" Experiments showed us that this is not indispensable, 
and that it is possible to aerate sufficiently before the pro- 
duction of alcohol be detectable. 

" And, further, the separation of the oxidized colouring 
matter is useless. 

" To ascertain the value of this method, we studied it 
under most favorable conditions, and made the following 
experiments at the Chateau clu Pech, belonging to Mrs. de 
Riviere, with the assistance of the manager, Mr. Ritouret. 

"On the 4th September, 1896, we started to fill, in the 
morning, a 300 hectolitre vat with Aramon vintage. After 
several hours, the vat being half full, we drew must by the 
bottom opening, and divided it into three casks. 

"No. 1. A 120-gallon cask, with the head knocked out, 
through the contents of which air was forced for one hour. 

"No. 2. A 120-gallon cask, strongly sulphured, to make 
wine by the old process. 

u No. 3. A 120-gallon cask, in which the wine was left to 
ferment naturally, to make pink wine. 

"The must drawn from the vat had a temperature of 
18 C, and was decidedly pink in colour. 

" The must, No. 1, after an hour's aeration, became brown 
coloured, the oxidized colouring matter remained in suspen- 
sion in the state of fine particles, which pass through any 
filter ; the next day, 5th of September, it was again aerated 
for one hour, the brown turbid must was then placed in a 
new cask and left to ferment. 

" Ten days after No. 1 was still slightly fermenting, turbid, 
but white with slightly yellowish tint ; it was racked, the 
colouring matter subsided gradually, and in February the 
liquid was of a bright yellow colour with a very slight 
turbidity. 

" No. 2 presented the maximum of decoloration and 
limpidity on the evening of the filling up ; ten days after it had 
not started to ferment. By error the sulphur had been used 
in excess, and we were obliged, in order to make the fer- 
mentation start, to rack it several times in contact with air ; 
during this operation the sulphurous anhydride gave by 
oxidation sulphuric acid, which conduced to the re-appear- 
ance of the colouring matter ; six weeks after the must was in 
tumultuous fermentation, and the colour re-appeared; now 



186 WINE-MAKING IN HOT CLIMATES. 

in February it still contains unfermented sugar, and is the 
most strongly coloured of the three. 

" No. 3 was decidedly pink, and still slightly fermenting 
ten days after ; ten weeks after it was still pink, bright and 
dry, and retained these characters. 

" The wine made by the aeration process only presents the 
difficulty of clarification, and we made several experiments 
on this subject. 

" First The filtration is infinitely easier and more rapid, 
as might be foreseen, with wine than with must. 

Second The addition of a small quantity of salt, by increas- 
ing the density of the particles in suspension, favours their 
subsidence ; but we do not advocate this method, as it affects 
the taste of the wine. 

" Third A slight fining gives a still better result ; with 10 
grammes of isinglass per hectolitre we obtained a bright 
wine of fine yellowish colour. 

" If a few drops of sulphuric or nitric acid be added to the 
wine before fining, it becomes pink, the colouring matter in 
suspension being dissolved by the acid ; prolonged action of 
air never has this result. If the acid is added after fining, 
the wine retains its yellowish colour, whatever may be the 
quantity of acid added. 

" It is, therefore, certain that it is the colouring matter in 
suspension which renders the wine turbid, and that it plays 
towards the finings the part of tannin, that the bright wine 
fined or filtered will never become pink again, as wine made 
by the sulphurous acid process does, for the colouring matter, 
instead of being simply masked, is completely separated. 

a What degree of aeration is necessary and sufficient ? 

" We determined the influence of prolonged aeration, and 
obtained the same results as Martinand. We will now show 
that the aeration of the must in No. 1 was excessive. The fol- 
lowing are the results of comparisons of the musts of three 
wines made in the cellar, taken the evening of the filling of 
the vat, and left in glass flasks to finish fermenting naturally, 
with five samples of the same must taken the same day from 
the bottom of the vat and submitted to aeration, varying in 
duration. The aeration was effected by means of a bellows 
connected with a glass tube, terminated in a finely-drawn- 
out point. These samples were afterwards left to ferment 
naturally. 



VILIFICATION OF WHITE WINE. 



187 



" With regard to their colour and classification, they may 
be placed as follows : 



Description of Sample. 


After One Month. 


After Two Months. 


Wine from No. 2. sul- 


Pink, in conseauence of 


Pink, in conseouenof 



phured 

Duplicate, not aerated 
Aerated one -quarter of 

an hour 
Wine from No. 3, pink* 

Aerated for half -an-hour 

Aerated for three-quar- 
ters of an hour 

Aerated one hour 

Wine from No. 1 (aerated 
for one hour by pump- 
ing in a cask) 



excess of sulphuring 

Pink, clear ... 
Colourless, very turbid 

Colourless, turbid 

Slightly yellow, turbid 
Slightly more yellow, a 

little less turbid 
Also as above 
Yellowish, turbid 



of excess of sul- 
phuring 

Pink, clear 

Colourless, very turbid 

Colourless, slightly 

turbid 

Flask broken 
Slightly more yellow, 

almost clear 
Also as above 
Also as above 



" These comparisons show that the yellow coloration is 
due to a more complete oxidation of the must, and the 
clarification of the wine seems to be more rapid as the 
aeration is prolonged. 

" The aeration made in the cellar on the evening of the 
first day was greater than that made in the flask in the 
laboratory ; by accident the flask No. 3 was broken, and the 
must through this absorbed more air. This was sufficient 
to discharge its colour. 

" It would appear, therefore, that in the first experiment 
in the cellar the aeration was excessive, and that white 
wines may be made from Aramon by slightly aerating the 
must with the pump, or by letting it fall in a shower 
through a perforated plate. 

" It is our intention to try this on a large scale next 
vintage. 

"It is easy to ascertain if the aeration has been suffi- 
cient to discharge all pink colour. The following process, 
which we adopted in the laboratory, should be used : 

" A few cubic centimetres of the must is passed through 
filtering paper ; when the liquid is nearly all through, 
a few cubic centimetres of an aqueous solution 
containing 10 per cent, of alcohol and 1 per cent. 

* The flask broke, and the wine remained in contact with air during one hour. 
It was then decanted. These operations were sufficient to render it colourless. 



188 WINE-MAKING IN HOT CLIMATES. 

tartaric acid is poured into the funnel. If the 
liquid passing through the filter is pink, the aera- 
tion is insufficient, and the pumping of air through 
the vessel must be continued. The solution used 
has a percentage of alcohol and acid equal to or 
greater than the wine to be made, so if the colour 
is not dissolved in this solution it follows that 
it will not be dissolved in the wine. 

" What is the value of the wines made by this new 
method ? They do not possess the defects of wines made 
by the use of sulphurous acid, and after comparing three 
wines made at Pech, the following results were obtained : 
"With regard to flavour, the aerated wine (No. 1) is green, 
nerveux, and fruity ; No. 2 still contains sugar, which pre- 
vents a fair comparison with the two others. It tastes of 
sulphur, and has no fruity flavour ; No. 3 is pink, has as 
much fruity flavour as No. 1, but is not so nerveux. 

" It might be thought that aeration would alter the con- 
stitution of the wine. We point out, however, that the 
must does not contain any volatile matters liable to be dis- 
sipated by the current of air. Here is the result given by 
analysis of these three wines : 

No. 1. No. 2. No. 3. 

Alcohol, per cent,, in vol. ... 10-1 ... 8-0 ... 10*1 

Total acidity, per litre ... 5-76 ... 6-77 ... 5-34 
Dry extract ... ... 15-95 ... 57-30 ... 16-90 

Ash ... ... ... 1-75 ... 2-65 .... 2'30 

Reducing sugar ... ... ... 37-39 ... 

" These results show that the alcoholic strength is the 
same for the white and pink wines, whatever process of 
manufacture is used. The 37 grammes of sugar in No. 2, 
which had not yet fermented, would give about 2 degrees of 
alcohol, which would bring the figure for No. 2 to the same 
as the others. 

" The total acidity is slightly higher in the aerated wines, 
but the difference is negligible. The high acidity in No. 2 
is due to the sulphurous anhydride transformed into sul- 
phuric acid.* 

u The dry extract of No. 1 is less than that of the pink 
wine No. 3. This is due to the precipitation of the colouring 

* The difference is such that it does not seem attributable to the sulphurous 
anhydride only ; for, if this were so, it would have required such a heavy dose 
that fermentation would have been rendered impossible. L. R. 



VINDICATION OF WHITE WINE. 189 

matter through oxidation. On the whole, the composition 
of wine made by this new process is practically the same 
as that of the corresponding pink wines. 

" In conclusion, it is to be hoped that this new method of 
manufacturing white wines will prove advantageous to both 
wine manufacturers and merchants. 

" 1st. In vineyards where Aramon is in excess, and where 
the wine obtained from it is deficient in alcohol and colour, it 
will be possible to transform a portion of the vintage into 
white wine, and thus get a better return. On the other 
hand, the Aramon being in smaller proportion in the rest of 
the vintage the wine will gain in colour. In years of 
abundant vintage, where the grapes are large and give 
lighter wine, deficient in dry extract and colour, a part of 
the must may be drained from the bottom of the fermenting 
vat and made into white wine. The remainder, fermenting 
with a greater proportion of marc, will consequently be 
richer in dry extract and colour. 

" 2nd. The total extraction of the must by pressing, as 
advocated by Martinand, will dispense with the costly and 
complicated plant necessary to extract the limited possible 
quantity of slightly coloured must from red grapes. 

" 3rd. It is probable that this method will be applicable 
to other red cepages, such as Carignan, Grenache, and 
Cinsaut, &c., producing wines of higher value ; this will be 
tried during next vintage. 

" 4th. The trade will obtain white wines of clean taste, 
and good keeping qualities, able to be used for the same 
purposes as wines from white grapes, and not presenting the 
defects of wines made by the use of sulphurous acid." 



190 WINE-MAKING IN HOT CLIMATES. 



CHAPTER VI. 



UTILIZATION OF BY-PRODUCTS. 

The by-products of wine manufacture are the marc from 
the press, the lees, and the tartar. Each of these by-pro- 
ducts has a definite value, arid bears a certain proportion to 
the value of the total vintage. 



Marc. 

It is necessary to distinguish between marc from white 
and red wine. 

The latter is usually utilized in the South of France for 
the production of piquettes, or the manufacture of spirit ; the 
alcohol may be obtained by direct distillation or by the 
distillation of the piquettes. 

Direct distillation is only possible in the case of red marc, 
and is not usually done by the vineyard proprietor, but by 
distillers working by contract. 

The alcohol obtained from the distillation of marc is very 
much in request in the East of France for immediate con- 
sumption, but is not thought much of in the South. Its 
value is always less than that of wine-spirit (brandy) ; for 
this reason we do not advocate direct distillation, as distilla- 
tion of piquettes gives a much finer product, and are of 
opinion that in our region the marc should only be used for 
the manufacture of good piquettes for immediate consump- 
tion or distillation, as the case may be. 

The object in manufacturing piquette is to obtain in as 
small a volume as possible the total alcohol remaining in 
the marc. 



UTILIZATION OF BY-PRODUCTS. 191 

Whatever may be thought about it, however well drained 
the marc may be, it always contains a large proportion of 
wine. 

Analyses made by Boussingault, Barral, Mares, Degrnlly, 
Bouffard, &c., show that the pressed and drained marc 
generally contains 70 per cent, of liquid, or, to be more 
correct, of volatile matters; in other words, this means that 
100 kilos, of drained marc contain 70 litres of wine. 

With the new process this figure is decreased, but never 
falls below 55 to 60 per cent. 

It is therefore absolutely necessary, if we do not extract 
this wine from the marc, to utilize the alcoholic contents 
in some way or other ; the only really practical means is in 
the manufacture of piquette. 

There are actually three methods of doing this, of very 
unequal practical value, as shown by Prof. Bouffard* : 

1st. Maceration ; 2nd. Sprinkling, or lixiviation ; 3rd. 
Methodical washing by displacement. 

For these three methods the marc must be disintegrated 
and rammed into a suitable vessel. 

To apply the maceration method, a certain quantity of 
water must be added to the rammed marc, and left in contact 
with it during a few hours ; the water is then racked off, 
and replaced by a fresh quantity, and so on till the racked- 
off water does not extract any more wine. 

This is a very defective method, furnishing very weak 
piquettes ; it does not answer the desideratum contained in 
the definition given, which is to accumulate in the smallest 
possible volume the integral quantity of alcohol contained 
in the marc. 

The second process, sprinkling or lixiviation of the marc, 
may be either intermittent or continuous, and is widely 
used in the South of France. 

A vessel filled with rammed marc is provided with an 
open tap at the bottom, and the upper surface of the 
marc is sprinkled by means of different devices (like lawn 



* Progres Agricole et Viticole. 



192 



WINE-MAKING IN HOT CLIMATES. 



sprinklers) Fig. 55, amongst which we may note the Bourdil 
hydraulic sprinkler, and Paul's piquette sprayer. 




Fig. 55. Hydraulic Sprinkler. 

The water descending through the mass diffuses with the 
wine contained in it, carrying away the wine by the tap, 
yielding piquettes which become weaker as the operation 
is continued. 

It is necessary in using this method to operate with 
great care, stopping the operation when the piquette falls 
below 2 per cent, of alcohol. On -mixing all the fractions 
a mixture of half the alcoholic strength of the original 
wine should result. 



UTILIZATION OF BY-PRODUCTS. 193 

There is in th$ lixiviation method a serious defect. This 
is the drawing downwards of an alcoholic liquid of less 
density than water, which has naturally a greater tendency 
to rise up. This drawing down is only obtained by estab- 
lishing a rapid current of water, which is done at the 
expense of the alcoholic strength. 

The third system methodical washing by displacement 
is easily done with suitable vessels, and is free from all the 
above criticisms. It exhausts the marc satisfactorily, and 
yields from the commencement till almost complete ex- 
haustion, piquettes nearly as strong as the original wine, or, 
at any rate, by mixing all the fractions a liquid of average 
alcoholic strength very near that of the wine results. Figure 
56 (p. 194) shows diagrammatical ly the arrangement to be 
adopted. It is easy to fix this up with any vessels or casks, 
varying in size according to the quantity of vintage to be 
treated. 

In methodical washing done by displacement we aim more 
at forcing the wine upwards than at obtaining diffusion ; 
theoretically the water acts only as a piston, adapting itself 
to the irregularities of surface, filling all the cavities, and 
pushing out the liquid, wetting those surfaces or imprisoned 
in the cavities. 

In practice this does not happen, however, as diffusion 
takes place ; but, as we have already pointed out in speak- 
ing of the non-pressed marc, the diffusion zone only forms a 
layer of a certain thickness, so that we can almost always 
obtain pure wine ' at the end of the system. The essential 
point in methodical displacement (per ascensum) that is to 
say, by means of a rising instead of a descending column of 
water is to carefully regulate the rate of flow of the water. 
The ascensional speed should always be slow enough not to 
drown the marc, as this would simply place the process on 
the same level -as that of maceration or lixiviation. 

One of the conditions for success depends on the arrange- 
ment of the marc, which must be well disintegrated and 
evenly rammed. 

The vats should be provided with false bottoms, under 
which the water enters. The first vat overflows into the 
second, the second into the third, and so on. Four vessels 
are sufficiently efficacious. 

It is easy to explain the good results given by this method. 

10649. N 



194 



WINE-MAKING IN HOT CLIMATES. 



CO 



D 



UTILIZATION OF BY-PRODUCTS. 195 

Instead of a continuous operation, let us consider the case 
of an intermittent one, and the four vessels full of marc, from 
wine giving- 10 per cent, of alcohol. 

If the marc contained 60 per cent, of wine, 100 kilos, 
would contain 60 litres. Let us wet or submerge the marc 
with as many times 60 litres of water as there are 100 
kilos, of marc, and let it remain in contact. The diffusion 
takes place progressively, and, after a few hours, the 
vessel will contain for each 100 kilos, of marc 120 litres 
of liquid, the alcoholic strength of which will be half that 
of the original wine that is to say, 5 per cent. 

Let us now pass 60 litres of this liquid into the second 
vessel, also charged with marc containing 60 per cent, of 
wine ; after contact the mixture will have an alcoholic 
strength not lying between 10 and 0, but between 10 and 5 
that is to say, 7*5 per cent. 

Through the same procedure the third vessel charged 
with the liquid from the second will yield a piquette con- 
taining 8*75 per cent, of alcohol, and the fourth vessel 
charged with the liquid from the third will yield a piquette 
containing 9' 5 per cent. 

In a continuous operation the results are the same, or 
even better, for in a well-performed operation the liquid over- 
flowing from the first vessel into the second would already 
have an alcoholic strength above half that of the wine. 

In practice it is usual to stop washing the first vat when 
the liquid overflowing into the second has become poor in 
colour, and contains 1J to 1 per cent, of alcohol. In a 
successful operation the alcoholic strength falls rapidly. 
In a few minutes to one hour, according to the size of the 
vessel, the piquettes fall from 5 or 6 per cent, to 1 per cent. 
The water delivery should then be directed into the second 
vessel, the first being disconnected, emptied, and recharged 
with fresh marc, and connected to the opposite end of the 
system. 

It is, therefore, the methodical washing by displacement 
which seems to be most recommendable. We think it is the 
only method enabling rich piquettes to be obtained, of good 
keeping qualities, and also more easily and economically 
distilled. The alcohol obtained by distillation of well and 
soundly made piquettes has none of the defects of that 
extracted from the marc direct ; on the contrary, it possesses 
all the qualities which give wine-spirit a higher value. 



196 WINE-MAKIXG IN HOT CLIMATES. 

With regard to niarc from white wines, we must operate 
differently ; the problem here is reversed, for it is must, a 
liquid denser than water, that has to be extracted from the 
marc. 

Sometimes the white marc is left to ferment as it comes 
out of the press, and is later on converted into piquette, or 
distilled directly ; in both cases the result is very unsatis- 
factory, the fermentations taking place in pressed marc are 
always bad. The piquettes obtained from it are execrable 
and cannot be used for consumption, and the alcohol result- 
ing from their distillation does not repay the cost of 
production. 

The direct distillation of fermented white marc does not 
give better results. 

It is therefore necessary to treat the marc directly it 
leaves the press, to accumulate its sugar contents in water, 
and leave the saccharine solution to ferment, distilling it 
ultimately. 

The operations are performed in the same vessels as in 
the case of red marc, but in this instance we must use the 
lixiviation method, spraying over the second vessel the 
liquid gathered from the first, and so on. 

The leaching of the first vat is stopped when the liquid 
leaving it does not taste sweet. 

It is imperative in this operation to act quickly, to avoid, 
as far as possible, too active fermentation in the mass. 

As in the case of the treatment of red marc, the exhausted 
vessels are emptied, charged again, and placed at the other 
end of the system, while the second vessel becomes in its 
turn the first. The marc exhausted in the manufacture of 
piquette cannot yield anything more, but constitutes a good 
food for cattle, and if not used for that purpose may be used 
for manure. 

The preservation of washed marc for cattle food is more 
difficult than that of marc simply taken from the press, for, 
in the latter case, the wine or alcohol it contains protects it 
in a certain measure against alterations. 

It is necessary to take more care for the preservation of 
washed marc. 

The best method consists in stratifying the marc with 
salt in the proportion of 2 to 3 per cent, in vats or silos 
compressed tightly, which is easily done by placing a lid 
weighted with full hogsheads on top, at the rate of 500 



UTILIZATION OF BY-PKODUCTS. 197 

kilos, per square metre of surface. Under this small but 
continuous pressure the height diminishes considerably, 
and a great quantity of water escapes from the bottom of 
the vat or silo, the mass becomes very compact, and only 
the first few centimetres become affected by fungi. 

The marc from white wines may be treated in a similar 
manner, the residues from the distillation of pique tte con- 
tain a great quantity of tartar, but we cannot think of 
extracting it. It has, however, a fertilizing value on account 
of the potash it contains, and should be thrown in the 
manure pit. It is indispensable to mix it with manure, for 
in the state it leaves the still it cannot be applied directly 
to the soil, as it would destroy the roots and kill the plants 
with which it came in contact, unless used in small quantity 
or treated with lime to first neutralize the acids. 

The direct distillation of marc assures the recovery of 
an important part of the tartar it contains, but this slight 
advantage does not counterbalance the other imperfections 
of the method. 

Lees and Tartar. The lees deposited by both red and 
white wines, during the time which elapses between the 
fermentation and the second racking, have considerable 
value, on account of the bitartrate of potash they contain. 
The lees from the debourbage (sedimentation) of white wines 
are only fit for manure. 

The lees should be treated to extract the wine they 
contain before being sold for tartar. 

However thick they may be, they contain, when leaving 
the cask or vat, more than 75 per cent, of their weight of 
wine. The simplest method to extract the wine consists in 
filling strong cloth bags with the lees, piling them in the press, 
and submitting them to slight but continuous pressure. 

The wines gathered in this manner are not of much value, 
but may be used for the still. However, submitted to 
judicious treatment they improve, and may be used for 
consumption. 

The pressed lees should be treated for their tartar by the 
wine-maker. This is a simple and remunerative operation, 
for the tartar obtained has always a higher value than that 
of the lees, and what is more, we retain in addition the 
residues from the treatment, which are first-class for manur- 
ing purposes. The value of tartar per unit is always less in 
the lees than in cream of tartar. 



198 WINK-MAKING IN HOT CLIMATES. 

Good lees in a dry state do not contain much more than 
25 per cent, of tartar, and the 25 kilos, of tartar is the only 
substance paid for by the buyer when fixing the price of 100 
kilos. The remaining 75 kilos, contain about 4 per cent, of 
nitrogen, which at the market price of 1'50 fr. per unit brings 
the value of the 75 kilos, to 4-50 fr. per unit. 

