Expeller pressed process of cocoa butter

Expeller cocoa bitter is the fat prepared by the expeller process from cocoa beans singly or in combination with cocoa nib, cocoa mass, cocoa presscake and low fat cocoa presscake. In the expeller, extrusion, or screw press, slightly different conditions prevail during extraction.

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 both 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 process of cocoa butter

Expeller pressure

An expeller press is a screw-type machine. The principle of the expeller press is to force the material to be extracted into a tapering tube by means of a rotating screw. The tube is perforated along its length by narrow slits and terminates in an adjustable cone that gives a variables gap between the cone and the tube exit.

The machine uses friction and continuous pressure from the screw drives to move and compress the material. The fat is forced out through the tube slit.

In processing of natural oils, the oils are crushed from seeds or grain, using the hydraulic action of an expeller press. No heat is involved in the pressing and no chemical antioxidants are added to preserve the oils. The oils seeps though small openings that do not allow seed fiber solids to pass through.

Expeller pressing yields less oil than solvent extraction, usually 50 to 70 percent of the oil, so expeller-pressed oils are usually more expansive than conventionally processed oils.
Expeller pressure