Soy Koji Spores

(1 customer review)

From: 6,00

The amount refers to how much wet substrate can be inoculated. For more info, click here.


This strain has been specifically bred to grow well on soybeans.
It has good fragrance, medium amount of amylase, but strong proteolytic power, which is perfect for hatcho miso.

Growing Koji on soybeans is a bit advanced, and we do not recommend to attempt this as your first koji. It is better to start with rice to get a good feeling for the process.

It is best to soak the soybeans for at least 12 hours. Drain them, and then steam them in a pressure cooker for 1 hour (if you dont’t have a pressure cooker, steam the beans in a normal steamer for 3 hours).
After steaming, make sure that the beans are not too wet. If they are too wet, Bacillus Subtilis will take over (Natto bacteria), which will result in slimy beans that smell like ammonia.
In order to avoid that, you can either dry them with a hairdrier a bit, or you could also dust them with starch/toasted flour, which will soak up any excess moisture.

Weight 0.8 g

For 5 kg, For 50 kg, For 200 kg

1 review for Soy Koji Spores

  1. Alex (verified owner)

    I use this on broad beans (aka fava beans) to make red oil doubanjiang (loosly based on this recipe: and it works quite well. You do need to be careful not to inoculate too long — it’s a trickier fermentation than koji rice. Competitor molds and bacillus like to get started around 48h, and I’ve lost a few trays to it.

    The key, I’ve found, is to think of it as a 36 hour process — you get 36 hours to grow koji, at which point you need to end the fermentation. The goal is that the koji get as far as it can in that time. This is a good koji for doing that with as it grows quickly on broad beans. I also use 2-3x the recommended amount of spores to give it every advantage I can. The recipe I link says to wait for it to sporulate, but I am not sure it’s necessary.

    I made my first batch 6 months ago using this spore line, and have already eaten some of it, so I know it works. I have a bunch more batches in various stages.

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