Eel

Eel is a snake-like, scaleless fish from the Anguilla genus, distinguished by an exceptionally high fat content—15–30% depending on season—which makes its flesh unusually rich, sweet, and succulent. Its raw flesh ranges from pale pinkish-white to opaque white when cooked, and the firm, moist texture separates into clean flakes. Eel has small, fine bones that become negligible in most preparations. The fish lives in fresh water but migrates to the ocean to spawn, giving its flesh a mild marine character with a clean finish rather than a strong fishiness. Because eel fat renders beautifully with heat, it remains juicy even when the interior appears underdone, making it forgiving in ways that leaner fish are not. The fish has been a staple in Japanese, British, Dutch, German, and Spanish cuisines for centuries, prized both for its distinctive flavor and its remarkable ability to absorb glazes, smoke, and sauces.

Two broad categories define the culinary world: freshwater Anguilla eels (Japanese unagi, European, and American) and marine eels (conger, moray). Japanese unagi dominates high-end cuisine, almost entirely farm-raised in controlled ponds where the diet is managed to produce clean, mild flesh with consistent fat. European and American eels carry a more pronounced muddy flavor from their wild freshwater habitats, requiring soaking in salted water or milk to draw out impurities. Both freshwater and marine species have strong cultural importance—jellied eel in London's East End, smoked eel across Northern Europe, unagi kabayaki in Japan—each preparation suited to the particular fat content and texture of its species.

Fresh eel is highly perishable and notoriously difficult to handle raw: the slime coat makes it extremely slippery, and live eels are vigorous and resilient. Most commercial eel is sold cleaned, filleted, or smoked, which sidesteps the most challenging prep work. Frozen eel, particularly flash-frozen unagi from Japan, has become excellent enough that most Japanese restaurants outside Japan rely on it exclusively. The fish's blood is toxic raw but completely harmless when cooked thoroughly. Sustainability is a pressing concern—European eel is critically endangered and strictly regulated—and farmed Japanese unagi now supplies the vast majority of the global market.