84 Manufacture and Preservation of Cider and Perry. 
Quantity per Imperial Pint. ■ 
Grains. 
Water 8292-41 
Alcohol 3(!7-G9 
Grape-sugar 31-67 
Gum and extractive matters 45-05 
Albuminous compounds 1*94 
Malic acid 44*86 
Mineral matter (ash) 18-38 
. 8802-00 
The above analysis shows that a large quantity of malic acid 
is present in the cider, as well as in the apple in its natural state, 
and it is this acid which gives the rough taste so much relished 
by cider drinkers, although in many writings upon this subject 
it is mistaken for either lactic or acetic acid. 
The first point to be secured is by the proper exposure of the 
fruit to the sun to get the starch and pectin, which is largely con- 
tained in unripe fruits, converted into grape-sugar as much as 
possible, and this change is further assisted by keeping the fruit 
some time after it is picked. After breaking or grinding the 
fruit, the first change results from the combination of the oxygen 
of the air with some of the materials of the fruit, upon which, 
no doubt, the colour depends, for, according to Liebig, " we are 
able, to produce from malic acid and ammonia aspartic acid,* 
which is colourless and crystallized, produces, when oxygen is 
present, by absorbing ammonia, the splendid red dye orcein." 
When a ripe apple is cut or broken through and exposed to the 
air, it becomes of a beautiful red colour in a short time, probably 
from the same action. Should this theory be right, it affords 
another inducement to gather the fruit as ripe as possible, for we 
know that cider made of unripe fruit is of a pale colour. 
From the albuminous substances in the fruit a vegetable fer- 
ment is formed, which, after the vinous fermentation is over, it 
is very essential to get rid of as completely as possible. This 
ferment acts by changing the grape-sugar into alcohol and car- 
bonic acid, thus : 1 equivalent of alcohol consists of 4 equiva- 
lents of carbon, 6 of hydrogen, and 2 of oxygen ; 1 ditto of 
carbonic acid of 1 equivalent of carbon, and 2 of oxygen ; 1 
ditto of grape-sugar of 12 equivalents of carbon, 12 of hydrogen, 
and 12 of oxygen ; and the change would be that each equivalent 
of grape-sugar produces 2 equivalents of alcohol and 4 of 
carbonic acid, thus : — 
Carbon. Hydrogen. Oxygen. 
2 equivalents of alcohol (G,, H c , 0, X 2) .. = 8 12 4 
4 equivalents of carbonic acid (C, 0 2 x 4).. = 4 0 8 
1 eq. of grape-sugar .. =12 12 12 
* Page 180, Letter 10, third edition. 
