Since soy flour can become packed in its bag or container, always stir it before measuring. Soy flour can be used as-is, or, for a pleasant nutty flavor, toast it before adding it to a recipe. Place the soy flour in a dry skillet and stir over medium heat for a few minutes.
Soy flour can be used as a thickening agent in gravies and sauces, or it can be added to baked goods. In baked products, soy adds tenderness and moisture and helps to keep products from becoming stale. Products containing soy flour brown more quickly, so it is sometimes necessary to either shorten the baking time or decrease the temperature slightly. For products that do not contain yeast, such as muffins and cookies, replace up to 1/4 the total amount of flour called for in a recipe with soy flour. For products that are yeast-raised, such as bread, replace up to 15% of the flour called for in the recipe by placing two tablespoons of soy flour in the cup before measuring each cup of flour. Using more soy flour than this will cause breads to be too heavy and dense, since soy flour is free of gluten, the protein that gives structure to yeast-raised baked products.
Soy flour also makes a good egg substitute in baked products. Replace one egg with 1 tablespoon of soy flour plus 1 tablespoon (15mL) of water.