Japanese eel is born in the sea (somewhere around the Philippines) and then migrates to rivers and lakes throughout Japan. It grows to about 50 cm in length. It is also extensively cultivated, a well-known center is Lake Hamanoko in Shizuoka. Nowadays, most eel is cultivated in China.
Unagi is a popular food in Japan and it never sells so well as during the hottest period of summer, as it is believed to give lots of stamina to bodies freaked out by the heat. Eel has a high-energy nutritional value. In the traditional calendar, that hottest period is called doyo, meaning the eighteen days before Risshu, the start of autumn. In this period, the day of the Ox (ushi no hi, also a designation from the traditional calendar) forms the peak of eel consumption, as it starts with an U sound, just like Unagi. That smacks of superstition, but in fact was a clever commercial trick: the Edo-period physicist Hiraga Gennai apparently started this custom to help a particular eel restaurant boost its flagging sales.But he was working well within the Japanese tradition: already the 8th c. Manyoshu poetry collection contains praise of the eel as wholesome summer food.
[Unagi (kabayaki). This eel is from Shimantogawa, Kochi, in Japan. Photo Ad Blankestijn]
In the past, eel was grilled on skewers. Nowadays, the charcoal grill is the most popular. The eel is filleted, skewered, grilled and dipped in a heavy sweet terayaki sauce. This way of grilling is called kabayaki. The thick sauce becomes a sort of aromatic, brown glaze, and the eel, dripping with fat, is tender and succulent. It is eaten with a dash of sansho, Japanese aromatic pepper.
There are two differences in eel cooking between East Japan (Kanto) and West Japan (Kansai). In the Kanto the eel is sliced down the back (the belly reminded people in the samurai town of Edo too much of harakiri) and down the belly in Kansai (Osaka was a merchant town). In the Kanto, the broiled fillets are steamed to make the meat more tender, and then returned to the grill, but in the Kansai the steaming process is skipped resulting in a richer taste.
Here are some unagi terms:
- kabayaki: broiled eel
- unadon: kabayaki served on a bowl of rice, with sauce
- unaju: kabayaki on a bed of rice (often in a lacquered box)
- kimosui: clear soup containing the liver (kimo) of the eel
- kimoyaki: appetizer of the grilled liver of the eel
- yawatamaki: eel wrapped around burdock (gobo) and broiled
- unazushi: unagi used as a topping for sushi. In the past, the leaner anago (conger eel) was more popular