What Einstein Told His Cook (21 page)

But that’s just about all he ever does. And by the time he reaches a restaurant, shells tightly clamped against the indignity of being yanked into the atmosphere, he isn’t even doing that much. He has no organs of sight or hearing and unquestionably feels neither pleasure nor pain, especially when numbed by being kept on ice. You call that living?

So much for biology. Now for the physics: How do you get the damn things open without killing
yourself
?

AW, SHUCKS!

I bought live clams at the fish market, but had the devil of a time getting them open. Is there any easy way?

A
lmost as much human resourcefulness has been expended on shucking clams as on opening childproof medicine bottles, but with far more injuries. People have seriously recommended everything from hammers, files, and hacksaws to execution in the microwave chamber. But brute force is entirely unnecessary, and microwave heat can seriously compromise their flavor.

To open clams the easy way, put them in the freezer for 20 to 30 minutes, depending on their size; you want to get them very cold but not frozen. In this anesthetized condition, they can’t hold on to their shells very tightly. Then, nestling the clam in a towel-protected hand, you press a flat, rounded clam knife—
not
a pointed oyster knife—between the shells at the slight indentation near the more pointed of the two ends. (That’s where the clam sticks out its siphons.) Sliding the knife against the inner surface of one shell, you cut the two shell-holding muscles (Techspeak: the adductor muscles), twist the shell off at the hinge and discard it. Then you detach the muscles in the same way from the remaining shell, leaving the clam in it. Add a dollop of half-and-half horseradish and chili sauce and maybe a dash of Tabasco or a spritz of lemon, and slide it into your mouth.

A clam knife. The flat blade is inserted between the shells, whereas an oyster knife is more pointed for “popping” the hinge.

COME CLEAN!

Once on vacation at the shore, I found a few live clams. I took them back to the hotel and asked the kitchen to prepare them for me. I wanted to eat them raw. After eating them, I asked the chef how he had prepared them. He said, “I opened them.” Why doesn’t this live creature, plucked straight out of its natural habitat, need to be cleaned or something before being eaten whole?

T
hey should be, but they really don’t have to be. That step is often skipped.

As they arrive from the ocean or the fish market, live clams generally need to be purged. When they were snatched from their snug little beds in the sand, they pulled in their siphons and clamped their shells together tightly, possibly trapping some sand and whatever other jetsam happened to be in the vicinity. Moreover, the clam has an alimentary canal akin to the vein in a shrimp. Although it won’t hurt you, it may be a bit gritty and isn’t the prettiest thing to eat. Best to clean it out.

So after scrubbing the outsides of their shells, treat your clams to a restful soak in mock seawater—a third of a cup of table salt per gallon of water—with a tablespoon or so of cornmeal stirred in, and leave them alone for about an hour. If you watch quietly (they spook at vibration, not actual sound), you’ll see them feeding on the cornmeal and cleaning themselves out. After a while, you’ll be surprised at how much ejected debris there will be at the bottom of the container. Leaving them there too long won’t do any good, though, because they’ll use up the oxygen in the water, slam their gates, and stop purging.

So many cookbooks and magazine articles tell us to purge live clams by soaking them in tap water, either with or without the cornmeal, but a moment’s reflection shows how useless that is. Although there are such things as freshwater clams, the ones we’re talking about live in salt water. If you were a saltwater clam plunged into fresh water, you’d clam up immediately, not daring to open your shells so much as a crack, hoping that the environment would eventually become more hospitably salty. So soaking clams in unsalted water accomplishes nothing. A soak in salt water of the right salinity, on the other hand, fools the clams into thinking they’re back home, whereupon they will stick out their siphons, feed, and purge themselves of debris.

Some restaurants skip the purging step, and their clams can be gritty. That’s less important if the clams are to be cooked, but sand in the bottom of the chowder bowl is a tip-off to this kitchen shortcut. At least you’ll know that the chowder was made from real live, rather than canned or frozen, clams.

Soft-shell clams, or steamer clams, have big siphons (“necks”) and can’t close their shells completely. They will therefore always have some sand in them. That’s why you swish them in clam broth before dipping them in melted butter and eating them.

