Uni: The Taste of the Sea, On the Plate

by JJ Proville
Antoinette Bruno Laurence Wallace
August 2009

Uni: for the chef, one of the most delicate, rich foods of all. Few naturally occurring ingredients offer the melting, sensuous texture and flavor profile that uni supplies. Though uni is most commonly appreciated in its raw form showcased solo, it also possesses an uncanny versatility when paired with other ingredients.

Most often (and mistakenly) referred to as the sea urchin’s roe or egg sack, uni refers to the gonad—the organ in males and females responsible for producing sperm or eggs. Visually, uni resembles a chunk of grainy custard, somewhat like the surface of the tongue, but in different shades of orange. Once actually on the tongue, it turns into a soft, pillowy sensation that gradually disappears, leaving behind what is to many chefs the ultimate expression of the ocean in a solid ingredient.

The bulk of the uni found in North American restaurants originate in coastal Californian waters.The rest are most likely shipped from sources in Maine and Canada (British Columbia and New Brunswick) and are also flown in from Japan via the long tentacles of Tokyo’s Tsukiji fish market.

Though it is most often associated with being a uniquely Japanese ingredient, uni hasn’t always been a part of culture in Japan the way noodles or tofu had. But over the last decades, the Japanese developed an insatiable thirst for the creature. Lacking the natural resources to supply their own demand, the Japanese turned their attention towards the abundant supplies of US uni, which was never considered a commodity until the late 1970’s.

The rapidly climbing demand would have a major effect on US fisheries. In the 1990's, the Maine sea urchin industry went from non-existent to becoming a major exporter, when fishermen realized what profits could be made. California has now become the largest exporter of uni to Japan. In the kelp-rich waters of Catalina and Santa Barbara, the urchin season is at its peak during the winter months, just in time to cater to the Japanese, who are at their peak consumption during the winter holidays.

Japanese chefs tend to be well-versed in matters of uni, and one New York-based chef with a deep passion for it is second generation sushi chef Sotohiro Kosugi of Soto. Japanese cuisine brought Chef Kosugi to the United States 22 years ago, where he cooked in San Francisco, Atlanta, and Boston.“Ten years ago, uni wasn’t popular” Kosugi says. At Soto, Kosugi wants to take advantage of the present popularity of uni to show diners how wonderful it is. Part of his approach is to showcase uni artistically, often in other styles than sushi and sashimi.

We encountered Chef Kosugi at his 2009 Madrid Fusion on-stage demonstration of uni powder technique (made by steaming the uni, drying it and then pushing it through a sieve), and a smoked uni (briefly steamed in a pan smoker with a single wood chip). Back in New York at Soto, Kosugi demonstrated his popular Uni Ika Sugomori Zukuri (translated as “Bird’s Nest from the Sea”) dish made with uni wrapped in thinly sliced Japanese squid and shiso leaf served with quail egg and a seasoned soy-sake reduction. The round package is rolled in thinly sliced dried seaweed to mimic the form of the sea urchin and then garnished with raw quail egg. It’s a fast and beautiful technique from a master in Japanese cuisine.

When a Chef Selects Uni

Fishy smelling uni simply won’t do—it must be received and served in a scrupulously fresh state. Whether on the tray or right out of the shell, uni should look dry, which indicates that it is properly holding moisture. It should not appear waterlogged or have a melting appearance, and it should give off a clean, crisp, salty ocean aroma. The chef should be looking for the usual signs of seafood freshness: bright color, firm texture, and a fresh, clean smell.

According to Kosugi, the quality of the uni is directly linked to what the sea urchin has been eating and where. “Uni usually tastes great when it’s been eating kelp. It’s very common knowledge to the Japanese chef that wherever kelp taste good, the uni is good”. The northern island of Hokkaido in particular is known for its kelp and its uni. (In Japan of course, dried kelp (or kombu) is a very important ingredient and taken very seriously.) This is also why California uni is so desirable, according to Kosugi. Uni from Catalina island is his first choice for the restaurant. If they don’t have it, he orders Japanese uni from Hokkaido.

“Each uni has a different texture each time” says Chef Kosugi. On the popular Japanese varieties of uni, Kosugi indicates that the larger Murasaki variety (purple; long spines) have lots of moisture and are softer. Bafun uni (green; short spines) have a denser texture and do not contain as much water as the Murasaki uni. The plumper Santa Barbara uni from California have more of a floral, sweet taste in contrast to the Maine uni, which have a more pronounced, brinier ocean taste.

During his presentation at Madrid Fusion, Kosugi praised the sea urchin from the Galician coast. At Japanese-trained chef Ricardo Sanz’s Kabuki in Madrid, we experienced the same Northern Spanish uni. It has a loose, runny texture much like egg yolk, and tastes minerally and earthy—almost like soil—and very unlike American sea urchin by all accounts.

Proper Storage and Handling

Once out of the shell, uni requires rinsing in order to be clean (there will be semi-digested seaweed inside the shell) and palatable. At Uni in Boston, Chef Chris Chung rinses his fresh uni in a bath of sake diluted with water after they are removed from the shell. The California Sea Urchin Commission offers a pictorial guide on how to safely remove the uni from a live sea urchin without getting pricked.

Uni should always be stored for service at around 40ºF (4ºC). For Kosugi, storing uni is all about preserving the integrity of the cell walls. He tries to keep his uni as close as possible to a constant 37ºF (3ºC). “At around 3.2ºC,” Kosugi explains, “water density is higher. If there are temperature fluctuations in the environment that holds the uni, the cells expand and eventually break, making the uni more watery”. Kosugi follows the same practice with the rest of his fish, which he keeps on ice in his walk-in and which he regularly checks with a handy infrared thermometer.

