Oysters

Live oysters keep as long as they stay alive — often 1–2 weeks if handled correctly, notably longer than clams or mussels. Shucked oysters keep 1–2 days refrigerated.

Store them cupped side down, flat side up, in a single layer under a damp cloth. That orientation keeps the oyster sitting in its own liquor instead of letting it drain out, and the liquor is what keeps the animal alive. Never seal them in plastic or submerge them in fresh water.

Do not store oysters on top of each other in a deep pile — the ones underneath are crushed and drain. A shallow tray in the coldest part of the refrigerator is ideal.

Shucked oysters should stay in their liquor in a sealed container and be used within a day or two. Freeze shucked oysters in their liquor for 2–3 months; they are only good for cooking afterwards.

Oysters carry the most serious raw-consumption risk of any food in common use, and it is worth being direct about it.

Vibrio vulnificus and Vibrio parahaemolyticus are marine bacteria that occur naturally in warm coastal waters. Oysters, as filter feeders, concentrate them. Vibrio vulnificus infection is uncommon but severe: for people with liver disease, diabetes, hemochromatosis, cancer, or a compromised immune system, it can cause bloodstream infection with a fatality rate above 30 percent. The CDC's advice for those groups is unambiguous — do not eat raw oysters at all.

Two widespread beliefs are false and worth correcting. Hot sauce, lemon juice, and alcohol do not kill Vibrio. And the "months with an R" rule is folklore that only loosely tracks water temperature; modern harvest controls and refrigeration matter far more than the calendar.

Cooking destroys Vibrio completely, so cooked oysters carry none of this risk.

For liveness, the tests are the usual ones: the shell should be tightly closed or should close when tapped, and it should feel heavy with liquor. A light, dry, or gaping oyster is dead — discard it. Fresh oysters smell of clean seawater; anything sour or sulfurous is a discard.