soz 
Feentta- of a solution of pure sugar, a quantity of yeast is also 
oe. necessary to excite the fermentation, and make it pass 
—Y—" into the vinous state. Nor is the influence of tempe- 
rature less essential: below 50° of Fahrenheit’s scale 
the vinous fermentation proceeds very rare and at 
the freezing point it is completely check Above 
70” the advances too rapidly, and unless it be 
duly moderated, is apt to into the acetous stage. 
Netareof ‘The nature and action have been the subj 
the fermem- OF chemical investigation. voisier ascertained, that, 
ciple, me besides the other e ts which are usually found in 
yout. vegetables, it contained a quantity of nitrogen in its 
composition, and so far evinced a connection with ani- 
malized matter, The researches of Fabroni, Thenard, 
and a re have demonstrated that the fermenting pro- 
perty of yeast is owing to the presence of a substance 
resemblirig gluten or albumen, which is derived from 
certain vegetable infusions, capable of spontaneous fer- 
When circumstances are sufficiently favourable for 
the vinous fermentation, the liquor, in passing into it, 
becomes somewhat turbid, and manifests a kind of'com- 
motion throughout its whole mass, Air bubbles begin 
to be separated, and being entangled by the floccu- 
Jent part of the liquid, occasion a frothy appearance on 
the surface. In the meantime, the temperature gradu- 
ally increases, and sometimes requires to be checked. 
The gas which is disengaged is found to consist chiefly 
of ic acid, mixed occasionally with a portion of 
hydrogen. At length, the extrication of air, and the 
intestine commotion with which it is accompanied, gra- 
dually diminish, and the process terminates by the li- 
quor recovering its transparency, If the fermented 
substance be now examined, it is found to have ex- 
changed its sweet taste for one of considerable pun- 
gency, and to have acquired the property of acting as 
a powerful stimulant on the animal system. 
The vinous fermentation depending in a great mea- 
the 
condurted without thevaid of atmospheric air ; and, in- 
deed, it has been found by experiment, that, if the air 
be excluded, while the gas disengaged by the fermenta- 
tion is to make its escape, the vinous product 
is stronger than when the process is carried on in open 
vessels, In that case, however, as Chaptal remarks, the 
fermentation advances more slowly. 
Products of — ‘The products to which the vinous fermentation gives 
Phenomena 
of the vi- 
nous fer. 
mentation. 
——— birth, resemble one another by ssing an intoxi- 
tien. cating quality, and Yielding, by distillation, a portion 
of alcohol ; but they differ considerably in their strength, 
odour and flavour. Their differences, in these respects, 
are owing, partly to the essential oils, and other proxi- 
mate principles which they derive from the substances 
submitted to the vinous process, and partly to the man- 
ner of conducting the fermentation. ey may be con- 
sidered as of two general descriptions : Wines, proper- 
ly so called, and the various kinds of ale or beer. 
Customs Wines are obtained by subjecting to fermentation the 
ings 
sweet juices of fruits, particularly that of the x 
The products are extremely diversified, and var oh 
vour and appearance with the climate, soil, and the na- 
ture and culture of the vine, as well as with the manner 
of carrying on the fermentative process. Hence wines 
are sweetish, and weaker or stronger, according as the 
saccharine matter of the grape is more or less abundant, 
and the fermentation more or less complete ; and th 
are and sparkling, when of the carbonic pes | 
wine. 
which is generated during the process, is retained, 
ion of carbon, the process may: be. 
FERMENTATION. 
Astringent wines derive their peculiar flavour from the Fermentas: 
astringent principle contained in the grape from which, p= 
they are formed. The colour is communicated by the —— 
external icle of the fruit, and t easily be pre- A 
vented, if necessary, by removing the husks, before fer, 
mentation. Wines of every description contain a cers a 
tain portion of supertartrate of potash, which’ gradual- 
ly separates from them, when they are left > i 
and to this is owing, in a great degree, the improvement 2 
Seer et r 
France producesa great variety of excellent wines, For prench 
daily use, carercy peaier> shonent Besgenes. heensanem wines. 
their principles are duly combined, and none of them pres 
dominates, so as to communicate a peculiarity of flavour: 
The wines of Orleans, after being matured by age, res 
semble those of Burgundy, The red wines of - 
pagne are highly prized for their excellence and deli« 
cng? though, in ;some cases, they possess, a pungent 
and sourish taste, from being, bottled before the cars 
bonic acid is sufficiently disctigeged by fermentation, 
The wines of Languedoc and Guienne are greatly - 
esteemed, on account of their tonic qualities, particu. ; 
larly when they are mellowed by age. Those of Ans 
jou are strong, spirituous, and intoxicating. ves 
The Rheriish and Moselle wines have a cool, 
taste, and readily intoxicate. Some Italian wines, such |lian,Spa — 
as those of Orviette, Vicenza, and Oran Christi, are mee and 
well fermented, and resemble the French wines. Those wines 
of Spain are in general boiled, sweet, and being but 
omg A fermented, cannot be reckoned wholesome, 
he wines of Rota and Alicant must, however, be-ex+ 
|, and are justly considered as useful stomachies. 
e wines of Portugal have been long in great demand 
in this country ; and, indeed, no wine can be accounts 
fat en craty mule yy og OL Se lies ha <a 
The wines formed other fruits, as currants, ae ope! 
eqooeelersiaty ANaDs pears, &c. are greatly inferior to \\° 
those obta from the grape. uices of these 
fruits abound too much with acid, too little with 
saccharine matter, to afford of themselves even tolera« 
ble wines; and they must, therefore, be ae omne 
the addition of sugar, before fermentation. e wines 
from the juices of the le and pear, denominated 
cyder and perry, contain a portion of the acids of 
ese fruits, and a considerable quantity . ic 
acid ; to the presence of the latter is owing their 
ness and sparkling property. Cherries furnish.a very 
» German, 
nee yan; 
en Ca ee ae 
pleasant wine ; apricots, and prunes, afford 
wines of an indifferent quality, ve. Sireuskey jatar 
The nutritive grains, and particularly barley, furnish Process of 
a fermented liquor of a vinous nature, called mi or beer, making ale _ 
The grain, after being converted into malt, is first re. ot beer. 
acid hatte chases auietsion ta eceadliocie Iealined Uae, | 
rollers. It is then, infused in hot water, at the tempe- | 
rature of about 160° or 170°, and allowed to macerate 4 
for a few hours; after which, the liquor is drawn. off, q 
and a fresh quantity of water is added. The infusion — q 
thus obtained, is i wort, Before being al- - ; 
lowed - ferment, the. wort ig ae with some. bitter. 
vegetable substance, commonly hops ;. partly. with.a 
view of correcting any ascescent tendency; and_partly 
of improving the flavour of the liquor. ‘0 
fermentation, a ppannity of yeast is added infu- 
sion, after it has been allowed to cool; but.the process. 
is usually checked before it has A a eM Ape oe 
ed, and the liquor is then off. When the object _ 
of the fermentation is to. obtain a wort for distillation. 
part of the grain, as we formerly observed, is used in a 
