Crabs take only minutes to smoke, but the character invested by this flavoring tastes like it took much longer. Smoking typically takes several hours, but crabs can't handle much time on the grill -- nor does their delicate flesh need it. You can't cold-smoke seafood, or smoke it at 80 to 90 degrees Fahrenheit, at home without risking foodborne illness. Crabs need to reach at least 145 F in under two hours to prevent bacterial growth. Set up a light wood -- peach, apple, almond or alder -- for crabs for a smokiness that won't assault their delicate flavor.
Wanted: Dead or Alive
Unless you live on the coast, chances are you have precooked and cleaned crabs -- which you want, or at least the state you want them in before smoking. Live crabs dislike being shut in a barbecue and suffocated with fruitwood smoke, and always attempt escape -- crabs fleeing certain death don't cook evenly.
If you have live hard-shell crabs, cook them in boiling water: 15 minutes for 1 1/2- to 2-pound crabs and 30 minutes for 3-pound crabs. Twist off the legs and claws and reserve the bodies for cleaning -- some of their tissue is edible, but you won't smoke it. Thaw frozen crab legs and crab claws in the refrigerator overnight.
Live Soft-Shell Crabs
You typically find soft-shell crabs in the frying pan, under the broiler or on the grill -- they fall apart when cooked in water. Live soft-shell crabs require a different preparation technique than live hard-shell crabs -- you clean these babies before you cook them. Clean soft-shell crabs only after you have the grill or smoker hot and ready to go.
Snip off the head using kitchen shears -- this kills the crab. Next, lift one side of the top shell and pull out the grey fingerlike-gills; repeat with the other side. Finally, pull off the apron, the soft shell on the underside of the crab. Rinse the crab under cold water; keep the cleaned crabs in the refrigerator on ice until you finish them all.
Dedicated smokers and charcoal kettle grills invest the best smoky aroma and flavor in delicate crabmeat. The air circulation in both are superior to gas, because the smoke contacts the food more uniformly -- but you can make a gas grill work for the short time needed to smoke crabs.
Set the smoker to 225 F after you fill the woodchip box and the water pan. Set the burners on the left and right of the gas grill to medium-high and leave the center off; wrap 1 cup of woodchips in aluminum foil, cut a few 1-inch-long slits in the packet and lay it on one of the burners. For a kettle grill, light 40 to 50 pieces of charcoal in a charcoal chimney starter and dump them on one side after they ash over. Set a pan of water on the other side and scatter woodchips on the coals.
Final Prep and Smoking
Crack hard-shell legs and claws in several places to grant the smoke access to the meat. Don't destroy the shell, but simply crack each piece every 1 to 1 1/2 inches. Coat the legs and claws with olive oil and season them. Lay the crab on the indirect part of the grill -- the part not above the burner or charcoal -- and smoke them until they reach 145 F, or about 15 minutes.
Coat the crabs with oil and season them to taste. Lay soft-shell crabs over the heat source and cook them until they turn red, about 3 or 4 minutes. Next, move them away from the heat and let them sit for about 15 minutes to impart a richer smokiness.