Home Made Soy Sauce Koji
Gentle, naturally rich in umami, and perfect for enhancing vegan cooking—this homemade Soy Sauce Koji is simple to make, forgiving for beginners, and endlessly rewarding. Enjoy it over vegetables, in dips, or your favorite grains.
Equipment
- Glass container or Jar
- Clean spoon
Ingredients
- 150 ml Soy Sauce Choose a simple soy sauce made from soybeans, wheat, and salt. Add more if needed as fermentation progresses.
- 150 g Fresh Rice Koji If you can't find fresh koji, dried rice koji can be used; adjust soy sauce accordingly.
Instructions
- Combine fresh rice koji and soy sauce: Put the fresh rice koji and soy sauce in a clean container.150 ml Soy Sauce, 150 g Fresh Rice Koji
- Mix gently: Mix thoroughly with a clean spoon. Cover lightly, leaving a small gap for the koji to breathe.
- Check the koji absorption: The next morning, the koji will have absorbed the soy sauce and the upper half may be dry. Add just enough soy sauce to cover the koji and mix gently.* For the first two days, if the surface looks dry, add a little more soy sauce—once or twice is usually enough.
- Stir daily: Stir roughly once a day with a clean spoon. In summer, it will be ready in about 1 week; in winter, about 2 weeks. You'll know it's ready when the koji can be easily crushed with your fingers.
- Check readiness: When fermentation is complete, the soy sauce flavor will be softened and the koji will have a sweet, mellow depth.
- Store: Close the lid tightly and store in the refrigerator. Use as a versatile seasoning in vegetables, dips, soups, or grains.
Notes
- Even if you forget to stir for a day, Soy Sauce Koji is forgiving—just resume gentle daily stirring when you remember.
- For more about Shio Koji and Onion Koji, see my related guides.