What Is Shoyu (Japanese Soy Sauce)? (醤油)
Soy sauce brewed from soybeans, wheat, salt and koji - classified in Japan into five official JAS types.
| Base ingredients | Soybeans, wheat, koji and salt water (brine), fermented as moromi mash and pressed |
|---|---|
| Official types | Five JAS types: koikuchi, usukuchi, tamari, saishikomi and shiro |
| Exports | Japanese soy sauce exports were about 54,000 tonnes worth $81 million in 2024, with the United States the largest market by value (trade-statistics based figures) |
Shoyu is a brewed seasoning, not just a salty liquid. In the standard (honjozo) method, koji grown on soybeans and roasted wheat is mixed with brine to form the moromi mash, which ferments and matures before pressing, pasteurisation and bottling.
Japan's agricultural standard (JAS) sorts shoyu into five types by ingredients and method, and those five types - not brand names - are the map for buying abroad. Koikuchi alone accounts for the great majority of shoyu made in Japan; the other four are regional or specialist types that solve specific cooking problems, as their pages explain.
See also
KoikuchiRelated page in this guide.Reading a shoyu label
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.