U.S. – Six Basic Wheat Classes

There are several hundred varieties of wheat produced in the United States, all of which fall into one of the six recognized classes of economic significance. Each of these six wheat classes has unique milling, baking and processing properties. Unfortunately, grain-grading standards often fail to accurately assess the quality characteristics required to meet end-use performance standards. The six official class groupings can be distinguished from each other in simple, observable ways. The class of a variety is determined by its hardness, the colour of its kernels and by its planting time. Through selective breeding, each class of wheat has developed its own relatively uniform characteristics relating to milling, baking or other food use. The six commercially recognized classes are as follows:
Fig. 12: Areas of U.S. wheat production by class (source: U.S. Wheat Assoc.)
Hard Red Winter (HRW), an important bread wheat, accounts for almost 40% of the U.S. wheat crop and wheat exports. This autumnseeded wheat is produced in the Great Plains, which extend from the Mississippi River west to the Rocky Mountains and from the Dakotas and Montana south to Texas (Fig. 12). Significant quantities are also produced in California. HRW has a reddishbrown bran coat; it is of moderate hardness and has mid-level protein content, usually averaging 11 - 12%. It is considered a good milling and baking wheat with characteristics that make it the wheat of choice for much of the North American white pan bread and bun products. There are no subclasses for this class of wheat.

Hard Red Spring (HRS), another important bread wheat, has the highest protein content, usually 13 - 14%, in addition to delivering excellent milling and baking characteristics. This spring-seeded wheat is primarily grown in the north central United States – North Dakota, South Dakota, Minnesota and Montana (Fig. 12). HRS comprises just over 20% of U.S. wheat exports. Subclasses based on the dark, hard and vitreous kernel content (DHV) include Dark Northern Spring (DNS), Northern Spring and Red Spring. HRS also has a reddish-brown outer layer.

Hard White (Winter) wheat (HWW) is the newest class of wheat to be grown in the United States. It is used for noodles, yeast breads and flat breads and is grown in California, Idaho, Kansas and Montana (Fig. 12). There are no subclasses. Currently, HWW is used primarily in domestic markets with limited quantities available for export. While similar to HRW in its hardness profile, HWW has a white outer layer that is believed to improve its taste profile in certain products. HWW is not a new crop. Farmers in China grow white wheat varieties and Australia is a major producer of white wheats.

Soft White (SW) is preferred for flat breads, cakes, pastries, crackers and noodles and is grown primarily in the Pacific Northwest (Fig. 12). Soft White is low-protein wheat with soft endosperm and a white outer layer. There are both winter and spring varieties of soft white, but SW is not classified by its growing season. The protein content of this wheat rarely exceeds 10%. SW represents just over 20% of total U.S. exports, primarily to Asia and the Middle East. Subclasses are Soft White, White Club and Western White.

Soft Red Winter (SRW) is grown in the eastern third of the United States (Fig. 12). SRW yields well for farmers but is relatively low in protein. Although it contains only about 10% protein, this wheat is considered a capable supplier of extensibility to a baker's formula and is therefore used as blending wheat in many export markets. SRW is used for cakes, pastries, flat breads, crackers and snack foods. This autumn-seeded wheat comprises about 14% of U.S. wheat exports. There are no subclasses of this class.

Durum, the hardest of all U.S. wheats, provides semolina for spaghetti, macaroni and other pasta products. This spring-seeded wheat is grown primarily in the same northern areas as hard red spring, while smaller winter-sown quantities are grown in Arizona and California (Fig. 12). Durum comprises nearly 5% of total U.S. wheat exports. Subclasses based on the percentage of vitreous kernel are Hard Amber Durum (HAD), Amber Durum (AD) and Durum.

(Modified from U.S. Wheat Assoc. website.)

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