Whole-wheat flour is a powdery substance, a basic food ingredient, derived by grinding or mashing the whole grain of wheat, also known as the wheatberry. Whole-wheat flour is used in baking of breads and other baked goods, and also typically mixed with other lighter "white" unbleached or bleached flours (that have been treated with flour bleaching agent(s)) to restore nutrients to the white flours (especially fiber, protein, and vitamins), texture, and body that are lost in milling and other processing to the finished baked goods or other food(s).
The word "whole" refers to the fact that all of the grain (bran, germ, and endosperm) is used and nothing is lost in the process of making the flour. This is in contrast to white, refined flours, which contain only the endosperm. Because the whole flour contains the remains of all of the grain, it has a textured, brownish appearance.
Whole-grain whole wheat flour is a robust, full-flavored flour containing vitamins, minerals and protein. Whole-grain whole wheat flour is more nutritious than refined white flour, although white flour may, in a process called food fortification, have some micronutrients lost in processing added back to the white flour (required by law in some jurisdictions). Fortified white wheat flour does not, however, contain the macronutrients of the wheat's bran and germ (especially fiber and protein) like whole-grain flour does. Whole grain is a good source of calcium, iron, fiber, and other minerals like selenium. Regular "whole wheat" flour commonly used commercially has 70% of the germ removed to prevent rancidity, and as such cannot be labeled "whole grain".
Whole-wheat flour has a shorter shelf life than white flour, as the higher oil content leads to rancidification if not stored properly, such as with refrigeration, or in other cool areas.
Often, whole wheat flour is not the main ingredient in baked goods, as it may add a certain "heaviness" that prevents them from rising as high as white flours. This can add to the cost per volume of the baked item, as it requires more flour to obtain the same volume, due to the fewer and smaller air pockets trapped in the raised goods. Thus, many baked goods advertised as whole-wheat are not entirely whole-wheat; they may contain some refined white wheat, as long as the majority of the wheat used is whole-wheat.
Nevertheless, it is possible to make a high-rising, light loaf of 100% whole-wheat bread, as long as one increases the water content of the dough (the bran and germ in whole wheat absorb more water than plain white flour), kneads the dough for a longer period of time to develop the gluten adequately, and allows for a longer rise before shaping the dough. Some bakers let the dough rise twice before shaping. The addition of fats, such as butter or oil, and milk products (fresh milk, powdered milk, buttermilk, yogurt, etc.) can also greatly assist the dough in rising.
White whole-wheat flour is flour milled from hard white spring wheat, rather than traditional red wheat. In the United Kingdom, whole-wheat flour is more commonly made from white wheat instead of red as in the United States. The difference is that soft white wheat has a lower gluten content and also lacks the tannins and phenolic acid that red wheat contain, causing white whole wheat to appear and taste more like refined red wheat; it is whitish in color and does not taste bitter.
White whole wheat has almost the same nutrient content as red whole wheat. However, soft white whole wheat has a lower gluten content and contains a lower protein content (between 9% and 11%) when compared with harder wheats like red (15–16% protein content) or golden wheat.][
Despite historical consumer preference for refined flour and the traditionally higher per-unit cost of whole grain, whole-wheat flour products are ascendant largely due to changing consumer attitudes. The Whole Grains Council industry association reports an approximate doubling of the whole-wheat flour production over the course of the years 2003 to 2007. In another visible example, whole-wheat bread has reached approximate parity with soft white bread as measured by slice volume in the United States; as of 2010, whole-wheat bread narrowly exceeds soft white bread as measured by dollar volume.