28 BULLETIN" 1413, U. S. DEPARTMENT OE AGRICULTURE 
no other constituent had been lost, would have a higher value as fer- 
tilizer material, or for feeding purposes, than the original cocoa. 
SOLVENT-EXTRACTED OR DEFATTED COCOA RESIDUE 
NATURE, ORIGIN, AND PRODUCTION 
The extracted or defatted cocoa residues that have been referred 
to consist of the cocoa matter that remains after extracting the 
fat from cocoa press cake or powder with a fat solvent. Cacao 
butter, because of its many desirable properties, vies with olive oil 
as the highest priced of the more common vegetable fats and oils 
produced in the United States. When, therefore, thousands of 
tons of cocoa cake, containing from 15 to more than 20 per cent 
of the valuable fat, became obtainable at a very low price, attempts 
to salvage the cacao fat on a commercial scale were bound to follow. 
Of the several fat-recovery processes tried out, however, only one 
based on solvent-extraction appears to have survived. 
Only one concern is known to be operating commercially in the 
United States on the recovery of cacao fat from cocoa cake or 
powder. This company, which has been engaged with apparent 
success for more than a year in the enterprise, operates a plant with 
a capacity for extracting several thousand tons of cocoa annually. 
The procesc employed is sometimes referred to as the Scott or 
MacGregor system of extraction, and commercially pure benzol is 
used as the solvent. The equipment of the plant is very similar 
to and of the same type as that described by Chalmers (10, p. 
83-92), and includes several large drum extractors, a solvent- 
recovery still with dephlegmator, tanks of special design for refining 
the fat, a sludge drier, grinding mills, and a refrigerating system. 
The principal features of the process, in brief, are (1) the ex- 
traction of the powdered cocoa cake with benzol on the counter- 
current principle, (2) separation of the solvent and dissolved fat 
from the extracted sludge by decantation, (3) recovery of the solvent 
by steam distillation, and (4) purification of the extracted cacao 
fat. 29 
After the solvent has been drawn off from the cocoa sludge as 
completely as possible, live steam is admitted to the extractor to 
volatilize and drive out the remainder of the benzol, so that it can 
be subsequently recovered by condensation. The crude, extracted 
cacao fat, after separation from the solvent, is subjected to very 
thorough refining. The refined product probably competes in the 
trade with ordinary cacao butter. 
The steam treatment to which the material is subjected in the 
extractor cooks the moist defatted cocoa, converting it into a sludge, 
which, as it is discharged from the drum, contains about 65 per 
cent of water. This cooked, extracted cocoa is then dried in a 
direct-heat, rotary drum drier, if there is a market for it. Other- 
wise it is wheeled outside of the factory and piled in the open near 
the drier shed until there is a demand for the dried product. Figure 
2 shows a large pile of the extracted-cocoa sludge that had accumu- 
lated during a period of slack demand. At the time of writing the 
only market for the dried sludge is that offered by the mixed- 
29 Certain novel features of the process are covered in United States Patents by Eddy 
(13), MacGregor {32), and Wilson (59). 
