Description
Kezuri bushi is the traditional Japanese technique of hand-shaving dried, fermented skipjack tuna (katsuobushi) into delicate flakes that form the umami foundation of dashi broth.
Technical
Through multiple stages of smoking, drying, and mold fermentation (Aspergillus glaucus), proteins are broken down into free amino acids like inosinic acid (IMP), creating potent umami compounds. The shaving process exposes different surface areas of the hardened fish block, affecting dissolution rates.
Culinary Significance
The thickness and uniformity of flakes directly impact dashi extraction efficiency and flavor profile, with professional chefs maintaining collections of specialized planes for different flake sizes.
Science
Primary Reaction
Proteolysis
Parameters
Temperature
22°C optimal
15°C to 30°C range
Time
6-9 months
3 months – 2 years
Equipment