The prominence of wheat as the world's largest crop (in 1981 world production was almost 1.7 thousand million tonnes, of which about 40% went directly to human food use) owes much to its almost unique ability to be baked into bread. This ability is largely attributable to the physico‐chemical properties of wheat proteins, which enable a leavened dough to rise by trapping the carbon dioxide, produced during yeast fermentation, as discrete, small gas cells — a structure that is ‘set’ during baking. Another important type of food made from wheat is pasta and the suitability of wheat for this end use is also governed by the properties of wheat proteins. The suitability of wheats for other uses, such as cracker, biscuit and cake manufacture and domestic flour is also affected by these proteins.