Barley flour is a fine powder made by grinding whole barley grain. Along with many other flours, it can be used to replace part of the wheat flour in a recipe for a different flavor and texture. It can also be used in other cooking applications, such as acting as a thickener in soups and sauces. Many natural foods stores carry this type of flour, and it can also be made at home.
A very hardy annual grain, barley has been grown all over the world as a food crop for thousands of years. Since it is more cold resistant than grains such as wheat, it was often grown in regions like Northern Europe. Hordeum vulgaris, as barley is formally known, is also very drought tolerant, making it an excellent choice of crop in regions with unreliable rainfall. A number of grain products are made from barley.
When barley is freshly harvested, it has a fibrous outer layer that must be removed to make hulled barley. Pearled barley is made by polishing the grain even further, yielding a smooth and rounded product, and barley flakes are made by flattening hulled barley. To make flour, the grain is ground in a mill.
There are two ways to make barley flour. Most commercial flour is made through a malting process in which whole barley is allowed to sprout and then rapidly dry. Malting changes the chemical structure of the grain slightly, and it is also the first step in brewing. It is also possible to find unmalted flour, or the flour at home by people who have a grain mill. Pearled or hulled barley can both be used, although malted barley flour has a higher nutritional value since it includes the rich hull of the grain.
Like other flours, barley flour can go rancid. It can be stored in a cool dry cupboard for one to two months, or in a freezer for three to four. When kept in the freezer, cooks can measure out the amount that they need to warm to room temperature, and put the rest back in the freezer. In yeast breads, the nutty flavor of barley can replace up to 25% of the regular flour, and in quick breads and other baked goods, it can be used to replace up to half of the flour called for by the recipe. It has a weaker gluten than wheat flour, so baked goods may have an unusual texture if too much is used.