Protein content of flour

Gluten only develops once flour is moistened and mixed, and the amount of protein in the flour sets how strong it can be. Hard wheat flours have more good-quality gluten than soft wheat flours, so they are considered the best for bread making.

Good bread flour should have about 13 percent gluten, according to one baking text. The higher gluten content lets hard flour produce a greater volume. Flour that lacks stability to hold during the whole fermentation may give small, flat bread.

Lower protein flours give tender, delicate crumbs, which suits cakes and pastry, while higher protein flours give chewy, structured breads. Bakers pick the flour by protein content to match the product they want.