Crab

Fresh picked crab meat keeps 2–4 days refrigerated; cooked crab in the shell keeps 3–4 days. Both want the coldest part of the fridge, over ice if possible.

There are three quite different products sold as crab meat and they do not share a shelf life. Fresh picked meat, sold in tubs at the counter, is the most perishable at 2–4 days. Pasteurized crab meat, in sealed cans usually kept refrigerated, keeps for months unopened and follows its package date — but once opened it drops to the same 2–4 days. Imitation crab is processed fish paste and follows its own package dating entirely.

Live crabs must be kept alive until cooking, in a cool, damp, ventilated container — never in fresh water or a sealed bag, both of which will kill them. Cook the same day.

Crab freezes acceptably for 2–4 months, best left in the shell, which protects the delicate meat.

Crab meat is among the most perishable foods in any grocery store, and the reason is enzymatic.

Crustacean flesh is rich in digestive enzymes that begin breaking down the muscle almost immediately after death — a process that continues in the refrigerator. This is why crab is traditionally cooked alive or within moments of death, and why picked meat has such a short window even when it is handled perfectly.

The pathogen of concern is Vibrio, a genus of marine bacteria that grows quickly in warm seafood and causes serious illness. Vibrio is the reason crab handling emphasizes continuous cold so heavily, and the reason a cooler bag for the drive home is not overcautious.

Pasteurized crab meat has been heated in its sealed can enough to destroy those organisms without cooking the meat further, which is what buys it months instead of days. Opening the can ends that protection completely.

Fresh crab should smell sweet and faintly of the sea. Ammonia is the decisive signal — as with shrimp, an ammoniac smell in crab means advanced decomposition, and cooking will not correct it. Discard.