The crustaceans, a family that includes lobsters, crayfish, shrimp and crabs, are some of the tastiest of all seafood. Diners who live in coastal areas or major cities can usually find them live at a good fishmonger, and high-quality frozen products are available almost anywhere. Most are easy to cook. For example, you can simply steam crab legs whole, with no need to crack or cut them until you're ready to eat them.
Fresh, Frozen and Pre-Cooked
Crabs can be purchased whole and fresh from your local fishmonger, or sometimes in packages of legs and claws. If fresh crab isn't an option in your area, or you just don't want to deal with a meal that starts out still alive, crab legs are also available frozen. Some are frozen and packaged raw, but more commonly -- especially with king crab and snow crab, which travel a long way to market -- they're precooked and blast-frozen either on the fishing boat or at a processing facility in or near the fishing boats' home port.
To steam crab legs, prepare either a large pot with a steamer insert or an electric steamer with a basket large enough to hold them. Bring the pot or steamer to a boil, and add the crab legs. Be careful to let the cloud of steam disperse before you reach in, or you could get seriously burned. Cover the pot or steamer and wait until steam begins to billow from under the lid again, then start your timer. Raw crab legs might take six to 10 minutes for small species, and 15 minutes or longer for Dungeness and other large crabs. Previously cooked crab legs typically take 10 minutes or less.
When To Cut
Ordinarily, crab legs are steamed whole. The shell protects the delicate flesh from the heat of the steam, and also prevents the meat from attracting any grit or shell fragments from the other legs. However, in some cases you might choose to cut the legs in half lengthwise. If the crab legs are frozen, cutting them in half enables you to reheat them in a shorter time. With either fresh or pre-cooked legs, it also provides an opportunity to flavor them more thoroughly through your choice of steaming liquid and seasonings. It takes a sharp, heavy knife or good kitchen shears to cut the frozen crab legs, and reasonably strong hands. Overall it's easier to cook the legs whole, and then split them.
Although plain salted water or seawater is the most common steaming liquid, other choices can bring an interesting flavor to the crab legs. For example white wine, beer and cider all impart a distinct taste to the crab. So will water, if it's first simmered with herbs, spices or a commercial seasoning mixture. Fish or vegetable broth are also excellent choices, though they might be difficult to clean from an electric steamer. You can also add flavor by lining the bottom of your steamer with herbs or seaweed. These ingredients will add a mild flavor to whole crab legs, but are much more effective when the legs are cut open.