Oyster liquor is the natural juice inside the oyster that keeps it alive once it's out of the water. There is only one criterion: the oyster must be capable of tightly closing its shell.. Open oysters should be tapped on the shell; a live oyster will close up and is safe to eat.. Oysters which are open and unresponsive are dead and must be discarded. Then he showed how to open and prepare them. This may sound cruel, but consider that the oyster is a very primitive creature, and has no brain. A shell that doesn't even close (or an oyster that comes gaping open) means it is D-E-A-D and you should not buy or eat it. This involves separating the oyster’s abductor muscle from the shell, which either kills it or renders it immobile. According to studies, "raw oysters (especially raw dead oysters) can carry some dangerous bacteria (vibrio vulnificus) with side effects such as diarrhea and vomiting," she says. You're at a greater risk of infection when choosing to eat raw oysters… These little guys are called pea crabs and are not only edible as well, but considered by some to be quite the lucky little treat. Keep the oyster alive as long as possible, to reduce the risk of bacterial contamination. They're alive until shucked, which kills them immediately. It is unacceptable to rinse or dump that juice out of the oyster before consuming it raw. Before serving, they are shucked. When you purchase oysters, they are typically kept alive on ice until it is time to prepare them. So, when exactly is an oyster no longer alive? And there is a little bit of truth to that. If it closes, that means the oyster is still alive and breathing. Fun related fact, oysters sometimes have tiny crabs inside their shells once shucked. Fresh oysters must be alive just before consumption or cooking.. In a recently-viewed episode of Good Eats, Alton Brown mentioned that properly stored in a refrigerator with a damp towel over the container, oysters could live as long as a week. Both raw alive and raw dead pose risks though, she says.