This finely ground flour is made from soybeans and, unlike many flours, is very high in protein (twice that of wheat flour) and low in carbohydrates. Soy flour is ordinarily mixed with other flours rather than being used alone. It has a wide variety of uses such as for baking and to bind sauces. In Japan, it's very popular for making confections. Soy flour is sold in natural food storessometimes under the name kinakoand in some supermarkets.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.