It is a doburoku with a water yeast yeast yeast base, and is unmistakably a perverted sake made with red rice (a.k.a. "rotten rice"). The rice used is Tono No. 1.
The problem is that the other day, the door of the refrigerator was left slightly open, and this was found at the very front of the door bag: ......
So I can't tell if this sourness is from the yeast or from over-fermentation. ...... At any rate, it's not a bad sourness.
The top aroma is cheese. The top aroma is cheese. I think it's a very strong mizu-hashiro (water yeast). The very shwashy flavor is probably due to fermentation. This sourness is vinegar, and pickles. It must be very bad for those who don't like it, because it seems to be a pervert.