Japan — Hokkaido and northern Pacific coast autumn migration; peak October harvest
Sanma (秋刀魚, Pacific saury, Cololabis saira) is Japan's definitive autumn fish — its kanji literally means 'autumn sword fish' (autumn + sword + fish), reflecting both its season and its elongated, blade-like shape. Sanma arrives in Japanese waters from September–October as schools migrate south from Hokkaido and the northern Pacific. It is extremely fatty at this time (natural oil content 20%+ in peak-condition fish), rich in DHA, and has a distinctive robust flavour more pronounced than most Japanese fish. The standard preparation is shioyaki (salt-grilled whole): the whole fish is salted 30 minutes before grilling, grilled over charcoal until the skin is crispy and the flesh barely translucent at the thickest point, served with grated daikon (oroshi daikon) and sudachi or kabosu. The sanma shioyaki is Japan's most universal autumn dinner — eaten in millions of homes simultaneously during the October peak season.
Rich, oily, robustly flavoured — one of Japan's most assertive fish; skin crisps beautifully under salt-grill; the internal organs add bitter depth; daikon acid and citrus cut through the fat creating the quintessential autumn balance
Salt sanma 30 minutes before grilling (the salt draws out surface moisture for crispy skin and seasons the flesh); grill on high heat without moving (the skin will crisp and release naturally — moving causes tearing); the internal fins (the darker internal organs) are edible and considered a delicacy by connoisseurs — slightly bitter, intensely flavourful; serve always with grated daikon which cuts through the oiliness.
The sanma season indicator: when sanma appears at supermarkets below ¥200 per fish, it is at peak supply and flavour — this is the signal to cook it that evening; home grilling: use a fish grill (sakana-yaki-ki) or a broiler with the rack very close to the element for maximum skin crisping; a squeeze of sudachi or kabosu over the grilled fish before eating is non-negotiable for authentic preparation; sanma sashimi (extremely fresh sanma, available only at peak season for 2–3 weeks) is extraordinary — the high oil content means the raw fish is almost buttery, served with grated ginger and soy.
Grilling too slowly at low heat (sanma skin needs high heat to crisp before the flesh overcooks); removing the internal organs before grilling (they are the flavour core of sanma — their bitterness is intentional and desirable; a sanma without its organs is considered incomplete); serving without daikon (the enzyme activity of fresh daikon breaks down the fish fat — it is functional, not just garnish).
Japanese Cooking: A Simple Art — Shizuo Tsuji