A grass of the genus Triticum, wheat is the second oldest (after barley) of cultivated cereals. It is now the most widely cultivated, exceeding rice in the quantity grown; but, since some types of wheat are used as animal fodder, it remains true that more people rely on rice than on wheat as their staple food.
Numerous wild grasses of the genus Triticum grow, or once grew, over a wide area of W. Asia. The story of how certain of them evolved first by natural processes and later by informed selection and breeding into the wheats now available is a complex one; see items under ‘Reading’ at the end of this article.
The situation now is that most cultivated wheat, indeed virtually all the wheat which is made into bread, belongs to the species T. aestivum; that this exists in thousands of different cultivars; that the introduction of dwarfing genes in the second half of the 20th century marked the opening of what may well be called ‘a new era’ in the development of wheat; and that the present large range of cultivars makes it possible for wheat to be grown in many different climates, and to meet more desiderata in quality and characteristics than ever before.
The other important species of wheat which is cultivated is T. turgidum var durum, which is especially suited to the manufacture of pasta and has probably been so used since about the 1st century bc, which available evidence suggests is when it first appeared.
But a long history precedes the situation thus summarized. By the beginning of recorded history wheat had already become firmly established all over temperate Asia and Europe, its cultivation limited only by climate. And, almost everywhere it was grown, wheat was the most esteemed of cereals, comparatively expensive and not for the poor, who continued to exist on lowlier grains such as barley and millet. This is shown by the name ‘wheat’ itself, which refers to the prized whiteness of wheat flour.
The Romans were highly dependent on wheat, and imported vast amounts from growing regions in their empire, including Britain. (When the Greek explorer Pytheas visited Britain around 330 bc, long before the Romans arrived, he found much wheat grown in SE Britain. The Britons built huge barns for threshing it in, he said: the implication in this statement is no doubt the first reference in literature to the uncertain British climate.) By ad 360 the Romans had built up wheat-growing in Britain to such an extent that wheat was exported from there to feed the army on the Rhine.
Although the ancient Egyptians, the first advanced bread-makers, no doubt had preferences among the kinds of wheat available, the Romans were the first to clearly distinguish ‘hard’ wheat, suitable for making bread, from ‘soft’ wheat. The Romans also valued other wheats for particular purposes: for example Apicius' recipes call specifically for spelt (see list opposite) in a recipe for crushed cooked wheat with mussels, and for stuffing fowl, and spelt was used for making pottages and in soups and sausages. Emmer (see list opposite) was used for making amulum (see wheat products and dishes), the Roman equivalent of cornflour. Both emmer and spelt were made into the flat, unleavened sheets which were the forerunners of pasta.
After the fall of the Empire the wheaten infrastructure created for it by the Romans tended to disintegrate. For example, the Saxon invaders of Britain, who preferred their native rye, greatly reduced the amount of wheat grown.
During the Middle Ages wheat recovered somewhat. It was, however, used mainly for the delicate bread of the rich, both in Britain and in the rest of Europe. Coarse bread for trenchers (slices used as plates) was made from barley or rye. The common bread of most people was maslin: wheat and rye ground together, and sometimes grown together (although this was not very successful, for the rye ripened before the wheat was ready). Poorer bread was made from barley or rye alone, or from rough mixtures of these with bean or pea meal, or even acorns. The principal type of wheat grown in Britain was cone wheat (see opposite). Wheat became the predominant bread grain only in the 18th century.
Wheat was first properly established in the New World in 1529, when the Spaniards began growing it in Mexico. As the continent was opened up by European expansion the enormously productive wheat-growing areas of the Midwest, Canada, and Argentina came to outstrip anywhere in the Old World, rivalling even the vast wheat region of the Ukraine. The last major wheat-growing country to begin cultivation was Australia in 1788. The leading wheat producers are now the USA, the Russian Federation, and China.
