Making brown rice koji is much more difficult than polished rice koji. More often than not I have failed. I thought I should try again when I noticed a bag of ecologically grown brown rice that looked like it might work (Italian, long grain). I washed and soaked 750 grams, which is less than usual but easier to manage. I then broke up and inoculated the rice with the same tane koji I use for the other rice cultures.

I put it into the terracotta trays.

Then into the heat chamber as usual.

After the first day growing, the smell seemed ‘off’ – as if a bacteria growth was going to take over and cause a bad culture that would have to be thrown out on the compost like many times before. With extra aeration and spreading out, the mold took hold again, and it turned out fine.

After two and a half days growing.

Spread out to dry.

Brown rice has a covering that is polished off when making white rice. This barrier hinders the koji mold from growing into the kernel. The trick is to soak and steam the rice just enough, so as to break this shell. That way the mold can get in. At the same time one must not let the rice get too soggy where bacteria thrive. Another method is to find a rice that is slightly polished but can still be considered brown rice. A little rice polishing machine would be good to have. I could polish it just right and throw in the polishings.

Brown rice koji making is for the experienced koji maker and whole foods enthusiast. It is more difficult to keep the mold growing ahead of the bacteria. It is also less efficient in enzyme production because the mold doesn’t get into all the grains.

So I recommend starting out koji making with white or polished rice, which is by far the easiest, while learning the procedure, the look, the smells, the consistencies, etc. Then move on to experiment with other grains.