Ask the Experts: How to buy and store uni

You’ll know that uni is fresh when it keeps its shape and isn't mushy. Uni is soft, melts in your mouth but should still have a little bit of bite, much like tofu.
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Always had a burning question but not sure who to ask? In our regular Ask the Experts section, we do all the noseying about so you don't have to.

In this edition of our regular series, we get Amanda Tan of specialist Japanese e-grocer Zairyo to give us the low-down on everyone’s favourite ingredient: uni, or Japanese sea urchin.


Born into a family that has been in the business of food distribution for over a decade, 26-year-old Ms Tan started specialty e-grocer Zairyo in 2014 to connect everyday Singaporeans with the freshest Japanese produce and homewares straight out of Japan.

By tapping on close connections with prized Japanese suppliers, Zairyo directly sources their premium Japanese seafood from fishermen in Tokyo’s Tsukiji fish market and flash-freeze the products before flying them right to diners’ doorsteps in Singapore.

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Dear Amanda, I'm thinking of serving sea urchin at my dinner party this weekend. What advice would you give for someone purchasing uni - what should I look out for, how long can I store them, and what beverages would you recommend pairing them with?

Always plan your meals at least three to four days in advance, so that you’ll know how much uni you’ll definitely need and when to order it. Uni is highly perishable so I do not recommend getting it off the shelves, unless you know for sure that they have just arrived from Japan. Hence, it's best to plan and order in time for it to arrive in Singapore.

You’ll know that uni is fresh when it keeps its shape and isn't mushy. Uni is soft, melts in your mouth but should still have a little bit of bite, much like tofu.

Types of uni
The four most common species of uni found here are Aka Uni, Bafun Uni, Murasaki Uni, Ensui Uni (or uni in salt water). The question I get most often is which is the best, and my answer has always been the same: they are all great, as the only difference lies in their taste profiles.

Aka Uni is most commonly served in casual sushi-yas; the taste is much stronger, and very umami with hints of bitterness. They are a little less refined than the rest of the other uni.

Bafun Uni is most commonly served in the higher-end sushi-yas; the taste is strong but less so than Aka Uni and they are much sweeter than Aka Uni. They tastes great with just about anything, but especially when savoured on its own.

Murasaki Uni is very seasonal. Their taste is much cleaner than Bafun’s, and they are much bigger in size and lighter in colour. Due to the taste profile of the Murasaki Uni, it goes best with sushi rice or on its own.

Ensui Uni is uni kept in a salt water solution that is concocted to mimic the salt levels of the sea where the uni is from. It is the best way to keep and enjoy uni. This is the sweetest and widely considered the best tasting of the lot (though taste is very subjective), in terms of sweetness and texture.

(Related: 8 Japanese Restaurants Listed in The Michelin Guide Singapore 2016)
Keeping uni in a salt water solution that is concocted to mimic the salt levels of the sea where the uni is from is the best way to store and enjoy uni.
Keeping uni in a salt water solution that is concocted to mimic the salt levels of the sea where the uni is from is the best way to store and enjoy uni.

Boxed vs live sea urchins
The only difference between buying sea urchins boxed or live is that, with the latter, you get to experience cracking the live sea urchin open and scooping out the uni yourself. You will also have to cleanse the uni in salt water after scooping it out of the shell. Uni in boxes are already processed and cleansed so they are stronger in flavour. As they go through a rather long process of segmenting the uni, boxed uni are actually of much better quality than the ones in the shell, hence the price difference between the two.

Live uni straight out of their shells
Live uni straight out of their shells

For consumption as sashimi, uni is best consumed within two days upon receipt. After which, you may choose keep for up to five days to cook it as a pasta or topped on chawanmushi, and so on. Do note that uni's texture will be compromised when frozen.

As for beverage pairing, a lot of it depends on how you prepare the sea urchin dishes. If you’re serving uni in a nigiri or just on its own (we like it just wrapped in nori), a sake or a rice-based pale ale would be fantastic. Enjoy!

(Related: Dine like a kaiseki pro with our 5 quick tips)

Stumped at the supermarket or perplexed in your pantry? Send any cooking questions you would like to have answered to lifestyle@michelin.sg with 'Ask the Experts' in the subject title and we’ll help you find the answer.

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