Oysters

Name: Oysters — bivalve molluscs with rough, irregular shells, attached to rocks and reefs in coastal waters, eaten raw, steamed, grilled or fried. Types include the Pacific oyster (Magallana gigas), the European flat oyster (Ostrea edulis) and the Atlantic or Eastern oyster (Crassostrea virginica). The Shellfish page covers them from a food-safety angle.

Description

Oysters have been eaten since ancient times, and were once so abundant and cheap that they were a staple food of the poor in cities such as London and New York. Overharvesting, disease and pollution devastated wild oyster reefs in the 19th and 20th centuries, and most oysters now come from farms, which also help to restore reefs and filter water.

Oysters take on the flavour of their waters (merroir), from sweet and mild to briny and metallic, and they are celebrated by connoisseurs, like wine. The old rule to eat them only in months with an “R” has to do with the warmer, spawning months, when they are softer and the risk of bacteria is higher.

Main nutrition value

Oysters are exceptionally rich in zinc, vitamin B12, copper, selenium and iron, with omega-3 fats, and they are among the most nutrient-dense foods, with very few calories.

How best to be consumed

Oysters are eaten raw or cooked, and need careful sourcing.

1. Shuck fresh live oysters with an oyster knife, and serve on ice with lemon, mignonette vinegar or hot sauce.
2. Grill or bake with garlic butter, breadcrumbs and cheese, as in Oysters Rockefeller or Kilpatrick.
3. Steam, poach or fry in light batter, or add to stews, soups and stuffing.
4. Buy from regulated suppliers, check shells are tightly closed or close when tapped, and keep on ice.
5. Cook them thoroughly if you are pregnant, elderly, have liver disease, or have a weak immune system.

Overconsumption could cause…

Oysters are healthy, but raw oysters carry real risk for some people.

1. Vibrio and norovirus infections from raw or undercooked shellfish, which can be serious in people with liver disease, diabetes or weak immunity. Vibrio vulnificus from raw oysters can be deadly in people with liver disease.
2. Shellfish poisoning (paralytic, diarrhetic or amnesic) from toxins made by algae that bivalves filter from the water, which cooking does not destroy, so buy from regulated sources and follow local shellfish warnings.
3. Shellfish allergy, which can be severe and is usually lifelong, so anyone allergic must avoid shellfish and check labels.
4. Heavy metals such as cadmium and, in some waters, other pollutants, which shellfish can concentrate, so vary your seafood and buy from clean waters.

GroupsMolluscsShellfishMolluscsLow fatLow sodiumRich in ironRich in seleniumRich in vitamin B12Rich in zincFresh

Made intoOyster Sauce

Related foodsScallopsClamsMusselsAbaloneWhelksCockles

Wikipedia — Oyster, used for origin, naming and history: https://en.wikipedia.org/wiki/Oyster