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Chocolate
©2009 Firebrand
Cocoa is derived from the cocoa bean, seed of the tree Theobroma cacao, in the family Sterculiaceae, to which the cultivated colas also belong. Chocolate is a paste made from the kernels of the cocoa tree and flavored with sugar, vanilla and other ingredients. Chocolate is highly nourishing. Roasted cocoa beans contain about 50 percent fat, 20 to 25 percent carbohydrate, and 15 to 20 percent protein. Because of the high fat and carbohydrate content, chocolate products are a valuable source of energy for athletes, soldiers, and others who perform strenuous physical activity. Chocolate also contains small amounts of caffeine, which is a mild stimulant. Chocolate beverage is made by dissolving chocolate in boiling water or milk. It was thus used by the Mexicans largely, as far back as the time of Montezuma.

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Cocoa Production
Originally wild in Central America the cacao tree can now be found on the large plantations in tropical America, Africa, and Asia. The principal producing countries are Ghana, Nigeria, Ivory Coast and Cameroon in Africa, and Brazil, Ecuador, Mexico and the Dominican Republic in America. There are numerous other countries producing cocoa on a smaller scale and of these New Guinea has increased its production considerably since 1950. Cocoa is generally grown under shade of thinned jungle or specially planted trees. Where steady winds blow, windbreaks are planted. The tree bears at four to five years, reaches maturity at ten to fifteen years, and continues for thirty to forty years. The tree is 5-8 m high, with broad-leaved luxuriant foliage. The flowers are small, pale pink or pale yellow, wax-like in texture; the fruit is produced in pods; buds, flowers and fruit at all stages of development are present simultaneously; the pods grow on the main trunk and branches. A tree produces hundreds or even thousands of flowers, of which only 5-40 per cent are pollinated, and a much smaller proportion reaches maturity. The pods, which differ in size, shape and color, contain 15—40 seeds or beans. Each bean is covered with a white pulp which has a pleasant acid taste, while the raw bean is bitter and unpleasant. There are two main varieties; Criollo, which has large plump seeds with white or pale violet cotyledons and pods which are typically pointed and rough, and Forastero which has smaller, thinner seeds with purple cotyledons and pods which are smoother, rounder and usually yellow when ripe. Hybrid trees are common in some countries, e.g. Trinidad. Criollo gives a distinctive flavor and moderate yield, Forastero a good chocolate flavor and high yield. The pods of these trees contain shell-covered cacao beans enmeshed in a gummy pulp. When ripe, the pods are hacked from the trees with machetes and opened, and their rinds are removed. A pod weighing 450 gm will produce 113 gm of fresh beans or 42 gm dried beans as sold commercially. Yields are measured in kg of dried beans per hectare and while in experiments yields of over 1360 kg per hectare have been achieved, on farms yields are commonly around 136 kg per hectare. Ripe pods are present throughout the year, but there are usually two harvests. The pods are separated from the tree by a cutlass (machete) or a hooked knife on a long pole (goulet). The pods are then cut open, and the beans and pulp scooped out; these are placed in heaps on the ground and covered with leaves, or in sweat boxes; the pulp ferments and drains away. After fermentation the beans are separated from the remaining pulp and dried in the sun or by artificial heat. The processes of fermentation and drying change the cotyledons to a chocolate brown (Forastero) or cinnamon (Criollo) color and these changes are an essential part in the development of the chocolate flavor. They are then placed in sacks for shipment. Fine, or flavor, grades of cacao, which constitute about 10 percent of world production, are cultivated in Venezuela, Ecuador, Trinidad, Sri Lanka, and Java. Lower-grade beans, which come from hardier trees with larger yields, are produced in Ghana, Brazil, the Ivory Coast, Nigeria, and Cameroon.

