【Reading】おおとろ

【English Name】Fatty Tuna

Otoro, positioned at the very highest grade in the world of sushi, is the part of the tuna's belly with the most abundant fat content. Its greatest appeal lies in how, the instant it is placed in the mouth, the fat melts out at body temperature and a smooth umami spreads.

The name "toro" originated from a single remark by a customer who visited Yoshino Sushi Honten. It is said to have arisen from describing the mouthfeel of the fat melting away smoothly as "a torori (melt-in-the-mouth) texture"; before that, the name "abu" was current for parts bearing much fat.

However, before the Edo period, the evaluation of fatty flesh was quite the opposite. The true prize of tuna was positioned as the lean red meat (akami), and parts high in fat tended to be shunned as quick to spoil. They were called by the derogatory term "neko-matagi" (meaning that even a cat would step over it), and discarding them was the norm. Added to a palate that regarded light white flesh as refined, the circumstance that the fat hindered the penetration of soy sauce and was unsuited to zuke (marinated) preservation also spurred their unpopularity.

Behind the complete reversal of evaluation lie the development of a distribution infrastructure centered on freezing and refrigeration, and a change in the recognition of the umami that animal fat brings. Thus the market value reversed, and it has now transformed into a high-grade ingredient fetching a price more than twice that of lean meat. Looking at the fat distribution of a single tuna, there is a pronounced tendency for fat to gather on the belly side over the back side, toward the head over the tail, and on the surface layer over the deep layer. Furthermore, with the advance of full-cycle aquaculture technology, the raising of individuals with fat distributed throughout the whole body is entering a realistic stage.