The wine-maker should, therefore, try and extract the 
tartar from the lees for two reasons first, because the tartar 
easily obtained at 80 per cent, strength can be sold at 
1*40 fr. per unit, while only 1 fr. or I'lO fr. would be paid for 
the tartar in the lees. Secondly, because it retains on the 
property an excellent manure, which costs nothing. 

It goes without saying, that it is not necessary to treat 
the lees every year. ' One may, after drying, store it, and 
treat it every other year according to the quantity. 

The extraction of tartar from lees is very simple. It only 
requires a large boiler and casks. 

The strength of the lees being known (we will see later on 
how it is ascertained), it is boiled with water, placing such 
a quantity of lees in the water as will represent about 7 kilos, 
of pure tartar per hectolitre of water. 

With lees of 25 per cent., about 30 kilos, of lees should, 
therefore, be added to one hectolitre of water. 

After a quarter of an hour's boiling, during which the 
mass is stirred, allow it to deposit for a few minutes ; the 
liquid is then passed through a piece of canvas stretched 
over a tub, and the operation started again; on cooling 
the water previously boiled with the lees, almost the whole 
of the tartar in solution is deposited. Each hectolitre of 
water used should yield about 6'5 kilos, of tartar, while 
a half kilo, remains dissolved, but is not lost, for the same 
water may be used again four or five times. 

If used a greater number of times it becomes rather 
viscous, preventing the rapid deposition of the tartar. It 
should, therefore, be renewed after four or five treatments. 

The residues remaining on the canvas, and the water, are 
sent to the manure pit. 

We can, even without much trouble, dispense with the fil- 
tration through canvas, and replace it by simple decan- 
tation ; in this case the boiling must be stopped, the liquid 
allowed to remain undisturbed for ten minutes or a quarter of 
an hour, then racked and placed in the depositing vessel. 
The residue is then removed from the boiler and sent to 
the manure pit, or kept dry till required. 



UTILIZATION OF BY-PRODUCTS. 199 

At the actual market value of tartar* 1-25 fr. per degree in 
cream of tartar, and 90 centimes in the lees. 1,000 kilos, 
of lees at 25 per per cent, would give by this treatment, 
deducting the possible loss: 

225 kilos, of tartar, at 1-25 fr. ... ... 281-25 fr. 

775 kilos, residue for manure, at 4-50 fr. 

per 100 kilos. ... ... ... 34*85 fr. 



Total 316-10 fr. 



While the direct sale of the lees would only bring- in 
225 fr. 

It is necessary to treat 1,000 kilos, of lees, to boil about 
35 hectolitres of water, the fuel used for this operation 
represents a sum much smaller than the credit difference. 
The labour itself does not add greatly to the expenses, 
and the work may be done during bad weather, when the men 
cannot attend to the ordinary out-door work. The figures 
quoted are exact, assuming that the lees are paid for on 
the real percentage of tartar, but this is almost never 
done; more often than not the lees are sold without pre- 
viously determining their strength, and are in fact fre- 
quently sold for almost nothing before the wine they 
contain has been separated, that is to say, in the form of 
a thick liquid containing 75 per cent, of 'wine. In this 
method of doing business everything is in favour of the 
buyer.f 

The tartar obtained from the crust deposited in the casks 
cannot be submitted to any treatment by the wine-maker, as 
the increased value it would acquire by refining would not 
compensate for the extra cost involved. As for the complete 
refining, it is an operation which only pays on a very large 
scale. 

The tartar deposited as a crust in the vats, and that 
extracted from the lees, should, therefore, only be sold on the 
percentage of bitartrate of potash contained ; but it is 
necessary for the wine-maker, who cannot wait for the 

* July, 1897. 

tThe boilers used for the destruction of the pyrale (caterpillar) on the 
stumps of vines may be used to furnish the boiling water for the treatment of 
the lees. In this case a simple cask may be used for the dissolution of the tar- 
tar, taking care, however, to charge the water with a little less lees on account of 
the difference of temperature, which will always be less if the water is removed 
from the boiler. 



200 WINE-MAKING IN HOT CLIMATES. 

result of a laboratory assay or accept that given by the 
buyer, to ascertain, at least approximately, the value of the 
tartar to be sold. 

Determination of the percentage of bitartrate of potash in 
the crust or lees. 

F. Chabert, Analyst at the (Enological Station of the 
Herault, has tried to realize the conditions under which 
the acidimetric method generally used in laboratories may be 
placed in the hands of persons not accustomed to chemical 
manipulations ; and, in order not to increase the laboratory 
outfit of the cellar, to use for this purpose the apparatus 
generally employed for measuring the acidity of the must. 

We require, as in the case of the acidimetre, 

A burette graduated in tenths of a cubic centimetre. 

A titrated alkaline solution of potash or soda. 

A glass flask of one litre capacity. 

An alcoholic solution of phenolphthalein. 

Litmus paper. 

Such is the material necessary for testing the tartar. 

A thorough sampling is the first condition necessary for a 
reliable analysis. 

If the tartar is contained in bags or placed in heaps, a 
handful is taken from different parts of every bag or heap. 
These are placed together, and will form a sample varying 
in size according to the bulk of the stock. This first 
sample should then be thoroughly crushed, well mixed, and 
divided into two parts. One-half is then replaced in the 
bags, the other half being re-submitted to the halving 
operation, and so on until a perfectly homogeneous mixture 
is obtained. An average sample is then drawn off, of four 
or five hundred grammes, which is powdered in a mortar, 
and serves for the analysis. 

Analysts usually operate on very small quantities, but it 
is better for persons not conversant with operations of this 
class to work on a rather large weight the possible errors 
are then only multiplied by a small figure, and do not 
notably influence the results calculated to 100. 

By working on 5 grammes of tartar, fair accuracy is 
obtained. The indispensable weighing is a delicate part of 
the work, for it must be done with a balance turning to 1 or 
2 centigrammes, and such balances are not often found in 
cellars. 



UTILIZATION OF BY-PRODUCTS. 201 

Any pharmacist or chemist can perform the weighing ; 
but we think that sufficient use might be found for a small 
balance to justify its purchase. The price, however, is a 
trifle, and does not exceed 20 francs (16s. 6d.). 

The 5 grammes of tartar or lees are placed in the glass 
flask, 300 to 400 cubic centimetres of distilled water 
added, and the contents boiled. Four or five minutes' boiling 
is sufficient to insure the complete solution of the cream of 
tartar. An insoluble residue always remains, of varying quan- 
tity, according as the operation is made on lees or crust. It is 
not necessary to decant, for in this case we should be obliged to 
wash the residue two or three times with 50 cubic centimetres 
of boiling water. It is on the solution of tartar and in the flask 
itself that the determination is made. Add to the solution, 
after boiling, four or five drops of phenolphthalein, then while 
constantly agitating the contents of the flask add the 
alkaline solution from the burette till the red colour appears 
and indicates the end of the operation the change of colour 
is readily detected after a few trials. With white tartars it 
is so decisive that one drop in excess of the alkaline solution 
is sufficient to cause the appearance of the colour. Its 
detection when working on red tartars is not so easy ; but' 
we may use a much surer although rather more tedious 
method, that is, by testing from time to time with litmus 
paper. 

When the end of the reaction is almost reached the mix- 
ture becomes bronze coloured. The appearance of this 
colour is an indication that the reaction is almost finished. 
If from this moment, after each two or three drops of the 
alkaline solution added, we remove a drop of the mixture by 
means of a stirring rod and place it on a strip of litmus 
paper, the paper will change colour and finally become 
pure blue, instead of the red colour it had in the pre- 
ceding case. This change of colour indicates the end of 
the operation. The analysis is now finished, and it only 
remains to translate the figures obtained into definite 
results. 

To arrive at the change of colour of the liquid, we used 
a certain volume of alkaline solution, as determined by the 
reading of the burette. .Let us suppose that the burette, 
filled to zero with the alkaline solution, reads at the end of 
the operation 15-6 c.c. This means that 15'6 c.c. were used 



202 WINE-MAKING IN HOT CLIMATES. 

to neutralize the acidity of the tartar ; this acidity is propor- 
tional to its content in tartar. It suffices, therefore, to know 
to what acidity 1 c.c. of the alkaline liquor corresponds, in 
order to ascertain by a very easy calculation the richness in 
tartar. Let us suppose, to make this quite clear, an alkaline 
liquor in which each cubic centimetre corresponds to 0-10 
gramme of tartaric acid, the ratio between tartaric acid and 
cream of tartar is 2*506, which means that 1 of tartaric 
acid corresponds to 2*506 of cream of tartar. The alkaline 
liquor will, therefore, in this case be equivalent to 0-2506 
per 1 c.c. used. 

Therefore, as we have used for 5 grammes of the solution 
of tartar, 15*6 c.c. of the alkaline liquor, the 5 grammes 
contained 

0.2506x15*6 = 3*909 gr. 
and, therefore, 100 grammes would contain 

3.909x20=78*18 gr. 

In this particular case the strength of the tartar is 78*18 
per cent. 

It is not indispensable for the alkaline liquor to be of 
the strength above mentioned. It may be of any strength, 
but if too weak, it becomes necessary to use large quan- 
tities and unnecessarily prolong the operation. If, on the 
contrary, the liquor is too strong, too small a volume is 
used, and the slightest error in reading the volume de- 
livered would be an appreciable factor in the quantities 
used. If, for instance, in the above case we had used a 
liquor four times stronger, an error of reading of 0*1 c.c. 
would have caused an error of 2 per cent, in the final result, 
while, with the solution adopted above, the same error of 
reading would only cause a final error of 0*5 per cent. 

The figure of 0*10 gr. of tartaric acid per c.c. used in the 
above example, allows a sufficiently close approximation, and 
we think it is well not to exceed it. The most convenient 
limits for the strength of the alkaline liquor correspond to 
from 0-05 to 0*10 of tartaric acid .per c.c., if the alkaline solu- 
tion varies between these limits it may be safely used. It 
will suffice in any case to multiply the known strength 
equivalent to tartaric acid, by the ratio 2*506 to obtain its 
equivalent in tartar. 



UTILIZATION OF BY-PKODUCTS. 203 

If, as often happens, the strength of the alkaline liquor 
is only known expressed as sulphuric acid, it may be con- 
verted to tartaric acid by multiplying by 1*53, and into 
bitartrate of potash by multiplying the result of the last 
multiplication by 2*506. 

Example. Take for example the alkaline liquor known 
as normal, very frequently used by analysts, and which may 
be easily purchased from any chemical laboratory, its 
strength is 0*049 in sulphuric acid per cubic centimetre, that 
is to say, that 1 cubic centimetre neutralizes 0*049 of sul- 
phuric acid, its equivalent in bitartrate of potash is from 
what we have seen above 0*049 x 1*53 x 2*506 = 0*188 of bitar- 
trate of potash. If 20*6 c.c. of this liquor were required to 
bring about the change of colour in a boiling solution of 
5 grammes of crude tartar, it means that the sample con- 
tains in 5 grammes 0*188 gr. x20*6 c.c. = 3*87 gr. 
and for 100 gr. 3*87 gr. x20 c.c. = 77*4 per cent. 

It is evident from the above that the testing is a simple 
operation. We may even use the alkaline liquor used for 
the determination of the acidity of the must, for, excepting 
the weighing and solution of the tartar, the operation is 
similar in every respect. All those accustomed to the mea- 
surement of the acidity of must will be able to perform this 
operation, with exactitude without further teaching. 

It is understood that we only determine by this method 
the bitartrate of potash present, and not the bitartrate of 
lime, but this is of no importance. The value is always 
based on the contents of bitartrate of potash. 

We urge upon wine-makers, who usually sell their tartar 
without any previous examination, to use the process above 
described, that is, if they do not wish to send the sample 
to a laboratory. They will very soon see the advantage 
resulting from the exact knowledge of the value of the goods 
placed on the market. Through the sale of the tartar, and 
by the use of the residues from the lees as manure, the 
wine-grower will every year make a net profit of 40 centimes 
per hectolitre of wine produced. 

If tartaric acid has been used for the vinification the 
figure must be increased. This increase will recuperate a 
great part of the expense entailed in the purchase of tartaric 
acid. 



204 WINE- MAKING IN HOT CLIMATES. 



CHAPTER VII. 

CARE TO BE GIVEN TO WINE. DEFECTS AND 
DISEASES. 

Normally constituted wine only requires packings made at 
opportune times, filling up the casks as often as considered 
necessary, in order to acquire perfect brightness and be pre- 
served against the germs which always exist in every 
vintage. 

The number of rackings to which wine must be submitted^ 
cannot be fixed a priori, neither can the way in which the 
rackings should be done, that is, either with or without con- 
tact with air. This depends on the constitution and future 
destiny of the wine ; the rackings should be numerous, and 
the aeration more or less intense according to the rapidity 
with which we desire to mature the wine. 

Racking is simply a kind of decantation or separation of 
the clear wine from the subsided lees. 

The first racking, which should be done a fortnight after 
the de-vatting, separates the wine from a great quantity of 
solid matters (yeast cells, vegetable particles in suspension, 
various micro-organisms), but it does not usually furnish 
bright wine. 

This is due to the wine being saturated with carbonic acid 
gas which is only slowly liberated. The fine bubbles during 
their disengagement keep the light particles of lees in sus- 
pension in the liquid. Frequently, where we have to deal 
with musts rich in sugar, and which still retain a small 
quantity of it after fermenting, a slow after fermentation 
continues during several weeks in the racked wine in such a 
way that the wine, always bright just after de-vatting, be- 
comes turbid again in a few days. 

The cold during the winter completely paralyses the work 
of the different ferments, and induces rapid sedimentation, 
and consequently rapid clearing of the wine. 

It is therefore when the wine, after the more or less pro- 
longed action of cold, has acquired complete brightness, that 
the second racking should be done. 



CARE TO BE GIVEN TO WINE. DEFECTS, ETC. 205 

In the South of France this generally corresponds to the 
middle of January.* If the wines still remain turbid it 
means that they are defective, and they will then have to 
be submitted to operations or manipulations somewhat more 
complex than simple racking. 

The selection of the day on which to perform the racking 
is not a matter of indifference. We should, on the contrary, 
always select a day when the barometer is high. There is a 
saying, in the South of France, that wine should always be 
racked or bottled when the mistral wind is blowing. This 
custom is very judicious, because when the mistral is blow- 
ing, the atmospheric pressure is always high. 

Wine always contains carbonic acid gas in solution, al- 
though a large quantity is liberated at the first racking ; 
long after the wine is found almost saturated with it, because 
the lees disengage it slowly but constantly. 

The solubility of gases in liquids is so much the greater 
as the pressure is higher, the temperature being equal, so 
that, if wine saturated with carbonic acid gas remains com- 
pletely still and clear on a fine day, when the atmospheric 
pressure is high, it is not so when the weather is unsettled, 
corresponding to a low pressure, on such days we will ob- 
serve a more or less rapid disengagement of gas, which does 
not take place without causing the liquid to become turbid. 

We should therefore not only choose a fine day for racking, 
but, to do it under still better conditions, choose a bright day 
preceded by several fine days. 

The wine, usually perfectly bright after the racking, almost 
always becomes slightly turbid a few days after. This is 
due to the fact that several solid matters only exist in 
solution in the wine in the presence of carbonic acid gas ; 
and that the oxygen, when the racking is made in presence 
of the air, renders some of the matters in solution in the 
wine insoluble, however, the result aimed at by the racking, 
that is to say, the separation from yeast cells, is attained. 
The subsidence of the solid matters taking place in the 
wine after the racking occurs very quickly, and the lees re- 
sulting are not detrimental. 

It goes without saying that racked wine should be placed 
in thoroughly cleansed casks, rendered wholesome by 
sulphuring. The cask should be left open for a few hours 

* In Victoria, in the Northern districts about the end of June; in the 
Southern districts, June to July (Trans.). 



206 WINE-MAKING IN HOT CLIMATES. 

before filling, to allow the sulphurous acid to escape ; this 
operation is necessary, for sulphuring, when done to render 
the cask wholesome, must be 4one so heavily that it would 
be detrimental to the wine if it were allowed to absorb it. 
However, if we should not introduce into the wine a large 
quantity of sulphurous acid, it does not mean that we should 
not sulphur at all. 

Sulphur always exerts a favorable action on both white 
and red wines, in spite of the opinions to the contrary with 
regard to the latter. 

Although it is necessary to sweep out the sulphur fumes 
by a good, draught before filling, we think it will always 
prove of advantage to burn, before filling, a small quantity 
of sulphur, which may be fixed at 1. gramme per hectolitre. 

Treated in this way, the wines of the South of France are 
sufficiently armed to enable them to pull through the 
summer, the casks only require to be kept completely filled. 

Whenever wine is not perfectly clear and bright after the 
January racking (in Victoria about June), it means that it 
is diseased. The disease must then be treated at once by 
proper methods, to enable the wine to become bright and 
clear. 



DEFECTS AND DISEASES OF WINE. 

It is necessary to distinguish between defective and 
diseased wine. 

A modification in the taste and physical aspect of wine 
constitutes a defect, but not a disease. The defects, especially 
those of taste, have a tendency to become attenuated by 
maturing. In any case, they do not get worse, while the 
modifications due to diseases, almost undetectable to the 
senses at first, increase to the extent of completely altering 
the constitution of the liquid and render it undrinkable, it 
an energetic treatment does not arrest the further progress 
of the evil. 

Wines are all the more liable to contract defects or 
diseases, as the vintage is less healthy, the vinification less 
carefully conducted, and the cellar material less thoroughly 
cleansed and looked after. 

In this, as in any other case, it is better to foresee the 
disease than to have to cure it. The absolute cleanliness of 
the cellar material, vessels, crushers, presses, pumps, hoses, 



CARE TO BE GIVEN TO WINE. DEFECTS, ETC. 207 

and even the cellar and its surroundings, will avoid a great 
many of the defects and diseases of wines, and to a greater 
extent than one might really think. A proper method of 
vinification will do the rest. The sight, smell, and taste, 
are all called upon to form an opinion of the wine. 

The tasse (Fig. 38) is a marvellous little instrument for 
observing wine, the play of light in it is an admirable help. 

The smell enables us to detect certain defects which, not 
interfering with the colour, would pass unnoticed by the eye. 

The degustation or tasting, performed with care, completes 
the impressions upon which are based a judgment of the 
wine. 

The whole mouth, tongue, palate, and even the throat, 
serve to define the indications of the smell. By drawing back 
the liquid in the rear of the mouth with a movement 
similar to that of deglutition, we sometimes notice in an 
exaggerated or increased manner characters previously 
detected by the smell, and may thus more exactly determine 
their nature and intensity. 

A yellowish colour is a frequent defect, and is independent 
of the cellar material. It is generally due to the abuse of 
racking during the course of fermentation. 

We know that a great quantity of air is necessary to the 
must before the start of the fermentations, but when it has 
once started a small quantity only is necessary. 

The practice of pumping over the head, excellent in so 
far as it gives more body to the wine, is often a cause of the 
yellow colour, because it is almost always done in presence 
of air, with wines always too hot. Hence the yellow colour 
of hastily-matured wine, which depreciates its commercial 
value. 

The pumping over the head during fermentation is often 
useful when the aeration is only necessary for a languishing 
fermentation, and when the yeast requires invigorating. 
The yellow colour will be avoided if care be taken not to 
aerate excessively. 

When the harm is done there is no other remedy but 
blending with other wines of finer colour and appearance. 

When the wine becomes of a bluish-red, more or less 
blackish colour, it is a sign of a true defect in constitution. 

Insufficient acidity in the vintage furnishes such dull wine, 
known as leaden, but the same shades of colour are found in 
almost all wines attacked by diseases due to microbes. 



208 WINK-MAKING IN HOT CLIMATES. 

We have shown two ways of guarding the vintage against 
deficiency of acidity, the use of the second crop, and tartaric 
acid. 

In vintaging early the resulting wine will always be acid 
enough. The first wines made are never leaden ; it is therefore 
necessary, when vintaging at normal maturity, to increase 
the percentage of acidity by the addition of tartaric acid. 

The last wines obtained from acidified vintage are as 
bright, fruity, and nerveux as the first made, while they are 
more alcoholic. 

For a made wine the remedy is still tartaric acid, provided 
the leaden appearance is due to a deficiency of acidity, and is 
not the first symptom of a serious disease. The leaden 
wines resulting from a deficiency of acidity do not present 
any peculiarity to the smell, which is not ordinarily the case 
with diseased wines, but they show to the taste more 
flabbiness, flatness, and rapidly lose their vinosity when 
mixed with water. The acidification by addition of tartaric 
acid is a lawful and efficacious means of remedying this 
defect, but the action of the remedy is incomparably more 
satisfactory when applied as a preveutative, that is to say, 
before the fermentation. 

To ameliorate this class of wines$ we should proceed by 
preliminary trials, on a quantity, to which tartaric acid is 
added in fractions of one decigramme, until the eye and 
the taste are satisfied with the operation. As a result, we 
will soon arrive at the amount necessary to be added to the 
wine, which usually lies between 50 and 100 grammes per 
hectolitre. 

An earthy taste or flavour is also a very frequent defect. 
This is detected by the smell and taste, and is rather difficult 
to define exactly. The name is of no assistance, for it leads 
us to suppose that the defect is due to the soil the wine 
originates from. This has always been the popular belief ; 
it simply means that we have been mistaken for a long 
while. 

" Of all the earthy tastes/' writes an author, u the most 
peculiar are those which are met with in Algerian wines 
derived from newly-trenched land, which had, before, borne 
Pistacia lentiscus, Jujube, dwarf Jackal Palm (Chamasrops 
humilis), &c. Such soil exhales fantastic odours, which 
are found again in the wine grown on it, not only smelling, 
but also tasting." 



