Mussels

Live mussels keep as long as they stay alive, usually 1–2 days refrigerated. Shucked mussel meat keeps 1–2 days.

Store them in a bowl under a damp cloth in the refrigerator — never sealed in plastic, never in fresh water. Mussels breathe, and an airtight bag kills them. Pour off any water that accumulates.

Leave the beard attached until just before cooking. Debearding kills the mussel, so pulling the beards in advance and refrigerating them overnight defeats the purpose of buying live shellfish. Debeard and scrub immediately before they go in the pot.

Most mussels sold now are rope-cultured rather than dredged, which means they arrive far cleaner and with much less grit than wild ones — usually a rinse is enough.

Cooked mussels keep 3–4 days refrigerated and freeze for 2–3 months in their liquor.

Mussels give the same binary liveness test as clams, with one wrinkle worth knowing.

A live mussel closes when tapped. Many mussels sit slightly open at rest, which alarms people unnecessarily — the test is whether it responds. Tap it or squeeze the shell: if it draws closed, even slowly, it is alive. If it stays open, it is dead, and it should be discarded. Cracked shells are discards regardless.

After cooking, the test inverts: mussels that failed to open were generally dead beforehand, and should not be eaten.

The underlying concern is the same as for other filter-feeding bivalves. Mussels process large volumes of seawater and concentrate whatever it contains — Vibrio species, norovirus, and, in areas affected by harmful algal blooms, the biotoxins responsible for paralytic shellfish poisoning. Those biotoxins are not destroyed by cooking, which is why commercial harvest-area monitoring and closures exist, and why mussels of unknown origin are a real risk.

Dead mussels decompose fast, developing a strong sour or sulfurous smell. Fresh ones smell of clean seawater and very little else.