At the plating stage, uni must reach the plate whole and intact, especially if used in sashimi or for garnish. Kosugi and Chung both favor a set of metal chopsticks to handle and plate the uni. Kosugi says that wooden ones work well, and Chung also recommends a small offset spatula.

Sourcing Uni

For Chung, ordering enough uni for the day is the best way to go about maintaining consistent quality. He prefers to work with live sea urchins from True World Foods when they are in season and orders trays during the rest of the year. He primarily uses the varieties from Santa Barbara and Maine, and always opts for the highest quality grade, whichever the application. “I’d rather have one grade so I don’t mix it up” says Chung.

During a busy week, Kosugi orders his uni (on trays, also from True World) on a daily basis, but most often he orders every two days, which is just fine according to him. Kosugi feels that the shell of the live sea urchin is not a good environment for the uni because of the high moisture level.

A note on sustainability: For the most part, uni is harvested by hand or with small-scale tools, leaving a smaller ecological footprint than most of the more popular sushi items. However, the two major sustainability advocates hold differing views on the status of uni: The Environmental Defense Fund gives sea urchin the green light for uni in general, while the Monterey Bay Seafood Aquarium advises that uni from Canada and California are the top choices, and that sea urchins in Maine suffer from low stocks and should be avoided.

Uni On the Plate

On a recent trip to Boston, Chef Chris Chung’s Tairagai and Uni with Garlic Soy, XO Sauce and Myoga (a gingery flower bud) introduced an unusual pairing of uni with pen shell, a type of clam native to Japan. The firm texture of the pen shell offered a fitting contrast to the creamy uni. Chung’s other uni dishes include a yellow tomato gazpacho topped with sea urchin and seaweed and brioche topped with uni, lightly toasted under the salamander, and dressed with tomatoes and peppers.

One of the most popular menu items from Chef George Mendes’ newly opened Portuguese-influenced Aldea features a crunchy piece of toast topped with pieces of creamy Santa Barbara uni (on trays, also from True World) underscored by the creative addition of mustard seeds, edible flowers, and a velvety cauliflower puree. It’s a visually decadent, texture-rich play that ends up luscious and full-flavored in the mouth.

At Restaurant Charlie in Las Vegas, the kitchen team serves Santa Barbara uni with apple barley and miso. Sommelier Desmond Echavarrie and mixologist Jeremy Merritt pair the dish with a white Müller-Thurgau wine and with a sparkling grape juice from Rheinhessen region. These both enhance the playfulness of the uni-apple flavor combination while keeping the dish light.

Uni can also be showcased in various emulsions, including sauces, soups, and mousses. Chef Harold Dieterle of Perilla takes advantage of the coagulating properties of the urchin gonad to thicken lobster stock and cream before chilling and double-charging the mixture in a food whipper. He dispenses the uni mousse onto a bed of crab and garnishes the dish with toasted rice pearls and more fresh uni to bring the collection of textures full circle.

At Asiate in New York’s Mandarin Oriental, Chef Brandon Kida prepares an uni cream to coat a delicate mound of soba noodles and caviar in his Buckwheat and Eggs —reminiscent of a eggy carbonara but with the salty caviar replacing pancetta. The uni cream contributes a silky mouthfeel and adds to the luxuriousness of the dish—not to mention the umami quotient.

While the French prefer to spread Mediterranean urchin on dark bread with butter, the Italians rejoice in its thickening properties to enhance pasta sauces. Case in point at New York’s shrine to Southern Italian cuisine: Convivio’s Sardinian-style gnocchi or Malloreddus. Chef de Cuisine Craig Wallen tosses uni into a hot pan with the pasta to thicken a sauce made with white wine, tomatoes, garlic, and crab. Wallen relies on the sweetness of the Grade A uni to attain the desired flavor profile of the dish, though according to him, Grade B uni makes an acceptable substitution.

At Bar Boulud in New York, Chef Damian Sansonetti meets the sauce/garnish application halfway by individually adorning his ethereal gnocchi individually with finely diced pieces of uni. The pink flecks of uni melt into a hot citrus coriander cream—barely noticeable in appearance but completely transformative in terms of overall taste and mouthfeel.

Uni Forever

As we have observed through our tasting research, uni possesses the ability to ostentatiously present itself into certain dishes or slink in unnoticed into others, but it never fails to lift the intensity and flavor of the overall dish. Chefs around the country have reached an understanding of the ingredient, harnessing its incomparable texture and umami flavor, putting it through old world methods and using it as a tool to build today’s post-nouvelle cuisine.

But even as uni’s star power makes it shine brightly on its own, it remains a humble ingredient from a simple sea creature that should be championed, respected, and appreciated by the chef. As uni-master chef Sotohiro Kosugi puts it, “uni is not an ugly creature; uni is beautiful!

Californian Uni Grades

A (a.k.a California Gold)
B (a.ka. “Premium California”)
C (a.k.a “Select California” or “Vana”)

Bright Orange
Orange/ Pale Orange
Pale Yellow

Slightly less firm; Gluey
Broken up; Soft;Creamy; More liquid; Usually frozen

Briny; Fresh; Sweet
Milder; Nutty; Crisp
Not as Sweet; Neutral;

Possible Uses
Raw; Sushi; Nigiri; Garnshing
Espumas; Sauces
Sauces; Emulsions; Mousses

Rough Price Range*
Trays: $14-$16
Trays: $8-$9


California: December to March

Maine: September to April

Japan: April to September

Mediterranean: October to April

Country Name

Japan: Uni

France: Oursin

Italy: Ricci di Mare

Spain: Erizo de Mar

Portugal: Ouriço do Mar

Greece: Achinos