Super Freezing is essentially the process of lowering temperatures of an object below that of it’s freezing point. This technique is commonly used for Bluefin Tuna / Hon-Maguro to ensure freshness and maintain quality – where temperatures are lowered rapidly to it’s Eutectic Point of an astonishing -60 degrees!
At -60 degrees, bacterial growth is halted, preventing the natural decomposition and quality deterioration of the catch.
The process starts aboard the fishing vessels, or factory ships, of our partners where Tuna is caught, gilled and gutted. Ikejime (活け締め) also takes place at this stage. Subsequently, these treated fishes are put into on-board freezing facilities where the Super Freezing process is completed in less than 24 hours.
Each catch is then brought back to inland factories where the Super Frozen Tuna is sawed into customised blocks for different customers. Upon reaching chefs and other customers, these Tuna slabs are thawed and can be consumed raw.
Given the advancements in on-board ship technology, it is no surprise why Super Frozen Tuna is often described to be “fresher than fresh”!