Ingredients:

  • 1 kg / 2.2 lbs Short Grain Rice
  • 1.2 L / 5 cups Water (for soaking & steaming)
  • 500g / 1.1 lbs Soybeans (dried, whole)
  • 2 L / 8.5 cups Water (for soaking and cooking soybeans)
  • 350g / 12 oz. Sea Salt
  • Aspergillus oryzae spores (koji starter)
  • Optional: Lacto bacteria culture

Instructions:

  1. Soak rice for several hours, then steam until cooked but firm.
  2. Cool the cooked rice to a specific temperature (follow koji starter instructions). Inoculate with Aspergillus oryzae spores, mixing thoroughly. Spread rice thinly on a tray and cover.
  3. Maintain optimal humidity and temperature (usually around 86°F/30°C) for several days, monitoring for koji growth (fluffy white mycelium).
  4. Soak soybeans overnight, then cook until very soft. Cool to room temperature.
  5. Combine the koji rice, cooked soybeans, and salt in the fermentation container. Add the water and mix thoroughly to create the moromi (fermentation mash). If using Lacto Bacteria add here.
  6. Allow fermentation to occur. For the first week stir daily. Regularly observe, monitoring for desired microbial activity. Maintain a consistent temperature.
  7. After the fermentation period (6-12 months or longer), press the moromi to extract the soy sauce. Pasteurize the raw soy sauce to kill unwanted microbes and stabilize the flavor.
  8. Bottle the pasteurized soy sauce and store in a cool, dark place.