I'm on my second try of making my own koji for sake, using the Taylor-Made AK instructions and starting with Vision's spores.
Both time I've ended up in the same place after 48 hours - some white fuzz, and a translucent blue/green tinge.
The first time, I wasn't sure what I had - I thought my Clorox wipe + Star San spray routine on the old cooler I'm using for a incubation chamber and/or using unsanitized utensils when touching the freshly cooled rice had given the koji another mold. I let the bluish tinted rice go for another 2 days in the incubator and it was covered in the green spores. (because I wasn't sure I had a monoculture, I dumped it). For the bulk of the incubation, every time I checked in, the lid of the cooler was dripping with condensation.
This time, I went crazy on sanitation. The cooler and everything in the incubator got a undiluted bleach wash. Everything else that touched the rice got a generous dose of star-san. 48 hours in, though, same result. I did have a few temp blips, though. The first 10 hours were at about 86 until I got my incubator straightened out. I switched to a new temp controller about halfway through - my older one I think was a few degrees low (set to 94, kept swinging aroung 96). And though I used the same humindity technique - a small dish of water in the incubator there was much less condensation. I tasted the koji at the 48 hr mark - about 1/2 hr ago. It was somewhat nutty, but the rice was kind of chalky.
After re-reading the Taylor guide and the posts on here, I think I have a koji monoculture, but that that the koji went to spore for a lack of moisture. I soaked the rice for 2 hours and steamed for 18 min. I used muslin in the steamer, cause the cheesecloth was messy the first time. The rice was firm to the tooth, but not unpleaseant.
Unless I'm mistaken, I'm gonna pull the moisture bowl, let the spores form, collect them, and try again with a much longer steam. Sound OK?
Also, will the bowl of water in the incubator supply enough humidity?