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 out through the perforations of the cylinder. Within the cylinder are compartments equipped with winged plates, or ribs, that keep the coffee constantly stirred up to facilitate the drying process. Another favorite is the O'Krassa. It is constructed on the principle just described, but differs in detail of construction from the Guardiola, and is able to dry its contents a few hours quicker. Hot air, steam, and electric heat are all employed in the various makes of coffee driers. A temperature from 65 deg. to 85 deg. centigrade is maintained during the drying process. [Illustration: O'KRASSA'S COFFEE DRIER COMBINED WITH DIRECT-FIRE HEATER] When thoroughly dry, the parchment can be crumbled between the fingers, and the bean within is too hard to be dented by finger nail or teeth. _Hulling, Peeling, and Polishing_