Oysters

As long as 2,000 years ago, the Romans so loved oysters that they imported them from all over the empire.

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Oysters are large shellfish with rough, fluted shells and creamy-white flesh that has a unique dusky flavor. Oysters grow wild in shallow intertidal areas, but many oysters in today’s market are grown by aquaculturists on strings or nets. Oysters have a long culinary history. As long as 2,000 years ago, the Romans so loved oysters that they imported them from all over the empire. These delicious shellfish haven’t lost their popularity since.

Varieties

Atlantic oysters, grown along the Atlantic Coast from Nova Scotia to Florida, are small, and have a relatively smooth shell and a mild taste. The Pacific oyster, a briny-tasting delicacy introduced from Japan in the 1920s, ranges in size from the tiny Kumamoto oyster to the large, heavy-shelled common Pacific oyster. Olympia oysters are a rare, slow-growing species native to the Pacific Coast. Flat oysters, natives of Europe, are grown in cold waters on both coasts of the United States. They have an intense yet delicate taste. Oysters get their specific taste from the areas where they are grown, and they are often sold under these place names. Oysters can be bought live in the shell, shucked, fresh or previously frozen, or smoked.

Buying and storing tips

Quality oysters are easy to recognize. Fresh oysters smell clean, like the ocean. The shells of live oysters are tightly sealed.

Refrigerate live oysters on a platter or cookie sheet, flat side up, covered with a damp towel. Although they should be cooked as soon as possible, they will keep this way for up to a week. Oysters should not be stored in water or in an airtight container as these methods will kill them.

Refrigerate shucked oysters and eat them the same day they are purchased.

Availability

Oysters spawn during the summer months, making them softer and less desirable then. However, thanks to imported oysters and special varieties of Pacific oysters that have been developed to avoid a spawning period, they are available year-round. Fresh oysters are considered at their prime during the fall and winter.

Preparation, uses, and tips

Inspect oysters to make sure they are tightly closed. To clean, rub the shells with a stiff brush under cold running water.

To shuck, hold the oyster cup flat side up with a glove or several paper towels. Insert an oyster knife or can opener (never a sharp knife), into the small opening near the hinge. Twist to open. Once the hinge gives, slide the knife along the top shell to sever the muscle. Take off the top shell and pick out any grit or pieces of broken shell. If the oyster is very gritty, hold the oyster and bottom shell under running water. Serve raw on crushed ice.

Grilling

Place live oysters flat-side-up directly on the grill, 6 inches (about 15 cm) above the coals. Oysters are done when the shells pop open, in about three minutes.

Pan frying

Heat frying pan, then add butter or oil. Dredge shucked oysters in flour or cornmeal with herbs and spices, if desired. Place oysters in the pan and sauté until brown, two to three minutes.

Deep frying

Pour oil into a wok or deep fryer; it should be at least 1 1/2 inches (about 3.8cm) deep, and the cooker should be less than half full of oil. Heat oil to 375°F (190°C), using a thermometer to monitor temperature. Dip oysters in batter, drain, then slip them into hot oil. Cook until brown, two to three minutes.

Steaming

Place 1/4-inch (0.635cm) water or beer (seasoning optional) in the bottom of a large pan. Add scrubbed live oysters, flat side up. Bring water to a boil, reduce heat, and simmer until shells open (six to eight minutes). Throw away oysters that don’t open. Serve oysters in bowls with broth.

Nutritional Highlights

Oysters (raw), 6 medium
Calories: 57
Protein: 5.9g
Carbohydrate: 3.3g
Total Fat: 2.1g
Fiber: 0.0g
*Excellent source of: Zinc (76mcg), and Vitamin B12 (16.3mcg)

*Foods that are an “excellent source” of a particular nutrient provide 20% or more of the Recommended Daily Value. Foods that are a “good source” of a particular nutrient provide between 10 and 20% of the Recommended Daily Value.

Oysters are not a source of omega-3 fatty acids.

Health benefits and concerns

Hives

Allergy to foods and food additives is a common cause of hives, especially in chronic cases. Shellfish are among the many foods reported to trigger hives most often. Numerous clinical studies demonstrate that diets that are free of foods or food additives that commonly trigger allergic reactions typically produce significant reductions in symptoms in 50–75% of people with chronic hives. People with hives should investigate the possibility that food allergies are causing their problem by consulting with a doctor.

Liver cirrhosis

Some people with cirrhosis and impaired bile flow (such as in Wilson’s disease or PBC) can have an excess amount of copper accumulate in the liver. If laboratory tests confirm copper excess, most doctors would recommend avoiding shellfish, which is rich in copper, along with recommending medical treatment to reduce copper stores.

Wilson’s disease

Most foods contain at least some copper, so it is not possible to avoid the metal completely. Foods high in copper, such as oysters, should be eliminated from the diet.

Health benefits and concerns for fish and seafood
Many health benefits and concerns associated with this food are applicable to other fish and seafood. Read about health benefits and concerns for fish and seafood for a full description.

The information presented in this website is for informational purposes only and was created by a team of U.S. registered dietitians and food experts. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements, making dietary changes, or before making any changes in prescribed medications.