Corn bran is a food product made from the tough outer layer of corn. Like the brans derived from other grain crops, corn bran is very high in fiber, and it can be used in a wide variety of ways. Many commercial food producers use corn bran as a filler in their foods, and to reduce the caloric value of snack foods. It can also be used in home cooking to increase the fiber content of various foods and to add texture.

Grains have three parts: the bran, the endosperm, and the germ. The bran is the hard outer shell which protects the grain from the elements. Inside the bran is the endosperm, the bulk of the grain, with the nutrient-rich germ at one end of the grain. In the event that grain is allowed to develop into a seedling, the bran will eventually split open to allow the roots and leaves of the baby plant to emerge.

Basic white flour, including white corn flour, is made from the endosperm alone. The endosperm has a soft, mild flavor, but it tends to be lower in fiber and nutrients than the grain as a whole. When the germ is included, the nutritional value increases, and when the bran is included to make whole grain flour, the fiber content also rises.

Corn bran can be processed and sold independently, or simply left on the corn as it is ground into flour. Many corn products such as grits include the bran and the germ for extra nutritional value, and some finer-ground corn flour products may be made with the bran intact as well. When whole grain corn flour is used in a recipe, it tends to be more coarse than white corn flour, with a more complicated texture and flavor.

When plain corn bran is added to a recipe, it greatly increases the fiber content. Corn bran can be used in things like cereal, chips, snack bars, and so forth to up the fiber. Because corn bran is largely indigestible, it has a minimal impact on calorie count, so foods designed for dieters are often made with corn bran to keep the calories low and the food filling. Corn bran is also low in carbohydrates, which is useful for cooks who want to reduce the carbohydrate content of their foods; many low carb foods use corn bran to add a corn flavor.

Health food stores and some major markets carry plain corn bran for home cooks to use. You may also notice corn bran in the ingredient lists of a range of foods such as tortillas, chips, muffins, health food bars, and so forth.