Soy flour is a powder made from crushed soybeans that can be combined with other types of flour in baked goods or used as a thickening agent in cooked dishes. Since soy flour is produced from soybeans rather than grains, it adds more protein to dishes than traditional white flour. Nutrition is not the only difference between soy flour and grain-based flours. Soy flour will not produce the same texture as other flour, so you cannot evenly swap the two in baked recipes but you can adjust the ratios.
Measure out the amount of all-purpose flour called for in a dough or other baked good recipe and add it to a bowl. Scoop out and remove 2 tbsp. of all-purpose flour for every one cup in your bowl and transfer it back into the flour container. For example, if you have 2 cups of all purpose flour, remove 4 tbsp.
Whisk or stir your soy flour before measuring it because it may clump up. Replace the all-purpose flour you removed with equal amounts of soy flour. Whisk or stir gently to completely incorporate the two flours together.
Prepare the rest of the dough or baked good ingredients as normal. Reduce your oven temperature by 25 degrees Fahrenheit than what is called for in your recipe because soy flour darkens more quickly than all-purpose flour and can make your item overly browned if you use a higher cooking temperature. Bake for the amount of time specified in your recipe directions
Set your stove to medium heat. Add 2 tbsp. of butter into a large skillet on your stove top for every 1 cup of sauce, soup or other liquid you want to thicken.
Sprinkle 2 tbsp. of soy flour directly on top of the butter for every 1 cup of liquid that needs thickened. Whisk the butter and soy flour briskly for about two minutes or until they form a lightly browned paste-like mixture.
Transfer your sauce, soup or other dish you want to thicken into the skillet and turn the stove to high. Whisk the butter and soy flour mixture into the rest of the ingredients until it starts to boil. Continue stirring the boiling mixture until it is thoroughly smooth and thickened.