Non-wheat flour is flour made from grains other than wheat. Flour is simply ground grain so there are many different possibilities. Non-wheat flours include those from legumes, nuts, rice, soy and corn. Most flours are not interchangeable, meaning that the results of a recipe could turn out very differently depending on what type of flour is used.
White wheat flour, also called all-purpose flour, is the most widely used flour in the United States. Since it doesn't use the bran or germ of the wheat, it isn't healthy and rich in fiber like whole wheat flour which does use the bran and germ. Some people have intolerances or allergies to wheat and need non-wheat flour.
Some popular non-wheat flours are made from grains such as quinoa, rye, corn, barley, buckwheat and amaranth. Many of these aren't used alone, but in combination with other flours. Amaranth flour is quite spicy and sweet and is used for cookies, pancakes and muffins. Buckwheat flour is popular for use in pancakes and pastas and is high in protein. Barley flour can be used in baked goods such as cookies.
Corn flour, often considered a by-product of corn meal, has been used for centuries by Native Americans in the Southwest. Corn flour is non-wheat flour made from yellow, blue or white varieties of corn. It gives a hearty, crispy appeal to breads, pancakes and doughnuts. Blue corn flour contains more protein than either yellow or white.
Nuts such as almonds or hazelnuts are also ground to make non-wheat flour and are high in protein. Nut flour is ground finer than ground nuts and that is really the only real difference between them. Italians and Hungarians traditionally bake and cook with chestnut flour. Nut flour of any type usually doesn't make up more than a quarter of the flour used in a recipe. When baking with non-wheat flour, the most important consideration is what other flours to use with it, especially if wheat flour won't be used.