CABE TO BE GIVEN TO WINE. DEFECTS, ETC. 209 

We do not believe much in the influence of newly-trenched 
soil, for the very simple reason that when the vine arrives 
at the productive state the soil is not newly-trenched, and 
has had time to get rid of all flavours that might have con- 
taminated it. 

Five or six years ago, wines with an earthy taste were the 
fashion in Algeria, and that whether they proceeded from 
old or young vines, from vines planted in ground cleared a 
great number of years before, or from newly-trenched ground. 
The wines produced from old ground had that defect even 
in a more accentuated degree, because they were more 
alcoholic. 

This is not so any longer. Certain vineyards which during 
the last twenty years produced wines having an earthy 
taste, now make clean-tasting wines, and this is simply due 
to the improved processes and methods of vinifaation. 
Formerly, the crushed vintage was left to itself, and allowed 
to ferment in a happy-go-lucky way, only de-vatting when 
the wine seemed to contain no more sugar, which usually 
happened fifteen or eighteen days after the fermentation 
started. It is entirely to this prolonged maceration, taking 
place at an excessive temperature, that we must attribute 
the origin of the earthy taste, and not to the earth itself. 
Since the application of the system of refrigerating musts, 
which enables regular and short fermentations to be made, 
the earthy taste due to newly-trenched ground has dis- 
appeared. 

In the South of France, the same causes produce the same 
effects, but only to a slight extent. The means of avoiding 
the earthy taste are very simple, only ferment for five or six 
days, and prevent the heating of the vat. If there are no 
means at disposal for cooling, and the vat becomes too hot, 
de-vat as soon as possible, even at the expense of the colour, 
for we believe that it is better to make wine of clean taste, 
and free from earthy taste, than wine rich in colour, and 
possessing an earthy taste. 

The remedy for the evil is almost useless. It consists 
in repeated rackings and heavy finings, which only result in 
attenuating the evil, without causing it to disappear, and in 
turn exhausting the wine ; the practice of blending is better 
than anything else. 

Wines sometimes develop a putrid smell, similar to that 
of sulphuretted hydrogen, caused by the presence of a very 

10649. O 



210 WINE-MAKING IN HOT CLIMATES. 

small quantity of sulphur remaining from the sulphuring 
during the summer, or, to the condition of the vat in which 
the fermentation was conducted. In the first case it is due to 
sulphuretted hydrogen, in the second case it is the result of 
more complex sulphuretted compounds, and then the defect is 
more tenacious. A very frequent cause of the putrid smell is 
the use of compounds for luting the vats, into the composition 
of which blood enters. The blood is generally thought to be 
more effective when putrefied. It is needless to state that 
this idea is without foundation. The sulphuretted taste is 
difficult to remove from the wine. We may, however, arrive 
at it by strongly sulphuring again, that is to say, by making 
the wine absorb sulphurous anhydride*, although it seems 
incredible at first. In reality the sulphuretted hydrogen is 
destroyed by the sulphurous anhydride, and the wine con- 
tracts the smell of the latter, which is very different from 
the former, and possesses the advantage of disappearing in 
time. 

To remove all other abnormal tastes, such as cask or 
mouldy taste, the use of olive oil is generally advocated. 

The wine is roused with 1 per cent, of olive oil which 
suffices to fix to its benefit, or to be more precise, to its 
detriment, the foreign taste contaminating the wine. 

We think it is only a second-rate method, the success of 
which is never complete. The olive oil used must be of the 
very best quality, which renders the method very expensive, 
anyhow, whatever be the quality of the oil used, the treat- 
ment always leaves in the wine, side by side with the more or 
less attenuated initial defect, a disagreeable oily character. 

Mustard powder used in a quantity of 30 or 40 grammes 
per hectolitre, and stirred with the wine, gave us results, 
which, without being good, are, however, preferable to those 
obtained with oil, we may sometimes succeed in rendering by 
this treatment, the consumption of wine possible, which was 
otherwise undrinkable. 

We have so far spoken of defects which do not lead to a 
gradual alteration of the wine. W^e will now describe the 
principal diseases which completely transform the wine if 
their evolution is complete. 

They are almost always the result of infinitely small 
organisms known as microbes, which play such an important 

* This reaction proceeds according to the equation 
2H 2 S + SO 2 = 2H 2 O + 2 S. (Trans.) 



PLATE III. 




Disease known as Flower, Mycoderma, vini. 




Vinegar Disease, MycoAenna aceti. 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 211 

part in our life, although they are so small, and the role of 
which, unsuspected previous to Pasteur's classical researches, 
now becomes more apparent every day. 

In oenology their importance is considerable. We know 
that they are the cause of the genesis of wine, that the mar- 
vellous transformation of sugar into a'lcohol is due to microbes, 
but these are salutary microbes. We are going to study now 
other microbes of noxious character, causing the destruction 
of the work of the first mentioned. 

It is curious to study the old authors in their explanations 
of the diseases of wines. It is a succession of fantastical 
interpretations, which they probably did not understand 
themselves, and which are certainly unintelligible to lay- 
men. 

For instance, we read about "the intimate connexion of 
the spirituous parts with the saline and mucilaginous mole- 
cules," which is about equivalent to the " movement of the 
humours" advocated by the old doctors, in treating affections 
of which they were ignorant of the real cause. 

The jleur (flower), Plate III., is the most common and 
benign of wine diseases. 

It only attacks wine when in contact with air ; the sur- 
face of the wine becomes covered with white spots, formed 
of a multitude of small organisms (microscopical fungi) 
which are termed mijcoderma vim, which entangled together 
form a regular scum, becoming wrinkled when further 
developed. 

This fungus is oval-shaped and reproduces by budding, 
affecting on a microscopical scale the shape of the branches 
of the common large oval-leaved cactus (Opuntia). It derives 
its nourishment from the wine, living principally at the ex- 
pense of the alcohol, the alcohol being transformed into 
carbon dioxide and water, that is to say, consumed, and the 
alcoholic strength of the wine naturally diminishes. 

However, for the action of the mycoderma vini to be appre- 
ciable, it requires to develop on a very large surface, compared 
with the volume of the wine, that is to say the ullage of the 
cask must be considerable. In ordinary cases where the 
flower only extends over a small surface of wine as in an almost 
filled cask, its action is quite insignificant. The case is the 
same in a bottle standing upright and badly corked. It is 
then only unsightly and does not injure the flavour in any 
way. 



212 WINE-MAKING IN HOT CLIMATES. 

It is not so with acetification or piqure, Plate III., which 
develops under exactly similar conditions, and in most cases 
follows the flower. 

In the case of acetification the general characters are not 
so pronounced at the start, instead of a regular scum com- 
pletely obscuring the surface of the liquid, it is a light 
transparent veil, a muslin instead of a thick blanket of flower. 
When acetification follows the flower, we observe rents in 
the blanket, rents which enlarge every day till the veil has 
replaced the blanket. 

This light veil is formed of micro-organisms known as 
mycoderma aceti or diplococcus aceti, infinitely smaller than 
mycoderma vini, and which can only be detected under a very 
high magnifying power. 

The cells appear to be shaped like two small balls, joined 
together in the form of the figure 8 ; when they take posses- 
sion of the wine the small balls join together forming chaplets, 
when they become old, the chaplets dislocate and are replaced 
by new ones formed of younger cells, while the old cells fall 
inert to the bottom of the liquid, forming by their accumula- 
tion, a viscous mass known as mother of vinegar. A very 
characteristic property of the acetic ferment is its extreme 
rapidity of reproduction when the conditions are favorable. 
In 24 hours, according to Duclaux, an almost imperceptible 
quantity of mycoderma aceti will cover a surface square metre 
of liquid, producing, if we assume the layer to be composed 
of one thickness of cells, 300,000,000,000' cells in that short 
space of time. 

The mycoderma aceti exerts an oxidizing action on alcohol, 
transforming it into acetic acid and water. 

Directly this action commences, the wine assumes a sour or 
vinegar taste. This is a very serious disease, for all the ex- 
tolled remedies are only insufficient palliatives, if the altera- 
tion is at all marked. 

Acetification often results in wine, through the acetification 
of the marc during fermentation conducted with a floating- 
head, and always takes place in casks which are left slightly 
ullaged, especially in cellars where the temperature is 
elevated. 

Certain wines are more liable than others to become 
attacked by mycoderma aceti; such are wines in which sugar 
is left after incomplete fermentation, wines of low alcoholic 



CARE TO BE GIVEN TO WINE. DEFECTS, ETC. 213 

strength, and wines worn out by age. Press wines are almost 
invariably slightly sour, and are very liable to become attacked 
by mycoderma aceti, if the casks are as already said not kept 
quite full. 

The remedies proposed are only palliatives, for, if it is pos- 
sible by destroying the cause of the evil through killing the 
micro-organisms to stop the progress of the disease, it does 
not, however, suppress the acid taste existing before the 
treatment. 

To destroy the acetic acid formed, lime, carbonate of lime, 
or what is the same thing, powdered marble, have been recom- 
mended. 

This is a bad remedy, and has the great disadvantage of 
introducing into the wine a substance (lime) foreign to the 
grape. The acid taste disappears, it is true, but its disap- 
pearance is not persistent for all time, and the wine contracts 
a strange taste which depreciates its value. 

The saturation of the acetic acid by certain potash salts, and 
particularly by neutral tartrate of potash, answers much better ; 
in this operation ordinary tartar (bitartrate of potash) which 
gradually subsides, and acetate of potash are formed. In this 
case the disappearance of the acid taste persists, under the 
conditions, however, that at the same time we stop or prevent 
the disease from continuing its development. There are to 
attain this end two means, apart from the general principle 
of sterilization ; they are to fill completely and close the vessel 
airtight, or to burn a sulphur wick in the empty space over 
the wine, so as to surmount the wine with a layer of sulphurous 
anhydride instead of air. Under these conditions the devel- 
opment of the mycoderma aceti is completely arrested and the 
wine does not move, a long as there are traces of sulphurous 
fumes in the empty part of the cask, so that we may preserve 
the contaminated wine for any length of time by the simple 
additional precaution of renewing now and then the sulphurous 
anhydride. 

Acetification is a common disease, but riot so frequent, 
however, as the tourne (turning), Plate IV. 

The tourne, or turning, attacks the tartaric acid, whether 
combined or otherwise, and transforms it into new com- 
pounds, imparting to the wine characters which entirely 
alter its nature. We have not to deal in this case, as in 
the two preceding, with organisms living on the surface of 



214 WIXE-MAKIXG IN HOT CLIMATES. 

the liquid, and which may be removed by simply protect- 
ing the surface, but with organisms living in the midst of 
the wine, which therefore render it cloudy, directly they 
begin to multiply. 

The tourne produces a special or peculiar cloudiness, which 
is a very definite symptom of this disease. If we examine by 
transmitted light, and in a thin layer, wine attacked by the 
tourne, and which has been slightly shaken, a shimmering 
appearance similar to the waves on watered silk is notice- 
able from the movements of the microbes it contains. This 
characteristic is 1 very transient, for the wavy appearance 
soon stops after shaking, but it is sufficient to be acquainted 
with this appearance to readily recognise it. 

The ferment of the tourne has a filamentary shape, very 
thin generally, and more or less curved according to its age. 
It occasions the decomposition of the tartaric acid, several 
different compounds resulting, such as tartronic, lactic, and 
acetic acids, and it ends by destroying not only all the tartar 
contained in the wine, but also that adhering to the wood or 
the vessel containing the wine. 

The tourne ferment is a veritable de-tartrater of the casks, 
and this is a fact known long since, when wines did not 
come out of the cellar directly after they were made, but 
were often eventually submitted to the distiller. 

Nowadays the disease is more rare, and it very seldom 
becomes sufficiently developed to enable us to notice the 
complete destruction of the tartar in wine. 

The tourne attacks all wines of low alcoholic strength. 
After the first invasion of mildew, the wines from mildewed 
vines were attacked, even in viticultural regions where 
tourne was previously unknown, by an alteration or disease 
which was for a long time regarded as altogether different. 
Gayon established by experiments and definite analyses that 
mildewed wines were simply attacked by tourne. 

When the disease is so far advanced that the taste of the 
wine is sensibly modified, nothing can be done. In past 
days the evil was not very great, because the still enabled 
us to turn the diseased wine into fair spirit, easily saleable, 
but to-day it is a disaster, for the market value depending 
on the alcoholic strength is so low that the loss is almost 
total. 

If the disease has not made much progress, and if the 
wine is still drinkable, the evil can fortunately be stopped 



PLATE IV. 




Disease known as "Tourne. 




Disease known as " Pousse." 



PLATE V. 




known as " Aintrtume " (Bitter) (Young). 




The same (Old). 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 215 

by the general system of treatment of diseases due to micro- 
organisms, which will be briefly described later on. 

Pousse (pushing), Plate IV., is the sister disease of tourne, 
but is less frequent, and only differs from it in this, that 
amongst the products of the destruction of the tartar, pro- 
pionic acid and carbon dioxide are formed. Carbon dioxide 
is a gas, the same which is liberated during vinous fermen- 
tation, and can only be dissolved in wine in limited propor- 
tion. If we consider a well-bunged cask filled with wine 
attacked by pousse, that is to say by a disease constituting a 
veritable source of carbon dioxide, pressure will be developed 
inside the cask, the result of which will be the pushing of 
the heads outwards, hence the name pousse (pushing). The 
pressure becomes so high sometimes that it results in the 
bursting of the cask. 

Pousse is due to a filamentary microbe, similar in form to 
that of tourne^ but shorter, thicker, and straighter, while 
that of tourne is always more of less curved. If the disease 
has not progressed too far it may be cured by the same 
means as those used for tourne. 

The disease known as amertume (bitter), Plate V., is very 
uncommon in the South of France. This is not due, as is 
generally supposed, to the fact that the disease is special to 
wines of grand cms, but simply that it requires a longer 
time to develop and acquire all its characters, therefore it 
can only be observed in old wines, and the wines of the South 
of France never get old enough to give the disease time to 
develop. As a matter of fact, the wines in the South of 
France are more liable to get this disease than any other, 
for the conditions of preservation and maturing are always 
more unfavorable in a warm climate than in a cold one. 

According to the researches of Pasteur and Duclaux, 
amertume progressively destroys the glycerine in the wine, 
forming volatile acids, amongst which acetic and butyric 
predominate. It is probable that these are not the only bodies 
formed, for, if this were the case, it would be difficult to 
explain the bitterness, sometimes very intense, which charac- 
terizes this disease. 

Amertume is due to a filamentary microbe, longer and 
thicker than those of either pousse or tourne, and which 
differs from them by its ramified appearance, which is similar 
to the branching of a tree. 



216 



WINE-MAKING IN HOT CLIMATES. 



When the disease is starting, the ferment is more or less 
isolated, relatively short and thick, and not ramified. It is 
when ageing that it becomes ramified and encrusted with 
colouring matter, which renders its detection more difficult, 
but at the same time gives it a more distinguishing character. 
Amertume is a disease to be feared in wines destined to be 
laid down, but it has no importance in the case of wines that 
are to be consumed young. 

Graisse (fat) is a disease more peculiar to white wines, 
and need not be much dreaded. It cannot be very common, 
if we judge by the difficulty we find in procuring wine 
characteristically attacked. Under its influence white wines 
assume a viscous condition, and flow like oil from the tap, 
and even, if more developed, like white of egg. 

Scientists do not know exactly under the influence of what 
decomposition this effect is produced. We can detect under 
the microscope chaplets of little balls similar to those of the 
mycoderma aceti, but rather larger, and surrounded by a 
kind of mucilaginous matter, but that is all. A violent 
stirring of the wine renders it quite fluid, and the addition 
of tannin acts as a temporary cure, as was shown by Francois 
very long ago. 

The definite cure of this disease, like that of any other 
disease caused by microbes, is easy to effect. 

A few years ago a new wine disease (but very old, no doubt) 
was discovered. It is known as mannitic fermentation, Fig. 
57. P. Carles, of Bordeaux, had in 1891 pointed out the 

presence of mannite in cer- 
tain wines. After a few 
experiments, he came to the 
conclusion that mannite was 
only found in wines made 
from figs. According to 
him the presence of mannite 
in wine indicated adultera- 
tion, the substitution or at 
least the admixture of 
grapes with figs. 

Having had an oppor- 
tunity of finding and char- 
acterizing mannite in wines, 
which we knew were made 
exclusively from grapes, we 




Fig. 57. Mannitic Ferment. 



CARE TO BE GIVEN TO WINE. DEFECTS, ETC. 217 

were induced to study its origin, and were able to show that 
we had to deal with a disease due to the action of micro- 
organisms attacking not only fig wines, but also the pure 
juice of the grape.* The same year we were able during a 
trip to Algeria to extend and define our observations on the 
subject, but were not able to isolate the living organism 
which produced among other bodies, that which characterized 
the disease, mannite.f 

Gayon and Dubourg studied the subject again in 1894, 
and thoroughly determined its evolution. They reproduced 
it in healthy wine, by inoculating it with the microbes they 
had succeeded in isolating. 

Mannitic wines usually contain an excess of sugar, and the 
total acidity is very great. The dry extract is very high, 
not only through the presence of sugar, but even after the 
sugar has been deducted. The bitartrate of potash does 
not seem to be attacked, if the wine is only invaded 
by the mannitic ferment, but it frequently happens that 
the disease develops concurrently with tourm, which 
destroys the tartar. 

The ferment appears in the shape of short and very small 
rods, immobile, which, instead of remaining independent 
and disseminated in the liquid, gather together in great 
numbers, forming colonies rather difficult to disintegrate. 
It only develops in wine containing sugar, for it is from 
its decomposition that mannite is formed. This disease is 
therefore only to be feared in the case of wines contain- 
ing sugar, or musts. It may develop during the alcoholic 
fermentation, and seriously alters the wine when the trans- 
formation of the alcohol through some cause or other lasts 
too long, as happens when the temperature of the vat 
exceeds the limit which wine yeast can support. 

The conditions favorable to mannitic fermentation of 
musts are naturally found in hot climates, and it was 
in Algeria and Spain that this disease was first noticed. 
Mannite only appears in French wines in exceptionally 
hot years. Contrary to the opinion of certain authors, 
mannitic fermentation is not a variety of tourne peculiar 

* Memoir es de la Society des sciences phi/, et nat. de Bordeaux. 28th July, 1892 
t L. Roos. Journal de pharm. et de chimie. 1893. 



218 WINE-MAKING IN HOT CLIMATES. 

to sweet wines ; the differences are in fact numerous. The 
following are those given by Gayon and Dubourg : 

1st. The mannitic ferment differs in shape, dimensions, 
and mode of grouping of the cells. 

2nd. It does not develop in wines free from sugar where 
the tourne ferment develops easily. 

3rd. The latter does not develop in sweet liquids, especi- 
ally in liquids artificially sweetened which are so favorable 
to the former. 

4th. The volatile acids produced during pure mannitic 
fermentation are exclusively composed of acetic acid, while 
if this acid exists in tourne wine there is side by side with it, 
and in greater proportion, other volatile acids. 

5th. While the tartar disappears in tourne wines it remains 
unattacked in mannitic wines. 

In fact, it is a disease which exists from the commence- 
ment, and it is this which renders it so difficult to obviate. 
It can only be avoided by attentively watching the tempera- 
ture of the vat.* 

There is a disease which has attracted considerable atten- 
tion in recent years, known as casse (breakage), but the 
origin of which does not seem to be due to microbes. 

Prof. Bouffard f drew attention to this disease, which he 
noticed was common in the 1893 wines, upon which he made 
his first studies. 

" The wine of a bright and clear colour in the cask becomes 
turbid when aerated for three or four hours, and a brown-red 
precipitate forms. If the wine is in a bottle kept still, the 
decolouration.commences on the surface, where a small iride- 
scent pellicle of colouring matter is formed which gradually 
affects the lower layers of wine, the sides of the glass become 
covered with an adherent deposit, and the wine becomes 
almost entirely decolourized, assuming a characteristic 
yellow-madeira colour. All these deposits consist of 
colouring matter, insoluble even in concentrated tartaric 
acid solutions. 

" The wine does not disengage any gas, as happens in other 
diseases. Its taste does not recall in any way pousse or 

* Comptes rendug de I' Academic des Sciences. 9th April, 1894. 
f Sterilization of the must previous to fermentation, and the use of pure 
cultivated yeasts afterwards, is a means of avoiding the disease. (Trans.) 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 219 

tourne. The taste may be compared to that of wines called 
rancid or madeirized, which are the characteristic of very old 
age." 

Prof. BoufFard concluded that the idea of the action of a 
microbe must be set aside, an opinion which has been accepted 
since the publication of his work. He was also able to indi- 
cate at the same time that sulphurous anhydride and heating 
were efficacious remedies. 

After Bouffard, various investigators studied this subject. 

Gouirand, of the Viticultural Station of Cognac, has shown 
that wine subject to casse (breakage) contains a soluble 
ferment,* a diastase of the same nature as that recently 
isolated by Bertrand and called oxydase, the characteristic 
property of which is to fix the oxygen of the air on the 
oxidizable matters with which the ferment is in contact. 
The mechanism of casse will then be an indirect oxidation of 
the colouring matter, resulting in it becoming insoluble* and 
therefore precipitating. 

Laborde, of the Agronomic Station of the Gironde, pointed 
out one of the possible sources of the diastase,! namely, the 
products of elimination of the Botrytis cinerea, the special 
mould of the grapes which plays such an important part in 
the vinification of Sauterne and Rhine wines. The diastasic 
cause of the casse would seem to be admitted by every one ; 
but Legatu, Professor of the Agricultural School at Moni> 
pellier, has just given a new interpretation based on the role 
of iron J: which has already gained a number of followers. 

According to Legatu, casse is not due to a pure and simple 
oxidation of the colouring matter, but to the oxidation of 
a ferrous salt, which in that state is incapable of forming an 
insoluble combination with the colouring matter, but which 
acquires that property by changing to the ferric state. 

