Wheat

Wheat, along with rice and maize, is one of the world’s most important grain crops, serving as a natural food source for much of the world’s population. The wheat grain is easily refined to raw foods such as flour, which can be used in countless recipes.

Background

Throughout the world, large portions of agricultural land are devoted to the production of wheat, Triticum aestivum. Wheat is the national food staple for dozens of countries and provides 20 percent of the total food calories for the world’s population; it is the major staple for about one-third of the world's population. In the United States, wheat constitutes a large part of the domestic economy, makes up a significant portion of the nation’s exports, and serves as the national bread crop.

The cultivation of wheat is older than the written history of humankind. Wheat’s place of origin is unknown, but many authorities believe that wheat may have grown wild in the Tigris and Euphrates valley and spread from there to the rest of the Old World. Wheat is mentioned in the first book of the Bible, was grown by Stone Age Europeans, and was reportedly produced in China as far back as 2700 BCE. Wheat was brought to the Americas by European settlers and was grown commercially in the Virginia Colony by 1618.

Into the mid-2020s, the world’s leading producers of wheat were (from greatest to least) China, the European Union, India, Russia, the United States, and Canada.

Botany and Classification

Wheat is an annual grass, but its structural morphology varies considerably depending on the type. The wheat flowers and subsequently the seed are borne on spikes originating from the top of the plant. Wheat is widely adapted throughout the world and can grow in many climates. It can be found growing from near the equator to 60 degrees north latitude. About the only places wheat does not grow are the climates that continually stay hot and moist.

Most commercially grown wheat can be separated into either hard grain wheat or soft grain wheat. Hard wheat is usually dark in color and possesses no white starch, while soft wheat is generally much lighter in color and shows a white starch. Both hard and soft wheat contain a protein called gluten, which enables leavened dough (dough after yeast has been added) to rise by trapping the gas bubbles produced during fermentation by the yeast, but hard wheat contains more gluten than soft wheat. As a result, the hard wheats are much more desirable for making bread. The weaker flour produced by the soft wheats is preferred for making biscuits, crackers, pie crusts, and starchy breakfast foods. The most common types of commercially planted wheat are common wheats, durum wheat, and club wheat.

The common wheats include hard red winter wheat, grown in Texas and northward through Kansas; hard red spring wheat, grown in the north central states (North and South Dakota, Idaho, Montana, and Minnesota); soft red winter wheat, grown in the east central United States (Ohio, Michigan, Missouri, Illinois, and Indiana); and soft white wheat, grown around the Great Lakes and in the far West. Hard red winter wheat and hard red spring wheat are primarily used in bread making, while soft red winter wheat and soft white wheat are chiefly utilized for making cakes, cookies, pies, and other pastries. The newest class of common wheats is the hard white wheat, which is closely related to red wheats. This type of wheat has a sweeter flavor, and it is used for making hard rolls, bulgur, and tortillas. Durum wheat is the hardest of all wheat and is also grown in the north central states. Durum wheat has an amber color and a high gluten content; this is why this type of wheat is primarily used for making pasta such as macaroni and spaghetti. Club wheat, also grown in the far West, is used to make the starchy flours required for making pastries. Additional wheat types include poulard, emmer, spelt, polish, and einkorn; these types are of little importance in the United States.

Production and Harvest

The production of wheat begins with the selection of the seed. So that high yields can be obtained, extreme care is taken to select only the highest-quality seed. For winter wheat, the seed is planted in the fall, generally at the time of the average first frost. This timing allows the crop to make a stand before winter but is not so early that it begins rank growth or starts to send up tall shoots. Spring wheat is generally planted as early as is practical in the spring, which is usually early March in areas where spring wheat is normally grown. In the United States, almost all wheat is planted by drilling the seed into the soil. Drilling provides for the best germination and the least amount of winter killing.

Harvest time for wheat is determined primarily by the moisture content of the grain. Most wheat in the United States is harvested with mechanical combines, and the ideal seed moisture for combine harvest is 12 to 13 percent. After harvesting, the grain is taken to the mill. During the milling process, the grain is washed and scoured to remove fuzz and foreign material. The grain is then tempered by soaking in water to toughen the bran. After tempering, the grain is crushed by a series of corrugated rollers. The bran, produced primarily in the seed coat, is then separated from the starch. The milled flour is often chemically bleached to improve the color and baking quality and enriched with vitamins and minerals to replace those lost by removing the bran. The average flour yield is 70 to 74 percent of the weight of the grain.

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