Tamari and Gluten-Free: The Accurate Version (たまりとグルテンフリー)
What can and cannot be claimed: most shoyu contains wheat, most tamari does not - and only the label settles it.
| Standard shoyu | Koikuchi, usukuchi, saishikomi and shiro are brewed with wheat and are not gluten-free |
|---|---|
| Tamari | Brewed mainly from soybeans; many products are made without wheat, but some contain a little |
| Labelling | 'Gluten-free' is a regulated claim that differs by country (for example thresholds and testing rules). A Japanese tamari without a gluten-free mark is not automatically certified gluten-free abroad |
The accurate version is short: if you must avoid gluten, do not rely on the type name. Choose a bottle that carries your own country's gluten-free label or an explicit 'wheat not used' statement from the maker, and re-check when you change brands, because recipes differ.
For cooking rather than medical need, tamari substitutes well for koikuchi: it is a little richer and less aromatic, and in cooked dishes the difference is small. In delicate dipping use, add a touch less, taste, and adjust.
See also
TamariRelated page in this guide.Substitutions: what works
Related page in this guide.
Sources: Ministry of Agriculture, Forestry and Fisheries (MAFF), 'Traditional Foods in Japan'; JAS soy sauce standards; Umami Information Center; Kikkoman official information; Wikipedia (CC BY-SA 4.0). Checked 6 November 2026.