Expeller cocoa butter usually has a stronger flavor and darker color than prime cocoa butter and is filtered with carbon or otherwise treated prior to use. The nib is normally steamed to assist the separation – chemically, the cocoa butter is the same as prime pressed. Expellers are also used to extract the fat from whole beans.
Often, expeller pressing is often applied to poorer grade nibs and may be assisted by steam treatment. It also used in some winnowing products, in which case the resultant cocoa butter is usually subjected to a refining process.
Expeller presses operate by using a rotating screw to force the material being extracted into tapering tube. The tube has slits along its length and terminates in a cone-shaped device which can be adjusted to vary the size of the outlet.
As material passes along the tube it is subject boith to continuously increasing pressure and to the shearing action of the screw. Cocoa butter is expressed through the slots in the sides of the tubes, while flakes of press cake emerge from the outlet at the end of the tube.
Expeller pressed cocoa butter
