The finely ground and sifted meal of any of various edible grains. Giant steel or stone rollers are used to break and grind the grain. The more naturally nutritious stone-ground flour is produced by grinding the grain between two slowly moving stones. This process crushes the grain without generating excess heat and separating the germ.
Wheat is the most common source of the multitude of flours used in cooking.
U.S. law requires that all flours not containing wheat germ must have niacin, riboflavin, thiamin and iron added. Flour can be bleached either naturally, as it ages, or chemically. Most flour on the market today is presifted, requiring only that it be stirred, then spooned into a measuring cup and leveled off. Because of the latter, it should be stored in the refrigerator to prevent rancidity. It makes particularly tender cakes and pastries.