Data

Fermentation type: wild/koji

Edible: No

Tastiness: N/A

Recipe

• 1 kg soybeans

Instructions

1. Soak the soybeans in water for 12 hours.
2. Cook the soybeans until they are soft. In my case, I started with pressure cooking, but then it turns out my pressure cooker had finally given up, so I did it “normally”, which took about an hour
3. Drain the soybeans
4. Mash the soybeans, adding some water if needed. It should be a paste, but not watery. You want a consistency that you can form into blocks, but it should be a bit chunky as well
5. Form the soybeans into 4 blocks
6. Dry the blocks for 2-3 days over a heating pad placed on a wire rack. Turn the blocks every so often
7. Put the blocks on a wire rack in the window so they get a bit of sun. I put some straw and some organic raw rice under mine, hoping they would catch the necessary microbes. Let them dry like this for 6 weeks, turning them every so often
8. After 6 weeks, put the blocks in a chamber that can hold ~32 degrees. I used a carton, and put in some straw and rice hulls here as well. Let them ferment for 2 weeks

Pictures

Mashing the soybeans

Meju blocks ready for drying

After 1 day

After 4 days

After 16 days

After 6 weeks, putting it in the chamber

After 6 weeks, picture of the chamber

Finished block

Finished block, broken apart

Notes

This was a failure. I never got any koji to take hold. Or possibly, some koji took hold (see the final picture where I have broken up the blocks), but not enough. Several things seem like factors I have to improve for next time:

1. I think the texture of my blocks was too chunky. The cracks were larger than in my reference pictures, which caused the blocks to dry out too fast
2. My straw was not organic and may have contained fungicides (thank you to my biologist friend E for pointing this out to me)
3. It’s possible getting the koji to take hold is a numbers game, and I simply didn’t have enough spores in my environment. Next time I may try cheating and introducing koji spores manually

The smell while drying the meju blocks was sometimes quite pungent, filling my apartment with the smell of sweaty feet. I think this was expected, but it wasn’t a very nice environment to have around you.

References

I mostly followed a recipe from Miso, Tempeh, Natto & Other Tasty Ferments by Kirsten K. Shockey and Christopher Shockey as well as one from QU Fermentation Studio