Something as simple as the type of flour used can determine the outcome of a recipe, especially in baking. Not all wheat flours are the same. White flour and wheat flour both come from wheat, but the variety of wheat and the amount of processing will affect how the flour acts in your recipes. All-purpose flour is readily available, but it should not be substituted when another type of flour, such as whole wheat pastry flour, is required. Knowing what makes these flours different will help you to understand why.
The main difference between types of flour is the amount of protein in them. Gluten is formed when the proteins in the flour react with water and are mixed together. The amount of gluten formed determines how the flour will act in baking applications. Different varieties of wheat yield flours with different protein levels. All-purpose flour, from a blend of hard and soft wheats, contains 7 to 12 percent protein in it compared to the 7 to 9 percent protein in pastry flours which use a lower protein variety of soft wheat.
All-purpose flour has a pale color and bland flavor from the refining process it goes through before being packaged. Bleached all-purpose flour has a bright white color. Some prefer the more natural look of unbleached all-purpose flour. Both are widely available in grocery stores. Whole wheat pastry flour is darker in color, lighter in texture and lends a lightly nutty flavor to foods. It must be stored in a cool, dark and dry spot such as the refrigerator to keep the germ in the flour from turning rancid. All-purpose flour lacks the germ and can be stored at room temperature, tightly sealed, for up to six months.
All wheat flours start out with whole wheat berries, also called kernels. To make all-purpose flour, the wheat kernel is stripped of its bran and germ and ground into a fine flour. Bleaching is an optional step taken by some companies to make bright white flour. It is made by grinding whole wheat kernels including the bran and germ into a flour with a finer grind than all-purpose whole wheat flour.
Baked goods made with all-purpose flour have a denser, chewier texture from the higher protein content in the flour. The protein combines with water in the recipe to produce gluten, which makes the baked goods tougher in texture. This is desirable in recipes where a dense texture is needed, such as chocolate chip cookies or dense breakfast breads. In pastries, this chewy texture is not needed or desired in the final result. The hallmark of many pastries is a light texture. This comes from using a lower protein pastry flour. Whole wheat pastry flour adds nutrition from the germ and bran of the wheat and a slightly nutty flavor compared to white pastry flour. The lighter texture of the whole wheat pastry flour can be replicated by using 2/3 cup whole wheat all-purpose flour combined with 1/3 cup whole wheat cake flour.
- Joy of Baking; Flour; Stephanie Jaworski,
- "The Art and Soul of Baking"; Cindy Mushet, et al.; 2008
- "Homegrown Whole Grains"; Sarah Pitzer; 2009
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