As you walk through the baking aisle at your local grocery store, the variety of different flours can be overwhelming. While all-purpose wheat flour, in its bleached or unbleached varieties, works for general baking, other options include bread flour, cake flour, pastry flour and self-rising flour. Other non-wheat flour alternatives include rice flour, rye flour and soy flour.
Bleached vs. Unbleached Flours
When people refer to bleached or unbleached flour, it is typically all-purpose wheat flour. While all all-purpose flour is actually bleached through a natural oxidizing process, flour labeled as bleached undergoes a chemical process using benzoyl peroxide or chlorine gas to create a bright white look. In addition to changing the physical color of the flour, this chemical process also reduces the protein content in the flour. Bakers making white cakes or breads often use the bleached flour to maintain a true white color.
When it comes to flour for baking, protein, or gluten, is the focus. The quality and quantity of gluten-forming protein in flour determines how the flour reacts in baking. Low-protein flour is softer and works in cakes, while high-protein flour works for chewy breads. All-purpose flour has a protein level between 8 and 13 percent. The amount varies between brands and flours due to the variety of wheat used. All-purpose flour is made from either hard red winter wheat, soft red winter wheat or a combination of both. Hard wheat contains 10 to 13 percent protein while soft contains 8 to 10 percent. Cake flower, used for light and fluffy cakes and cookies, typically has a protein amount of 6 to 8 percent while bread flour is 12 to 14 percent.
Types of Flours
With wheat flours, you have all-purpose, whole wheat, cake, pastry, bread and self-rising flours. These flours all contain some percentage of protein. Self-rising flour is the same as all-purpose in terms of protein, however, baking soda, baking powder and salt are added. Whole wheat flour is less processed and contains more fiber, making it coarse and not usually the best choice for cakes and cookies. In addition to wheat flours, various gluten-free flours, such as rice flour, rye flour, tapioca flour and soy flour. These flours do not contain protein and often require the addition of gluten substitutes in traditional baking recipes.
Flour and Gluten Substitutions
Other flours can be substituted for the typical all-purpose variety, with some consideration. If the recipe is a delicate pastry or cake, high-protein bread flour is not recommended, while cake flour is not recommended for breads. In addition to considering protein content, measurements often vary. For instance, when using cake flour in place of all-purpose, measure an additional 2 tablespoons for every cup. For rice flour, use 7/8 of a cup of rice flour instead of a full cup. For wheat flour, remove a tablespoon of flour for each full cup. In addition to measurement changes, gluten-free flours, such as rice flour, may need the addition of a gluten substitute, such as xanthum gum or guar gum. Add 1 teaspoon for each cup of gluten-free flour.