unadon

Unadon compresses unagi (eel) and don (donburi, a rice bowl) into two syllables. The eel is Anguilla japonica, the Japanese freshwater eel, which spawns somewhere in the western Pacific. The exact spawning location was not confirmed until 2009, when Japanese researchers traced eggs to the Mariana Trench area. Grilled eel over rice was documented in Edo-period texts and woodblock prints well before the donburi format standardized the dish into its present form.

The dish took its canonical shape in the late Edo period under a technique called kabayaki: the eel is split along the back, deboned, skewered, then steamed in the Kanto style of Tokyo or grilled directly in the Kansai style of Osaka, before being brushed with a tare sauce of soy, mirin, and sugar and grilled again over charcoal. The Kanto steaming step produces a softer, fattier result. The Kansai method leaves the flesh slightly firmer and more charred. Both schools have devoted partisans who consider the other method a mistake.

The custom of eating unadon on Doyo no Ushi no Hi, the midsummer day of the ox in the traditional lunisolar calendar falling around late July, is traced to the eighteenth century. The scholar Hiraga Gennai is said to have advised an eel seller whose summer sales were slow to post a sign claiming that eel was especially fortifying on that calendar day. Sales rose. The tradition hardened into near-mandatory national practice, and Japan now consumes approximately 100,000 tons of eel annually, most of it concentrated near that single day.

Because Anguilla japonica cannot be bred in captivity through its full life cycle, the industry depends on wild-caught glass eels raised in tanks. The IUCN listed the species as endangered in 2014. This makes unadon a dish with a documented ecological cost attached to every bowl. Some restaurants now serve substitute preparations using farmed catfish in the kabayaki style, labeled unagi-fuu, meaning eel-style, rather than unagi.