What is unagi? The story behind freshwater eel in Japanese cuisine
Unagi is the Japanese term for freshwater eel, most commonly the Japanese eel (Anguilla japonica), a long snake-shaped fish that has been farmed and eaten in Japan for centuries. Grilled and lacquered with a sweet soy-based glaze, it shows up on sushi rolls, draped over rice in donburi bowls, and tucked into bento boxes around the world. The dish carries deep cultural weight in Japan, where eating unagi during the hottest months is a tradition tied to stamina and energy.
In Australia, unagi has moved well beyond specialty Japanese restaurants into everyday food courts, supermarket delis, and trendy bowl shops in Sydney and Melbourne. Australian diners who once knew eel only from canned varieties or occasional trips to Asia can now order fresh grilled unagi at suburban sushi bars and izakaya-style venues. The rise of poke-style bowls and wider acceptance of Japanese flavours have made unagi don a familiar sight on lunchtime menus from Brisbane to Perth.
The eel behind the name
Unagi refers to several species in the Anguilla genus, but the fish most diners meet in sushi restaurants is the Japanese eel, Anguilla japonica. It is a catadromous fish, spawning in the Pacific Ocean and maturing in freshwater rivers, lakes, and estuaries. Because juveniles, called glass eels, are tiny and almost transparent, catching them in the wild at commercial scale is impractical. That is why almost every unagi served in restaurants is farmed.
The life cycle begins offshore, where adults breed and whose larvae drift on currents for months before reaching the coast. Once they metamorphose into glass eels, they are collected and grown out in ponds or tanks for roughly six to twelve months. The fish are fed a formulated diet before processing, which gives farmed unagi its consistent size and flavour.
Australia imports the bulk of its unagi from Japan, China, and Taiwan. Domestically, eel aquaculture remains a small niche, and strict biosecurity rules make bringing live eels across the border difficult. Food Standards Australia New Zealand (FSANZ) oversees labelling and safety, and imported products must meet the same contaminant thresholds applied to other fish sold in Australian shops.
From glass eel to grilled delicacy
Processing unagi is a craft that takes years to master. Once the eels reach market size, they are dispatched, filleted, and deboned by hand. The fillets are then skewered and grilled over charcoal, a step that draws off excess fat and gives the flesh its smoky aroma. After the first grill, the fillets are steamed to soften the texture, then dipped into tare, a sweet soy-based sauce made from soy sauce, mirin, sugar, and sake.
The final pass over the charcoal caramelises the sauce, leaving the eel glossy and lightly charred. This multi-step approach is what separates authentic unagi from simply grilled eel. In Japan, two regional styles dominate: Kanto-style, where the eel is grilled first and then steamed, and Kansai-style, where the eel is grilled straight through without steaming. Both end with a generous brush of tare.
Australian chefs who focus on Japanese cuisine often lean toward the Kanto method for its softer, almost custardy texture. The sweetness of the tare pairs neatly with Australian palates that already enjoy glaze-heavy proteins such as teriyaki chicken or honey-glazed salmon. Restaurants in Sydney's CBD and Melbourne's inner suburbs frequently steam their eel in-house to control the final glaze and seasoning.
Unagi and anago side by side
Many diners confuse unagi with anago, the saltwater conger eel that also appears on sushi menus. While both are eels used in Japanese cooking, they come from different families and offer distinct experiences. The table below outlines the main differences.
| Feature | Unagi | Anago |
|---|---|---|
| Water type | Freshwater | Saltwater |
| Species | Anguilla japonica | Conger myriaster |
| Flavour | Rich, sweet, smoky | Delicate, mild, lightly salted |
| Texture | Firm, slightly chewy | Tender, flaky |
| Common serving | Unagi don, nigiri, rolls | Anago nigiri, tempura |
| Season peak | Summer | Year-round |
| Prep style | Grilled with tare | Steamed or tempura |
Australia's appetite for richer, bolder flavours helps explain why unagi tends to outsell anago in most Australian Japanese restaurants. Anago appears more often in traditional sushi counters in Tokyo-style venues in Sydney and Melbourne, and diners can request it at any well-stocked Japanese restaurant that lists it on the menu.
How unagi tastes
Unagi has a flavour often described as the meeting point between lake-fed fish and slow-cooked meat. The flesh is rich and oily without being heavy, and the tare adds a caramelised sweetness that balances the natural fattiness. Because the eel spends part of its life in freshwater, the taste is softer than ocean fish, with subtle earthy notes that come from the pond environment.
The texture shifts depending on preparation. Kanto-style unagi, steamed after grilling, melts in the mouth and feels almost custardy. Kansai-style unagi, grilled straight through, has a firmer bite and a more pronounced char. Both are typically served warm, which is unusual in sushi bars where most fish is presented cold.
For Australians new to unagi, the closest reference point might be ocean trout or kingfish belly in texture, combined with the sweetness of teriyaki sauce baked into the protein itself. That built-in flavour is one reason unagi works so well in hand rolls and bowl formats, where few extra sauces are needed.
Where unagi shines on the menu
Common ways to enjoy unagi include:
- Unagi nigiri, a slice of grilled eel brushed with tare, draped over a small mound of seasoned rice and banded with a strip of nori.
- Unagi don (sometimes called unadon), a rice bowl layered with eel, pickled vegetables, and a generous pour of extra tare.
- Dragon rolls and special rolls, where unagi is paired with avocado, cucumber, and crunchy toppings.
- Unagi over cold somen or udon, a lighter preparation that combines warm eel with chilled noodles, popular in summer.
At most Japanese venues, unagi often features in combination platters so diners can try it grilled, in rolls, and over rice in a single visit. The versatility also explains why it appears in lunch specials, where Japanese restaurants compete for the office crowd looking for a quick, protein-rich midday meal.
Unagi in Australia: availability and rules
Australians who want to buy unagi for home cooking usually head to the seafood counter at larger supermarkets in capital cities, or to Japanese grocers in suburbs like Chatswood in Sydney, Box Hill in Melbourne, or Sunnybank in Brisbane. Vacuum-sealed, pre-grilled fillets imported from Japan, Taiwan, or China are the most common retail product. Fresh, locally grilled unagi is rare outside restaurants, because almost no Australian farms raise eels to commercial size.
Sustainability is a growing concern. The Japanese eel is listed as endangered by the International Union for Conservation of Nature, and Australian consumers increasingly ask where their seafood comes from. Many restaurants now display sourcing information, and some chains have moved to closed-loop farmed eel that meets certification standards recognised under Australian food labelling laws.
Practical points for Australian diners include:
- Check country-of-origin labelling, mandatory under Australian Consumer Law for most seafood products.
- Look for restaurants that disclose whether their eel is farmed or wild-caught.
- Avoid raw preparations of eel in Australia, since it is always served cooked to meet local food safety expectations.
- Pair unagi with a light salad or pickles, since the dish itself is rich and salty.
Curious to compare traditional preparations side by side? At Sushi Ya Garden City on Long Island, the kitchen serves freshwater eel across sushi, sashimi, hibachi, and lunch specials, giving diners a clear roadmap of how unagi moves from grill to plate.