Home made Shio Koji (塩麹)
Shio Koji is a naturally fermented, additive-free Japanese seasoning that brings gentle sweetness, umami, and depth to your dishes. It works especially well in vegan cooking, enhancing the flavor of vegetables, grains, and even plant-based cheeses. You can also use it as a salt alternative to reduce sodium while keeping your meals flavorful.
Equipment
- Bowl
- Glass container or Jar
Ingredients
- 100 g Fresh Rice Koji
- 35 g Natural Salt
- 110 g Water
Instructions
- Mix Rice Koji and Salt: Place the fresh rice koji and salt in a clean bowl. Gently mix by hand until the salt is evenly distributed. * This step awakens the enzymes in the koji, which will slowly transform the mixture into a naturally sweet and umami-rich seasoning.100 g Fresh Rice Koji, 35 g Natural Salt
- Transfer and Add Water: Move the mixture into a clean glass jar or food-safe container. Add just enough water to cover the koji. Cover lightly with a lid or plastic wrap, keeping it slightly loose so the koji can “breathe” during fermentation. Store at room temperature, away from direct sunlight.110 g Water
- Check and Adjust: The next morning, the koji will have absorbed some water. If the top looks dry, add a little more to fully cover the grains. * The amount of water may need to be adjusted depending on the season and the moisture content of your koji.* For the first two days, if the surface looks dry, add a little more water—once or twice is usually enough.
- Daily Stirring: Cover the jar lightly again and leave it at room temperature. Stir gently once a day with a clean spoon to ensure even fermentation.
- Fermentation Time: Shio Koji is ready after about 1 week in summer or 2 weeks in winter.* The finished mixture will have a sweet aroma, and the grains will appear soft and plump, almost losing their individual shape.
- Final Texture and Storage: The koji should be soft and easily mashed between your fingers. The saltiness will mellow, and the umami flavor will deepen. Store the finished Shio Koji in the refrigerator to preserve its flavor.
Notes
- Keep the lid slightly loose during fermentation so the koji can breathe.
- Avoid adding too much water; a thick, well-balanced Shio Koji is easier to use in cooking.
- Low salt content shortens shelf life, so maintain the proper ratio of salt to koji.