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Processing Cocoa
The first step in making chocolate is cleaning and roasting the cacao beans in revolving ovens at high temperatures. This process develops both color and flavor. Mechanical sieves and magnetic separators remove foreign substances from beans, which are roasted in revolving drums heated by oil, coke fires, gas jets, or super-heated steam. This brings out the aroma and facilitates breaking of the bean into small pieces ('nibs') and winnowing away of shell. After roasting, the beans are passed between rollers and broken into small pieces, called nibs. During the same process, air currents remove the dry shells, which are used for cattle food and fertilizer. Different varieties of roasted nibs are then blended and finely ground. Owing to the high fat ('cocoa butter') content (56 per cent), grinding produces a smooth, bitter-tasting, viscous dark-brown liquid, as the fat is melted by the heat generated. When cool the liquid solidifies. Most cocoas are now made by the Dutch process in which the mass is 'alkalized'. Hydraulic presses, exerting pressure up to 422 kg/cm2, extract a fixed proportion of cocoa butter, which is refined for chocolate manufacture and other purposes. Cocoa remains as dry hard cakes, which are broken up, ground and reground to powder. In a modern factory all stages of production, including tin-making, are embodied in a series of 'linked processes' involving automatic machinery, gravity being largely used for conveyance of material. Chocolate liquor is the base for the production of all chocolate products, including bitter chocolate, milk chocolate, sweet and semisweet chocolates, cocoa, and cocoa butter. Bitter chocolate, which is also called baker's chocolate, is made by cooling the chocolate liquor until it hardens into solid blocks. Bitter chocolate is widely used in cooking to make icings and batters for cakes and other kinds of baked goods. Milk chocolate is prepared by mixing warm chocolate liquor with additional cocoa butter, sugar, powdered milk, and flavoring, such as vanilla, almond, or cinnamon. The mixture is then churned to a smooth liquid and poured into molds to harden. Milk chocolate is popular as a candy and as a candy coating. Sweet and semisweet chocolates are similar in content to milk chocolate, but they do not contain milk. They are used for making candies, cookies, and cakes. Some chocolate products are prepared from chocolate liquor that has had most of the cocoa butter removed. The remaining part of the liquor is cooled and crushed, forming the reddish-brown powder known as cocoa. Sweetened cocoa powder mixed with hot milk or water is a popular beverage. The chief by-product of chocolate manufacture is cocoa butter, a fatty white substance that tastes and smells like chocolate. Cocoa butter is used as a base for medicinal salves and ointments because it does not become rancid.

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While cocoa powder consists of bean minus some of its cocoa butter, chocolate contains the full butter content of bean plus extra cocoa butter added to compensate for increased bulk due to inclusion of sugar. Eating chocolate is of two main kinds: molded and couverture (or confectionery). Couverture for covering fruits, nuts, biscuits, preserves, and other 'centers' needs a higher proportion of butter than chocolate for molding into blocks. Balance in production of cocoa and chocolate is therefore important to the manufacturer. He does not want to buy cocoa butter nor, generally speaking, to produce a surplus, though there is a market for this in the manufacture of other confectionery and of cosmetics and other pharmaceutical preparations. In chocolate manufacture finely powdered sugar, extra cocoa butter, and cocoa 'mass' or nib are mixed and ground in a melangeur, in which heavy granite rollers rotate on a revolving granite bed. The material is kept warm enough to be plastic and is delivered to a series of refining machines. The first consists of rolls revolving at different speeds and delivers the chocolate in dry, flaky condition. Another process is conching (so called from the shape of the machine: French conche, a shell) in which semi-liquid mixture is mechanically kneaded for long periods. Finally, the chocolate must be 'tempered' so that the fats will solidify quickly on cooling with good color and gloss. For confectionery chocolate a fluid product is required. 'Centers' pass on a moving wire mesh under a curtain of chocolate. Decoration is added with a fork or other implement. Handcovering is also practiced, centers being dipped into bowls of liquid chocolate with a decorating fork. Molded chocolate is less liquid. It is run into molds, shaken mechanically, and knocked out (in form of blocks, bars, sticks, etc.) when cool and set hard. Fruit (e.g. raisins) and nuts (whole or chopped) can be mixed in before molding. Milk chocolate is made with dried powdered milk or with fresh liquid milk. In the latter case, partially evaporated milk is mixed with the chocolate mass and sugar. Factories for this purpose have been established in dairy-districts and the partially finished product ('crumb') is sent to the parent factory for the final stages of manufacture.

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Credits
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Cover photograph by Zsuzsanna Kilián

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