Salt (Sodium chloride)
Salt
Japanese: 塩（しお）
A fundamental ingredient controlling fermentation and enhancing preservation.
In miso making, salt serves not just as seasoning but as fermentation regulator. Higher concentration suppresses microbial activity; lower promotes it. This balance determines speed and final flavor.
Typical miso has 10-13% salt concentration. Creating an environment where only salt-tolerant yeasts and lactic acid bacteria survive prevents contamination while allowing desirable fermentation. Salt type also influences flavor. Sun-dried salt, rich in minerals, yields mellow results. Refined salt gives sharper salinity. Choosing salt is another pleasure of miso making.