Description
Slow enzymatic breakdown of soy proteins and carbohydrates by koji mold (Aspergillus oryzae) and lactic acid bacteria at controlled low temperatures.
Technical
Extended proteolysis (soy glycinin → glutamic acid) and Maillard reactions between reducing sugars and amino acids create umami compounds like N-(1-deoxy-D-fructos-1-yl)-L-glutamate (Fru-Glu).
Culinary Significance
Develops profound depth of flavor unattainable in short-term fermentations, with balanced sweetness, umami, and lingering savory notes.
Science
Primary Reaction
Proteolysis + Maillard pathways
Parameters
Temperature
12°C optimal
8°C to 15°C range
Time
36 months
24 months – 60 months
Equipment
Cedar fermentation barrelsStone weights (20% mass)Washed linen cloth