This topic started in the Mesh thread, so I am moving it here to prevent a total loss of that.
Wait, that was you? That was an excellent class, freely given by a studied and gentlemanly person. He gave us the rest of that bottle of what I presume is koji jin sake. It portends a whole other world of interests.
I didn't know anything about koji jin or kin until your post, but wow, it is a huge part of Japanese food culture.