COFFEE. 
15 
This pernicious change may best be avoided by strewing 
over the berries, when the roasting is completed, and while 
the vessel in which it has been done is still hot, some pow- 
dered white or brown sugar (half-an-ounce to one pound of 
coffee is sufficient). The sugar melts immediately, and by 
well shaking or turning the roaster quickly, it spreads over 
all the berries, and gives each one a fine glaze, impervious 
to the atmosphere. They have then a shining appearance, as 
though covered with a varnish, and they in consequence lose 
their smell entirely, which, however, returns in a high degree 
as soon as they are ground. 
After this operation, they are to be shaken out rapidly from 
the roaster and spread on a cold plate of iron, so that they 
may cool as soon as possible. If the hot berries are allowed 
to remain heaped together, they begin to sweat, and when 
the quantity is large the heating process, by the influence of 
air, increases to such a degree that at last they take fire 
spontaneously. The roasted and glazed berries should be 
kept in a dry place, because the covering of sugar attracts 
moisture. 
If the raw berries are boiled in water, from 23 to 24 per 
cent, of soluble matter is extracted. On being roasted till 
they assume a pale-chestnut colour, they lose 15 to 16 per 
cent., and the extract obtained from these by means of boiling 
water is 20 to 21 per cent, of the weight of the unroasted 
berries. The loss in weight of the extract is much larger 
when the roasting process is carried on till the colour of the 
berries is dark-brown or black. At the same time that the 
berries lose in weight by roasting they gain in volume by 
swelling; 100 volume of green berries give, after roasting-, 
a volume of 150 to 160; or two pint measures of unroasted 
berries give three pints when roasted. 
The usual methods of preparing coffee are, 1st, b j filtration ; 
2nd, by infusion ; 3rd, by boiling. 
Filtration gives often, but not always, a good cup of coffee. 
When the pouring the boiling water over the ground coffee 
is done slowly, the drops in passing come in contact with too 
much air, whose oxygen works a change in the aromatic 
particles, and often destroys them entirely. The extraction, 
moreover, is incomplete. Instead of 20 to 21 per cent, the 
water dissolves only 11 to 15 per cent., and 7 to 10 per cent, 
is lost. 
Infusion is accomplished by making the water boil, and 
then putting in the ground coffee ; the vessel being imme- 
diately taken off the fire and allowed to stand quietly for 
about ten minutes. The coffee is ready for use when the 
powder swimming on the surface falls to the bottom on 
