Methods of increasing the isoflavone aglycone concentration in a soy-containing comestible comprising maintaining the comestible in a temperature of from about 20.degree. C. to about 70.degree. C., for a period of from about 1 minute to about four hours, wherein the method results in an increase in isoflavone aglycone concentration. In some instances, additional .beta.-glucosidase can be added, and in some instances, additional processing steps, such as baking, can be included.