<<Disclaimer: Verify this information before applying it to your situation.>> From: "SAN-J INTERNATIONAL" <[log in to unmask]> To answer your question, we use naturally fermented corn alcohol to preserve freshness. Our wheat free tamari doesn't contain any wheat, rye, oats or barley. Please let us know if we can be of further assistance. Sincerely, Misako Binford San-J International, Inc.