Oysters can be purchased unopened, opened on half shell, or in jars. The true oyster afficionados would say that an oyster should be eaten the day its opened, be unwashed and sitting in its own juice. Buy the day you plan to eat them.
Keep opened oysters in the fridge wrapped in foil. They should be eaten the day of purchase. Unopened can be stored in the crisper section of the fridge wrapped in newspaper - use within 48 hours. Store unopened oysters in layers on the curved side to preserve their juice.
Tips & Tricks:
Open an oyster by holding it in one hand wrapped in a tea towel to prevent cutting yourself on the hard shell. Hold the oyster flat side up and, using an oyster knife, insert it into the hinge. Work the knife using a levering action until you feel it give. Dispense with the upper shell and rest the opened oyster on a bed of rock salt.
A serve of oysters is equal to about 6 oysters.
There's no better way than eating an oyster straight out of the shell served with lemon wedges and cracked black pepper.