Crab is a crustacean delicacy that does not require much effort to prepare and is usually served plain or with simple dressings, such as lemon, melted butter or cocktail sauce. Prepared crab is high in protein and low in calories and fat. Crab is moderately high in cholesterol and sodium. Because crabs have a short shelf life, cook live crabs instead of buying dead crabs. Buy dead crabs from reputable fishmongers to avoid potential contamination. Dead crabs should be frozen or refrigerated and eaten within 24 hours.

Bring a large pot of water to a rolling boil. You can boil fresh seawater to cook the crabs in, or salt the water yourself if you are using fresh water. The salt in seawater adds extra flavor to the crab.

Pick up a dead crab with the tongs and place it into the boiling water.

Cover the pot with a lid and cook the crab for 15 to 20 minutes, or until the shell turns from blue to bright red. If you aren't sure whether the crab is cooked, crack one of the shells open and look at the meat inside. The meat should be white and opaque. If you are cooking a frozen, pre-cooked crab, boil it for only five minutes.

Remove the crab from the boiling water using tongs, and plunge the crab into a bowl of ice water to stop the meat from cooking any further. Crab is usually served cold, but you can eat the crab warm if you desire.