e. The
saccharine matter is loosened by fermentation in from twenty-four to
thirty-two hours. The mass is kept stirred up for a short time; and, in
general practise, the water is drawn off from above, the light pulp
floating at the top being removed at the same time. The same tanks are
often used for washing, but a better practise is to have separate tanks.

Some planters permit the pulped coffee to ferment in water. This is
called the wet fermentation process. Others drain off the water from the
tanks and conduct the fermenting operation in a semi-dry state, called
the dry fermentation process.

The coffee bean, when introduced into the fermentation tanks, is
enclosed in a parchment shell made slimy by its closely adhering
saccharine coat. After fermentation, which not only loosens the
remaining pulp but also softens the membranous covering, the beans are
given a final washing, either in washing tanks or by being run through
mechanical washers. The type of washing machine generally used consists
of a cylindrical tub having a vertical spindle fitted with a number of
stirrers, or arms, which, in rotating, stir and lift up the parchment
coffee. In another type, the cylinder is horizontal; but the operation
is similar.

_Drying_

The next step in preparation is drying. The coffee, which is still "in
the parchment," but is now known as washed coffee, is spread out thinly
on a drying ground, as in the dry method. However, if the weather is
unsuitable or can not be depended upon to remain fair for the necessary
length of time, there are machines which can be used to dry the coffee
satisfactorily. On some plantations, the drying is started in the open
and finished by machine. The machines dry the coffee in twenty-four
hours, while ten days are required by the sun.

[Illustration: THE SMOUT PEELER AND POLISHER]

The object of the drying machine is to dry the parchment of the coffee
so that it may be removed as readily as the skin on a peanut; and this
object is achieved in the most approved machines by keeping a hot
current of air stirring through the beans. One of the best-liked types,
the Guardiola, resembles the cylinder of a coffee-roasting machine. It
is made of perforated steel plates in cylinder form, and is carried on a
hollow shaft through which the hot air is circulated by a pressure fan.
The beans are rotated in the revolving cylinder; and as the hot air
strikes the wet coffee, it creates a steam that passes