Neutral yeast (non-killer yeast)

A neutral yeast is a type of sake yeast with a specific characteristic: it is not aggressive toward other yeasts. Yeasts that produce killer toxins can kill surrounding yeasts with those toxins, but a neutral yeast does not release such toxins, so it can coexist with other yeasts. Because of this property, neutral yeasts can be used together with a variety of other yeasts during fermentation, which helps maintain a more stable fermentation environment. In this way, they play a role in steadily improving the flavor and quality of sake.