Lobster tails are often cleaned prior to being sold, so minimal preparation is needed before cooking. But in case you're preparing your own lobster tails, or your tails require a bit of tidying up, you can easily clean lobster tails at home. In addition to washing, the other primary concern is removing the vein and digestive tract from the tails.
Washing the Exterior
Rinse off the tail's exterior in cold water to remove any preservatives that may have transferred during the storing process, including juices from other seafood products. If you're purchasing live lobster, washing is key to remove any debris floating in the lobster tank. To ensure the lobsters are clean, scrub the shell only, not the exposed meat, with a stiff brush under running water. Do not submerge the tail in water as the meat can absorb the liquid, creating a watery tasting lobster.
Cleaning Off Tomalley
Tomalley is the green, runny material present in the lobster head and, in some cases, on the exposed flesh of the tail. It's the lobster's liver and pancreas. While you can eat it, it is not recommended as it can contain accumulated toxins. Remove tomalley by brushing it away gently with your fingers under running water. Remove larger pieces or difficult to remove bits with a damp paper towel.
Deveining the Whole Tail
The vein running through the center of the tail -- translucent white and black -- is the lobster's digestive tract. While some fishmongers remove the vein prior to sale, others don't. To remove the vein from a whole, uncut lobster, grab the exposed vein at the fleshy end of the tail and pull. It comes out in one long piece. For a better grip, grasp it with a piece of folded paper towel or a clean dishcloth.
If the vein doesn't show through on the exposed portion of the tail, remove it by curling the tail inward, so the round, hard, outer shell is the only part of the shell visible. Poke a skewer through the membrane between the sections of the shell, along the center of the tail. Dig around with the point until the vein is visible, and pull it out with the tip of the skewer. Pull out the vein with your hands, grasping with paper towel or a dishcloth for more traction if necessary.
Cutting the Tail
You can also devein a lobster tail by cutting the tail open. Butterfly the tail by cutting it lengthwise, through the center of the tail, on the harder, rounded side of the tail. Use kitchen shears or a sharp chef's knife, and remove the exposed vein with your hands. Halving the tail lengthwise also exposes the vein, making it easy for you to remove. With butterflied or halved tails, brush the meat with oil or clarified butter, or cover the meat with plastic wrap prior to cooking to ensure the meat stays moist.