The Smout Peeler and Polisher, with Cylinder Open Showing Cone

The last step in the preparation process is called hulling or peeling, both words accurately describing the purpose of the operation. Some husking machines for hulling or peeling parchment coffee are polishers as well. This work may be done on the plantation or at the port of shipment just before the coffee is shipped abroad. Sometimes the coffee is exported in parchment, and is cleaned in the country of consumption; but practically all coffee entering the United States arrives without its parchment.

Peeling machines, more accurately named hullers, work on the principle of rubbing the beans between a revolving inner cylinder and an outer covering of woven wire. Machines of this type vary in construction. Some have screw-like inner cylinders, or turbines, others having plain cone-shaped cores on which are knobs and ribs that rub the beans against one another and the outer shell. Practically all types have sieve or exhaust-fan attachments, which draw the loosened parchment and silver skin into one compartment, while the cleaned beans pass into another.

Krull Hulling Machine (German)

Anderson Hulling Machine (German)

Eureka Separator and Grader (American)

Caracolillo (Peaberry) Separator (American)

Engelberg Huller and Separator (American)

The American Coffee Huller and Polisher

WELL KNOWN AMERICAN AND GERMAN HULLING AND SEPARATING MACHINES

Polishers of various makes are sometimes used just to remove the silver skin and to give the beans a special polish. Some countries demand a highly polished coffee; and to supply this demand, the beans are sent through another huller having a phosphor-bronze cylinder and cone. Much Guadeloupe coffee is prepared in this way, and is known as café bonifieur from the fact that the polishing machine is called in Guadeloupe the bonifieur (improver). It is also called café de luxe. Coffee that has not received the extra polish is described as habitant; while coffee in the parchment is known as café en parché. Extra polished coffee is much in demand in the London, Hamburg, and other European markets. A favorite machine for producing this kind of coffee is the Smout combined peeler and polisher, the invention of Jules Smout, a Swiss. Don Roberto O'Krassa also has produced a highly satisfactory combined peeler and polisher.

For hulling dry cherry coffee there are several excellent makes of machines. In one style, the hulling takes place between a rotating disk and the casing of the machine. In another, it takes place between a rotary drum covered with a steel plate punched with vertical bulbs, and a chilled iron hulling-plate with pyramidal teeth cast on the plate. Both are adjustable to different varieties of coffee. In still another type of machine, the hulling takes place between steel ribs on an internal cylinder, and an adjustable knife, or hulling blade, in front of the machine.