Compound or Cooking Chocolate - again confusingly sometimes known as Baker’s or Baking Chocolate or ‘Pâte à Glacer’ - is also widely commercially used for cooking and cake decorations. It usually contains little or no cocoa butter which is replaced with a hydrogenated (chemical) or fractionated (natural) fat and lecithin stabiliser. (Large amounts of cheap and plentiful vegetable oils, such as soya bean and cottonseed, are converted to soft solids like margarine or lard by a process of hydrogenation. To remove any unpleasant smell or offensive taste so that they can be used for cooking, the oils are hydrogenated by heating to a temperature of about 200° C [392° F] and mixed with fine particles of nickel as a catalyst while under 3 to 4 atmospheres [units of pressure] of hydrogen. These artificially produced fat products are used extensively in foods.)
