Soft-shell crabs come to market from about April to October. They’re not a separate species of crab; rather, a soft-shell crab is a blue crab (found on the East and Gulf coasts) that has just shed its hard shell and has been plucked from the sea within hours after molting. The best way to judge freshness is to smell, so at the market, ask for a whiff: softshell crabs should smell pleasantly like the ocean. Also, have the fishmonger poke the crab’s outside to show you that it’s good and soft.
Soft-shell crabs are sold live and thus need a little preparation before you cook them. Once trimmed, the whole crab is edible. Trimming is quite simple but does involve snipping off the eyes, pulling out the gill tissue under the two flaps on the crab’s underside, and pulling off the crab’s apron. (If all this makes you queasy, it’s fine to request that the fish merchant clean your crabs; they usually ask, anyway.) In either case, hurry the crabs home and eat them the same day.
Soft-shell crabs are best cooked simply: rinse them and pat them dry, and then dredge them in some flour seasoned with salt and a pinch of chili powder, if you like. Then sauté the crabs in butter until browned on each side, deglaze the pan with some lemon or lime juice, and drizzle the pan sauce over the crabs.