Shōsan kangen-kin

Nitrate-reducing bacteria

The collective name for bacteria with the capability to reduce nitrates to produce nitrous acid. In the early stages of kimoto-school shubo, this ability to produce nitrous acid is used to suppress the growth of wild yeast, and lactic acid bacteria multiply in the meantime. The nitrate reducing bacteria are killed by the acid created by the lactic acid bacteria, and it is only then that seishu kobo (long first “o”; sake yeast) propagates.