If it is not a live oyster, keep it fresh in a foam box covered with ice for 1-2 weeks, or keep it in the refrigerator for only one or two days.
Oysters can usually be eaten raw and can be cooked in many different ways. They are usually used to make soup, oyster sauce or baked goods. Oysters that are shelled in advance can be eaten raw if they are fresh, but they are not as delicious as those that are not shelled. It is impossible to judge the freshness of oysters before they are opened. Never eat oysters with loose and shriveled meat. Put them in clean fresh water before cooking. Even if the oysters are cooked for a little longer, the oyster meat will be mushy and chewy. Usually, the cooking time should not exceed 5 minutes, and the oyster meat should be taken out of the water when the edge begins to wrinkle.