Whole wheat flour is a powdery substance derived by grinding or mashing the whole wheat berry. It is used in baking but typically mixed with other "white" flours to add nutrition, texture, fiber, and body to the finished product. Usually, whole wheat flour is not the main ingredients of baked goods due to its quality to add texture and a certain "heaviness" to baked goods which prevents them from rising as well as white flours. This adds 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.

The word "whole" refers to the fact that all of the berry is used and nothing is lost in the process of making the flour, rather than referring to the complete berry in its natural grown state. Because the flour contains the remains of all of the berry it has a textured, brownish appearance.

"Brown" bread made from whole wheat flour is more nutritious than "white" bread made from white, refined, flour even though nutrients are added back to the white flour. This is because whole wheat bread is less refined and retains more of the naturally occurring vitamins and minerals. This is important to nutrition because while we have identified many of the vitamins and minerals occurring naturally in foods, there remain doubts that we have identified them all. Much less confidence attends our understanding of minimum daily requirements of these vitamins and minerals and any such published numbers can only be used as guidelines.