Description
A proto-fermented seasoning made through salt-driven enzymatic breakdown of grains and fish.
Technical
Hishio involves Aspergillus oryzae (麹菌) and halophilic bacteria breaking down proteins into glutamates (umami) and carbohydrates into simple sugars. Fish enzymes (endogenous proteases) accelerate autolysis.
Culinary Significance
Served as both condiment and protein source, often diluted into soups or used to preserve vegetables.
Science
Primary Reaction
Proteolysis → free amino acids (especially glutamic acid)
Parameters
Temperature
20°C optimal
10°C to 30°C range
Time
9 months
3 months – 3 years
Equipment
Unglazed ceramic jars (tsukemono ki)Straw-weighted wooden lidsStone pressers