BETWEEN A ROCK AND A CARAPACE

Clam and oyster shells are hard as a rock, but shrimp and crab shells look like thin plastic. Why the difference?

W
e call them all shells because they are worn on the outside, but when we talk about “shellfish,” we’re including two totally different classes of animals: crustaceans and mollusks.

Among the crustaceans are crabs, lobsters, shrimps, and prawns. Their shells are horny, flexible plates of hinged “armor.” The top covering of a crab or lobster is called its carapace. (I had to throw that in to justify the pun in the heading.)

Crustaceans make their thin shells out of mostly organic matter—chitin (KITE-in), a complex carbohydrate that they manufacture from the foods they eat. You won’t enjoy knowing this, but shrimps, crabs, and lobsters are closely related to insects and scorpions, which also make their outer crusts of chitin. (If that grosses you out, be aware that many biologists now prefer to believe that crustaceans and insects evolved independently. Biologists like seafood, too, you know.)

On the other hand, bivalve mollusks—clams, oysters, mussels, scallops, and other critters that live between pairs of hard shells—make their shells out of mostly inorganic minerals that they take out of the ocean, primarily calcium carbonate, the same versatile substance that limestone, marble, and eggshells are made of. The next time you have a whole clam or mussel on your plate, notice the curved growth lines or ridges that are parallel to the outer edges. These represent the successive additions of new shell material, deposited by the animal whenever it grew enough to need more room, usually during the warm seasons.

The two different kinds of shells in crustaceans and mollusks mean that the creatures have to devise two different strategies for growth. Mollusks, which grow by adding more material to the outer edges of their shells, in effect let out their pants, while crustaceans manufacture whole new suits.

When a crab or lobster gets too big for its breeches, it molts: It splits the seams of its shell, crawls out, and makes a new one in a larger size. If we catch one just after the act of disrobing, we may be treated to the Epicurean delight of a soft-shell crab or lobster. The “soft shells” are the new shells in the earliest stages of construction.

The Atlantic blue crab, for example, needs twenty-four to seventy-two hours to complete this construction job, which gives salivating predators like us just enough time to catch them—which isn’t easy, because being shorn of their armor, they hide in the eel grass and have to be scraped out. But if we’re lucky, we can catch them out in the open just before they molt. Skilled watermen can tell at a glance when a crab is getting close to shedding its shell, and when such “peelers” are found, they’re kept in a special pen until the deed is done.

And then what do we do with them? Why, we cook them as soon as possible and eat the whole things. Why spend time picking the meat out of a shell when we can find crabs without shells? All we have to do is three little cleanup steps, which are best done while the crabs are still alive.

Okay, if you’re squeamish get your fishmonger to do it for you. But here’s what needs to be done. (1) Tear off and discard the abdominal apron (see below). (2) Cut off and discard the eyes and mouth parts, which are on the long side between the two big claws. (3) Lift up the pointed tips to find and remove the feathery gills or, as exuberant folklorists like to call them, the devil’s fingers. They call them that because gills are effective filters for any toxic impurities that might be in the water, and eating them can be risky. Besides, they don’t taste very good. And what about “all that yellow-green stuff” inside the crabs? Don’t ask. Just eat it. It’s delicious.

Male blue crabs are generally bigger than females, and are used mostly for steamin’ and pickin’, while the females are used more for canning. How do you tell a male crab from a female, you ask? Look at the underside, and you’ll see an “apron,” a thin flap of shell that covers most of the abdomen. If the apron is shaped exactly like the Capitol dome in Washington, D.C. (honest!), it’s a mature female, or sook. If the apron is shaped like the Eiffel Tower in Paris, it’s a male, or jimmie. But if it’s a young, immature female, the apron looks like a Capitol dome with a bit of Eiffel Tower at the top. During the last molting before maturity, she discards the tower part.

Oh, and have you ever wondered why those drab, blackish green crab and lobster shells turn red when cooked? The red color, a chemical called astaxanthin, is present but not visible in the uncooked shells because it is tied up (Techspeak: complexed) with certain proteins to form blue and yellow compounds that together look green. When heated, the astaxanthin-protein complex breaks up, releasing free astaxanthin.