How Long Does Mussels (Raw, in Shell) Last?

Live mussels need to be cooked within a day or two of purchase and should be stored loose in a bowl covered with a damp towel, never sealed in an airtight bag or submerged in water, since they're still alive and need some airflow to survive until they're cooked.

A live mussel that stays open and doesn't close when tapped is already dead and should be discarded before cooking rather than cooked anyway, since a mussel that dies before cooking begins breaking down in a way that isn't safe to eat. A strong fishy or ammonia smell from the batch overall, rather than a clean ocean scent, is a broader sign the whole batch has started to turn and shouldn't be used even if a few individual shells still look fine. After cooking, any mussel that remained closed should also be discarded, following the same one rule that governs mussels in both directions — closed before cooking is alive and fine, closed after cooking is a shell that never opened and should be treated as unsafe.

Live mussels stored submerged in water or sealed in an airtight bag, rather than loose under a damp towel with some airflow, will suffocate and die well before their normal 1-2 day window, so how they're stored matters just as much as how long they've been home.

See Mussels (Raw, in Shell)'s full storage & shelf-life guide (with spoilage signs) →