All in all, I think it came out really well! The finished kōji had this incredible, indescribable taste/smell. Maybe kind of, flowers and mangos and peaches? I used it to make a ton of miso.

I used Modernist Pantry kōji kin and organic basmati white rice, and a makeshift immersion circulator/floating water bath incubator thingy. The rice was steamed in unbleached muslin cloth until just a little undercooked, then the same cloth was used to line a metal tray. The rice was spread into hills and valleys, covered with more muslin, then tented with some aluminum foil over the whole thing. The foil was mostly to keep condensation from dripping off the roof of the incubator onto the muslin cloth.

I put it in the incubator with the circulator st to 90 F.I stirred it at 12 hours and again at 24. It got appropriately matted, and for the most part it wasn't too wet. However, there were a few spots where I think it was getting on towards sporulation already, as you can see here:

Could have been some extra humidity collecting in those darker spots? The tinfoil tent kept the incubator condensation from dripping on it, but I guess nothing prevented the tinfoil condensation from dripping lol... Anyway, the entire process seemed to go way faster than all the guides lead me to believe. I broke it all up as best I could and put it back in set at 84 F with the lid open for lower humidity. By 24 hours it was maintaining about 97 F on its own.