" This new interpretation, according to him, is not contra- 
dictory to the actually admitted influence of an oxydase, but 
in the case studied, the part played by this diastase (if it 
exists) has not consisted in rendering the colouring matter 
insoluble, but in favouring the phenomena of oxidation 
which always takes place in diluted solutions of ferrous salts. 
The insolubility of the colouring matter follows in consequence 
of the formation of a new ferric compound. 

* Comptes rendus. April, 1895. 

t Comptes rendus. 1896. 

Comptes rendus. June, 1897. 

10649. P 



220 WINE-MAKING IN HOT CLIMATES. 

Legatn and myself tried to give this theory experimental 
verification. Our researches are condensed in the following 
note, abstracted from the Pr ogres agricole et viticole : 

" It is clear that the above note brings a new element of 
discussion to the scientific study of casse in wines, but does 
not establish upon sufficient experimental basis the part 
played by that element. 

"It answers the question, it indicates a very plausible 
theory, but does not solve the problem or establish that 
theory. 

u We have endeavoured by experimental researches re- 
cently undertaken to gather facts which would throw some 
light on the action of iron in the casse of wines. 

"At that time of the year the difficulty of procuring 
suitable samples of wines limited the extent of our 
researches. It is difficult to find wines of good character 
not containing any sulphurous acid, and it is not to wines 
liable to casse, but already cured, that we- should have re- 
course in order to systematically reproduce the casse. On 
the other hand, the non-cured casse wines have already been 
scibrnitted to treatment, to rackings at least, they are par- 
tially attacked and their primitive state cannot be deter- 
mined. However, the few samples we obtained enabled 
us to observe facts which are in perfect accordance with the 
new interpretation. 

"It seems actually established that there are two 
varieties of casse. First, blue casse, which is observed in 
rich wines of an intense colouration, the true type of which 
is met with in the Jacquez, vinified without the addition 
of tartaric acid ; secondly, the brown casse characterized by 
the more or less brownish colour of the precipitate, and 
in the partial or total substitution of yellow for the original 
colour. As will be seen, this distinction does not seem 
fundamental. 

" No wine susceptible to complete decolouration by ex- 
posure to the air was noticed, one only took a slightly 
madeira-red colour. 

" It was found to be indispensable to study the precipitate 
resulting from casse. 

" We were surprised to find in this precipitate so far 
considered as oxidized colouring matter a notable amount of 
mineral matters, amongst which iron was in considerable 
proportion. 



CARE TO BE GIVEN TO WINE. DEFECTS, ETC. 221 

" Examples. A wine of Montauban attacked strongly by 
brown casse, but, however, not completely decolourized, was 
left for two days exposed to the. action of the air. 

" The precipitate formed, collected on a Chamberland 
candle, washed with distilled water till the washings were 
no longer coloured, dried in a vacuum and incinerated 
gave 

Mineral matters ... ... 17'3 per cent. 

Iron ... ... ... 5-0 

"Wine made from Jacquez cepage, originating in the 
Herault, not easily turning blue under the action of the 
air, gave, however, for half a litre, 110 milligrames of dry 
bluish-black precipitate, in which we found 2 per cent, of 
iron together with silica. In this particular case, as with 
all Jacquez, the wine had thrown down already a deposit 
which was found to be rich in iron.* 

tl All the precipitates from blue casse have been found to 
be rich in iron. 

" We therefore consider, as a constant and well-established 
fact that a wine which breaks throws out iron. 

"Is it not probable that blue casse is due to formation of 
ferric tannate, while brown casse is due to the formation of 
cenolate of iron ? The close relation between oenoline and 
tannin f adds more weight to the above hypothesis, conse- 
quently are we not naturally led to see the cause of the casse 
in an excessive amount of iron. 

" One of the first confirmations of this hypothesis must 
be looked for in the comparison between the intensity of 
the casse and the amount of iron. Now, one of us has 
already established^ by numerous analyses that the 
Jacquez wines, so predisposed to casse, are also in a general 
way remarkably rich in iron. This is a clue, but the exact 
determination of that element in the must and in the wine 

* Prof. Bouffard (Ann. de I'Ecole not. d 1 Agriculture de MontpeUier, t. II. 
1886) states "From facts observed, one may admit that the violet matter 
(deposited by the Jacquez) is the result of oxidation, and perhaps, as we hope 
to prove, a combination with the iron contained in wine, as a kind of tannate of 
iron. The precipitation only takes place after the aeration through the staves 
of the cask has been sufficient." Is not this the way casse proceeds ? Bouffard 
distinguishes, however, this special casse from that we are studying, while it is 
only regarded by Legatu and myself as a simple variation. (L.R.) 

t L. Hugounenq. Recherches nouvelles sur les vins. Imp. A. btorck, Lyon. 

J L. Roos, Giraud and David. Analyse chimique des vins de 1'He'rault 
Recolte. 1890. Bull de la Soc. cenlrale d'agric. de V Herault. 

p ^ 



222 AVINE-MAKING IN HOT CLIMATES. 

directly after de-vatting would present more interest. How- 
ever, this co-relation has already been verified for the Jacquez, 
as also for other samples. 

" As a second confirmation, a sound wine (but not charged 
with sulphurous acid) should break when we increase the per- 
centage of iron, a fact already established in the above note 
and confirmed since by new trials with various ferrous salts. 

" In the third place, the treatments indicated against the 
natural casse, must be of the same value in wines in which 
the casse has been induced artificially. Sulphurous acid is 
so active against artificial casse that it is impossible to 
obtain it even in wines which have simply been racked into 
a sulphured cask. Example : A wine upon which trials of 
artificial casse remained without results was subsequently 
found to contain 32 milligrammes of sulphurous acid pel- 
litre ; re the heating, we have only studied its effect in an 
incomplete way, and wall only mention that the absolute 
efficacy of this cure has been disputed. However, from our 
first researches it is evident that wine acquires by heating 
the property of holding the iron in solution more perfectly. 
There is therefore in the above results a point strong enough 
for an interpretation of casse independent of any oxidizing 
diastase to which the disease is to-day attributed.* 

" It is interesting to try and produce the phenomenon . of 
the casse under conditions excluding the presence of 
diastase. 

"To arrive at this, renoline free from iron and even 
mineral matter was isolated by the Hugounenq process. 
The use of strong alcohol for dissolving the ceuoline excludes 
any diastase. The product of this dissolution was used to 
colour an alcoholic solution of tartaric acid containing some 
iron introduced in the form of ferrous hydrate. The mixture 
became turbid a few hours afterwards, forming a reddish 
precipitate similar to that of brown casse. At the same 
time the liquid was covered with an iridescent pellicle, as 
observed in natural casse, and affected the reddish-yellow 
colouration so characteristic of casse wines. This fact leads 
us to think that the presence of an oxydase is not indispen- 
sable to the casse. 

" However, the facts given above seem to have as much 
weight as those advanced in favour of the diastase theory. 

* Theory of Gouirand, supported by numerous experimenters. 



CAEE TO BE GIVEN TO WINE. DEFECTS, ETC. 223 

" We may even produce artificial casse, absolutely similar 
to the natural casse, while the oxydases only furnish, accord- 
ing to certain authors, a near image. 

" And, what is more, the knowledge of oxydases and of 
their mode of action was until recently very vague. During 
the course of our researches Bertram! * established that a 
(dose behaviour existed between the oxidizing action of 
those bodies and of manganese, in the form of manganous 
hydrated salts, as the only conveyer of oxygen in the pheno- 
menon of oxydation observed. The intervention of man- 
ganese being proved indispensable to the action of the 
oxydases, did not surprise us much. We are in presence, 
as in our own argument, of a metallic oxide. 

" The manganous and ferrous salts have very similar 
properties, from the point of view of the transformations 
brought about by oxygen. With regard to this, the ferrous 
salts have even a more marked activity. 

" Manganese exists in wines, but in scarcely detectable 
quantities. We cannot define its action in casse, but may 
state that the precipitates obtained in the wines affected by 
casse naturally, are always free from it. Manganese only 
exists in the liquid. 

" As we were able in our experiments to produce the casse 
in a liquid completely free from manganese, we do not 
consider for a moment that it is necessary to invoke that 
metal to explain the natural casse. 

" In all cases the phenomenon of the precipitation remains 
a function of the iron. 

" In short, in this particular case, we do not see the 
utility of manganese united or not to a diastase as an 
oxidizing agent ; anyhow, it does not enter into the compo- 
sition of the precipitate." 

Soon after its publication, Legatu's paper was the object of 
a violent critique from Cazeneuve. This criticism, remark- 
able for its vivacity, does not adduce any serious argument 
against Legatu's theory, which we found, on the contrary, 
strongly supported by the works of various experimenters. 

" Sometimes we lose sight of the fact," says Bourquelot,t 
"that the oxydases may be produced with oxydizing matters 
which cannot be looked upon as true oxidising ferments." 

* Comptes rendus de I' Academic des Sciences. 14th June, 1897. 
t Journal de Pharmacie et de Chemie. May, 1897. 



224 WINE-MAKING IN HOT CLIMATES. 

Villiers* shows that in a purely inorganic liquid, through 
the action of a nianganous salt, very important oxidizing 
phenomena result, where the manganese can only be looked 
upon as an oxygen conveyer, considering the great quantities 
fixed through its action. 

A. Livache* studied the action of different metallic oxides on 
the oxidation of linseed oil, and quotes manganese as the most 
active, but similar effects were obtained with other oxides, 
notably that of iron, which gave results of the same class. 
although taking longer to obtain. Bertrand, to whom is due 
the most interesting work on the oxidizing ferments, has just 
found a close co-relation between their action and the presence 
of manganese in their composition.* 

Legatu's theory does not negative the existence of oxidases, 
it only establishes that the casse of wines may not be due to 
diastase, or at least admitting a casse due to diastase, there is 
another, quite similar, in which the oxidizing ferment plays 
no part. 

The effect of heat in preventing casse is often advanced to 
strengthen the hypothesis of a diastase, as soluble ferments are 
always paralysed by heating. But we have seen that wine 
acquires through heating the property of retaining the iron 
compounds in solution. 'We also know that organic com- 
pounds exist, into the composition of which iron enters, and 
which do not give any reaction for that metal. Would not, 
in this particular case, the action of the heat be to fix the 
iron in a state unattackable by oxygen ? Whatever it be, if 
we admit, and this is generally admitted even by the advo- 
cates of diastase, a casse special to the Jacquez, and closely 
related to the excessive quantity of iron those wines contain, 
why deny the existence and the theoretical interest of a simi- 
lar affection in the wines of other cepages, the analyses of 
which show quantities of iron equal and even superior to that 
contained in Jacquez. 



TREATMENT OF DISEASED WINES. 

Heating. Whether due to microbes or not (such as casse), 
the diseases above mentioned all give way to heating. 

Observations conducted systematically have shown that no 
living being, neither any reproductive organ of a living being 
(seed, egg, spore) can resist a temperature of 120 C. At 

* Comptes rendus. June, 1897. 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 

that temperature, dry or moist, all life is suppressed; but if, 
instead of operating in air or water, we operate in another 
gas, vapour, or liquid, the temperature may be considerably 
lowered and still remain just as effective. 

Thus, in the case of wine, which is, after all, a solution of 
alcohol and different acid substances, it is sufficient to raise 
it to a temperature of 60 C. (140 F.) for a few minutes to 
annihilate any living organism. 

Heating is, therefore, a veritable sterilization based upon 
the destruction of all living organisms, and we see what can 
be expected from the application of such a process. 

The description of the machines for the heating of wines, 
Pasteurizers, or CEnotherms, does not come within the scope 
of this work. The reader will find all desirable information 
in the study published by Prof. U. Gayon on these machines.* 

We will simply give a condensed account of the conditions 
necessary for efficient pasteurization. The wine to be heated 
should be almost clear, for the solution of the matters in 
suspension, under the influence of heat, is to be feared 
solution which is always accompanied by a defective taste. 
We should, therefore, if not filter at least rack, and avoid the 
passage of the turbid part through the Pasteurizer. 

For the wine to preserve all its qualities, and not to lose 
any colour through the heating, it must pass by the required 
temperature (60 C.), and come down to its initial tempera- 
ture without coming in contact with air, so as to prevent the 
action of oxygen taking place during any of the phases of the 
operation. The extreme temperature which the wine should 
reach must not be the average of very different temperatures 
applied to different parts of the wine, but only the average 
of very close temperatures. If, for instance, we pass wine 
through a coil submerged in constantly boiling water, coupled 
with a worm submerged in cold water, although the wine at 
the exit may be obtained at the same temperature as at the 
entrance, the heating is defective. In this case, the wine in 
immediate contact with the metal would be submitted to a 
high temperature (almost 100 C.), while that in the centre 
of the tube would only be slightly heated. The average tem- 
perature resulting from the mixture of these will, no doubt, 
be sufficient to insure sterilization, but the wine will have 
contracted a special cooked taste, because certain parts have 
been overheated. 

* U. Gayon. Etude sur les appareils de pasteurization de vins. Extraitde 
la Revue de Viticulture. Feret et Fils. Bordeaux. 



226 WIXE-MAKIXG IX HOT CLIMATES. 

In order not to lose the beneficial action of pasteurization, 
and avoid contamination of the wine, it should be passed 
direct into sterilized casks. In most cases, washing the 
casks with boiling* water is sufficient, but the sterilization 
is more certain, and it is more convenient in practice to 
steam them. 

The wine heated under these conditions has nothing to 
fear from diseases, and will not acquire as a result modi- 
fications of colour or taste. When kept in well-bunged 
casks, it may be preserved without further alteration of 
any kind, and has even acquired a special resistance to the 
germs which might accidentally contaminate it. Heating 
has made great strides during the last few years, but has 
still greater progress to make, actually pasteurizers are 
always to be found in wine merchants' cellars, even of 
medium importance ; but they are still rare in the vine- 
grower's cellar. However, the advantages are so definite, 
that little by little they force their way into, and will very 
soon be part of the current material of every cellar. 



FILTERING AND FINING. 

To cure diseased wine, or to be more precise, to hinder 
the development of the disease, we should kill the microbes 
causing it, or separate them completely from the wine in 
which they exist, Filtering is a solution of this problem, 
but is only efficacious if it is perfect, and to be perfect it 
requires expensive apparatus provided with powerful me- 
chanical appliances. 

A large filtering plant was established quite lately at 
Algiers. The filters employed were of the well-known type 
Chamberland porcelain candle, tile results obtained with 
this plant were equivalent to those given by heating from the 
point of view of sterilization, but this is a remedy only 
practical for cellars in the immediate neighbourhood of 
such a plant. 

Most filters do not insure sterilization. Their effect i& 
excellent in many cases, but quite useless when we have 
to deal with diseases due to microbes. The disease is 
almost preferable, when we have not at disposal a good 
pasteurizer. 

The matters used for fining are distinguished according 
to their mode of action. Finings only acting mechanically 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 'J^T 

(sand, Spanish clay, paper pulp). Finings forming with 
the acids of the wine, partly soluble salts, chalk, marble^ 
powdered oysters, plaster (all useless), and last the finings 
coagulated by substances in the wine. 

The latter class only are true finings, and should alone 
be used. They are all bodies known in chemistry as 
albumenoids, all acting in the same manner, and forming 
with tannin insoluble flocculent precipitates of a density 
slightly greater than that of the wine, and which con- 
sequently only gradually settle to the bottom dragging 
down as in a net of infinitely small meshes, all the solid 
particles, whatever their tenuity may be, which float in the 
midst of the wine. This makes fining a very special class 
of filtration. 

The different albumenous clarifiers are : several albumens., 
white of egg, blood, milk, gelatine, isinglass. 

These substances are the base of all the products prepared 
by the trade, and sold more or less modified under various 
names and aspects. The commercial liquid finings are always 
solutions of these compounds rendered non-putrescible by 
the addition of antiseptics, very often sulphurous acid> 
combined or not, but, unfortunately, sometimes also bodies 
interdicted in the manipulation of wine, and which are found 
afterwards in the treated wines, such as boric acid and 
salicylic acid. The possibility of getting involved very 
innocently in a police prosecution case should render the 
proprietor very distrustful of these finings. This is to be 
regretted, for the preliminary preparation required by the 
albumenoids used for fining is generally very well done by 
the trade. 

The egg albumenoids are used without any preparation 
other than separation from the yolk and beating up with 
water. 

Fresh blood, or better, serum, that is to say, the clear 
amber-coloured liquid which separates after coagulation, is 
used without any further preparation. 

Natural milk is only used for the clarification of vinegar. 

Whites of eggs are usually used in the proportion of two- 
per hectolitre (four per hogshead). Blood, or serum, in a 
quantity of 50 cubic centimetres per hectolitre. 

In both cases the method of operating consists in diluting 
the clarifying matter with a small quantity of water (the 
five thousandth part of the volume to be treated), pouring 



228 WIXE-MAKIXG IX HOT CLIMATES. 

the prepared mixture into the wine, and energetically rousing 
by appropriate means, according to the capacity of the 
vessel, and allowing the wine to remain undisturbed until 
the complete subsidence occurs of the precipitate formed. 
The subsidence takes usually from three to eight days, after 
which racking separates the wine perfectly bright. 

Egg and blood albumen are both sold in commerce in a 
solid state, but in that form are always expensive, and lose 
their main advantage, which is the simplicity of their 
manipulation when liquid. 

Gelatine requires a rather longer preparation. It is found 
in commerce in the shape of transparent sheets, slightly 
yellow or quite colourless if the gelatine is pure. It swells 
without dissolving in cold water, but dissolves very readily 
in warm water. Gelatine is obtained by boiling bones, 
tendons, cartilage, and other abattoir waste at a temperature 
over 100 C. under pressure. 

Dissolved in water, it has the property of forming a jelly 
on cooling, if the solution is sufficiently concentrated. AVe 
should, therefore, be careful when preparing it as a simple 
solution in warm water, to dilute it enough to avoid coagula- 
tion when cold. In the proportion of 5 per cent, the 
dissolved- gelatine remains liquid at ordinary temperatures. 
The liquid clarifiers with a gelatine base, sold in commerce, 
-are almost always stronger than 5 per cent., but to keep 
them liquid they are heated under pressure at a temperature 
of 128 C. By this treatment the gelatine loses its charac- 
teristic property of forming, with tannin, an insoluble com- 
pound, and that of solidifying on cooling. 

If, perhaps, it is of some utility for the trade to obtain 
concentrated solutions, it is not necessary for the wine-maker, 
-and the solutions at 5 per cent., which any one can make 
without the use of special appliances, will render the same 
services. In cases where the proprietor requires to keep the 
gelatinous solution prepared in this way he should add to 
it 1 per cent, of bisulphite of potash to render it 
unputrescible. 

Two hundred cubic centimetres of this solution are sufficient 
to clarify one hectolitre (22 gallons) of wine, the operation 
being conducted in exactly the same way as with white of 
egg or blood. 

Fish isinglass obtained by the desiccation of the natatory 
bladder of certain fish is very recommendable for white 



CABE TO BE GIVEN TO WINE. DEFECTS, ETC. 229 

wines. Its use seems at first very expensive, as the price of 
a good quality is 30 francs per kilogramme, but the quantity 
necessary is so small that the price of the fining for one 
hectolitre is not, after all, much greater than when using 
gelatine. 

Two grammes of fish isinglass are ample to clarify one 
hectolitre of white wine. The preparation of this isinglass 
takes longer than that of gelatine. The sheet of dry isinglass 
is first split in three thin sections, then placed in a vessel, 
covered with cold water, and allowed to remain for 10 or 12 
hours, during which it swells. 

" After that the mass is sprayed with boiling water, beating 
it continually meanwhile. At first it forms a thick paste, 
becoming almost fluid when the total quantity of water 
added reaches 50 litres for one kilogramme of isinglass. 

The main element for success in this preparation consists 
in the thorough division of the isinglass. If we possess the 
means of rasping it, and making a kind of coarse powder, a 
thick liquid free from lumps is then easily made. If means 
of rasping it are not at hand, the emulsion may be heated 
for a few minutes, but it is better in this operation not to 
let the temperature rise to 100 C. 

Two hundred cubic centimetres of this solution of fish 
isinglass of 2 per cent, strength will be sufficient to fine one 
hectolitre of wine. The 200 cubic centimetres should be 
first diluted with half a litre of water, adding it by instal- 
ments, the mixture is then further diluted with wine, and 
introduced into the cask, stirring energetically during the 
addition, and then left alone during sedimentation. 

It goes without saying that the wine-maker may insure 
the preservation of the prepared solution of fish isinglass, in 
the same way as in the case of gelatine, by adding 1 per cent, 
of bisulphite of potash, and may, therefore, in one single 
operation prepare the fining required for a whole year. 

Precautions to be taken to insure the efficacy of fining. 
For fining to give good results the treated wines should 
remain perfectly still during the whole time necessary for 
the deposition of the fluffy precipitate formed through the 
action of the tannin in the wine on the albumen or gelatine. 
It is sometimes said that wines do not take, or do not take 
the finings easily, this may be due to different causes. 

One of the most frequent in white wines is deficiency of 
tannin, certain kinds of white wines, especially those obtained 



230 WINK-MAKING IN HOT CLIMATES. 

from red grapes by the fermentation of the first fraction 
of drained juice, are very poor in tannin, and consequently 
cannot produce the coagulation necessary to insure the 
success of the operation. The remedy consists in the 
addition of tannin to the wine in a quantity of 25 to 30 
grammes per hectolitre. 

It is easy to place in evidence a deficiency of tannin by 
the following simple process. 

