_Manufacture of Cocoa and Chocolate._--The beans are cleaned and sorted to remove foreign bodies of all kinds and also graded into sizes to secure uniformity in roasting. The latter process is carried out in rotating iron drums in which the beans are heated to a temperature of about 260° to 280° F., and results in developing the aroma, partially converting the starch into dextrin, and eliminating bitter constituents. The beans also dry and their shells become crisp. In the next process the beans are gently crushed and winnowed, whereby the light shells are removed, and after removal by sifting of the "germs" the beans are left in the form of the irregular cocoa-nibs occasionally seen in shops. Cocoa-nibs may be infused with water and drunk, but for most people the beverage is too rich, containing the whole of the cacao-fat or cacao-butter. This fat is extracted from the carefully ground nibs by employing great hydraulic pressure in heated presses. The fat exudes and solidifies. When fresh it is yellowish-white, but becomes quite white on keeping. It is very valuable for pharmaceutical purposes and is a constituent of many pomades. With care it can be kept for a long time without going rancid.
After the extraction of the fat the resulting mass is ground to a fine powder when it is ready for use in the ordinary way. Many preparations on the market are of course not pure cocoa but contain admixtures of various starchy and other bodies.
The shells of the beans separated by the winnowing process contain theobromine, and their infusion with water is sometimes used as a substitute for coffee, under the name "miserabile." More recently they have been put to good account as a cattle food.
In the preparation of chocolate the preliminary processes of cleaning, sorting, roasting and removing the shells, and grinding the nibs, are followed as for cocoa. The fat, however, is not extracted, but sugar, and sometimes other materials also, are added to the ground pasty mass, together with suitable flavouring materials, as for example vanilla. The greatest care is taken in the process and elaborate grinding and mixing machinery employed. The final result is a semi-liquid mass which is moulded into the familiar tablets or other forms in which chocolate comes on the market.