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The subsequent vattings are also leavened from those already in 
full fermentation, and thus the process is continued all through the 
vintage. This must be done at the right moment, as reference tw 
the paragraphs dealing with the various kinds of ferments show 
that at the start the “apiculate” yeasts predominate, and at the end 
the Mycoderma vini, or “flower of wine,’ and the bacteria of acetic 
acid and of lactic fermentations, and also other undesirable micro- 
organisms are not uncommon. During the height of the fermenta- 
tion, on the other hand, the “elliptical” yeast, or true wine yeast, 
has a good hold of the fermenting mass, and is then in a healthy 
and thriving condition. 
In the course of his researches on beer, Pasteur demonstrated 
that several kinds of fermentation cannot proceed simultaneously 
and with equal intensity in a suitable liquid, and that the most 
energetic always masters and overpowers the others. The point 
to bear in mind is, therefore, to surround the particular kind of 
fermentation one strives to achieve with the conditions most favour- 
able to its proper completion. 
INFLUENCE OF TEMPERATURE DURING FERMENTATION. 
Fermentation is the result of combustion. That combustion, as 
we have seen, is initiated whenever the yeast fungi have access to 
the sweet juice of the grape. 
According to the researches of scientists, and in the first in- 
stance to Berthelot, 180 grammes of grape sugar, in being trans- 
formed into aleohol and carbonic acid gas, generate 71 calories, or 
enough heat to raise the temperature of a must containing 20 per 
cent. sugar and fermenting completely to 128° F., provided all the 
heat were accummulated in the fermenting vessel without loss, 
This fact, demonstrated by theory, does not, however, oceur in 
practice. Several sources of leakage tend to reduce that tempera- 
ture, such as the radiation of heat through the staves or sides of 
the vat, the evaporation which takes place from the surface of the 
liquid, the bursting on the surface of the hot bubbles of the carbonic 
acid gas, which escapes through the air. Were it not for these 
sources of diffusion of generated heat, the yeast would soon be 
paralysed or killed, and the vat would get “stuck.” 
What that amount of heat is, at any given moment, within 
the mass in fermentation, can thus be expressed in the terms of a 
mathematical equation :— 
The temperature of the fermenting mass is equal to that of the 
grapes at the time of crushing, plus that due to the heat evolved 
during the fermentation, less that lost by radiation and evaporation. 
Tt is a matter of common observation that, unless checked, the 
temperature of a 600 or 700-gallon vat in Australia rises from 20° 
to 25° F. during fermentation. In other words, grapes crushed at 
