Very interesting... I have been experimenting more lately with fermented foods. They are very good for you. I've had my sourdough starter for years now. Recently started brewing my own kombucha, from my own home-grown scoby. Have used the Umai bags for dry-aging, but this is intriguing. I'll be adding the koji rice to my Amazon shopping list. Since you can't dry age individual steaks (only large primal cuts), this is definitely worth a try. Could be quite useful.