Northern Pacific Ocean and Sea of Okhotsk; primarily caught in Hokkaido waters (Abashiri, Kushiro, Hakodate auction markets); significant catches also from Tohoku (Iwate, Miyagi) during storm-free autumn-winter seasons; priced at auction with highest grades reaching Tsukiji/Toyosu premium records
Kinki (キンキ, Sebastolobus macrochir, broadbanded thornyhead) and kichiji (キチジ, Sebastolobus alascanus, shortspine thornyhead, also called biwamasu) are deep-water rockfish from Japan's northern Pacific and Sea of Okhotsk that rank among the most prized and expensive fish in Japanese cuisine. Both species are caught at depths of 200–800m in extremely cold Hokkaido and Tohoku waters, and their isolation in these deep cold environments produces extremely high intramuscular fat content. Kinki is slightly larger (30–40cm) and is the more prestige-laden of the two; its market price at Tokyo's Toyosu regularly reaches 30,000–50,000 yen per kilogram at auction for premium specimens. The flesh of kinki is white to pale pink, extraordinarily rich with fat marbled through the muscle — more comparable to fatty tuna in fat content than to typical white fish. The fat is sweet and buttery with a characteristic deep-sea mineral richness. The canonical preparation is kinki no nitsuke (煮付け) — braised in sake, soy, mirin, and sugar in a ratio calibrated for the fish's intense fat, which renders and enriches the braising liquid. The fish is cooked skin-side up and spooned continuously with the sauce (kake-jiru) as the fat emulsifies into the braise. A secondary preparation is shioyaki (salt-grill) — the skin crisps to lacquer-dark and the fat renders through the flesh. The combination of deep-sea fat richness, difficult sourcing from northern Hokkaido's storm-prone fishing grounds, and the fish's relatively slow growth rate explains the extreme pricing. 'Kinki wo taberu' ('to eat kinki') is in Japanese culinary writing shorthand for the ultimate luxury fish experience.
Extraordinary fat richness with a deep, sweet, cold-sea mineral complexity; the fat is softer and more buttery than akamutsu (nodoguro); nitsuke enriched with kinki fat is simultaneously the richest and cleanest fish sauce achievable — it coats the palate like butter but finishes with clean ocean depth
{"Deep-sea cold habitat at 200–800m produces fat content comparable to premium fatty tuna in white fish","Nitsuke (soy-sake braise) is the canonical preparation — the fat enriches the braising liquid into a glossy, unctuous sauce","Kake-jiru (continuous basting) during nitsuke prevents drying and ensures even fat distribution through the sauce","Pricing reflects sourcing difficulty (Hokkaido storm season fishing) and extremely slow growth at cold depths","Skin must be preserved and cooked — the skin layer carries concentrated fat and is the richest part of the fish"}
{"Kinki nitsuke ratio: 100ml sake, 50ml soy, 50ml mirin, 1 tsp sugar per portion — start with sake, bring to boil to evaporate alcohol, add soy, mirin, sugar, then add fish skin-side up","Cook at a bare simmer, covered with an otoshibuta (drop lid) — the lid creates a basting environment where the liquid bubbles up and coats the fish surface continuously","At 15–18 minutes, the fish is done when a chopstick inserted near the spine passes with minimal resistance; remove from heat and baste once more with the concentrated sauce","The braising liquid can be reduced further after removing the fish and spooned over as a finishing glaze — this concentrates the kinki fat into an extraordinary sauce","For shioyaki: salt 30 minutes before cooking, dry thoroughly, grill at medium-high with skin toward flame first — 8 minutes skin-side, 4 minutes flesh-side; the skin should crackle and char at edges"}
{"Overcooking kinki — the high fat content means the flesh stays moist longer than lean fish, but at very high heat the fat renders completely and the flesh becomes dry","Using too sweet a braising ratio — kinki's inherent fat sweetness means the braising liquid needs less sugar than for leaner fish nitsuke","Discarding the braising liquid after nitsuke — the kinki fat-enriched sauce is extraordinarily flavourful and should be served alongside","Removing skin before cooking — the skin is the richest part; to serve skinless is to waste the defining quality"}
Nihon Ryori Taizen — Tsuji Shizuo; Japanese Regional Seafood — Hokkaido Fisheries Documentation