MANUFACTURE 



125 



Diagram of Cacao Bean Cleaning Machine. 



This is a box fitted with shaking sieves down which the cacao 

 beans pass in a current of air. Having come over some large and very 

 powerful magnets, which take out any nails or fragments of iron, 

 they fall on to a sieve (|-inch holes) which the engineer describes as 

 " rapidly reciprocating and arranged on a slight incline and mounted 

 on spring bars." This allows grit to pass through. The beans then 

 roll down a plane on to a sieve (f-inch holes) which separates the 

 broken beans, and finally on to a sieve with oblong holes which 

 allows the beans to fall through whilst retaining the clusters. The 

 beans encounter a strong blast of air which brushes from them any 

 shell or dust clinging to them. 



(c) Roasting the Beans. 



As with coffee so with cacao, the characteristic 

 flavour and aroma are only developed on roasting. 

 Messrs. Rainbridge and Davies (chemists to Messrs. 

 Rowntree) have shown that the aroma of cacao is 

 chiefly due to an amazingly minute quantity (0.0006 

 per cent.) of linalool, a colourless liquid with a power- 

 ful fragrant odour, a modification of which occurs in 

 bergamot, coriander and lavender. Everyone notices 

 the aromatic odour which permeates the atmosphere 



