Japan — yanagiba knife tradition in Osaka and Tokyo; sashimi cutting as the primary application of single-bevel knife mastery
The yanagiba (柳刃, 'willow blade') — Japan's long, single-bevel sashimi knife — is the primary tool for producing professional-quality sashimi and represents the apex of Japanese knife-cutting philosophy. Single-bevel construction (only one side is ground; the other is flat, called the ura) allows the blade to be honed to an extreme sharpness level impossible with Western double-bevel knives, and the flat back side causes the cut to separate cleanly without compressing the fish cell walls (which would release liquid and damage delicate textures). The yanagiba blade length (typically 27–30cm for professional use) allows a single drawing cut the entire length of many fish fillets — the ideal sashimi technique makes a single, long, drawing motion from heel to tip without applying downward pressure, allowing the blade's weight and edge to do the work. Cutting styles for different fish: hira-zukuri (flat cut) — the standard 5–7mm thick slice for most firm-fleshed fish; usu-zukuri (thin slice) — paper-thin 2–3mm cuts for delicate white fish like hirame (flounder), produced by cutting at a very shallow angle; yori-zukuri (diagonal) — thick diagonal cuts for firmfleshed fish that benefit from more structural presence; kaku-zukuri (square cut) for tuna. The ura (flat back side of single-bevel blade) keeps the cut-off piece adhering to the flat until the cut completes, then cleanly releasing — this prevents smearing or tearing at the cut's completion.
Knife skill affects flavour directly in sashimi: a perfectly clean yanagiba cut produces a translucent, smooth-surfaced slice with intact cell walls — the fish's natural moisture stays within the cells until the moment of eating; a torn or compressed cut releases liquid pre-consumption, producing a slightly dull, wet surface and diminished flavour; the difference between a master's sashimi and adequate sashimi is entirely visible and entirely tasteable
{"Single drawing motion from heel to tip — never a back-and-forth sawing motion which tears fish fibres","No downward pressure: the blade's weight and edge should do the work; pressing down compresses cell walls and damages the cut surface","The ura (flat side) faces the cut-off piece: this creates a clean release as the cut completes","Single-bevel maintenance: the flat back (ura) must never be ground on a whetstone — maintaining absolute flatness is essential","Blade angle for usu-zukuri: 15–20° from horizontal produces the thin diagonal slice characteristic of delicate white fish presentation","The board: Japanese sashimi requires a flat, clean wooden board — the wood should be slightly damp to prevent sliding"}
{"The sound of a proper yanagiba cut: a clean, almost silent slice with no resistance noise — sound indicates drag, which indicates either dull blade or applied pressure","Length of blade matters for specific tasks: longer yanagiba (33cm) for large tuna blocks; shorter (24cm) for smaller fish and precision detail work","Osaka yanagiba versus Tokyo yanagiba: Osaka-style has a more pointed tip (efficient for working around the pin bones); Tokyo-style has a more rounded tip","The mirror polish on a yanagiba ura: the flat back should be polished to a reflective mirror — this can be checked by looking at the reflection","Whetstone sharpening sequence for yanagiba: coarse (400–600 grit) for repair, medium (1000–2000 grit) for sharpening, fine (6000–8000 grit) for finishing — always finishing the bevel side, only strop-polishing the ura"}
{"Using a back-and-forth sawing motion — this tears fish fibres rather than separating them cleanly","Applying downward pressure during the cut — compression damages the cell walls, releasing liquid and producing a less clean surface","Grinding the ura (flat back) on a whetstone — the ura is only polished on a flat strop or flat water stone; any grinding creates a hollow that loses the flat-release property","Using a double-bevel knife for sashimi — the V-ground edge pushes cells apart rather than separating them; acceptable but produces a slightly rougher cut","Cutting fish straight from refrigerator — cold fish fibres are more brittle; allowing 5–10 minutes of ambient temperature rest improves cut quality"}
Japanese Knife Reference; Sashimi Technique Documentation