Portions of the wine to be fined are placed in two glasses ; 
in one in its natural state, in the other with the addition of 
tannin. After the tannin is dissolved, add to both in equal 
amount (very small) four or five drops of the fining to be 
used. If the wine is rich enough in tannin to take the 
fining, the precipitation will be almost the same or equal in 
both glasses, while if the wine requires the addition of tannin, 
the precipitate will be much heavier in the glass to which 
tannin was added. 

We may again place the fining in one hectolitre of wine, 
and stir in a small quantity of dissolved tannin. If the 
precipitate does not increase, the wine will not require the 
addition of tannin. 

Another cause of failure in the fining of wines results from 
the wines being saturated with carbonic acid gas, which, 
gradually disengaging, forms little bubbles bursting at the 
surface, carrying during their upward movement small par- 
ticles of fining, which remain suspended in the wine. This 
trouble may be avoided by racking in presence of air, when 
the wines abandon enough carbonic acid gas for that re- 
maining to keep in solution during slight alterations of" 
atmospheric pressure. 

Finally, another cause of failure is met with in wines 
attacked by microbe diseases, if we do not previously 
paralyze the microbes. While at work the microbes pro- 
duce movements in the wine, by gaseous disengagement or 
formation of liquid currents ; these are no doubt slight,, 
but sufficient to prevent the normal action of the fining. 

They may be paralyzed by the use of sulphurous acid 
in a quantity of 10, 12, or 15 grammes per hectolitre.. 
The most convenient way of applying the sulphurous acid 
is that already described in the vinification of white wines, 
namely, sulphwing with the pump. If the reader refers 
back he will see that the operation is easy, and does not 
complicate the operation of fining. (See page 178.) 



CAKE TO BE GIVEN TO WINE. DEFECTS, ETC. 231 



Let us suppose a cask of wine of 200 hectolitres attacked 
by toarne is required to be fined, and that the quantity of 
sulphurous acid necessary to paralyze the microbe be 12 
centigrammes per litre, or 12 grammes per hectolitre, the 
mode of operation would be as follows : Weigh 1,200 
grammes of sulphur, burn it, and force the vapours into 
the cask, as previously explained; this being done, place 
in a tub the necessary quantity of lining, 40 litres of a 
solution of gelatine of 5 per cent, strength (i.e., 200 cubic 
centimetres per hectolitre), dilute with an equal volume 
of wine, then with the pump used for sulphuring force 
the mixture into the cask, and continue pumping air into 
it after the tub is emptied to insure thorough agitation, 
after that wait till the clarification is complete. 

The fining with such a quantity of sulphurous acid pre- 
sents evidently certain inconveniences, for the colour 
diminishes and the fined wine acquires a decided taste of sul- 
phurous acid. However, these faults are only transient, the 
colour comes back after one or two rackings, and the sul- 
phurous acid taste fades away completely, especially if the 
sulphuring has been done with pure sulphur, and not with 
sulphured cloths. For the sulphur compounds formed by 
the burning of cloth, although in very small quantity, give 
rise to a very persistent smell in the wine. 

Notwithstanding these inconveniences, the fining after pre- 
vious sulphuring is excellent for all diseased wines, which 
after such a treatment will be able to keep, and which other- 
wise would certainly have entailed loss. 

Sulphuring, followed by fining, is after all similar in its 
mode of action and effect to the use of different commercial 
mixtures, placed for sale under high-sounding names, and at 
prices still more high-sounding. All those which are lawful 
are mixtures of sulphurous acid and albumenoids, obscured 
under trade names ; many are excellent, and could be recom- 
mended if it were not for their exorbitant price. If the 
proprietor wishes to use ready-prepared finings, care should 
always be taken to apply to firms of repute, and insist upon 
a guarantee as to the composition, if it is desired to avoid 
the risk of prosecution. 



232 WINE-MAKING IN HOT CLIMATES. 



APPENDIX. 



Extract from " The Vine in Australia" by Dr. A. C. Kelly. 
Published in 1841. 

CHAPTER ON FERMENTATION. 

"In the warmer parts of Australia the vintage begins 
sometimes in February, and is generally over in March, a 
season when the weather is occasionally very hot. It is by 
no means an uncommon occurrence for the temperature to 
remain for some days above 90 F. during the day, and 
never under 80 at night. Must, fermenting under such 
heat, rises many degrees above the highest temperature of 
the air ten degrees probably. The effect of this high tem- 
perature is by no means so injurious as might have been 
anticipated. Much good wine has been made whose tem- 
perature during fermentation has risen to 100 F. The 
temperature of 86 is the limit beyond which a sound 
healthy fermentation cannot be maintained in beer and other 
worts, and such was thought to be the case also with grape 
must ; the opinions of modern oenologues, however, have 
undergone a change on this subject. "An acquaintance 
with many details with which we are still ignorant is, how- 
ever, necessary in order to investigate thoroughly the in- 
fluence of temperature upon a well-tasted wine, which 
should not spoil with age. The grapes of each country, 
ripened under different degrees of summer warmth, and 
very unequally rich in constituents, require different 
temperatures during fermentation ; and different tempera- 
tures are required for grapes which are the product of a 
warmer or colder summer. But we are still ignorant on 
these points. All we know is, that a high temperature 
during autumn promotes fermentation, and a low one is 
detrimental to it ; that inequality of temperature during 
fermentation is extremely injurious, and not infrequently 
spoils the wine altogether."* Baron Liebig, in writing 

* Mulder. Chemistry of wine. 



APPENDIX. 233 

to the late Mr. King on the wines of New South Wales, 
says : " As the wine of Irrawang contains an ample 
quantity of saccharine matter, I deem it expedient that you 
should allow it to ferment at the highest possible tem- 
perature." 

The illustrious chemist, however, would surely set some 
limit to the temperature. One thing is certain, that it is 
only very strong must which can be allowed to rise so 
high as it does with us in Australia. The weak must of 
the North of France and the Rhine, whose specific gravity 
may be about 106, would pass into vinegar were it ex- 
posed to a temperature of 90 and upwards. 

In colder countries large vats are employed as best suited 
to maintain the temperature of the fermenting mass, but 
they would be objectionable where it is desirable to keep 
the vats cool. How to keep down the temperature of the 
fermenting must, is the most difficult problem the Australian 
wine-grower has to solve. " Experience has taught us 
that the temperature of fermenting wine cannot be kept 
down by the use of underground cellars, unless the quantity 
be insignificant. We prefer a wooden building above ground, 
with the means of admitting free currents of air on all 
sides. Any accession of heat which a hot day may occasion 
is more than compensated for by the cool night air, which 
has free admission on all sides. A large body of wine will 
rapidly heat an underground cellar, and it caimot be cooled 
down again for many days."* 

" A free admission of air to the surface of the fermenting 
liquor has the effect of keeping down the temperature. To 
this we shall revert shortly. Where it is desirable to exclude 
the air, as in the fermentation of red wines, some other 
means are required to prevent the fermenting liquor from 
rising to an excessive heat, as it must do under a tempe- 
rature of the air of 90 or upwards. This may be effected by 
means of a refrigerating apparatus such as the annexed, which 
is sufficiently simple to require no particular explanation. It 
is simply a pipe formed like the worm of a still, through 
which the cold water from a cistern flows, and is dis- 
charged again outside. The entrance and exit parts of 
the pipe are placed close together, in order to interfere as 
little as possible with the fixing of a false lid, and also 

* Rough Notes Sir W. Macarthur. 



234 WINE-MAKING IN HOT CLIMATES. 

to facilitate the strengthening it by a frame. By means 
of a long flexible tube, to Jit on by a coupling screw, the 
apparatus may be applied to a vat at a distance from 
the cistern. The supply of water for the cistern must of 
course be from a well or underground tank, whose tem- 
perature is moderate ; and care must be taken that it 
does not lower the temperature too much. This refrigerator 
has been used with excellent effect in this colony, but was 
given up from a dread, perhaps a needless one, of the effect 
of the metal, block tin, upon the wine. The same apparatus 
is used during warm weather in some breweries in Britain, 
where great care is employed in conducting the fermenta- 
tion, and where it is essential to maintain a steady tempera- 
ture. When the temperature is low the same may be used 
to keep up sufficient heat in the liquid by passing hot water 
through it. 

" The chief objection that can be brought against this 
refrigerator is the material of which it is constructed. The 
powerful action of the tartar upon metals, already alluded 
to, forbids the employment of any metallic implements 
which are to come in contact with grape-juice. Silver is the 
only metal which is not much acted on by tartar ; and a 
copper tube, electro-plated at that part which is immersed 
in the fermenting must, would, probably, be not too expen- 
sive to forbid its use. An iron or copper tube, enamelled, 
would also be an excellent material for the purpose. Glass 
might be employed for the construction of refrigerators ; it 
could be protected by a wooden frame, and as it is only the 
portion immersed which is affected by the tartar, the entrance 
and exit pipes may be constructed of metal. The only 
objection to glass is its slow conducting power, but this may 
be so far obviated by giving it a larger surface. 

" It is surprising to find so little attention paid to tempera- 
ture in the fermentation of wine in these colonies. If the 
general principles of fermentation are of universal appli- 
cation, we have no reason to treat grape-juice as if it were 
an exception ; and expect that it can be fermented success- 
fully when we disregard the conditions under which alone a 
healthy fermentation can be conducted. Grape-juice cer- 
tainly ferments more readily and completely than any other 
fermentable substance, and has, perhaps, less tendency to 
go into the acetous 'state ; and wine-makers, trusting too 
much to its power to resist the deteriorating influences to 



APPENDIX. 235 

which it is often exposed, do not consider it necessary to 
abide by the laws which regulate the fermentation of other 
substances, but take extreme liberties with the grape must. 
For example, the temperature of the fermenting must may 
rise to 100, and sometimes several degrees above it, and 
the resulting wine may be sound and good. The conclusion 
drawn from this is that wine may be fermented at a very 
high temperature without injury. Not without injury cer-, 
tainly, as the following experiment shows : A quantity of 
purple grapes was crushed during very hot weather, the 
temperature of the air being above 90 during the day and 
never under 80 at night. The must and skins were put 
into a vat of 250 gallons, and a false lid placed as usual to 
keep down the mark. There was more than sufficient to fill 
the vat to the proper height ; and the remainder, about 
40 gallons, was put into a small vat (a port wine pipe having 
the head out), a false lid was also fitted into this. The fer- 
mentation commenced in each the following day, and in two 
days the temperature rose considerably during the tumul- 
tuous fermentation ; but that of the larger vat was, at least, 
8 higher than the temperature of the smaller. After this 
the progress of the attenuation showed a marked difference 
in the two vats. In the smaller it went on steadily, and in 
three days after the height of the fermentation it had fully 
attenuated itself, giving a specific gravity of 100, and was 
racked off clear and in fine condition ; whereas the larger 
vat attenuated very slowly. On the third day after the 
violent fermentation its specific gravity was still 102*5 ; the 
following day it had come down very little, showing 102, 
and was full of yeasty matter floating through it. It was 
racked off into casks, to undergo the secondary fermentation ; 
and, although eventually it attenuated after some time, it 
was an inferior wine to that drawn from the smaller vat. 

" It has been often remarked that the first experiments in 
wine-making are generally the most successful, but it is easy 
to divine the reason of this. The first quantities made are 
generally very small, 40 or 50 gallons or less ; the tempera- 
ture of so small a body of fermenting liquor seldom rises 
high, and the process goes on under much more favorable 
circumstances in this respect than in the subsequent vintages, 
when the fermentation is generally conducted in quantities 
of from one to several hundred gallons, when the increase of 
temperature is necessarily greater. 



10649. 



236 WINE-MAKING IN HOT CLIMATES. 

" The fermentation of grape-juice is so entirely a natural 
process, and goes through its course so perfectly, under 
favorable circumstances, that we are apt to become careless, 
and say that we are trusting the process to nature when, in 
fact, we are counteracting her operations, and going in direct 
opposition to the conditions under which fermentation can 
proceed with success. There certainly exists in the grape a 
vital energy, a sort of vis medicatrix, which not only resists 
many evil influences to which it is exposed, but seems also 
to correct them when they have occurred. 

" To none of the conditions necessary to a sound healthy 
fermentation ought we to pay more attention than tempera- 
ture ; and there is, probably, none which is so much 
neglected. This arises, doubtless, from the difficulty, and, 
I may say, the supposed impossibility of counteracting the 
excessive heat of the climate. The construction of an 
apparatus for keeping down the temperature, of the nature 
and form already alluded to, would be neither difficult nor 
costly, and of its beneficial influence on the fermenting 
process, and the resulting wine, there can be little doubt, for 
the great majority of our wines are fermented at too high 
a temperature. When we find writers such as Liebig and 
Mulder recommending a high temperature for the fermen- 
tation of the wines of warm climates, we solace ourselves 
with the idea that we are on the safe side in this respect, 
forgetting that what these writers would consider a high 
temperature is, probably, 86 F., the highest point assigned 
to a healthy fermentation ; but supposing that they allow a 
higher limit say 10 above it, still this is far below what 
the fermenting vats of these colonies often attain, for in 
many cases they must rise 10 degrees higher still, to 106, 
or 20 above the limit already indicated as that beyond 
which the fermentation does not go on favorably. This is a 
temperature surely never contemplated by any of these 
writers, and which no must ought ever to be allowed to 
attain. 

a The effect of a very tumultuous fermentation in beer, 
caused by a high temperature, is thus described by Dr. 
Ure * : < When the action is too violent, these barmy 
glutinous matters get comminuted and dispersed through 
the liquor, and can never afterwards be thoroughly 

* Dictionary of Arts and Manufactures. 



APPENDIX. 237 

separated. A portion of the same feculent matter becomes, 
moreover, permanently dissolved during this furious commo- 
tion by the alcohol that is generated. Thus, beer loses not 
merely its agreeable flavour and limpidity, but is apt to 
spoil from the slightest causes. The slower, more regularly 
progressive, and less interrupted, therefore, the fermentation 
is, so much better will the product be.' If such are the 
results of a too violent fermentation in beer, we cannot 
doubt that it must also have an injurious effect on wine. 

" The grapes of the warm districts of these colonies, which 
attain a specific gravity of 112, or more, are able to bear, 
and probably require, a very high temperature to complete 
their fermentation ; the exact limit we cannot define, but we 
may venture to say that 95 is a temperature beyond which it 
would not be advisable to allow any wine to rise, and probably 
90 is the highest it ought ever to attain" 



Q2 



238 WINE-MAKING IN HOT CLIMATES. 

THE CONTROL OF THE TEMPERATURE IN 
WINE FERMENTATION. 



BY A. P. HAYNE,* DIKECTOK OF VITICULTURE, CALIFORNIA. 
BULLETIN No. 117, UNIVERSITY OF CALIFORNIA, 1897. 



The Control of the Temperature. The fermentation of 
wine must or the juice of the grape results in the main in the 
splitting up of the sugar it contains into almost equal parts 
of alcohol and carbonic acid gas. While there are other 
products of fermentation, it is not essential for our immediate 
purpose to dwell on them in this connexion. The transfor- 
mation of sugar into carbonic acid gas and alcohol is a 
chemical action caused by minute plants or ferments called 
yeast. It is well known that all chemical changes of this 
sort produce heat ; and thus it will be seen that the tempera- 
ture of a fermenting mass of a sugar solution (grape juice), 
while it depends to a certain extent upon the outside tem- 
perature, is chiefly dependent upon the amount of heat 
generated within the tank itself. The amount of heat then 
that is produced in a fermenting tank depends upon, first, 
the per cent, of sugar in the must and the quantity of 
must ; second, the facilities offered by the tank and air for 
carrying off the heat generated by fermentation, or con- 
ductivity of the tank walls, the amount of surface exposed 
to the air, the circulation of the must within the tank, &c. ; 
third, the activity of the yeast cells, i.e. 9 the rapidity of 
fermentation. 

Percentage of Sugar. The amount of sugar in the must 
varies from year to year in the same place with the same 
varieties. In hot countries there is, other things being equal, 
more sugar in the must than in cold countries. Some 
varieties of grapes give more sugar than others ; and as high 
alcoholic strength is, unfortunately, paid for as such by the 
merchant, grape growers are apt to select those varieties 
that produce the most sugar, and hence alcohol in the wine, 
regardless of true quality. While this may be proper 
enough in cold climates, it works great injury to the general 
reputation of the wines of warmer countries, for alcohol is 

* Diplome de VEcole d 1 Agriculture de Montpellier. 



APPENDIX. 239 

not the only desideratum in wine. In hot climates there is 
almost always, with the excess of sugar, a correspondingly 
smaller amount of acid. It is, however, important to note 
that very high sugar contents of must and low acid generally 
go together, and that they are both, as a rule, undesirable. 

Ex-cess of Neat. The amount of heat generated within 
the fermenting tank is very great, being sufficient, theoreti- 
cally, to raise above boiling point the whole of a must rich 
in sugar. Practically, however, the heat is generated 
gradually ; and much of it is carried off by the gas generated, 
as well as through the walls of the vat, and from the surface 
of the fermenting liquid ; otherwise fermentation beyond a 
certain point would be impossible. This fact has taught 
wine-makers in warm countries the necessity of a free circu- 
lation of air in the fermenting room, unless that air is hotter 
than the temperature of the fermenting mass. Hence the 
benefit of the practice of fermenting in small packages with 
thin walls : first, because of less actual amount or quantity 
of heat (calories) generated ; and, second, because of the 
facility with which this heat can be carried off, and thus the 
equilibrium between the temperature of the fermenting mass 
and the outside air be maintained. This has led many wine- 
makers to have their tanks made of small diameter, of great 
height, and of very thin material of -high conductivity, such 
as thin enamelled iron. While this certainly enables the 
operator to completely control the temperature, it has proved 
far too expensive for general use. But, unquestionably, the 
growing custom of using very large tanks is essentially bad 
practice. 

Activity of the Yeast. The third factor in the problem is 
the activity of the yeast-cell. There are many circumstances 
that modify this activity. First it must be remembered that 
the yeasts are plants/ and that, in a general way, their 
growth (activity) is modified by the same conditions that 
affect the higher plants growing in the fields. Extremes 
either of heat or cold are unfavorable to their maximum 
development, Thus in cold climates the wine-maker keeps 
a fire constantly burning in the fermenting-room, while in 
hot countries all his energies are bent on reducing the 
temperature to that most favorable for proper fermentation. 

It is also noted that the higher plants have different 
" optimum " temperatures ; for there are tropical plants, 
plants of temperate regions, and plants that grow in the 
arctic regions. It is the same, within certain limits, with 



240 WINE-MAKING IN HOT CLIMATES. 

the yeast-plants. This variation is, as yet, but little known, 
for it is within but a few years that serious attention has 
been given to this branch of science so magnificently set 
forth by Pasteur. Suffice it to say that something has been 
done, and that the beer brewers have put these principles in 
practice with eminent success. Now the yeast-plant of the 
brewers splits up sugar into alcohol and carbonic acid gas, 
just as the wine-yeasts do, and is influenced by exactly the 
same conditions. 

In th case of the seeds of the higher plants of all kinds, 
activity does not begin until the proper temperature has 
been reached. Should the temperature in spring rise slowly, 
the growth of all plant life is correspondingly slow ; but so 
surely as a sudden great rise in temperature takes place, 
plant life will be intensified by it until, when excessive 
temperatures are attained, it is either paralyzed temporarily 
or the plant may die. 

Similarly, if the grapes arrive at the fermenting tank 
much heated, then we may look for a sudden violent 
development of yeast-plants or fermentation. This is 
unfavorable for several reasons : first, because the heat is 
generated so rapidly that a due amount cannot be carried 
off in time by conduction, and high temperature is reached 
very quickly, whereby the yeast may be paralyzed or killed. 
But more than this ; within certain limits each degree of 
sugar in the ' must means a corresponding amount of heat 
generated in the tank. Now, if fermentation starts in at a 
low temperature, say T)6 degrees F., the generation of heat 
will be slow at first, and the rate of fermentation will be 
correspondingly slow, and apparently less heat will be 
generated than if started at a higher temperature ; because 
much is lost by conduction, although the amount is actually 
the same. The starting point was so low that the heat that 
was not carried off by conduction is not sufficient, when 
added to the initial temperature, to carry it to the killing 
point. Let the initial point be 75 degrees F., as is frequently 
the case, then the extra heat added by the greater rapidity 
of fermentation will carry the temperature, without doubt, 
to the death limit. Hence the many efforts made to get the 
grapes into the tank in a cool state. Wherever this can be 
done, the fermentation usually goes through well ; but 
practically this is possible only on a small scale. Hence in 
a warm climate like that of California the initial tempera- 
ture of the must is always over 60 degrees F., and in some 



APPENDIX. 241 

cases over 76 degrees F. The danger arising from over- 
heating is, therefore, naturally to be expected. Actually, 
at all the wineries of this State, over-heating does occur 
almost continually, and great financial losses result there- 
from. 

Nourishment. But aside from the general climatic con- 
ditions, all plants are profoundly modified in their growth 
by the nourishment they receive from the soil in which they 
grow. Aside from the sugar required to nourish the yeast- 
plant, one of the most important factors in the problem of 
its growth is the acid. There are other factors, but these 
are not essential in this connexion. Now, just as there are 
plants that will grow in alkali soil, and others that will 
not, so there are yeast plants that will thrive in a non- 
acid medium, and others that will not. 

Diseases of Wine. This brings us to the plants that 
cause the diseases of wine ; for it should be understood 
once for all, that a " spoilt " wine is spoiled not spon- 
.taneously, but by the growing in it of some minute plant 
which uses the substances of the wine to nourish itself, 
and to produce both its natural products, most of which 
are foreign to normal wine, and unpalatable besides. Thus 
the bacteria of putrefaction destroy otherwise edible meat 
and render it unfit for human consumption. In the same 
manner all diseased or " spoilt " wines have been rendered 
so by some plant of a lower order than the yeast-plant 
that gave it its quality. 

