Japan (Hokkaido and Toyama Bay primary sources; cold deep-water Pacific and Sea of Japan habitats)
Ama-ebi (甘エビ, 'sweet shrimp' — Pandalus borealis, northern shrimp) is one of Japan's most prized raw shellfish — served exclusively as sashimi or sushi due to the dramatic texture transformation that occurs when heat is applied (the flesh becomes tough and loses its defining sweetness). The shrimp are caught in deep, cold northern Pacific and Sea of Japan waters, particularly off Hokkaido and the Toyama Bay, and are remarkable for their natural sweetness derived from high concentrations of glycine amino acid in the raw flesh — a sweetness that disappears entirely when the protein denatures under heat. Premium ama-ebi at high-end sushi restaurants are served very fresh (ideally same-day), peeled but with the heads still attached for subsequent deep-frying as karaage: the shrimp heads, fried until completely crisp, are consumed whole as a textural counterpoint to the delicate raw tail. The heads contain the roe (in season), concentrated fat, and the same sweet shrimp flavour rendered into crisp, salty-sweet form. Standard service: the peeled raw tails with wasabi and soy, or as gunkan-maki (battleship sushi) with a strip of nori, sometimes with a tiny amount of shiso or ikura. The characteristic translucent pale pink-orange colour and the glassy, almost liquid tenderness of the raw flesh are the quality indicators.
Extraordinary natural sweetness from glycine amino acids; glassy, almost liquid raw tenderness; clean, oceanic; crisp fried head contrasts dramatically with the delicate raw tail
{"Never apply heat — heat denatures the glycine amino acids immediately, destroying the defining sweetness","Deep-fry the heads (10 seconds at 180°C) immediately after serving the raw tails — crisp counterpoint","Fresh same-day quality essential: sweetness deteriorates rapidly after death and processing","Glycine amino acid is responsible for the sweet taste — only accessible raw","Hokkaido and Toyama Bay as primary sources; Toyama Bay ama-ebi in winter is particularly prized"}
{"At sushi counter: specify you'd like the heads fried at the same time as the tails are served","For home preparation: heads in 2cm oil in a very hot small pan for 10–15 seconds until translucent-to-opaque and crisp","A single drop of ponzu with ama-ebi rather than soy — the citrus acidity lifts the sweetness without overpowering","Toyama Bay ama-ebi in February–March: peak season coincides with winter white shrimp season; seek out if visiting the region"}
{"Cooking ama-ebi in any preparation — loses all defining sweetness and texture immediately","Discarding heads — the deep-fried heads are as much a part of the dish as the raw tails","Serving with heavy dipping accompaniment that overwhelms the delicate sweetness","Over-marinating or pre-dressing with soy — the sweetness is the point; minimal seasoning"}
The Japanese Kitchen — Hiroko Shimbo; Japanese Cooking: A Simple Art — Shizuo Tsuji