Most of the wheat used within the United States is milled into a wide variety of flours including all-purpose flour, bread flour, whole-wheat flour, unbleached flour, semolina, and brown flour. Wheat flour is used to such an extent that it is usually understood that “flour” refers to wheat flour. Other types of flour are usually labeled as “barley flour”, “rye flour”, and so on.
The wheat grain consists of the following components: 1) Bran: the nutrient packed layers covering the inner kernel that may or may not be used, depending on the type of product that is processed from the wheat. 2) Germ: the oily part of the seed or kernel from which a new wheat plant sprouts and like the bran, is full of nutrients. 3) Endosperm: (or kernel) the largest portion of the grain containing most of the protein and carbohydrates, but only small quantities of vitamins and minerals. For many wheat products, it is often the only part of the grain that is used.
Wheat is categorized into three basic groups according to: 1) Kernel Hardness: hard wheat varieties are high in protein. The more protein in the wheat, the more gluten is formed when flour milled from the wheat is combined with liquid. Gluten provides dough with elasticity and the ability to stretch as the leavening agent produces carbon dioxide gas, which enables dough to rise effectively. Soft wheat varieties have less protein than hard wheat so the gluten forming capacity of the flour milled from soft wheat is not as great, making soft wheat flour a good choice for cakes and pastries. 2) Bran Color: the fibrous outer layers of the inner kernel that are either a variation of red or white. 3) Growing Season: spring wheat is planted in the spring and harvested in the late summer and fall in locations where the winters are cold. Winter wheat is best suited to locations where the winters are shorter and less severe. It is planted during the autumn months, lies dormant during the winter, sprouts in the late winter or early spring, and is ready for harvesting in the early summer.
In the United States, wheat is classified as: 1) Hard White, 2) Hard Red Winter, and 3) Hard Red Spring, (all of which are used for yeast breads and similar products); 4) Soft White and 5) Soft Red Winter, (which are both used for products, such as cakes, cookies, and pastries that do not require the same level of leavening capability as yeast breads); and 6) Durum, (which is used for pasta and noodles).