As already explained, the most important kinds of wheat now cultivated are those for making bread, hard varieties of T. aestivum. (‘Hardness’ in wheat means that the proteins in it contain a large proportion of glutenin, the main protein that forms the gluten which gives a good texture to bread. For the role of gluten, see bread.) Hard wheats are what are mainly grown in the wheat-producing areas of N. America, and other main regions including those of S. America and the former Soviet Union.
The other important species, T. durum, is hard in a different sense. It is literally, physically hard. When the grains are ground they splinter into chips of an almost glassy quality. These are semolina, the basis of N. African couscous, but most important in the making of pasta. Durum wheat has been grown for centuries in Italy for this purpose, the best coming from Lazio, the province around Rome. However, local production is not sufficient. Up to the end of the 19th century much was imported from the Ukraine; it was known as ‘Taganrog wheat’ after the name of the port on the Sea of Azov from which it was shipped. Nowadays, most of it comes from N. Dakota and Manitoba.
There are other species, listed below, in alphabetical sequence:
The structure of the ear and grains of wheat is similar to that of many other cereals and grasses. The ear has a tower-like structure consisting of ‘storeys’ called ‘spikelets’, each containing two to five flowers of which some but not all develop into grains. In einkorn (German for ‘single grain’, reflected in its botanical name monococcum) the grains are arranged singly. In emmer they have a paired arrangement. In more advanced wheats they are thickly clustered. Each grain is covered with a husk called the ‘lemma’ which may or may not have a long hair or ‘beard’ on the tip; modern wheats include bearded and beardless varieties. The beard is quite useful in making it harder for birds to get at the seeds; Indian farmers like bearded wheat for this reason.
When grain is threshed the seeds are separated from the husk and the rest of the ear. In former times threshing used to be quite laborious, particularly with the older, ‘hulled’ types of wheat with firmly attached husks, as opposed to the later ‘free threshing’ varieties. The freshly harvested ears were first given a time to dry, then any of several methods was used: flails to beat the ears; stamping on them; driving oxen around on them so that their hooves did the threshing; or dragging a spiked sledge over them. Then the chaff—the husks and debris—was ‘winnowed’ or blown off the heavier grain with the aid of the wind or with fans. Later, machinery was introduced, and now threshing is done instantly inside a combine harvester.
The threshed grain is still covered in a brown (or red) coat, the bran. The coat has several layers. At the tip there are sparse, fine hairs, and inside the base, where the seed is attached to the ear, is the embryo or germ, which will grow into a new plant if allowed to. Most of the inside of the seed is taken up by the endosperm, which is mainly starch and acts as a food store for the developing embryo. In a typical wheat grain 85 per cent of the mass is endosperm, 13 per cent bran, and 2 per cent germ.
Wheat contains more protein than rice or most other staple cereals. Its protein, which is present with the starch in the endosperm, is important in two ways. First, it makes wheat the most nutritious of common staple grains. The protein supplies all the amino acids which are needed in human diet, except that it is rather low in lysine and, not so seriously, in tryptophan and methionine. By a happy coincidence beans and other pulses are rich in lysine, so a diet of wheat products and pulses, common in many poor areas, is well balanced even if hardly any animal foods (whose protein is complete, with all the amino acids) are eaten. Secondly, the protein gives wheat its superior quality as a bread-making grain. Wheat contains proteins of five main groups; albumins, globulins, and proteoses, which are water soluble; and glutenin and gliadin, which are not. Wheat has much more glutenin and gliadin than do other cereals. It is these proteins which form gluten in bread-making, giving wheat bread its pleasantly elastic texture. Hard wheats, the kind for bread, contain more of them than do soft wheats.
The form in which wheat reaches the consumer, whether directly or through a baker, varies. It may be one of the products listed in wheat products and dishes. But it is most often flour, which is a subject on its own; see flour.
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.
Aykroyd, W. R., and Doughty, Joyce (1970), Wheat in Human Nutrition, Rome: FAO.
