When I butcher a live lobster to remove the tail for grilling or sautéing, is it important to cook it right away, or can I keep it in the refrigerator a few hours?
When any animal is killed, rigor mortis, or the stiffening of muscle tissue after death, begins to set in quickly. Over time, the phenomenon is reversed, when enzymes known as proteases break down the contracted muscle fibers to return the meat to a soft, pliable (and edible) state.
With large animals such as cows, pigs, and lambs, there are no adverse effects to the meat contracting and then softening—in fact, resting or aging beef after slaughter results in a more tender texture. With lobsters, however, conventional wisdom holds that a rest after death toughens the flesh. To see for ourselves, we bought a number of live lobsters and butchered them to remove the tails. We cooked some of the tails immediately, then waited intervals of one, two, four, six, and 12 hours before cooking the remainder. The lobster tails that were cooked immediately after butchering (before rigor mortis set in) had an ideal firm and meaty texture. The tails cooked after a rest of one or two hours were dense and rubbery; those cooked four, six, and 12 hours after butchering were mushy.
Our science editor explained why: Unlike in mammals, rigor mortis in lobsters begins to set in within minutes. With a wait of one or two hours after death, lobster meat will be tough and rubbery. However, as the flesh begins to soften again (sometime after two hours), a phenomenon occurs that doesn’t happen in pork, beef, or lamb: The tissues loosen and start to come apart, resulting in a mushy, broken-down texture. The bottom line? Cook tails just after removing them from fresh-killed lobsters. If you’re dealing with a whole lobster, plunge it live into boiling water or cook it immediately after killing it.