When shopping for fresh shellfish, markets must display their harvest date, look for oysters no more than 5-6 days out of the water.
Generally, it’s best to eat them within one or two days. Check for freshness before preparing. If oysters are gaping (which they do naturally) give them a firm tap and they should close up again and not stay sprung open. Discard those that are open.
You can store oysters in your refrigerator for up to a week. Place oysters on their deeper cup side to keep the liquid from seeping out, and cover with dampened paper towels or cloths to prevent them from drying out.
Live shellfish should never be stored in air-tight containers or bags as they can die from lack of oxygen. Do not store live shellfish directly on ice, since the melting fresh water may kill them.