Ichiya-miso (One-night Miso)

Ichiya-miso is a quick miso made by combining rice koji with cooked soybeans and leaving them overnight. Full fermentation has barely begun, but koji enzymes start breaking down proteins and starches, producing subtle sweetness and umami. It has gained attention as an introduction to miso-making and as a hands-on lesson in fermentation mechanics. Starting with one-night miso, then following aging over months and years, you experience firsthand that fermentation is an art of time. It is ideal for making miso with children. By the next morning, flavor changes are tangible, sparking the realization that fermentation is fascinating. One-night miso is the first step in nurturing curiosity about fermentation.