About Urchin

Uni, the edible portion of a sea urchin, is used for culinary delicacies in many parts of the world and is typically served at sushi bars and restaurants.

While uni is graded by its taste, texture, and appearance, California uni is unique due to the water temperature and the food source for the sea urchin.

a basket of california sea urchin
diver holding an urchin

About Sea Urchins & California Uni

Sea Urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids.

While about 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone, there are four main species of sea urchins located along the nearshore waters of California:

  1. Lytechinus anamesus (white urchin)
  2. Centrostephanus coronatus (coronado urchin)
  3. Strongylocentrotus purpuratus (purple urchin)
  4. Strongylocentrotus franciscanus (red urchin).

The sea urchins targeted for harvesting for the purposes of food consumption in California are the red and purple sea urchins. Both male and female Sea Urchins are harvested for their gonads, which are commonly referred to as uni (pronounced Oooo-Knee).

The reefs located in the nearshore waters of California provide an ideal environment for healthy thriving sea urchins with waters from 52-68 degrees fahrenheit Sea Urchins eat the kelp in these waters. The two main types of kelp found on the California Coast (Macrocystic pyrifera) Giant Kelp and (Nereocystis) Bull Kelp provide a rich food source for the sea urchin. This rich food source influences the taste of the roe (uni) of the sea urchin.

Purchasing a Quality Product

Early in their work, the members of the Commission felt that quality was a key target to direct their focus.

The quality of the ocean environment in terms of water and habitat quality certainly is important. But, the quality of sea urchin products in the marketplace is critical to strengthening the economics and financial rewards for processors and divers alike.

To ensure quality uni the Commission established comprehensive “Best Practices” standards for use by divers and processors. When these Best Practices become the industry norm, customers worldwide will know that uni harvested and produced in California will provide a pleasing and unique seafood selection for the public. Furthermore, they will know when they buy from California, they can count on consistent high quality that is true to how it is represented. As consumers learn about quality uni and the reliable quality of uni from California, it is anticipated they will prefer California uni to other competing products.

It is necessary to first define the criteria for quality

There are four main attributes of uni that need to be considered; texture, freshness, color, and taste. Texture for quality uni is firm like cold butter. Freshness entails having a salty, clean ocean scent. Color should have brighter hues of gold, yellow, and orange. The targeted taste is sweet, crisp, and clean for high quality uni.

california uni processing
uni sushi

Grades for California Uni quality

uni grade A

California Gold

Bright gold, yellow or orange color; firm buttery texture; fresh salty ocean scent; and with a sweet buttery taste. Uni sections are large and complete intact pieces. This is exceptionally high-grade uni for use in top quality sushi. (formerly grade A)

uni grade b

Premium California

Gold, yellow or orange color but less brilliant than California Gold; firm buttery texture; salty ocean scent; with a crisp and nutty taste. Uni sections are smaller but still primarily intact pieces. Premium uni is used for sushi, soups, salads, or combination dishes where uni is the featured item. (formerly grade B)

uni grade A

Select California

Medium hues of yellow and orange or even tending to brown in color; salty ocean scent; softer creamy texture; with a more neutral nutty taste. Uni may be intact sections but can consist of broken pieces of the other grades. Frequently Select is packaged and shipped frozen. Uses include soups, sauces and dishes where the uni is mixed with other ingredients, including other seafood. (formerly grade C)

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The Preparation of Uni

From the ocean floor to your dinner plate, uni is a fresh and delicious seafood option. Uni is prepared by cracking the shell of the sea urchin, separating the uni, rinsing off the uni, and serving. It does not require any cooking or heating. Simply follow the steps below.

step 1

Step 1

Locate the mouth on the underside of the Sea Urchin

step 2

Step 2

With a knife or shears cut out the mouth and a portion of the shell

step 3

Step 3

Drain the water into a bowl and then coop the edible “uni” out of the shell

step 4

Step 4

Rinse the uni in fresh water to separate undesirable

step 5

Step 5

Continue to pick out any undesirable parts (i.e. spines or guts)

step 6

Step 6

Do a final inspection and remove any undesirable parts

Check out this great video that walks you through these steps