The Great Plains of the United States and Canada form one huge production engine for barley, wheat, and sorghum. Wheat is by far the dominant cereal grain produced, which explains why the Great Plains is commonly referred to as the "Breadbasket of the World." There are three classes of wheat produced in the region. Eastern Alberta, Saskatchewan, southwestern Manitoba, northeastern Montana, North Dakota, northwestern Minnesota, and northern South Dakota are the major production area for hard red spring wheat and durum wheat. Hard red spring wheat is a high-protein wheat used as a blending wheat to upgrade the quality of lower-quality wheats and is also the source of flour for specialty breads such as hard rolls. Durum wheat is the source of semolina, a granular product used in the production of high-quality pasta products. The Plains states from South Dakota to Texas and from Montana to Colorado are the source of hard red winter wheat, a slightly lower protein wheat than hard red spring wheat. The flour from hard red winter wheat is used primarily in the production of pan breads.
In 1998 the United States produced an estimated total of 69.61 million metric tons of wheat. This included hard red winter wheat, hard red spring wheat, soft red winter wheat, soft white wheat, and durum wheat. The Great Plains states of the United States produced 46.14 million metric tons, or 72 percent of that total. Total wheat production in Canada in 1998 was 24.40 million metric tons, with the Prairie Provinces producing 93 percent of that total.
The number of flour mills and total milling capacity in the United States for 1997 were 195 and 1,395,323 hundredweights (cwts), respectively. Much of the milling of the wheats produced in the Great Plains is done either within or relatively close to the grain production states. Plains states had the following number of mills and flour production capacity in 1997: Colorado (4; 22,000 cwts); Kansas (18; 154,640 cwts); Montana (4; 16,880 cwts); Nebraska (5; 26,570 cwts); North Dakota (1; 19,000 cwts); Oklahoma (4; 31,200 cwts); South Dakota (1; 4,000 cwts); and Texas (8; 64,560 cwts). This gives a combined total of 45 flour mills and milling capacity of 338,850 cwts. There is a similar concentration of durum milling in the Plains, with North Dakota (4; 19,555 cwts) the leading state. In all, seven of the twenty-three durum mills in the country are in North Dakota, Montana, and Nebraska. The Prairie Provinces are also an important location for both flour and semolina production. Close to 30 percent of the flour and 40 percent of the semolina milling capacity of Canada are in Alberta, Saskatchewan, and Manitoba.
The three major flour-milling companies in the U.S. Great Plain states are Archer Daniels Midland Milling Company, ConAgra Grain Processing Company, and Cargill Foods Flour Milling. In the Prairie Provinces the leading companies are Archer Daniels Midland Milling Company, CSP Foods, and Robin Hood Multifoods, Inc. The three major durummilling companies operating in or close to the U.S. portion of the Plains states are Archer Daniels Midland Milling Company, General Mills, and Harvest States. In the Prairie Provinces, durum-milling companies include Ellison Milling Company and Robin Hood Multifoods, Inc.
Wheat milling and flour extraction have come a long way from the days of stone grinding. Today wheat milling is a high-throughput, automated process that extracts flour from the wheat in high volume to meet the needs of the baking industry. An average bushel of wheat weighs sixty pounds, from which the miller hopes to "extract" about forty-five pounds of flour (75 percent) and fifteen pounds of millfeed (25 percent).
When wheat arrives at the mill by truck, ship, barge, or rail, samples are taken to ensure it meets purchase quality specifications for milling and baking or other end use needs. Results from inspection and quality testing determine how the wheat will be handled and stored. The wheat is blended and stored in large bins on the basis of the desired end product. Grain storage is a critical component of wheat handling to ensure it does not go out of condition prior to milling.
The first step in the milling process is to clean the wheat of extraneous material picked up in the harvesting process. Foreign materials such as metal, sticks, stones, straw, seeds, and other grains are removed in steps by a magnetic separator, vibrating screens, a destoner, a disc separator, and a scourer. Once the wheat is cleaned, water is added to it in precise amounts in a process called tempering. This is done to toughen the bran and mellow the inner portion of the wheat kernel (the endosperm), facilitating separation of the kernel components. Tempered wheat is stored in bins for twelve to twenty-four hours, depending on the class of the wheat. After proper tempering, the wheat passes through an impact scourer (entoleter) that breaks apart and removes unsound kernels and then moves to the grinding bins (large hoppers that feed the wheat to the grinding rolls).
Mill rolls are corrugated and paired, and they counterrotate at different speeds. One pass between the first break rolls begins the separation of the bran, endosperm, and germ. Feeding the tempered wheat to the first break rolls begins a gradual reduction process whereby middlings or coarse particles of endosperm are graded and separated from the bran by sieves and purifiers. Each size is returned to appropriate rollers, and the process is repeated until the desired flour is produced. The flour is then bleached and enriched with three B vitamins (thiamin, niacin, and riboflavin), iron, and folic acid. Family flour for retail sale is packed in 5-, 10-, or 25-pound bags. Bakery flour may be packed in 50- or 100- pound bags or shipped in bulk trucks or railcars.
See also AGRICULTURE: Wheat.
Brendan J. Donnelly Kansas State University
Grain and Milling Annual. Kansas City MO: Sosland Publishing Company, 1998.
1998 Crop Quality Report. Washington DC: U.S. Wheat Associates, Inc., 1998.