Wheat is a type of grass grown all over the world for its highly nutritious and useful grain. It is one of the top three most produced crops in the world, along with corn and rice. Wheat has been cultivated for over 10,000 years and probably originates in the Fertile Crescent, along with other staple crops. A wide range of products are made from it by humans, including most famously flour, which is made from the grain itself.
Today, wheat is a grass that grows between 2 and 4 feet (0.6 to 1.2 meters) tall. The physical appearance of the grain is familiar to most consumers, with a long stalk that terminates in a tightly formed cluster of plump kernels enclosed by a beard of bristly spikes. The plant is an annual, which means that at the end of each year, fields must be plowed and prepared again to grow the grass.
Ancestral wheats probably looked very different, with much smaller kernels. The early domesticators obviously wanted to select for plants with particularly large kernels, since more nutrition could be eked out from each stalk. Because wheat is generally a self pollinating plant, each plant tends to produce clones of itself. When farmers want to hybridize a strain, they must physically pollinate the different plants. Farmers blending wheat for various purposes usually combine different seeds at harvest time and spread them evenly over the field.
The crops grown in the United States fall into two categories: winter wheat, which is planted in the fall and matures in the summer, and spring wheat, which is planted after the danger of frost is over and also matures in the summer. The plant's characteristic golden color at harvest time is well known and often appears in artwork.
When wheat is ready for harvest, the heads of the grain start to bend the stalks with the weight of the kernels. This, in combination with the golden color, indicates that it is ready. After harvest, the grain is separated from the stalks and chaff. The stalks are used in a variety of applications: mulch, construction material, and animal bedding, for example. On organic farms, livestock are often turned loose on the field after harvest to clean up the leftovers.
Once the kernels have been separated, they can be ground into flour. There are many classifications for flour, depending on what part of the seed is used and how hard the endosperm, the largest part of the kernel, is. The kernels have three parts: the small germ, the large endosperm, and the rough outer casing known as the bran. Hard wheats are suitable for making pasta and bread, and soft wheats are used for other products that do not require a high gluten content.
If a flour is made solely from the endosperm, it is known as white flour. If the germ is ground as well, the product is called germ flour. Flour that uses the whole kernel is called whole wheat. When making flour that doesn't use the whole kernel, the bran and germ are processed and sold separately.
After harvest, the field is cleared and prepared for planting again. Farmers using good rotation practices do not plant it in sequential years, although they may return to the field later.