While there are a several varieties of hard-shell crabs available in the United States, the most plentiful of those sold whole and live are Dungeness crabs from the Pacific Coast and blue crabs from the Atlantic and Gulf coasts. Purchase the crabs the day you want to prepare them, and make sure they are alive and moving, not listless. Here's how to cook them:
Step 1: Prepping the whole crabs
Grasp live crabs from behind, firmly holding the back two legs on each side. Rinse under cold running water.
Step 2: Boiling the whole crabs
To boil 3 pounds live hard-shell blue crabs, bring 8 quarts water and 2 teaspoons salt to boiling in a 12- to 16-quart pot. Add crabs. Simmer, covered, for 10 minutes or until crabs turn pink. Drain crabs in a colander and cool slightly. For Dungeness crabs, cook as directed, increasing cooking time to up to 20 minutes for larger crabs.
Preparing frozen, precooked crab legs
The most common crab legs are from king crabs, also called Alaskan king crabs, and snow Crabs. Crab legs usually range in size from about 4 to 8 ounces per leg. When purchasing, plan on about one leg or 6 ounces per serving. Since almost all crab legs are sold precooked and frozen, thaw them in the refrigerator before using.
Here are four ways to cook them:
Steamed crab legs: Place thawed crab legs in a steamer basket in a very large skillet. If necessary, bend crab legs at the joints to fit in the steamer basket. Add water to the skillet just to below the basket. Bring to boiling. Cover and steam for 5 to 6 minutes or until heated through.
Boiled crab legs: Place thawed crab legs in a large pot of boiling salted water. Return to boiling. Cook, uncovered, for 4 to 5 minutes or until heated through.
Broiled crab legs: Preheat broiler. Place thawed split crab legs, cut side up, on the greased unheated rack of a broiler pan. If desired, brush with melted butter and a little lemon juice. Broil 4 to 6 inches from the heat for 3 to 4 minutes or until heated through.
Tip: If you can't find split crab legs, purchase whole legs and use kitchen sheers to cut through the lighter-color underside of each thawed leg. Lay partially split legs on a cutting board, and cut through each hard shell with a sharp knife, completely splitting the legs.
Grilled crab legs: Place thawed split crab legs, shell side down, on the grill rack of a charcoal grill directly over medium coals. Grill, uncovered, for 8 minutes or until heated through. If desired, brush with melted butter halfway through the grilling time.
Step 3: Harvesting the meat
For split legs, pull the shell apart with your fingers. Use a small seafood fork to remove the meat from the legs and claws.