Uni Sea Urchin Sushi Guide: Grades and Season

Uni (雲丹) is the gonad of the sea urchin — sweet, creamy and briny. In Hong Kong you'll see it on gunkan at chains, generous mounds at omakase counters and in uni bowls. Quality depends on species, origin, grade and season.

Uni in brief. Bafun (エゾバフン): deep orange, firmer, bold and rich. Murasaki (キタムラサキ): pale yellow, softer, mild and sweet. Grades: by colour, firmness and lobe size — top grades go to nigiri. Season: depends on species and region; sources disagree.

Main types

Bafun uni (short-spined) is deep orange, firmer and intensely umami, and usually costs more. Murasaki uni (northern purple) is pale yellow, softer and sweeter with a cleaner finish. Hokkaido uni is the benchmark; Santa Barbara (US) uni is more affordable.

Grades

Uni is graded by colour, firmness and the size and shape of the lobes. Suppliers use grade labels such as B (general use), A (premium sushi bars) and A+ (high-end restaurants). As a rule, high grades go to nigiri; mid grades go to gunkan and rice bowls.

Season

Seasons depend on species and fishing area, and published guides disagree. One supplier says bafun peaks in summer (June–August) and murasaki in winter (November–February); another says murasaki peaks in summer and bafun from late summer to winter. Ask the chef what is in season that day.

Uni in Hong Kong

Chains offer affordable uni: Genki Sushi has run an uni platter reduced from HKD 88 to HKD 78, and Kerry Hotel's weekend Japanese buffet (to 30 November 2026) includes sea urchin hand rolls. Omakase counters serve premium Hokkaido uni. See the best omakase in Hong Kong.

Fresh uni test: lobes should be firm and intact, glossy and sweet-smelling. Mushy, collapsed lobes or a bitter, metallic smell mean it's past its best.

Import note: since 24 August 2023, Hong Kong has banned seafood from ten Japanese prefectures, including Tokyo. Hokkaido is not on the list, so Hokkaido uni is still imported. See Japanese seafood sourcing.

Uni is a raw, delicate food. It spoils quickly. Diners who should avoid raw seafood — including pregnant women and young children — should skip it. Some diners have reported off-smelling uni even at well-rated shops.

Common questions

What is the best uni?

Hokkaido bafun uni is usually the most prized.

Why is uni expensive?

It is delicate, hand-processed and spoils quickly.

Where else can I look?

See our sushi fish guide.

Compiled by our editorial team from Japanese seafood and sushi references, chef-informed tuna guides, Hong Kong Centre for Food Safety and Department of Health guidance, and chain menus, retrieved September 2026. Fat percentages are approximate and vary by fish, season and source. General information only, not medical or dietary advice.