Importance of Proper Temperature. Returning to the 
question of temperature, it has been established beyond the 
possibility of rational dispute that, in the majority of cases, 
those temperatures most favorable to the wine-yeast plant 
are unfavorable for the development and growth of disease- 
plants or bacteria, and vice versa. 

In a general way we may say that the wine-yeast is a 
plant of the temperate zone, while the disease bacilli are 
plants of the tropics ; the one requiring moderate heat 
for its normal growth, and the other requiring a much 
higher temperature in order to grow and act at all. This 
explains the practice of keeping wine in cool cellars. This 
is a very important point. High temperatures are very 
unfavorable for normal wine-yeast, and very favorable to 
the bacteria which cause wines to spoil. After the limit 
of temperature favorable to the yeast-plant has been passed, 
the quality of the wine deteriorates with great rapidity : 



242 WINE-MAKING IN HOT CLIMATES. 

not necessarily because the wine-yeast is actually killed, 
nor that its action has ceased altogether ; but that its 
activity has been checked, and that the harmful bacteria 
have begun their work ; producing, not alcohol, carbonic 
acid gas, glycerine, &c., but their own characteristic pro- 
ducts, such as mannite, acetic, lactic, and butyric acids, 
&c., &c. 

Paralysis and Death of Yeast-plants. The degree of 
paralysis of the yeast-plant depends upon the temperature 
and composition of the must. The absolute point of 
temperature at which paralysis or death will overtake the 
yeast-plant cannot be fixed absolutely, as it depends upon 
the variety of ferment or yeast-plant, as well as upon the 
conditions in which it works best. For normal musts 
with a normal yeast, the death point is generally from 
98 to 100 degrees F. Some varieties of yeast (and 
these are few) will stand more heat, most of them suffer- 
ing greatly before this point is reached ; the must als3 
should be of a composition naturally favorable to them. 
Before this point is reached the bacteria begin to develop, 
while the wine-yeast stops growth ; and the wine, if not 
spoiled, is rendered of less value than it would have been 
had the temperature remained lower. 

Effect on Bouquet and Aroma. It should be noted in this 
connexion that, with certain reservations, the general rule 
is that the lower the temperature of fermentation the better 
the aroma and bouquet of the wine. In other words, the 
proper regulation of the temperature of the must during the 
first or tumultuous fermentation means the production of a 
wine richer in alcohol, of better keeping qualities, and better 
quality throughout. 

Use of Antiseptics and Antiferments. With this review 
of the general principles governing fermentation, we come 
to the practical lessons deducible therefrom. We have had 
occasion to note the heavy annual loss to wine-makers from 
" stuck tanks," resulting either in the total destruction of the 
wine, or the partial loss of its market value. We have also 
had occasion to listen to the criticisms of the purchasers of 
Californian wine, both abroad and in this country ; and in 
by far the greater number of cases the fault found was not 
so much with the quality (for well-made Californian wine 
compares favorably, grade for grade, with any in the world) 
but in the unsoundness, i.e. the tendency to spoil on the 
hands of the purchaser before reaching the consumer. This 



APPENDIX. 243 

lias led to the use of antiseptics, " anti-ferments," that is 
poisons which kill outright or paralyze, not only the wine- 
yeast but all bacteria that might intervene, and in some 
cases the consumer as well. The making of wine at high 
temperatures is simply inviting the use of antiseptics; for, 
as a matter of fact, unsound wine can only be marketed by 
the use of some powerful agent, to keep the bacteria in check. 
Few wine-makers realize the great harm done to the reputa- 
tion of Californian wines by a few unscrupulous or ignorant 
dealers who systematically buy up unsound wines, "doctor" 
them, and ship them abroad. The sooner the use of anti- 
septics of any kind (except pure wine alcohol) is stopped, 
the better it will be for all concerned in viticulture. It is to 
be regretted that there is no law enforced that punishes 
those who use dangerous drugs in wine. 

Stuck Tanks. A " stuck tank " is a very common occur- 
rence at most ' all wineries in California, as well as in all 
countries having similar climates. It means that the yeast 
germs that convert the juice of the grape into wine have 
suddenly ceased their normal action, and fermentation proper 
has ceased, while bacterian activity has started up ; result- 
ing either in the total or partial loss of the wine. One wine- 
maker of this State told us that his loss from stuck tanks 
amounted in a single season to 10,000 dollars ; and there are 
but few who do not suffer to a certain extent from this 
trouble. 

As has been shown, the commonest cause of stuck tanks 
is too high temperature. The trouble is not by any means 
confined to California ; but is the curse of all wine-making 
countries in the warmer parts of the world, viz., all 
Southern Europe, North and South Africa, Australia, &c. 
The wine-maker of these countries has been found to be less 
self-complacent than his California brother, and has made 
serious efforts to control the temperature of fermentation. 

Methods of reducing Temperature. By some wine-makers 
the amount of sugar was reduced by the addition of water. 
This, in many cases proved of great service, but in others 
it was not so; for the water also reduces the acid and the 
body of the wine, and unless there be sufficient acid, nor- 
mal fermentation does not take place, save under excep- 
tional circumstances. Others tried to reduce the tempera- 
ture of the wine by the addition of ice to the fermenting 
tank. This had not only the same effect as the addition 
of water but proved utterly impracticable in the case of 



244 WIXE-MAKING IN HOT CLIMATES. 

red wine and is not economical. Some tried the use of 
metal spiral coils plunged in the fermenting tank through 
which cold water was passed. This proved successful in 
the case of wine fermenting without skins or stems (white 
wine); but was impracticable in 'all cases where the skins 
and stems were left in the tank, owing to the impossi- 
bility of sufficiently mixing the hot and cold parts of the 
fermenting mass. Others tried metal tanks, but this was 
found to be too expensive. 

Again, some tried pumping the wine from the bottom 
of the tank over into the top and allowing it to spread 
out into a spray. This accomplished two results: it cooled 
the wine slightly (but very slightly) and especially did it 
revive the partially paralyzed yeast cells by giving them a 
fresh supply of free oxygen. The fatal defect of this 
practice was found to be the too great oxidation and 
evaporation of the alcohol, which took place at high tem- 
peratures, the wine becoming too highly charged with acetic 
acid (vinegar-sour). Nevertheless, this pumping over of 
the wine of stuck tanks, or tanks that threaten to stick, 
is now widely practised all the world over, and in the case 
of a sudden stopping of fermentation it is necessarily done 
to supplement the addition of fresh must in active fermen- 
tation used to finish the conversion of the sugar into 
alcohol and carbonic acid gas. 

Experiments at the University. Convinced of the neces- 
sity of controlling the temperature of the fermentation of 
wines in this State (just as the brewers do that of iheir 
fermenting wort to a fraction of a degree, always getting 
a product the value of which is known beforehand), the 
Viticultural Staff of the College of Agriculture set about 
to devise some practical method for attaining this end. 
It was only after having completed the experiments with 
the apparatus herewith described, that we received detailed 
data of the European experiments with the refrigeration 
of wine. We give below a complete description, first, of 
the French apparatus; second, of the one first devised at the 
Experiment Station; and, third, of the one modified as found 
advisable after thorough trial. 

Apparatus used in other Countries. Figure 21 (page 116) 
represents one of the forms of the apparatus now used 
throughout Northern Africa and Southern France. As will 
be seen, it consists essentially of two columns, each made up 
of nineteen thin, well-tinned, horizontal copper tubes. These 



APPENDIX. 245 

tubes are 13 feet long by 1 inches in diameter. The total 
length of the tubes through which the wine passes is thus 
nearly 500 feet. These tubes are fitted into solid bronze 
castings, closed by means of a bronze plate over a rubber 
washer, with thumb-screws. The two columns are connected 
by a tube (3 fig. 21) running diagonally from the top of one 
column to the bottom of the other, so that the hot wine enter- 
ing at the lower end (7 fig. 21) of the first column, and after 
passing upwards and completing the circuit in this column, 
passes to the bottom of the second column, from which again 
it escapes at the top. Above the two columns of tubes is a 
large metal water-box, having two rows of holes in the bottom 
corresponding to the two columns, from which cold water is 
allowed to drip as the warm wine is pumped through the 
tubes. Under the apparatus is a metal box, which catches 
the drip of warmed water. Each column of tubes has a 
stop-cock (13), which allows rapid emptying of the wine 
when pumping is stopped. The apparatus is, as before said, 
now actually in use in other countries, and we are indebted 
to the excellent report of Messrs. Miintz and Rousseaux in 
La Revue de Viticulture for the results of their exhaustive 
experiments conducted in France during the past season, 
1896, as well as during the season of 1895. 

The first defects that strike one in this apparatus is the 
unwieldiness and expense, as well as the large amount of 
labour required to force a IJ-in. stream of wine through 
such a length of tubing at a working rate ; then the amount 
of water used in cooling the wine must be very large, unless 
the temperature of this water be considerably below that of 
the wine. As in the case of the use of ice, it will do well 
when all conditions are most favorable. 

In a recent article, giving a resume" of the two seasons' 
experiments, Messrs. Miintz and Rousseaux tell us that to 
work the apparatus a gang of four men, working in relays, 
is required to pump 40 hectolitres or 1,060 gallons per hour. 
With a motor engine double this amount could be pumped 
through, but the quantity of water needed in this case for 
the proper cooling of the wine is enormous, amounting to 
from one to one-and-a-half times the amount of wine passed 
through ; or far more cold water than is generally to be had 
at the average California winery. 

The reduction of temperature was in some cases very 
great, but depended altogether upon the rate of pumping, 



246 



WINE-MAKING IN HOT CLIMATES. 



the amount of water dripping over the tubes, and the initial 
temperature of this water. There was an average reduction, 
however, of from 10 to 12 degrees F., but in some cases a 
maximum of as much as 20 degrees when slow pumping was 
practised. The cost of cooling the wine was, on an average, 
one-thirteenth of one cent per gallon. 

From the careful tests made by these eminent scientists, 
the remarkable benefits of cooling the fermenting mass was 
strikingly shown. In all cases a certain lot of the same 
must was fermented in the usual way as a check to the 
experiment, and in every case the cooled wine was sounder 
and of far better quality. Microscopic examination showed 
that the uncooled wine was teeming with harmful bacteria, 
while the amount of unfermented sugar remaining was very 
considerably more than in the case where the wine had been 
cooled. The University experiments showed this as strikingly 
as did those of Miintz and Rousseaux. 

We give below a table taken from La Revue de Viticul- 
ture, in which some of these results are set forth. Unfortu- 
nately the recent disastrous fire at the Agricultural Building 
at the University destroyed all the notes taken at each tank 
cooled, so that we can but give the general results. These 
results were, however, looked over but a few days before the 
fire, and, being compared with those made in France by 
Miintz with his apparatus, were found to be essentially in 
accord, as appears from the data given below. We give 
below the exact figures obtained by these observers. This 
shows the matter to be not of something " theoretical " and 
untried, but something that has been tried by several, and 
proved to be a practical success. 

The experiments were made in the Rousillon district of 
France, near the Eastern Pyrenees, during the season of 
1896, with Carignane grapes. 



. 


Maximum tempera- 
ture of the must 
during fermentation. 


Alcohol per cent. 


Unfermented 
Sugar. 


Cooled Wine 

5 5 5 

Uncooled Wine .. 


96 (F.) 
96-8 
99-5 
102-2 
104-0 


11-00 

11-45 
11-50 
10-20 
10-10 


59 
65 
2-60 
3-30 



APPENDIX. 247 

It will be recollected that experiments made by Prof. 
Hilgard at the University, in 1887, gave almost precisely 
similar results as to alcohol percentage when hot and cool 
fermentations were compared. (See Report of the College 
of Agriculture on Methods of Fermentation of 188687, 
p. 28.) 

The effects of high temperature on the composition of the 
wine may be further illustrated by some other analytical 
results from the French experimenters, Miintz and Rous- 
seaux, who found in 1895 that a wine which had attained a 
maximum temperature of 98'5 degrees F., during fermenta- 
tion showed on analysis '066 per cent, of ammonia, while 
another wine made from the same lot of grapes, which 
attained a maximum of 104 degrees, showed -60 per cent. 
Similar results were obtained in 1896, when maxima tem- 
peratures of 94 degrees and 104 degrees gave '03 per cent, 
and -22 per cent, of ammonia respectively. It is clear, 
therefore, that serious chemical differences and defects are 
produced in the wine by high temperature fermentations 
apart from the swarms of disease bacteria which are always 
present in such wine. Of the wines made by Miintz and 
Rousseaux in their 1896 experiments, those that were not 
cooled threaten to spoil already ; while those that were 
cooled are in perfect condition. 

EXPERIMENTS MADE BY THE UNIVERSITY AT NATOMA, 
SACRAMENTO COUNTY, AND AT EVERGREEN, SANTA 
CLARA COUNTY. 

Apparatus used. The results of Miintz and Rousseaux 
were amply confirmed by the investigations undertaken by 
the Viticultural Staff during the season of 1896 at the 
Natorna Vineyard in Sacramento County, and at Mr. 
Wehner's at Evergreen, near San Jose. The apparatus 
used by us differed greatly from that used by Miintz and 
Rousseaux, and the many others abroad who practised 
refrigeration during fermentation at the same time. 

Not being able to avail ourselves of the detail of the 
numerous experiments undertaken along the same lines 
abroad during the past few years, we had to construct our 
apparatus independently upon what we considered the most 
promising lines ; fortunately, as it turned out, committing 
few mistakes and obtaining results that show our system 
to be far superior to any thus far proposed for California 



248 



WINE-MAKING IN HOT CLIMATES. 



conditions. However, experience has shown ns the desirability 
of certain changes and modifications as hereinafter shown, 
especially as mechanical power for pumping and crushing is 
available at nearly all wineries of this State. 

The apparatus 
shown in figure 2 
is the one de- 
signed and used 
by us in the ex- 
periments. It 
will be observed 
that in so far as 
the pumping of 
the heated wine 
through tinned 
copper tubes 
goes, the princi- 
ples are identical 
with those of the 
French appara- 
tus. The method 
of pumping is 
the same as is 
in practice at 
wineries for 
drawing off the 
newly fermented 
wine from the 
fermenting tank. 
The wine is 
drawn off from 
the bottom of 
the tank, and 
strained through 
a sieve into a 
tub, from which 
it is pumped 
through the ap- 
paratus into the 
top of the tank 
again. In other 

respects there are important differences ; thus, instead of two 
columns consisting of 498 lineal feet of tubing, our apparatus 
consisted of a single column of only 42 feet of tubing. The 





APPENDIX. 240 

tinned copper tubing instead of being perfectly round is very 
much flattened, thereby giving greater cooling surface to the 
same volume of wine, a material improvement on the French 
system of round tubes. It consists of fourteen pieces 3 feet 
long and 4 inches broad by 1^- inches deep. These tubes are 
fitted into bronze castings, which are closed by plates fitting 
over rubber washers, and fastened by thumb-screws, thus 
allowing the tubes to be readily cleaned in cases of obstruc- 
tions that might occur in the pumping through of the 
muddy, partly-fermented must. 

METHODS OF COOLING. 

Water-box. In our first experiments the whole apparatus, 
that is to say the column of tubes, was fitted into a box, tin- 
lined and filled with water. A constant supply of fresh water 
entered the box at the bottom, escaping from the top, while 
the wine entered the top of the apparatus and escaped at the 
bottom, in order that the coldest wine should come in con- 
tact with the coldest water, and vice versd. It is well known 
that this arrangement will give the greatest amount of 
cooling effect. 

It was found that by the use of a very large quantity of 
water the wine could be sufficiently cooled, but the excessive 
amount of water thus required caused us to abandon this 
system. In special cases, where an unlimited water supply 
is to be had without too great expense, this system should 
be adopted, for though the cost of water-box and installation 
will about offset the cost of the blower and canvas sleeve, 
hereinafter described, it has the advantage of doing away 
with the necessity of the command of power. In case this 
system is adopted, it is well to use a greater length of tubing 
than would be required where the spray and the air current 
are used. Roughly speaking, the amount of water used in 
this case should be from 1^ to 2J times the volume of wine 
pumped through the apparatus. 

Drip, Spray, and Blast. Instead of depending upon the 
simple dripping of the water over the tubes to effect the 
reduction of temperature of the warm wine, a great saving of 
tubing, as well as labour in pumping, was found to be 
effected by the use of a fine spray of water carried by a strong 
blast of air, thus combining the effects of cold water and 
evaporation. The quick evaporation brought about by the 
dry air prevailing at our vintage season, when mingled with 



250 WINE-MAKING IN HOT CLIMATES. 

a fine spray, produces a cooling effect far in excess of what 
could be obtained from the ordinary water at the wineries 
alone. This is important, for at many of the wineries the 
water available is very warm and the difference between the 
temperature of the water and the wine to be cooled is so 
slight that it would be impossible to effect a proper amount 
of cooling, unless enormous volumes of water were used. 

The proper proportions between the air blast and the 
amount of water sprayed is of the utmost importance. It is 
readily understood that a weak blast with a large amount of 
coarsely-sprayed water would leave the temperature of the 
water almost unchanged when it reaches the cooler, and 
would, therefore, amount to little more than the dripping- 
practised in the French apparatus ; while if the blast be in 
excess and the water deficient, the amount of water carried 
may not be sufficient to utilize the evaporative power of the 
blast, nor to thoroughly wet the tubes. Again, to insure 
the maximum cooling from evaporation, the spray should be 
so fine that within the short distance from the nozzle to the 
tubes the air may become fully saturated, and both cooled 
to the fullest extent. Of course, the heavier the blast the 
more water spray can be carried and cooled by it. To pro- 
duce the requisite fineness of spray, an adequate water 
pressure is necessary. 

Another factor of the utmost importance is the dryness, 
or what is technically called the " relative humidity " of the 
air used. During the vintage season this is frequently as 
low as 33 per cent, outside of the ivinery, and the intense 
evaporating effect producible under such conditions should 
be utilized by connecting the intake with the outer air. This, 
of course, can be done either by a canvas tube stretched by 
hoops, or by a board flume. 

When, as may happen near the coast, the moist condition 
of the air is unfavorable to strong evaporation, the water 
temperature, on the contrary, is frequently itself so low that 
an energetic spray without a blast may suffice to do the 
necessary amount of cooling. 

It will be noted, therefore, that the best conditions for 
cooling will vary, not only in different localities, but on 
different days, and according to the prevailing wind ; so that 
it is impossible to prescribe the exact strength of blast or 
quantity of spray that should be used. But a few experi- 
ments will determine the best practice in any given locality. 



APPENDIX. 251 

In our experiments the blast of air was generated by 
means of an 18-in. " double " (8-wing) blower, or " exhaust- 
ikn " reversed. The water escaped from a battery of three 
Vermorel nozzles placed immediately in front of the blower. 

A conical canvas sleeve attached to the outlet of the 
blower and 5 J feet away to the circumference of the cooler- 
frame prevents the loss of blast and spray. 

The "double" 18-in. blower requires under ordinary 
circumstances less than one-half horse-power to run it at a 
rate of 1,000 revolutions per minute, and thus, with a free 
supply, will pass 3,000 cubic feet per minute through it. 
The 24-in. " double " blower requires about the same horse- 
power to run it, but requires only 900 revolutions per minute 
to send through 5,000 cubic feet in the same time. It should 
be remembered that the best efficiency of every blower is 
limited to a definite velocity of revolution. The figures 
above given refer to the most favorable velocities for the sizes 
mentioned. The one costs 40 dollars (less discount) while 
the latter costs 50 dollars. In order that the apparatus may 
be available at small-scale wineries, where no steam is used, 
it may be well to state that a small gas engine, run with 
common " distillate " and giving 2 J horse-power, can be 
had for 187 dollars (less discount). The cost of running 
such a motor is 1 cent per horse-power per hour; a trifling 
expense, especially as the motor, once started, will run itself, 
so that one man can attend to the pumping of the wine and 
the running of the engine at the same time. Indeed, with a 
little fitting, such an engine could be made to do all the 
pumping in the cellar, and there are no labourers who will 
do 1 horse-power of work for a cent an hour. 

While the French apparatus was movable, ours was of 
necessity fixed, but with one man at the pump at Mr. 
Wehner's place it was found that he could pump from the 
most distant tank at the rate of 1,000 gallons per hour, in 
some cases as much as 1,400 gallons. At this rate a reduc- 
tion of temperature of from 10 to 13 degrees was obtained in 
the wine. The temperature was taken at the point where 
the wine left the tank and again where it re-entered the 
tank after having passed through the cooler. 

Precautions. We found that the much-feared deposit of 
cream of tartar on the inside of the tubes was very slight 
indeed. It would seem that while warm wine on cooling 
will deposit cream of tartar on the lining of the vessel, wine 

10649. R 



252 WINE-MAKING IN HOT CLIMATES. 

constantly in motion (as when being pumped) will not 
deposit much. Even after long use it was found that the 
thin coating of cream of tartar on the inside of the tubes 
could be removed by pumping the apparatus full of water 
and leaving it over night after a few barrels had been pumped 
through. The apparatus should be flushed out at least once 
in twenty-four hours, for the deposit of cream of tartar, be 
it ever so slight, interferes greatly with the conduction of 
heat, and anything that has this effect must be carefully 
avoided. Even the surface of the tubes should be polished 
once a day with ashes or lye, for there forms on the surface 
after a day's use a " greasy " film, due to the lubricant neces- 
sarily used in the blower, which not only interferes with the 
conduction of heat, but causes the water to run in streaks 
over the surface instead of spreading over it, much cooling 
surface being thus lost. 

The seeds and skins should be kept out as well as possible 
from the pump and consequently from the apparatus. By 
exercising due precaution in this regard, we did not have to 
clean the apparatus from this cause once during the entire 
trial. 

