Deba Knife Fish Butchery Japanese Technique
Japanese professional kitchen — deba knife tradition developed alongside fishing culture
The deba (出刃, protruding blade) is Japan's fish butchery knife — a thick-spined, single-bevel blade ranging from 15-21cm, designed specifically for breaking down whole fish. The thick spine allows force application against backbones and heads; the single bevel creates the acute angle needed for filleting close to bone. Three-piece filleting (sanmai oroshi): top fillet, backbone, bottom fillet. Five-piece (gomai oroshi): for flat fish like flounder (hirame) and sole. The deba's geometry allows the edge to glide along the backbone with minimal waste — a skilled practitioner leaves minimal flesh on the skeleton. A separate small deba (kodeba) handles sardines and smaller fish.