Cocoa And Chocolate
The Tree, The Bean The Beverage

108 THE COCOA AND CHOCOLATE INDUSTRY judgment, and this is necessary because cacao beans, like all natural products, show appreciable variations in size, dryness, and so forth. The apparatus in which the roasting is conducted is very similar to a coffee-roaster. It consists essentially of a heated rotating cylinder. The heat may be supplied by a coke fire, gas jets, or by superheated steam. The period of roasting and the heat supplied depend on the results desired. Some roasting amounts to little more than drying, while in other cases it is carried to within an ace of burning. The time varies from thirty minutes to two hours, and the temperature attained is com-paratively low, being from 100° C. to 140° C. The roasters are fitted with a neat sampling device which enables small quantities of the beans to be removed from time to time without stopping the operation. The supervisor breaks the beans, applies his highly-trained nose to the crisp and fragrant fragments, and passes judgment. If the roast is satisfactory, the beans are immediately discharged from the roaster and rapidly cooled by a blast of cold air to stop any further changes due to heat. The roasting of cacao not only first creates, and then develops, the chocolate aroma, but also changes the colour of the kernel, even though it be slate or purple, to a chocolate brown. Further, it loosens the husk or shell, so that the removal of this in the next operation is greatly facilitated. The moisture falls from 6 or 7 per cent in the raw to 1 or 2 per cent in the roasted bean. Besides water, acetic acid and other bodies are driven off during roasting, so that the total loss averages about 7 per cent. With regard to the chocolate aroma, Messrs. Bain-bridge and Davies have made an investigation of the aroma and flavour of cocoa and chocolate. They dis-tilled over 4,000 Ibs. of cacao beans and obtained less