COCOA BY-PRODUCTS 6 
liminary treatment to which it has been subjected. It is believed 
that the data reported by Knapp and McLellan (25) and by Silber- 
berg (4-4) are representative for clean, raw seeds. The percentage 
of shell obtained by hand separation varied from 7.3 to 15.8, and 
the percentage of germ from 0.5 to 0.9, the remainder representing 
the nib. The averages given by Silberberg are — shell 12.1 per cent, 
germ 0.7 per cent. Knapp and McLellan state that roasting de- 
creases the percentage of shell from 1 to 3 per cent. TVinton, 
Silverman, and Bailey (60) separated the shells from 17 samples of 
carefully roasted beans and found the average content of pure shells 
iu the roasted beans to be 11.54 per cent. 
The proportion of nibs and by-products obtained from commercial 
cacao varies with the source of the beans and the manner in which 
they are prepared. Knapp 's figures (&£) undoubtedly can be ac- 
cepted as representing the general average for factory practice, at 
least in England. Starting with 100 pounds of raw beans, as 
imported, he assumes a loss of 7 pounds in roasting and separating, 
and gives the average yield as 78.5 pounds of usable nibs (containing 
2 per cent of practically inseparable shell material), 10.5 pounds 
of commercial shells, and 4 pounds of " smalls," which is about 
one-third fine shell material, and includes the hard, rodlike radicles 
or germs. From other analyses it is evident that the germs do not 
amount to more than 12 ounces. American manufacturers have 
reported yields of 79 to 82 pounds of finished nibs, and losses of 4 to 
8 pounds in separating and roasting' 100 pounds of raw beans. 
Evaporation of moisture commonly accounts for from 4 to 6 pounds 
of the loss, the remainder being due to foreign matter and rejected 
beans. The refuse material (about 14 pounds) consists of the 
shells fraction and the " fines," which correspond to the English 
" smalls " and include the germs, very fine shell and nib particles, 
and dust. The separated shells fraction may amount to 6 to 12 
pounds, depending on the type of equipment and factory practice. 
In good practice the nibs are the only portion of the cacao bean 
used in the manufacture of the primary products. However, abso- 
lutely perfect separation of nibs from shells is not attainable in 
factory work. Several investigators (00, .% 26, U, 58) agree 
that in the nibs or straight chocolate 2 per cent of shell refuse is 
a fair allowable limit. 
PRIMARY PRODUCTS 
Chocolate is prepared from the separated nibs by prolonged 
grinding in special mills. Because of the high content of cacao 
butter present in the nibs, and a slight heating of the burrstones, 
the chocolate becomes plastic or fluid in the milling, and this has 
given rise to the designation "chocolate liquor." "Plain choco- 
late " is also known to the trade as " chocolate liquor." The fluid 
chocolate usually is run into molds, in which it solidifies on cooling. 
Cocoa or powdered cocoa and " breakfast cocoa," 4 on the other 
hand, represent that part of the cacao nibs remaining after express- 
ing a varying proportion of the cacao butter from chocolate liquor, 
either freshly prepared from the nibs or from cake chocolate. The 
cacao butter is expressed from the hot liquor in heated hydraulic 
4 Breakfast cocoa is cocoa which contains not less than 22 per cent of cacao fat (52). 
