From 927 CE to 2026 — the lineage of Japanese food centered on koji, mapped as six turning points.

1. Nara — Heian

   Era01

   Nara — Heian

   ca. 700–927

   Brewing as a State Enterprise

   From the Nara to Heian period, sake brewing with rice and koji was organized as a major imperial enterprise. The Engishiki (927 CE) records the structure of the Imperial Sake Brewer's office (Sake-no-tsukasa) under the Ministry of the Imperial Household, along with detailed methods for sake, vinegar, and soybean condiments — demonstrating that koji fermentation was already part of state infrastructure.

2. Muromachi

   Era02

   Muromachi

   ca. 1400–1500

   Tane-Koji Trade — The World's First Pure Culture Industry

   In the Muromachi period, a specialized trade called tane-koji-ya (koji-starter merchants), centered in Kyoto, became established. They mastered the technology of cultivating and selling koji mold spores in pure form, supplying sake breweries and miso producers across the country — recognized in world fermentation history as one of the earliest industrialized cases of pure microbial culture.

3. Edo

   Era03

   Edo

   1603–1868

   The Brewing Economy at Its Peak

   During the Edo period, koji-derived fermented foods — refined sake, miso, soy sauce, mirin, vinegar, and pickles — became staples of daily diet. Regional brands took shape (Nada and Itami sake, Kishu soy sauce, Shinshu miso) and distribution networks matured. Koji became both cultural capital and economic capital, with quality preserved through artisanal knowledge and intuition.

4. Meiji

   Era04

   Meiji

   1876–1890

   Scientific Naming — Koji Mold Enters the Lab

   In 1876, German chemist Hermann Ahlburg isolated the koji mold at Tokyo Medical School. Ferdinand Cohn later described it as Eurotium oryzae, and around 1890 European researchers led by Westergaard finalized its present scientific name, Aspergillus oryzae. This marked the moment when a body of empirical Japanese knowledge entered the vocabulary of world science.

5. Showa — Heisei

   Era05

   Showa — Heisei

   1950–2010

   Fermentation Engineering and Functional Research

   Post-war, fermentation engineering modernized rapidly, culminating in the full genome sequencing of A. oryzae in 2005. In parallel, research accumulated on functional components derived from koji — resistant protein, GABA, bioactive peptides. In 2006, the Brewing Society of Japan officially designated Aspergillus oryzae as Japan's national fungus (kokkin).

6. Reiwa — Today

   Era06

   Reiwa — Today

   2018–2026

   Koji Sweetener Goes Global

   ORYZAE Inc. founded in 2018, advancing the social implementation of resistant-protein-rich koji sweeteners under the Oryzae Sauce program. ¥470M raised in July 2024. U.S. debut at Expo West 2026 in March 2026. A 1,300-year lineage is now being translated into a choice for the world's food.