Control of Temperature. We found, as did Miintz and 
Rousseaux, that when the wine passed 100 degrees F. cooling 
was useless, for the ferments or yeasts were too badly 
injured -to be revived. Thus a tank at Natoma (where the 
conditions were unfavorable on account of hot weather) was 
fermented with some Algerian yeast, and was allowed to go as 
high as 104 degrees F. The tank "stuck" before fermen- 
tation was finished, and it could not be revived by cooling. 

Miintz and Rousseaux state that if a tank is cooled before 
the temperature reaches the danger limit there need be no 
fear that a subsequent rise to this limit will take place. We 
found at Mr. Wehner's that under the conditions existing, 
when the temperature in the tank reached 88 degrees F., if we 
pumped about one-half or two-thirds of the contents of the 
tank through the cooler, nothing disastrous ever happened, 
although the fermentation kept right on and the rise in 
temperature continued, yet it seemed that a sufficient amount 
of heat (calories) had been removed from the fermenting 
mass to enable it to complete fermentation without reaching 
the danger point. This favorable result, however, must 
largely depend upon special conditions, and should not be 
relied upon so as to relax vigilance. 



APPENDIX. 253 

Considering; the fact that low temperature fermentation 
gives a wine of a different composition from that fermented 
at high temperature, and leaving for a moment the killing 
of the yeast out of the question, it is evident that it would 
pay to keep the temperature constantly below the danger 
limit on account of the superior quality of the resulting 
wine. 

It might not pay in ordinary cases to go to this expense 
for quality alone, yet if extra fine wine is to be made, extra 
care must be bestowed upon it. 

Aeration of the Wine. It was deemed advisable to aerate 
the wine whenever it was pumped over. In order to accom- 
plish this, and at the same time to prevent the cooled wine 
from forming a channel in the cap and passing at once to 
the bottom and thus leaving the warmer wine at the top, we 
caused the wine to escape from the end of the hose in a 
fan-like jet, the direction of which was, from time to time, so 
changed as to reach all parts of the cap during the cooling. 
In this way the cap was very greatly cooled, which is 
important, as it is the hottest part of the fermenting mass 
in a tank. 

In all cases where the cooling took place at or about 
88 degrees F., the tank " went dry " perfectly well, and the 
resulting wine was drier and far clearer than in case of the 
wine not cooled and aerated. This was especially noticeable 
in cases where pure cultures of yeast were used, especially 
some of the foreign varieties. 

In some cases we tried the use of an extra empty tank 
into which the cooled wine from the first tank pumped was 
put, and the cooled wine from subsequent tanks was pumped 
into the first tank. At the end of a certain time the wine 
first cooled was pumped into the last tank. In this way one 
avoids cooling the same wine or part of it twice, but an 
extra pumping is thus necessitated. The avoidance of cooling 
wine that has just been cooled and pumped back to the top 
of the tank is certainly an important problem, that must be 
solved by each wine-maker according to circumstances. We 
would suggest that a storage tank, at a greater elevation 
than the fermenting tank, be used as a common receptacle 
for all cooled wine. As soon as a sufficient amount 
of wine in any given tank has been cooled, it can be 
returned by gravity, and thus all danger of wasting energy 
by pumping the same wine twice through the cooler can 

R 2 



254 WINE-MAKING IX HOT CLIMATES. 

be avoided. It is true that there will be an extra amount 
of labour required to force the cooled wine to a greater 
level than that of the fermenting tank. 

Faults of the Apparatus. It was found that with our 
first apparatus we had made the mistake of placing the tubes 
too far apart (2J inches), losing thereby a very considerable 
amount of air and spray. This we had to remedy for the 
time by filling up the space with 2-in. slats ; but this, of 
course, caused a great waste of cooling effect. We, there- 
fore, in our modified apparatus, recommend that the tubes 
be placed 1 inch apart, which is the practical limit for the 
successful soldering of the tubes into the castings, more 
especially when the tubes are of such greater width as we 
now find desirable. The horizontal position, moreover, will 
always prove a source of waste, on account of allowing too 
ready a passage for the current of air and spray. It was 
also found that for large scale operations the cooling capacity 
of the apparatus was not adequate. 



THE NEW APPARATUS. 

In the construction of the new apparatus the need of 
greater capacity was first considered. The lengthening of 
the tubes, as in the French model, renders it very cumbersome ; 
and it, therefore, seemed preferable to retain the same length 
of tubes, but to give them an increased cooling surface by 
enlarging their dimensions to 5^ inches x 1-J inches, and to use 
two batteries or columns placed one behind the other. This 
arrangement would serve in any case to utilize better the 
cooling current, which must always waste through a single 
system of tubes, however placed. Moreover, the increased 
cooling surface obtained by widening the tubes does not 
involve an increase of friction, as would a lengthening of 
tubes, to attain the same purpose. 

Another modification deemed wise is to have the extremi- 
ties of the tubes closed by a single bronze casting instead of 
separate castings for each pair of tubes. These castings 
are fastened by thumb-screws over rubber washers, as in 
the case of the first machine. The advantages are that it 
not only requires fewer thumb-screws (and hence allows 
greater rapidity in cleaning), but also that the solidity of 
the whole apparatus is greatly enhanced, and the necessity 
for an extra frame is done awav with. We found that with 



APPENDIX. 



255 



the great number of small castings it was difficult to keep 
any frame from " giving " a little. (See Fig. 3.) 




1 1 







Relative Position of the Sets of Tubes In order to 
determine as nearly as possible the various conditions need- 
ful to secure the best results, two sets of tubes of twelve 
each were placed in a convenient frame, and so suspended 



256 WINE-MAKING IN HOT CLIMATES. 

on chains that both their distance and their relative positions 
could be readily changed at will. While this would not 
enable us to determine exactly all the best conditions in the 
completed arrangement, it would at least enable us to avoid 
such mistakes as rendered the first apparatus to some 
extent unsatisfactory. 

It soon became apparent that so long as the tubes in the 
two sets were placed parallel to each other, whether 
horizontally, or inclined upwards or downwards, even when 
arranged as closely as practically possible, and so as to 
break joint, there was a great waste of spray, and therefore 
of cooling power, in the rear or the second column. The 
obvious remedy was to place them at an angle to each other, 
so that the current could be considerably checked and its 
direction completely changed before being allowed to emerge 
at the rear end of the apparatus. It remained to be deter- 
mined whether the relative inclinations should be in the 
form of a V or of an A, and what the angle of the inclina- 
tion should be. It was evidently not desirable to make this 
angle steeper than necessary to accomplish the purpose. 

Points observed. In making the experiments the points 
observed were : First, the absence of any considerable waste 
of spray beyond the second column ; second, the approxi- 
mate equality of the drip of water from both sets ; third, 
the diminution of temperature obtainable with varying 
strength of spray and blast. We could thus as nearly as 
possible estimate the results likely to be obtained by the 
apparatus when completed. In all experiments so far 
made the two sets were placed as near together as practi- 
cally possible. As to the first point it was found that the 
least waste of spray occurred when the tubes were placed 
1 inch apart in the inverted Y (A) position, and that for 
this purpose an angle of 30 degrees was sufficient. 

Second, it was further found that under these conditions 
the drip from the two sets of tubes was most nearly equalized, 
and that their entire surfaces remained well wetted. 

As regards the third point, it was found that in the 
space between the two sets the temperature was mainly 
governed by the strength of the blast and the amount 
and kind of spray used. In this respect our preliminary 
experiments could give only comparative values, since the 



APPENDIX. 257 

saturation of the air at Berkeley at the time was between 
75 and 80 per cent., and the air temperature varying but 
slightly above and below 60 degrees F. 

Air Blast and Spray. No mechanical power being avail- 
able at the time at Berkeley, we had to restrict ourselves in 
the use of the blower to such a velocity as could be obtained 
by the power of two men, which was between 700 and 750 
revolutions per minute, obtaining probably about two-thirds 
to three-quarters of the effect of the blower, or about 2,000 
or 2,500 cubic feet per minute. 

It was quickly noted that, as transmitted through the 
pyramidal canvas sleeve directly, the distribution of the 
wind over the surface of the tubes was very unequal, being 
very strong at the circumference, and almost null in the 
middle, on account of the centrifugal action of the blower. 
This inequality was effectually done away with by the inter- 
position between the blower and the pyramidal sleeve of a 
cylindrical sleeve 3J feet long. 

As regards the spray, a comparison of the reduction of 
temperatures obtained with the rather coarse spray here- 
tofore employed, with that obtained from a standard cyclone 
nozzle yielding very fine spray, showed that the latter was 
by far the most efficacious, besides which it permits of a 
shortening of the pyramidal portion of the sleeve, on account 
of the rapidity with which evaporation can take place. To 
attain this end, however, it is necessary that the pressure 
should be sufficiently high ; that is, nearly such as is 
obtained with spray pumps not less. Manifestly the coarse 
spray carried with it too much of the original high tem- 
perature of the water. It was also found, however, that a 
single nozzle of this kind does not yield a sufficiently large 
quantity of water, and that, therefore, a combination or 
battery of such nozzles should be used, varying in number 
according to the water pressure and the strength of blast at 
command. In our apparatus we have adopted five as pro- 
bably sufficient. 

It is easy to so arrange the battery of nozzles as to 
conform to the flare of the pyramidal sleeve, in order not 
to waste the spray upon the canvas on the one hand, nor 
to leave part of the space unutilized on the other. 

Beneath the apparatus should be placed a shallow box 
to catch the drip, which should be drained off through a 
pipe or trough. A screen may be placed in the rear of 



258 WINE-MAKING IN HOT CLIMATES. 

the apparatus to catch the spray that has passed through, 
and may be of boards, sacks, or any thing that is con- 
venient. If the apparatus be placed facing a door or 
window, no screen is necessary. The current of air in itself 
is not objectionable in a hot winery. The drawback to the 
free circulation of the current of air and spray is that the 
workmen working immediately in front of it after coming 
from some hot part of the cellar are in danger of contracting 
colds, or even pneumonia. 

Conclusions. Accepting, then, the fact that in California 
the tendency is to ferment at high temperatures, on account 
of the initial as well as the air temperatures being higher 
than in cooler countries, such as the Medoc, Burgundy, the 
Rhine, Champagne, &c., and also the fact that in this State 
we use exceptionally large fermenting tanks, and that our 
musts are, as a rule,' very high in sugar, and, in many cases, 
low in acid, the simple question is Shall we not attempt 
to overcome these natural defects of our climate, and con- 
trol fermentation, just as wine-makers of other countries do 
under similar circumstances, and as the brewers have long 
done under all circumstances ? 

Competition is now so keen that if we would succeed we 
must place on the market a wine that is equal, if not superior 
to that of other countries. Under favorable conditions we 
produce a wine that is equal to any in the world, but under 
unfavorable conditions we make wines that are distinctly 
inferior. 

It is the custom at all the wineries of the State, in case of 
the tank threatening to " sick," to pump the wine from 
the bottom over the top, at the same time aerating it by 
causing it to fall in a spray. Should the cooling apparatus 
be used in connexion with this procedure, there would be 
no extra cost beyond the original expense of the apparatus, 
which will last indefinitely with proper care. 

An apparatus such as we recommend will cost very little 
compared with the enormous saving that can be effected in a 
single unfavorable season. To provide several for use at a 
large winery should not cost over 1,000 dollars, while for a 
winery of ordinary size an apparatus capable of reducing 
the temperature of the wine a minimum of 10 degrees at the 
rate of 1,000 gallons per hour, would cost far less. Messrs. 
Miintz and Rousseaux found that the cost of cooling wine in 
France with their cumbersome apparatus was one-thirteenth 



APPENDIX. 259 

of a cent per gallon. This includes four men at 70 cents 
per day for pumping, and the wear and tear, interest on the 
original cost of the apparatus, and all possible extra 
expenses. It would not cost much over one-twelfth of a 
cent per gallon in this country, even if we had to buy a 
200-dollar motor (2^ h.p.) in addition to the apparatus 
itself. It need not cost any more than this, for the motor 
takes care of itself when once started, and any extra horse- 
power could be used to advantage in pumping wine from one 
tank to another. 

In conclusion, we wish to express the sincere thanks of the 
University to those who helped us with suggestions, money, 
and material. 

Messrs. Toulouse and Delorieux, of 622 Commercial-street, 
San Francisco, constructed the apparatus according to our 
designs, and it is due in no small degree to the extra time 
and trouble bestowed by them tipon its construction and 
modifications that the experiments proved successful. 

Mr. D. M. Doub, of 137 First-street, San Francisco, came 
forward in the most public-spirited manner, loaning us 
several of the " blowers " and " exhaust-fans " needed. But 
for such liberality the experiments could not have been 
undertaken '. 

The Pelton Water-wheel Co. also helped us not only with 
the loan of machinery, but also by making for us on the 
shortest possible notice such alterations as were suddenly 
found necessary. 

Mr. J. Henshaw Ward provided for our exclusive use at 
the Natoma Vineyard 150-00 dollars worth of the best wine 
hose, not otherwise obtainable. 

Mr. J. H. Wheeler and Mr. J. Rennie, the lessees of the 
Natoma Vineyard, allowed us to use part of the vintage and 
cellar. 

To Mr. Wm. Wehner, of Evergreen, we are especially 
indebted, not only for the use of the cellar, vintage, 
labourers, &c., but for the hospitality and attention he 
bestowed upon us. The kindness and assistance we received 
at his hands was exceptional. 

Descriptions of the apparatus used abroad are given along- 
side of the form we have devised, so that the wine-maker 
may choose between them. 

All that we desire is that some kind of effort shall be 
made to control temperatures, be it the use of ice, water, 



260 WINE-MAKING IN HOT CLIMATES. 

air, or anything else ; for it is certain that if the tempera- 
ture is controlled there will be an improvement of from 10 
to 1 00 per cent, in the quality of Californian wine. 

The Viticultural Staff of the College of Agriculture will 
cheerfully confer and advise with any persons interested in 
this subject, and assistance in the construction or working of 
coolers of any sort will be given. While we think that our 
apparatus is better than any of the rest, all that we desire 
is that there be some sort of cooling apparatus used, and 
if our efforts contribute to the attainment of this end we 
will be satisfied. 



APPENDIX. 261 



THE METRIC SYSTEM. 

MEASURE. 

The Metric System takes for its basis the distance froni 
the Equator to the Pole, dividing this into ten million parts. 
One such part is a metre. The words denoting multiples 
of the Metric standards are derived from the Greek, and 
those denoting divisions, from the Latin, thus : 

10 metres equal one decametre. 
100 hectometre. 

1,000 ,, kilometre. 

10,000 myriametre. 

T V of a metre equals one decimetre. 
T <5- centimetre. 

Tihm millimetre. 

WEIGHT. 

The weight of one cubic centimetre of water at 4C. is the 
standard, and is called a gramme. 

10 grammes equal one decagramme. 
100 hectogramme. 

1,000 kilogramme. 

T V decigramme. 

centigramme. 

milligramme. 



FLUID MEASURE. 

The volume of a cubic decimetre is the standard, and is 
called a litre. 

1 00 litres equal one hectolitre. 
^ decilitre. 
T U centilitre. 
lAo milhhtre. 

The hectolitre is the wholesale standard for wine. One 
hectolitre of water weighs 100 kilos. 



262 



WINE-MAKING IN HOT CLIMATES. 



THE METRIC AND BRITISH SYSTEMS. 
METRIC MEASUKES. 



One metre 


= 39-37079 inches. 


One decimetre = 3'937 


5 


One centimetre = 0'3937 


One millimetre = 0-0394 


Millimetres = Inches. 


Centimetres Inches. 


Millimetres. Inches. 


Centimetres. Inches. 


Centimetres. Inches. 


1 = 0-039 


1 = 0-394 


10 = 3-94 


2 = 0-079 


2 = 0-787 


20 - 7-87 


3 = 0-118 


3 = 1-181 


30 i= 11-81 


4 = 0-157 


4 1*575 


40 rz 15-75 


5 = 0-197 


5 - 1-969 


50 zr 19-69 


6 = 0-236 


6 - 2-362 


60 - 23-62 


7 = 0-270 


7 - 2-756 


70 - 27-56 


8 = 0-315 


8 = 3-150 


80 zz 31-50 


9 - 0-354 


9 = 3-543 


90 = 35-43 


METRES = FEET. 


Metres. ft. in. Metres. ft. in. Metres. ft. yds. 


1 - 3 3g 


10 = 32 10 


100 = 328 = 109 


2 = 6 6J 


20 - 65 7 


200 = 656 = 219 


3 = 9 10 


30 = 98 5 300 - 984 = 328 


4 = 13 li 


40 = 131 3 400 = 1,312 - 437 


5 = 16 r> 


50 - 164 500 - 1,640 = 547 


6 = 19 8 


60 - 197 600 - 1,968 = 656 


7 = 22 11J 


70 - 230 


TOO -2,297 - 766 


8 = 26 3 


80 - 262 800 = 2,625 = 875 


9 = 29 6J 


90 - 295 900 - 2,953 = 984 



ATTEND IX. 



263 



SQUARE METRES = SQUARE FEET SQUARE YARDS. 



Square metres. 

0929 = 
1 = 
2 = 
3 = 
4 = 
5 
6 = 

(< 

/ 
8 = 
9 = 
9-29 = 
10 = 
20 = 
50 = 


Square feet. 
1 

10-76 
21-53 
32-29 
43-06 
53-82 
64-59 
75*35 
86-11 
96-88 
100 
107-64 
215-29 
538-21 





Square yards. 

1-196 
2-39 
3-59 

4-78 
5.98 . 
7-18 
8-37 
9-57 
10-76 
10-76 
11-96 
23-92 
59-80 


92-90 


zz 


1,000 





59-80 


100 


zr 


1,076-43 





119-60 


500 





5,382-15 





598-02 


1,000 


== 


10,764-30 


;= 


1,196-03 


Square feet. 




Square yards. 




Square metres. 


9 





1 





84 


10 





1 





929 


18 





2 





1-67 


27 





3 





2-51 


36 





4 





3-34 


45 





5 





4-18 


54 


- 


6 





5-02 


63 





7 





5-85 


72 





8 





6-69 


81 





9 





7-52 


90 





10 





8-36 


100 


- 


10 





9-29 


180 


- 


20 





16-72 


450 





50 





41-80 


900 





100 





83-61 


1,000 





100 


~ 


92-90 


4,500 





500 





418-05 


9,000 


== 


1,000 





836-10 



264 WINE-MAKING IN HOT CLIMATES. 

CUBIC METRES = CUBIC FEET = CUBIC YARDS. 



Cubic 


Cubic 


Cubic 


Cubic 


Cubic 


Cubic 


metres. 


feet. 


yards. 


metres. 


feet. 


yards. 


1 = 


35-32 


= 1-31 


9 - 


317-85 


= 11-77 


2 = 


70-63 


zz 2-62 


10 zz 


353-17 


= 13-08 


3 = 


105-95 


- 3-92 15 = 


529-75 


= 19-62 


4 = 


141-27 


= 5-23 20 = 


706-33 


= 26-16 


5 =r 


176-58 


6-54 50 zz 


1,765-83 


zz 65-40 


/-* 


211-90 


- 7-85 100 - 


3,531-66 


=z 130-80 


< zz 


247-22 


- 9-16 


500 zz 


17,658-29 


- 654-01 


8 zz 


282-53 


= 10-46 j 


1,000 = 


35,316-58 


= 1,308-02 



1 cubic metre of water at 4 C. weighs 1,000 kilos. 
1 cubic foot = 0-0283 cubic metre. 
1 cubic yard = 0-7645 cubic metre. 

COMPARATIVE PRESSURE PER SQUARE CENTIMETRE 
AND PER SQUARE INCH. 



Grammes per 
square centimetre. 


Lbs. per 
square inch. 


Kilos, per 
square centimetre. 


Lbs. per 
square inch. 


50 





0-71 


1 





14-22 


100 





1-42 


52 





28-45 


200 





2-84 


3 





42-67 


300 





4-27 


4 





56-89 


400 





5-69 


5 





71-11 


500 





7-11 


6 





85-34 


600 





8-53 


7 





99-56 


700 





9-96 


8 





113-78 


800 





11-38 


9 





128-01 


900 


=3 


12-80 


10 





142-23 



METRIC WEIGHTS. 



One decigramme 
One gramme 
One decagramme 
One hectogramme 
One kilogramme 



1-543 grain. 
15-4323 grains. 
0-353 oz. avoirdupois. 
3-527 ozs. 
2-2046 Ibs. 



APPENDIX. 



265 



OUNCES AVOIRDUPOIS TO GRAMMES. 



Ozs. 

i 
i 

t 

1 

o 

rW 

3 
4 
5 

6 

7 



Grins. 

7 
14 



57 
85 
113 
142 
170 
198 



Ozs. 

8 

9 

10 
11 
12 
13 
14 
15 
16 or lib. 



Grms. 

227 
255 
283 
312 
310 
369 
397 
425 
454 



METRIC FLUID MEASURES. 



One hectolitre 
One decalitre 
One litre 
One decilitre 
One centilitre 
One millilitre 



= 22-01 gallons. 

= 2-201 

= 0-22 or 1-76 pint. 

= 3oz. 4dr. 10'4min. 

= 2dr. 4-9min. 

= 16-9 minims. 



One pint 

One quart (2 pints) 
One gallon (4 quarts) 
One peck (2 gallons) 
One bushel (8 gallons) 
One quarter (4 bushels) 



0-5679 litre. 
1-1359 ., 
4-5435 
9-0869 
36-34766 
2-9078 hectolitres. 



266 



WINE-MAKING IN HOT CLIMATES. 



Conversion of 
Thermometer 
Scales. 


ll 

u. 


!! 


! 







" 


210- : 

200- 






~ 




- 


_E 


- 


; 


_ 90 


_ 


. L 


- 


7t>_ 




i 




- 


: -fio 


-^ 


! 


