Storage of Flours

All flours, even white flour, have a limited shelf life. In fact, millers recommend that flours, especially whole grain flours, be stored for no more than six months. The main change that occurs is the oxidation of oils when flour is exposed to air. The result is rancid, cardboard-like off flavors. While whole wheat flour, wheat germ, and bran are most likely to oxidize because of their high oil content, even the small amount of oil present in white flour—about 1 percent—eventually causes flavor changes. To avoid problems, rotate stock by following the FIFO rule (first in, first out) and do not add new flour to old. Flour should be stored covered and in a cool, dry area, particularly in the hot, humid days of summer. This prevents the flour from absorbing moisture and odors and from attracting insects and rodents. Whole grain flours, being more nutritious than white flours, are most susceptible to infestation from insects and rodents. Wheat germ and whole wheat flour are ideally stored under refrigeration, if not used within a few months.