Over in the West, eels are perhaps only seen at the local aquariums, peeping out from a cave or tunnel—scaring a few kids in the process. However, in Japan, eels are considered a delicacy, grilled, lathered in a sticky, sweet sauce, laid over rice and enjoyed all year round.
We’re here to tell you all the slippery details, including the types of Japanese eels, how they taste, and why they’re enjoyed even more during the summer (and Ox Day, in particular).
Are eels eaten in Japan?
Absolutely! Eels are eaten across Japan, regardless of the season. However, eels are enjoyed in higher quantities during the summer months as they’re believed to give you stamina—something that’s sorely needed to weather the humid Japanese summer.
What does Japanese eel taste like?
The taste of Japanese eel varies by the type of eel and how it’s prepared—sometimes crispy, sometimes chewy—but it is often salty, slightly sweet and meaty. The most popular way of eating Japanese eel is to grill it with a sweet and savory sauce called “kabayaki sauce,” made of soy sauce, mirin, sugar and sometimes sake.
Types of eels eaten in Japan
Unagi: Freshwater eel
Unagi (うなぎ) is specifically freshwater eel (Anguilla japonica); they are recognizable for their plump body and dark hue. They live in rivers, streams and lakes, though they travel to the ocean to breed and spawn. Unagi is the most popular eel to consume in Japan, often grilled over charcoal and brushed with a sweet-savory kabayaki sauce.
Anago: Saltwater conger eel
Anago (穴子) is a saltwater eel that spawns and lives in the sea. Compared to unagi, it has a slimmer body and a lighter color. It is also served differently, often being steamed or simmered before being grilled.
As the freshwater eel population has been declining in recent years, anago is seen as an alternative option to reduce unagi consumption.
Unagi vs Anago: What’s the difference?
Unagi freshwater eels live in freshwater, while anago conger eels live in the ocean. In terms of cuisine, unagi has a higher fat content, which lends it a rich, buttery flavor. Anago, however, provides a more lean meat and is fluffier in texture and milder in taste. This difference in both texture and taste may be due to their different cooking methods, with anago often being steamed or simmered, while unagi is grilled and covered in a thick sweet-savory sauce.
Are Japanese eels healthy?
Japanese eel is a great source of vitamins A, D and B12. Vitamin A and vitamin B12 are important for eye health, energy production, optimal immune function, and more. Vitamin D acts as a hormone, and all cells in the body require it; as a result, it supports our immune health and the skeletal system (Source: Nutrition Advance).
Ox Day: Why do Japanese people eat eels on this day?
What is Ox Day (丑の日)?
In Japanese tradition, Ox Day—also known as Doyo no Ushi no Hi (土用の丑の日)—refers to the day between seasons. This is known as the day of the ox according to the Chinese zodiac, and is set in the Doyo period, an “18-day period before the start of each season in the traditional Japanese lunisolar calendar” (Source).
Ox Day takes places in Natsu Doyo (夏土用) the 18-day period that transitions from summer into fall.
Why does Japan eat unagi on Ox Day?
Ox Day occurs in one of the hottest periods of Japanese summer. Unagi is said to be a good source of stamina during this time, helping people to endure the stifling Japanese heat.
This custom began in the middle of the 18th century, believed to have been started by Hiraga Gennai (1726-1779), a playwright, scientist and inventor who said that eating eel on the day of the ox had restored his energy. Whether there’s truth to this claim, we can’t confirm, but it’s true that the custom continues to this day.
Did you know? Unagi isn’t the only thing eaten on Ox Day. It’s said that any food starting with “u” (う) will support your immune system and stop you from getting ill.
This includes kyuri (cucumber), suika (watermelon), kabocha (pumpkin), and nigauri (bitter melon). “None of these start with u,” you screamed? True, but they’re all classified within the squash and gourd family of Cucurbitaceae, which translates to uri (ウリ) in Japanese.
Another classic summer dish is udon—chewy wheat-based noodles—which can be served cold.
Are Japanese eels sustainable?
According to Seafood Watch, “the production of Japanese eels is considered 100% reliant on endangered and critically endangered wild populations for farm stock.”
Unfortunately, Japanese eels—and many eels on a global scale—are currently endangered and overfished, with unagi freshwater eels being one of those most affected.
However, there was a breakthrough in sustainable eel fishing in 2023. Researchers at Kindai University were able to achieve “full-cycle aquaculture of Japanese eels after raising larvae from eggs spawned by artificially incubated adults,” meaning that they were not captured from the wild (Source: The Asahi Shimbun).
Though this process is still in its early stages and not yet ready for commercial use, the idea is that this will reduce the need to capture wild eels in the future.
Where to try eel in Japan?
Take a look through our related articles below and discover a selection of unagi and anago eel restaurants in Japan:
