Blue crabs, found along the Atlantic Coast from Massachusetts to Florida and in the Gulf of Mexico, shed their shells once each year. This is a natural part of the shellfish's growth cycle and occurs between April and September.
The new shell begins to harden in four to five days, but crabs harvested just after molting are almost entirely edible and considered a culinary delicacy. Soft-shelled crabs are available fresh now through August, frozen the rest of the year.
Blue crabs are one of the smaller varieties, weighing between 4 ounces and 16 ounces and averaging 5 inches to 7 inches across the back. During harvesting, fishermen look for crabs with red-tipped claws--an indication that the animal will shed its shell within 48 hours.
Because of their small size, allow one crab as an appetizer serving, two to three for an entree.
To prepare soft-shelled crabs for cooking, use kitchen scissors to cut a strip from the front just behind the eyes (Step 1). This also removes the mouth and antennae.