What Is Sea Cucumber?

A Guide to Buying and Cooking With Sea Cucumber

A serving of braised spiny sea cucumber in a broth
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The sea cucumber is an oblong-shaped, gelatinous creature that is of the class Holothuroidea and distantly related to starfish and sea urchins. The sea cucumber comes by its name honestly as it is indeed shaped like a cucumber. This marine animal is considered a delicacy in many different cuisines but is most popular in China and other Asian countries. It is prevalent on the floor of the Pacific Ocean and is harvested either by divers or commercially farmed in large, manmade ponds. Sea cucumber is sold dried and frozen and needs to be boiled before it is added to stir-fries and braised dishes.

Fast Facts

  • Shelf Life: 2 to 3 years
  • Varieties: fresh, dried, and frozen
  • Most Common Cuisine: Asian

What Is Sea Cucumber?

There are hundreds of varieties of sea cucumber found in oceans throughout the world. Depending on where you travel, you'll find it called everything from the romantic-sounding bêche-de-mer to the somewhat less attractive "sea rat." The Chinese name for sea cucumber is hai shen, which translates roughly into "sea ginseng," perhaps referring to the food's reputed medicinal properties.

Although sometimes sold fresh, it is more often that the sea cucumber will be dried right after harvest, known as bêche-de-mer or repang, and requires rehydration before cooking. Sea cucumber is also sold frozen and will need to be defrosted before using it. It is 1 to 3 inches thick and no more than 6 inches in length, and is very expensive, although depending on the variety will range in price.

Varieties

There are many different varieties of sea cucumber and the edible ones can be divided into three categories: prickly sea cucumber, bald sea cucumber, and white teat sea cucumber. The most expensive type, the prickly sea cucumber is elongated and dark in color, with a spiny exterior. It's prized for its crunchy and slightly springy texture. Those from Japan will have the highest price tag since they are the largest and superior in quality.

Bald sea cucumber can be found in the Middle East, Africa, and Australia. It has a plumper body than the prickly sea cucumber and a rounder head. Its thick layer of flesh makes this variety softer than others. The white teat sea cucumber is named as such for its off-white skin with white dots and comes from Indonesia, Australia, and Africa.

Sea Cucumber Uses

Sea cucumber can be eaten raw, fried, and pickled, but it's most often added to dishes dried where it will then rehydrate and take on its signature, slimy texture.

Like tofu, sea cucumber is bland but has the ability to soak up the flavors of foods and seasonings it is cooked with. This is why it is often used in soups, stir-fries, and certain braised dishes; it is also combined with other seafood, meats, and spices, as well as typical Chinese ingredients like winter melon, cabbage, and mushrooms.

How to Prepare Sea Cucumber

Frozen sea cucumber needs to be thawed before using, while the dried has to be rehydrated prior to adding to a recipe. If you have purchased dried sea cucumber, most likely the guts have been removed (if not, you will have to do this yourself). The rehydrating process for dried sea cucumber needs to begin ahead of time as it can take several days (usually four to six days). The fresher the sea cucumber, and the higher its quality, the less time it will take to rehydrate.

To rehydrate, place the sea cucumber in a large bowl and cover with water. Let it sit at room temperature for two to three days, changing the water daily. Then, scrape the outside with a butter knife to remove any white residue that formed during dehydration. If it's soft enough to open up (there will be a slit where the innards were removed), scrape the inside as well. Return the sea cucumber to a fresh bowl of water and remove it when it has doubled in size and soft—this could take an additional day or two.

To prepare frozen sea cucumber for cooking, it needs to thaw in the refrigerator overnight in its original packaging. To defrost more quickly, thaw in the microwave or in water. For the microwave method, remove the sea cucumber from the packaging, place in a microwave-safe bowl, and microwave on the defrost setting for 2 to 4 minutes. To thaw in water, keep the sea cucumber in its packaging and submerge in a bowl of cold water for 1 to 2 hours, changing the water every half hour. No matter if microwaved or thawed in water, make sure to use the sea cucumber that day.

Sea cucumber
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Braised sea cucumber
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Millet stewed cucumber
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sea cucumber or trepang, cut into small pieces, in a jar of glass, metal spoon, wooden cutting table, dark light
Sergey Kurganskiy / Getty Images

How to Cook With Sea Cucumber

Whether frozen or dried, sea cucumber is cooked in the same way. Add the sea cucumber to a large pot of boiling water, cover, and cook for 1 hour. If after an hour the sea cucumber is not soft, boil it in fresh water for an additional 30 to 90 minutes, testing for doneness every 10 to 15 minutes. The sea cucumber should be soft but also bounce back a little when pressed. Make sure not to overcook it or else it will fall apart. Allow the sea cucumber to rest in the water until it has fully cooled.

What Does It Taste Like?

Sea cucumber has a very neutral taste and is quite bland but will take on the flavors of the other ingredients it is cooked along with. The appeal lies more in the texture, which is somewhat gelatinous while remaining solid, the desired consistency in Chinese gastronomy.

Sea Cucumber Recipes

Because of the sea cucumber's delicate texture, it should be added toward the end of the recipe so it doesn't fall apart during cooking. As it is a favored ingredient in China, you will find many Asian recipes including sea cucumber.

Where to Buy Sea Cucumber

Fresh sea cucumber that has already been cleaned and soaked is often available in Asian markets in the cold foods section or in containers of water. It will be easier to find dried and frozen sea cucumber, both of which are packed in sealed pouches. Sea cucumber can also be ordered online.

The methods for choosing the best product are smelling and touching. The sea cucumber should not smell bad—a slightly fishy odor is OK, but it should not be strong. In terms of texture, pick a sea cucumber that is between soft and rock hard. Also, choose a package where there isn't a lot of white film on the exteriors of the sea cucumbers—this will make them harder to clean.

Storage

Dried sea cucumber can be stored in its original packaging in a cool, dry place like the pantry for up to three years. Frozen should be kept in the freezer in the packaging it came in and will last 24 months. Frozen sea cucumber that has been thawed in the fridge overnight can be stored in the refrigerator for two to three days.