Gluten is a special type of protein that is commonly found in rye, wheat, and barley. Therefore, it is found in most types of cereals and in many types of bread. Not all foods from the grain family, however, contain gluten. Examples of grains that do not have gluten include wild rice, corn, buckwheat, millet, amaranth, quinoa, teff, oats, soybeans, and sunflower seeds.

Gluten can be removed from wheat flour by rinsing bread dough and kneading it until all of the starch is removed. Gluten helps make bread elastic and provides it with the chewy texture it has when eaten. For this reason, gluten that is removed from dough is sticky and feels much like chewing gum.

Gluten provides many additional important qualities to bread. For example, gluten keeps the gases that are released during fermentation in the dough, so the bread is able to rise before it is baked. In addition, gluten firms up when it is cooked and, with the help of starch, helps ensure the bread maintains its proper shape.

Gluten also has an absorbent quality, which is why bread is capable of soaking up broth. Because of this feature, gluten is often used by those on a vegetarian diet as an imitation meat. On the downside, gluten is believed to be partly responsible for causing bread to become stale.

Some people suffer from a disease called celiac disease, which is an allergy to gluten. Individuals with celiac disease must eat foods that do not contain gluten in order to prevent illness. If improperly treated, celiac disease can be fatal. In addition, care must be taken when eating grains that do not contain gluten, particularly oats and teff, as they are commonly grown near foods with gluten or processed in the same bins. Catholic sufferers of celiac disease must also exercise precaution, as wheat, which contains gluten, is a required ingredient in the wafers used for certain religious ceremonies.