In the forgotten batch of our homemade miso (we made it last September), we noticed a pool of very dark liquid on the surface. That's the very natural soy sauce. In fact, the origin of soy sauce is the by product of miso. So we scooped it up and tasted...gorgeous. The white stuff is not mold, it's concentrated amino acid from fermentation of miso.
We removed it and mixed the miso again. It's going to sleep in our basement for another 6 months or so.
