Sorghum bicolor (formerly vulgare), a cereal related and similar to and sometimes confused with millet, is an important staple food of the upland, drier parts of Africa and India. In other parts of the world it is chiefly grown as animal fodder. It is native to Africa, and was probably first cultivated in Ethiopia between 4000 and 3000 bc. It spread thence to W. Africa, the Near East, India, and China, and later to the New World.
In appearance sorghum is a typical grass with long, flat leaves and large, feathery seed heads. The main cultivated varieties vary considerably in the colour of the seeds and in the size of the plant. The tallest may reach a height of 6 m (20′); but dwarf varieties, low enough to be harvested by machinery, have also been developed.
Among the numerous cultivars, it is generally true that those with white grains (especially Black African and White Pearl, the latter being the most highly esteemed in India) are used for food, while the red-seeded kinds are for making beer.
The flavour of the better grain sorghums is robust and resembles that of buckwheat. The grains may be eaten whole or as a flour. Such flour is coarse and lacks gluten, so is more suited to making porridge than bread; but Indians make sorghum meal into chapatis and similar unleavened breads.
The saccharatum group of cultivars are not grown for grain, but for the sap in their thick stems, the source of sorghum syrup. These sweet sorghums are sometimes called ‘sorgo’ or ‘Chinese sugar cane’. The syrup is produced from them by methods akin to those used in the processing of sugar cane.
Sorghum is only suitable for making syrup, not for the production of solid sugar. The reason is that only a third of its sugar content is sucrose (common sugar), which crystallizes easily. The major part consists of dextrose and fructose, which do not readily crystallize, and some gummy dextrin.
In its usual form, sorghum syrup is a sticky, dark brown product which has only been partly refined and which has a flavour like that of sugar-cane molasses, see sugar. The dextrin can, however, cause it to set solid. And in China a technique of evaporation is used to turn it into dried strips, yellow-brown in colour.
In the USA, in the 19th and early 20th centuries, sorghum syrup was popular as a cheap alternative to maple syrup. Production, mainly in the southern states, was as much as 20 million gallons or more annually. It is still produced and used, but to a lesser extent.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
