Cacao or Cocoa 



135 



object in cleaning and sorting the beans is to get rid of all foreign substances, such as sand, 

 pieces of stone, etc., which later on might damage the rollers of the grinding-machine. 

 Impurities also spoil the aroma of the cocoa when it is roasted and lower its solubility. 



The beans are cleaned by placing them in long barrel-shaped sieves which are made to rotate 

 slowly. The meshes of the sieve must be of such a size that everything smaller than cacao- 

 beans themselves can pass through. At the same time a draught created by powerful fans 

 carries away dust. The sieves are so made that the beans are at the same time sorted into 

 three groups — large, medium, and small. The material to be roasted thus consists of beans 

 of equal size, which is of advantage because if beans of unequal size were roasted together 

 the small ones would spoil by the time the large beans were sufficiently roasted. 



Roasting the Beans 



The beans are next exposed to a high temperature, that is to say, they are roasted. 

 This roasting serves several purposes. First of all the aroma of the beans is increased and 

 the starch is partially changed into dextrin, a substance which is more soluble in water than 

 starch. The bitter substances which the beans contain are partly eliminated, the shells 

 become dry and crisp, and the beans themselves dry, which renders them more easily ground. 

 The flavour of the beans is greatly improved by the roasting. 



The roasting is carried out in large iron drums, each of which may hold a ton or more of 

 beans. Coke fires, gas, or better, superheated steam are employed, and great care and 

 judgment are necessary to obtain the best results. The temperature for roasting cacao-beans 

 is not so high as that for roasting coffee ; experience has shown that the best temperature lies 

 between 260° and 280° F. The beans should not be left too long in the machine, and they are 

 turned continually. The iron boxes are accordingly made to revolve. The temperature in 

 the boxes is carefully regulated, although it must by no means be constant throughout the 

 whole process. The time required for roasting depends on the quantity of beans roasted at once 

 and on the kind of beans. Therefore, the roaster should always be a reliable and experienced 

 person. To prevent too great a loss of aroma and to cause the beans to be shelled more easily, 

 they are cooled suddenly after the roasting is completed. 



Breaking and Shelling the Beans 



The roasted beans are now " broken down " and the shells removed. The beans are 

 gently cracked and exposed to a powerful air-blast which can be regulated according to the 

 coarseness or the fineness of 

 the fragments ; a gentle wind 

 is made to blow when the 

 beans are broken into very 

 small pieces, and a more vio- 

 lent one when the pieces are 

 bigger, so that the separa- 

 tion of the particles of beans 

 from the larger, but specifi- 

 cally lighter, shells is effected 

 with great accuracy. 



For the preparation of 

 chocolate it is important to 

 sift the broken beans once 

 more, in order to get out the 

 harder germs, the powder of 

 which leaves a sediment in stone floor for drying cacao-beans in the open air 



