We Butchered & Tasted a 200kg Tuna With a Sushi Master

The return of bluefin tuna to British waters, specifically off Cornwall, presents a monumental ingredient opportunity for UK kitchens. In this masterclass, the Fallow team joins forces with third-generation sushi master Endo Kazutoshi to break down a massive 200kg Cornish bluefin tuna. For any chef handling large pelagic fish, understanding the precise breakdown of this apex predator is essential for managing yield, texture, and flavour profiles across the entire menu.

Sectioning the Giant: Akami to Otoro

Butchering a fish of this scale requires specialized knowledge of its muscle structure and fat distribution. Master Endo demonstrates how the fat content shifts dramatically throughout the carcass. Chefs learn to identify and separate the classic primal cuts: the lean, deep-red akami from the upper back, the medium-fatty chutoro along the side, and the highly prized, buttery otoro from the lower belly. Beyond these common cuts, the breakdown reveals rarer, highly sought-after sections such as the collar (kama), head meat, and the delicate meat scraped from the bones (nakaochi), each demanding specific preparation methods.

Techniques for Precision and Preservation

Breaking down a 200kg carcass is an exercise in structural anatomy and razor-sharp knife skills. The process requires steady, decisive strokes to avoid bruising the delicate flesh or tearing the fat-rich belly layers. Master Endo explains how to handle each section to maintain temperature and prevent oxidationOxidationA chemical process caused by exposure to oxygen that can alter colour, flavour, texture or nutritional properties., which quickly ruins the vibrant colour of the loin. Chefs will observe the transition from heavy primal butchery to the micro-precision required for sashimiSashimiJapanese preparation of precisely cut raw fish or seafood served without cooking. and omakaseOmakaseA Japanese dining style in which the chef selects and serves the dishes.-style sushi. Understanding how to portion these distinct zones allows a kitchen to optimize its margins, sending pristine blocks to the raw bar while routing richer, tendon-heavy cuts to the grillGrillTo cook using direct radiant heat. or curing chamber.