How to Tell If Mussels and Clams Are Bad
Quick answer
Throw out live mussels or clams that stay open when tapped, or any that don't open after cooking. Also toss any with a strong or sour smell, cracked shells, or a dried-out look. Cook live ones within 1 to 2 days.
When in doubt, throw it out. Bacteria that cause food poisoning often don't change the smell or look. Go by the time limits below too.
Signs Mussels and Clams have gone bad
- Shells that stay open when tapped. A live mussel or clam should close, or slowly close, when you tap it or give it a squeeze. If it stays gaping, it's dead and not safe to cook.
- Shells that don't open after cooking. Closed shells after cooking were likely dead before they hit the pot. Don't pry them open, just discard them.
- Strong, sour, or fishy smell. Live shellfish smell clean and briny. A rotten, sulfurous, or ammonia-like smell means they've died and begun to decay.
- Cracked, broken, or heavy-with-mud shells. Damaged shells can mean the animal is dead or weak. Very heavy shells that feel full of mud or sand are often dead as well.
- Dry, shriveled, or discolored meat. Shucked meat should look plump and moist. Gray, shrunken, or slimy meat means it's too far gone.
Looks weird, but it's fine
- Beard on mussels. The fibrous threads sticking out are called the beard, and they're normal. Pull it off before cooking.
- Barnacles and sand on the shells. Wild shellfish often arrive with debris, which is harmless. Scrub them under cold running water.
- Slightly open shells that close when tapped. Some live mussels relax and open a bit in the fridge. If a quick tap makes them close, they're alive and fine.
How long do Mussels and Clams last?
| Where | How long | Note |
|---|---|---|
| Fridge (live) | 1 to 2 days | Open container covered with a damp cloth, not sealed |
| Fridge (shucked) | Up to 2 days | In their liquor, tightly covered |
| Fridge (cooked) | 3 to 4 days | Sealed container |
| Freezer (cooked or shucked) | 2 to 3 months for best quality | Do not freeze live ones |
How to store them
- Keep live shellfish in a bowl in the fridge under a damp towel and never in a sealed bag or submerged in fresh water, which will kill them.
- Toss any dead ones before you store and again before you cook, and discard any that fail the tap test.
- Cook and eat them the day you buy them whenever possible, since they spoil fast and can't be rescued by cooking.
Use it up before it turns
Frank Pepe's White Clam Pizza (The New Haven Original, Made at Home) 
Legal Sea Foods New England Clam Chowder (The Presidential Inauguration Recipe, Made at Home) 
Maggiano's Linguine alle Vongole (Clams in White Wine-Butter Sauce) 
Red Lobster Admiral's Feast (Fried Shrimp, Flounder, Clam Strips, and Bay Scallops) Frequently asked questions
Should you throw out mussels that don't open when cooked?
Yes. Closed shells after cooking were dead before cooking, so discard them. Don't try to force them open.
How do I tell if a clam is alive before cooking?
Tap an open clam on the counter or squeeze it lightly. If it closes, it's alive. If it stays open, throw it away.
Can I eat mussels that smell a little fishy?
Live mussels should smell like the ocean, not fishy. A strong or sour fishy smell means they have started to spoil, and it's best to throw them out.
More food freshness guides
General guidance based on USDA FoodKeeper. Storage times are estimates and conditions vary. When in doubt, throw it out.