Picked up two types of premade Koji:

• “yellow koji” traditionally used for miso, soy sauce, and sake
• “white koji” from the brew store that is traditionally use for shochu. Evidently, it produces citric (instead of lactic) acid. However, some sake maker do use it for a refreshing summer flavor. Guess I’ll give it a try.

Inspired by this video to try again at growing my own from spores. However, this is “pre-made” and I can skip right to mixing it all up! The suggested ratio is:

• 1 part koji – 20oz dry weight
• 4 parts rice – 80oz, or 5lb dry weight
• 6 parts water – 120oz, or about a gallon

Process:

• For two batches, I’ll need to cook up 10lbs of rice.
  • Using calrose (sushi rice), soak 2 hours or overnight.
  • Gently rinse and drain
  • Steamed for 30min until tender, but still firm
• 2026-03-14
  • In each of 2 containers:
    • Add
      • Cooked rice
      • 1.25 gallons of cold water (160oz total accounts for the dry koji rice, more could be added, but ABV will be lower)
      • Koji
      • Yeast nutrient
      • Yeast (Wyeast sake)
      • Some recipes add citric acid/hops to sanitize, but this would alter the flavor drastically.
        • An active yeast and the slow release of sugars from the koji should take care of things
        • However, a larger batch where you add more rice/koji each week could require something.
• 2026-03-30
  • Fermentation on both is complete
  • Seperated the rice from the liquid
    • In this case it was less of “racking” and more just pouring it through strainers.
    • Resulted in over 2 gallons per batch
    • Time to cold crash to clarify
  • The lees is known as kasu and has a lot of uses. I will be saving it.
• 2026-03-31
  • Both settled, but the white koji settled quite a bit more (1/4) vs the yellow (1/2)
  • However, the liquid is also quite cloudy. Cold crashing my help.
  • Ordered some “super kleer” ( kieselsol and chitosan)
  • According to this video, bentonite and other common clarifiers don’t work well on sake.

Source for white koji spores: https://www.etsy.com/listing/1516312119/white-koji-starter-20g-to-make-15-kg?ref=cart