~ 


170 = 
160 - 


I - 


60-- 


:70 


- 




_; 


If ft ^ 


- 


I 


HOE 





50= = 


130? 


- 


-- 


- 





120: 


^jTrv 




Ov 


1 V ' 







i 


r- 


- 


LOOj 




; 


1-t<> 


I 




~3$~ 


90-1 




- 


-^0 


--_ 


80j 


= 


~zZ- 






- 


70 


-20 


- 


= 




- 


60^ 




~ 


50 1 




ia- 




- 


40 




- - 




E 


i 


-e- 


30- 




. 


20 f 


- 


- 


ITT 


- 


10 j 


iu: 


o^? 




- 









Salleron's Portable Mustimetre. 



INDEX. 26' 



GENERAL INDEX. 



Page 

TRANSLATORS' PREFACE ... ... ... ... .. i 

CHAPTER I. Fermentation ... ... ... ... ... 3 

Alcoholic fermentation ... , ... ... ... 4 

Vinous fermentation ... ... ... ... ... 8 

CHAPTER II. Study of the Grape ... ... .., ... 12 

Maturation ... ... ... ... ... ... 12 

Formation of sugars in the grape ... ... ... ... '13 

Composition of ripe grapes of different cepages in the South of 

France ... ... ... ... ... ... 19 

Composition of grapes of the principal cepages of the South of 

France ... ... ... ... ... ... 26 

Aramon cepage ... ... _.;.. ... ... ... 26 

Carignan cepage ... ... ... .,. ... ... 28 

Petit Bouschet cepage ... ... -~'... ' ... ... 30 

Picquepoul blanc cepage ... ... ... ... ... 32 

Matters brought to the vat by 100 kilos of vintage ... ... 34 

CHAPTER III. Vintage ... ... .... ... ... 36 

Determination of sugar ... ... ... ... ... 37 

Determination of acidity ... ... ... ... ... 39 

Mode of operating ... .. ... ... ... 42 

Influence of the time of vintage on the quality of wines ... 45 

Improvement of certain vintages ... ... ... ... 53 

Deficient acidity ... ... ... ... ... ... 54 

CHAPTER IV. Vinification ... ... ... ... ... 56 

Vinification of red wine ... ... ... ... ... 56 

Crushers ... ... ... ... ... 56 

Stemming ... ... ... ... ... ... 65 

Stemmers ... ... ... ... ... ... 66 

Advantages of stemming ... ... ... ... ... 68 

Vatting... ... ... 72 

Aeration of the vintage ... ... ... ... 72 

Contribution to the study of vinous fermentation. Influence of 

temperature (L. Roos and F. Chabert) ... ... ... 76 

Opinions of various authorities as to the best temperature for 

fermentation ... ... ... ... 78 

Methods and apparatus employed . . . 

Study of fermentations 

Influence of temperature on the yield of alcohol ... ... 86 

work of different yeasts 

loss of alcohol 

/, total acidity of wine 

Action of temperature on the yeast 

Influence of the temperature on the quantity of nitrogen 
Influence of the temperature of fermentation on the yield in 

alcohol ... 

10649. S 



268 WINE-MAKING IN HOT CLIMATES. 

Page 
CHAPTER IV. Vinification continued. 

Influence of the temperature of vinous fermentation on the 

qualities of wine ... ... ... ... ... 103 

Influence of the temperature of fermentation on the keeping 

quality of wine ... ... ... ... ... ... 106 

Refrigeration of musts during fermentation ... ... ... 107 

Study of various must refrigerators ... ... ... 115 

Method of taking the temperature of a fermenting va't . . . 126 

Fermenting house ... ... ... ... ... 130 

Fermenting vessels ... ... ... . . . . . 131 

Fermentation ... ... ... ... ... ... 133 

Pollacci's experiments ... ... . ... ... 134 

Duration of vatting ... ... ... ... ... 145 

Various additions to the vat ... ... ... ... 147 

Acidification ... ... ... ... 147 

Plastering ... ... ... ... ... 148 

Phosphating... .. ... 148 

Selected yeasts ... ... ... ... ... 149 

De- vatting (Decuvage) ... ... ... ... 151 

Exhaustion of the marc ... ... ... ... ... 152 

Presses ... ... ... ... ... ... ... 152 

Intermittent presses ... ... ... .. ... 152 

Continuous presses ... ... ... ... ... 156 

Exhaustion of marc without presses ... 163 

CHAPTER V. Vinification of White Wine ... 169 

Viuifi cation of white varieties ... ... ... ... 169 

Fermentation ... ... ... ... ... 179 

Manufacture of white wine from red grapes ... ... 1 80 

New method for the Vinification of white wines ... ... 183 

CHAPTER VI. Utilization of By-products ... ... ... 190 

Marc ... ... ... ... ... ... ... 190 

Lees and tartar ... ... ... ... ... ... 197 

Determination of the percentage of bitartrate of potash in the 

crust or lees ... ... ... ... 200 

CHAPTER VII. Care to be given to Wine. Defects and Diseases 204 

Defects and diseases of wine ... ... ... ... 206 

Treatment of diseased wines ... ... ... ... 224 

Heating (Pasteurizing) ... ... ... ... ... 224 

Filtering and fining ... ... ... ... ... 226 

Precautions to be taken to insure the efficacy of fining . . . 229 

APPENDIX. 

Extract from " The Vine in Australia" by Dr. A. C. Kelly, 1841. 

Chapter on fermentation ... ... ... ... ... 232 

The control of the temperature in wine fermentation, by A. P. 
Hayne, Director of Viticulture, California, Bulletin No. 117, 

University of California, 1 897 ... ... ... ... 238 

The metric system ... ... ... ... ... ... 261 

The metric and British systems ... ... ... ... 262 

Conversion of thermometer scales ... ... 266 



INDEX. 269 



ALPHABETICAL INDEX. 

Page 
A. 

Acetification ... ... ... ... ... ... ... 212 

Acid, sulphurous (used in vinification of white wine) ... 170 

Acid, sulphurous (use in diseases) ... ... ... ... 230 

Acid, tartaric (addition of) ... ... ... ... 54 

Acidification... ... ... ... ... ... ... 147 

Acidimetre ... ... ... ... ... ... ... 40 

Acidity (defect of) ... ... ... ... ... 53 

Acidity (determination of) ... ... ... ... ... 39 

Acidity (influence of temperature on total acidity of wine) ... 92 

Advantages of stemming .. ... ... ... ... 68 

Aeration of vintage ... ... ... ... ... ... 72 

Albumen (fining of wine) ... ... ... ... ... 228 

Alcohol (influence of temperature of fermentation on the yield of) ... 86 

Alcohol (influence of temperature on the loss of) ... ... 92 

Alcoholic fermentation ... ... ... ... ... 4 

Amelioration of vintage ... ... ... ... ... 53 

Amertume (disease of) ... ... ... ... ... 215 

Analysis of sugar in must ... ... ... ... ... 37 

Analysis of acidity in must ... ... ... ... ... 39 

Apparatus used for the study of fermentation at constant 

temperature ... ... ... ... ... ... 81 

Apparatus used for collecting the alcohol carried away mechanically 

during fermentation ... ... ... ... ... 91 

Aramon (composition of grapes) ... ... ... ... 26 

Arrangement of Coste-Floret, for fermentation ... ... ... 137 

Arrangement of Ermens, for refrigeration ... ... ... 108 

Arrangement in the laboratory showing the displacement of wine 

by water ... ... ... ... ... ... 164 

Auto-regulator for fermentation ... ... ... ... 142 

Auto-regulator fixed on vat ... ... ... ... ... 143 

Automatic registering apparatus for gas liberated during fermenta- 
tion, of Houdaille ... ... ... ... ... 83 

B. 

Blood, its use in fining ... ... ... ... ... 227 

Bouquet of wines, its origin ... ... ... ... ... 23 

Break jet, for spraying must ... ... ... ... ... 139 

By-products, utilization of ... ... ... ... ... 190 

C. 

Cambon's apparatus ... ... ... ... ... . 141 



Care to be given to wine 

Carignan (composition of grape) 

Casse (disease of) 

Climagene chimney ... 

Climagene chimney. Dessoliers (arrangement of cellular bricks) 

Clarifying of wines 

Colour of wine (yellow colour) . . . 



204 
28 
218 
112 
112 
226 
207 



Colouring matter of grapes ... ... ... ... ... 22 



270 WINE-MAKING IN HOT CLIMATES. 

Page 

Composition of must ... ... ... ... ... ... 20 

Composition of ripe grapes of principal cepayes .. ... ... 34 

Composition of principal cepages ... ... ... ... 26 

Composition of experimental wines (stemming) ... ... ... 70 

Composition of medium-sized canes (table) ... ... ... 16 

Composition of medium-sized canes (diagram) ... ... ... 17 

Composition of stalks ... ... ... ... ... ... 19 

Composition of seeds ... ... ... ... ... ... 24 

Continuous press ... ... ... ... ... ... 156 

Contribution to the study of vinous fermentations ... ... 76 

Contribution to the study of vinous fermentations (conclusions) . . 98 

Correction of the saccharine strength of must ... ... ... 54 

Crushers ... ... ... ... ... ... ... 56 

Crusher (side view of Blaquieres) ... ... ... ... 59 

Crusher (top view of Blaquieres) ... ... ... ... 60 

Crusher (front view of Blaquieres) ... ... ... ... 59 

Crusher (arrangement of cylinder on vat) ... ... ... 57 

Crusher, drainer, and stemmer (side view of Blaquieres) ... ... 67 

Crushing ... ... ... ... ... ... ... 56 

D. 

Debourbage ... ... ... ... ... ... ... 169 

Defects and diseases of vines ... ... ... ... ... 206 

Determination of the strength of crude tartar in lees ... ... 200 

De-vatting ... ... ... ... .. ... 151 

Diplococcus aceti ... ... ... ... ... ... 212 

Disease of acetification (vinegar) ... ... ... ... 212 

Disease of amertume (bitter) ... ... ... ... ... 215 

Disease of casse (breakage) ... ... ... ... ... 218 

Disease of fleur (flower) ... .. ... ... ... 211 

Disease of graisse (fat) ... ... ... ... '... 216 

Disease of pousse (pushing) ... ... ... ... ... 215 

Disease of tourne (turning) ... ... ... ... ... 213 

Diseased wines, treatment of ... ... ... ... ... 224 

Diseases, treatment used in ... ... ... .. ... 224 

Diseases of wines .'.. ... ... ... ... ... 206 

Drainage of marcs ... ... ... ... ... ... 152 

Drainage of marcs without press ... ... ... ... 163 

E. 

Earthy taste... ... ... ... ... ... ... 208 

F. 

Fermentation ... ... ... ... ... ... 133 

Fermentation (alcoholic) ... ... ... ... ... 4 

Fermentation (duration of) ... ... ... ... ... 145 

Fermentation, experiments of Pollacci ... ... ... ... 134 

Fermentation (products of alcoholic) ... ... ... ... 6 

Fermentation (with single submerged head) ... ... ... 136 

Fermentation (with multiple submerged heads) ... ... ... 136 

Fermentation (arrangement of Coste-Floret) ... ... ... 137 

Fermentation, mannitic ... ... ... ... ... 216 

Fermentation, vinous ... ... ... ... ... ... 8 

Fermentations (contributions to the study of vinous) ... ... 76 



INDEX. 271 

Page 

Fermentation (opinions of different authors as to the best tempera- 
ture of vinous) ... ... ... ... ... 7& 

Fermenting vats ... ... ... ... ... 131 

Filling of casks ... ... ... ... ... ... 204 

Filtering ... ... ... '.'.'. '.. 226 

Fleur (disease of) ... ... ... ... ... ... 211 

Formation of sugar in grapes ... ... ... ... ... 13 

G. 

Gelatine, its use in the fhui; f wine ... ... ... ... 228 

Glucometre, Guyot ... ... ... ... ... ... 37 

Graisse (disease of) ... ... ... , ... ... ... 216 

I. 

Influence of temperature of fermentation on the total acidity of wine 92 

Influence of temperature of fermentation on the loss of alcohol ... 91 

Influence of temperature of fermentation on the yield of alcohol ... 98 
Influence of temperature of fermentation on the quantity of nitrogen 

in wine ... ... ... ... ... ... ... 93 

Influence of temperature of fermentation on the quality of wine . . . 103 

Influence of temperature of fermentation on the composition of wine 86 

Influence of temperature on the action of yeasts ... ... 92 

Intermittent presses ... ... ... ... ... ... 52 

L. 

Leaden-coloured wine ... ... ... ... ... 207 

Lees, of wine ... .-.; ... ... ... ... 197 

M. 

Marc, utilization of ... ... ... ... ... ... 190 

Manufacture of white wines ... .-- ... ... ... 169 

Manufacture of white wine, new process for ... ... ... 183 

Manufacture of white wine from red grapes ... ... ... 180 

Manufacture of red wine ... ... ... ... ... 56 

Matters brought to the vat by 100 kilos of vintage . ... ... 34 

Matters, colouring of grapes ... ' ... ... ... ... 22 

Milk, its use in fining ... ... ... ... ... 227 

Must, its composition .. . ... .., ... ... ... 20 

Mustard powder, use of ... ... ... ... ... 210 

Mustimetre, Salleron ... ... ... ... ... ... 38 

Mutage ... ... ... ... ... 171 

Muteuses ... ... ... .., ... ... ... 171 

Muteuse, Coste-Floret ... ... ... ... ... 171 

Muteuse, P. Paul ... 172 

Muteuse, du Bosquet ... ... ... ... 173 

Muteuse, Thomas and Roos ... ... ... ... ... 175 

Muteuse, Thomas and Roos, arrangement for the bung hole ... 176 

Mycoderma aceti 

Mycoderma vini ... ... ... ... ... 211 

0. 

Opinion of different authors on the best temperatures of fermenta- 
tion ... ... ... ... 78 

Origin of the perfume of wine ... 23 

Olive oil, its use in diseases of wine ,.. ... .. ... 210 



272 WINE-MAKING IN HOT CLIMATES. 

P. Page 

Petit-Bouschet, composition of grape ... ... ... ... 30 

Phosphating . . . ... ... ... ... ... 148 

Picquepoul, composition of grape ... ... ... ... 32 

Piquettes ... ... ... ... ... ... ... 190 

Piquettes, plan of arrangement for ... ... ... ... 194 

Plastering ... ... ... ... ... 148 

Pousse ... ... ... ... ... ... 215 

Precaution to be observed to insure success in fining ... ... 229 

Presses ... ... ... ... ... ... ... 152 

Presses, continuous ... ... ... ... ... ... 156 

Presses, type of continuous ... ... ... ... ... 157 

Presses, intermittent ... ... ... ... ... 152 

Presses, type of ordinary ... ... ... ... ... 153 

Press, with spring load ... ... .. ... ... 154 

Pumping the must over the head ... ... ... ... 138 

Q. 

Quality of wines, action of acidity on ... ... ... ... 47 

Qualitj 7 of wines, influence of the time of vintage on ... ... 45 

Quality of wines, influence of the temperature of fermentation on ... 103 

R. 

Racking ... ... ... ... ... ... ... 152 

Refrigeration, arrangement of Ermens ... ... ... ... 108 

Refrigeration of must during fermentation ... ... ... 107 

Refrigerators for must during fermentation ... ... ... 108 

Refrigerators for musts, trials of ... ... ... ... 120 

Refrigerator, Andrieu ... ... ... ... ... 124 

Refrigerator, Muntz and Rousseau ... ... ... ... 116 

Refrigerator, Paul ... ... ... . ... ... ... 117 

Refrigerator, Rouviere Hue ... ... ... ... ... 122 

S. 

Saccharomyces apiculatus ... ... ... ... ... 9 

Saccharomyces cere visse ... ... ... ... ... 6 

Saccharomyces ellipsoideus .. ... ... ... ... 9 

Seeds, grape, composition of ... ... ... ... ... 24 

Smell, putrid, in wine ... ... ... ... ... 210 

Stalks, grape, composition of ... ... ... ... ... 21 

Stemmers ... ... ... ... ... ... ... 66 

Stemmer, arrangement on vat ... ... ... .. ... 66 

Stemming ... ... ... ... ... ... ... 65 

Stemming, when necessary ... ... ... ... ... 68 

Stemming, composition of wines experimented on ... ... 70 

Sulphuring ... ... ... ... ... ... ... 230 

Sulphuring with pump ... ... ... ... ... 231 

Sugar, determination of ... ,.. .... ... ... 37 

Sulphite, alkaline, uses of ... ... ... ... ... 170 

T. 

Table showing the nitrogen content of wines made at different 

temperatures ... ... ... ... ... ... 94 

Tables, comparing fermentation at different temperatures ... 95 

Tap Trabut, for aeration of musts ... ... ... ... 140 



INDEX. 273 

Page 

Tartar, crude, determination of ... ... ... 200 

Temperature of fermenting vat, measurement of ... 126 

Temperature of fermentations, opinions of various authors on the 

best ... ... ... ... ... ._ _ 7g 

Thermometer, self -registering ... ... ... 127 

Treatment of diseased wines ... ... 224 

Trials of must refrigerators ... ... ... ... 115 

Tube, acidimetric, Salleron ... ... ... 49 

Turbine, aero-crushing ... ... ... ][[ QI 

Type of continuous press ... .. ... 157 

Type of intermittent press ... ... ... ... 153 

U. 

Utilization of by-products ... ... 190 

Utilization of by-products, marc .. .. 190 

Utilization of by-products, lees and tartars ... ... 197 

V. 

Vats, arrangement of fermenting ... ... ... 136 

Vessels used in fermentation .., ... ... ... 131 

Vintage ... ... ... ... ... ... ... 35 

Vintage, aeration of ... ... ... ... ... ... 72 

Vintage, improvement of certain ... ... ... 53 

W. 

Wines, care to be given to ... ... ... ... ... 204 

Wines, treatment of diseases of ... ... ... 224 

Wines, leaden colour of ... ... ... ... ... 207 

Y. 

Yeast, action of temperature on ... ... ... ... 92 

Yeast, beer ... ... ... ... ... ... ... 6 

Yeast, wine ... ... ... ... ... ... ... 8 

Yeast, composition of ... ... ... ... ... 7 

Yeast, influence of temperature on the work of different ... ... 90 

Yeasts, selected ... ... ... ... ... ... 149 

Yellow colour of wine ... ... ... ... ... 207 



By Authority : ROBT. S. BRAIN, Government Printer, Melbourne. 



PUBLICATIONS RELATING TO VITICULTURE, 



BY W. PERCY WILKINSON. 

THE ALCOHOLIC STRENGTH OF VICTORIAN WINES EXHIBITED AT THE 
MELBOURNE INTERNATIONAL EXHIBITION 1888. Official record, Mel- 
bourne Centennial International Exhibition, pp. 305-317, 8vo. 
Melbourne, 1888-9. 

THE ALCOHOLIC STRENGTH OF VICTORIAN WINES. Journal of the Board 
of Viticulture, No. 5, pp. 81-96. Melbourne, 1892. 

THE SUGAR STRENGTH AND ACIDITY OF VICTORIAN MUSTS, WITH 
REFERENCE TO THE ALCOHOLIC STRENGTH OF VICTORIAN WlNES. 

Part 1. Report of the Australasian Association for the Advance- 

ment of Science, pp. 306-315. Adelaide, 1893. 
Part 2. Proceedings of the. Royal Society of Victoria, pp. 89-118. 
Melbourne, 1894. 

ACIDITY IN MUSTS. Editorial Note. Translated from the Revue de 
Viticulture, pp. 239, 240. 1895. The Australian Vigneron, pp. 
330, 331. Sydney, 1895. 

REFRIGERATION IN WINK-MAKING. A. Barbier. Translated from the 
Revue de Viticulture, pp. 374-376. 1895. The Australian Vigneron, 
p. 379. Sydney, 1896. 

WINE-MAKING IN HOT CLIMATES. U. Gayon. Translated from the 
Revue de Viticulture. January, 1896. The Australian Vigneron, 
pp. 386, 387. Sydney, 1896. 

A RESUME OF MM. MUNTZ AND ROUSSEAUX'S STUDIES ON* THE IMPORT- 
ANCE OF REFRIGERATION OF MUSTS IN WINE-MAKING. Translated 
from the Revue de Viticulture. 1896. Extract from The Australian 
Vigneron, p. 20. Sydney, 1896. 

SALICYLIC ACID IN WINE (LAWS IN EUROPE RELATING TO). The Aus- 
tralian Vigneron, pp. 63, 64. Sydney, 1896. 

THE ESTIMATION OF FUSEL OIL IN SPIRITS : OFFICIAL METHOD OF THE 
GERMAN GOVERNMENT. Extract from The Australian Vigneron, 
p. 8. Sydney, 1898. 

AMERICAN VINES : THEIR ADAPTATION, CULTURE, GRAFTING, AND PRO- 
PAGATION. By P. Viala and L. Ravaz. Translated abridgement of 
the second French edition. By W. Percy Wilkinson and Joseph 
Gassies, pp. viii., 88. Melbourne, 1897. 

AN EXAMINATION OF THE WINES RETAILED IN VICTORIA. Australasian 
Association for Advancement of Science. Melbourne, 1900'. 



BY RAYMOND DUBOIS, 

THE COMPOSITION OF NATURAL WINES. A paper read before the Aus- 
tralasian Association for Advancement of Science. Melbourne, 1900. 






14 DAY USE 

RETURN TO DESK FROM WHICH BORROWED D 

LOAN DEPT. 



This book is due on the last date stamped below, 
or on the date to which renewed. Renewals only: 

Tel. No. 642-3405 

Renewals may be made 4 days priod to date due. 
Renewed books are subject to immediate recall. 



or 




HI 




LD21A-60m-8,'70 
(N8837slO)476 A-32 



General Library h-Z. 

University of California 
Berkeley