What Einstein Kept Under His Hat: Secrets of Science in the Kitchen (31 page)

The very large so-called
diver scallops
(10 or fewer per pound) have supposedly been hand-harvested by scuba divers rather than dredged from the sea bottom. Because of their impressive size, relative scarcity, and consequent high price, you’ll find them only at expensive restaurants. But don’t swallow the scuba story hook, line, and sinker. There’s nothing to prevent a restaurant from calling any large scallop a diver, if it so chooses.

Using their big adductor muscles, scallops in the wild can clap their shells together forcefully, shooting themselves through the water by jet propulsion to escape a predatory fish or starfish. (It’s a jungle down there.) They can even aim their spurts of water to propel themselves in almost any direction, although most often “forward” by jetting water straight out the hinge end.

You think that’s wild? Wait’ll you hear this. Many scallops have blue eyes. No kidding. They’re the only bivalves that have eyes at all, much less baby blues. If you peek in between the shells of a scallop, you’ll see two rows of fifty or more tiny eye dots, staring back at you from the critter’s front edge, or mantle. While a scallop can’t exactly read the bottom line on an eye chart, it can distinguish changes in light intensity, and that’s a good enough warning that it’s time to scoot away from any stranger that darkens its door.

One of my most exciting experiences (I know: You’ll think I need to get a life) was wading among live scallops in the shallows off Cape Cod and watching each one jet away the instant my shadow fell upon him and her. (Note to editor: That’s him
and
her, not him
or
her; most scallops are hermaphrodites.) In Europe, the female red roe is saved and served along with the adductor muscle, covered with a cream sauce, topped with browned bread crumbs, and called
coquilles St. Jacques
.

Scallop muscles have a tendency to dry out and lose weight, decreasing their per-pound value in the marketplace. So wholesalers, and even the fishing boat crews themselves during a long trip, may soak them in fresh water or in a solution of sodium tripolyphosphate (STP) to keep them hydrated. Because scallop meat is naturally saturated with salty seawater, osmosis will force water into it from the less salty soaking liquid. The STP helps the scallop to retain that water. Soaked scallop meats are called “wet”or processed scallops to distinguish them from unsoaked or “dry” scallops.

Processed scallops that have been loaded with water will be excessively heavy and should rightfully be sold at a lower price per pound. (Consumers, take note.) Processed or “wet” scallops will be almost pure white (the phosphate acts also as a bleach) rather than their natural ivory, creamy, or pinkish color, and they will be resting in a milky, sticky liquid that makes them tend to clump together. They’re a disaster to sauté, because they’ll release their excess water into the pan and steam instead of browning.

The role of the FDA? It monitors the water content of scallop products. Back home in the sea, scallops are 75 percent to 80 percent water. If a commercial product contains more than 80 percent water, the FDA requires that it be labeled an “
x
% Water-Added Scallop Product” and, if applicable, “Processed with Sodium Tripolyphosphate.” Scallops containing more than 84 percent water may not be sold at all. So much for that “The FDA made me do it” cop-out.

The problem is that these FDA-mandated labels are affixed to the wholesale buckets and you may never see them in the retail market. So buy your scallops only from a fishmonger whom you trust not to sell wet scallops at dry-scallop prices. Why pay $7 to $14 a pound, depending on size and season, for water?

When I buy raw shrimp, sometimes they’re gray and sometimes they’re pink, almost as if they’d been cooked. Are the pink ones somehow less fresh?

....

N
o, they’re just different species. Some are pinker and some are grayer, even when they’re still gamboling about on the ocean floor. But all of their shells turn bright pink when cooked. That color is in the shells all along, but it is masked by darker colors that break down when heated.

At least in the case of domestic Atlantic shrimp, the shallow-water ones are more or less sand-colored for maximum camouflage against the sandy bottom. In deep water, where the prevailing light has a bluish cast, they can afford to be pink, because reddish pigments don’t reflect much blue light and therefore don’t show up.

Unless you live near the shrimp-boat docks, all the shrimp that you buy were almost certainly frozen fresh from the boat or even when still on the boat, and shipped to market in that condition. At the market, they thaw out batches of shrimp to put in the display case. Like a lot of other seafood, however, shrimp begins to spoil quickly after being thawed. Fortunately, you carry with you at all times an exquisitely sensitive instrument for detecting spoilage: your nose. Any odor at all, other than that of a fresh ocean breeze, is your cue to buy something else for dinner. So don’t be afraid to ask to smell a sample of the shrimp up close before you make your purchase.

(Once, I almost got my head handed to me by an indignant fishmonger on the waterfront in Marseilles when I picked up a squid and sniffed it. I hadn’t realized that I was dealing with the fisherman himself, straight off the boat. How much fresher could it be?)

What does the “scampi” mean in “shrimp scampi”?

....

I
t sounds like a way of preparing shrimp, and in a way it is. But in a way it isn’t.

Scampi
is the Italian name for a species of large prawns known also as Dublin Bay prawns. And what is a prawn? Strictly speaking, it’s a crustacean more closely related to a lobster than to a shrimp. But the name depends on where you live.

There are literally millions of species of animals in the sea, including twenty-six thousand known varieties of crustaceans. A lot of these critters look pretty much alike, and the same species may be known by many different names around the world. What we call a shrimp over here may be called a prawn over there. And it often is. Or vice versa. Or maybe not. (I hope that’s clear.)

In Europe and most other parts of the world, a prawn is a specific variety of large (up to 9 inches long) crustacean with long antennae and skinny, lobster-like front claws. It is not a shrimp because shrimp have no claws. Instead, prawns are very similar to what we call crayfish or crawfish in the United States (or, in Louisiana, “mud bugs”). The prawns from Ireland’s Dublin Bay are reputedly top o’ the heap,
begorrah
!

On a French menu, the word
crevette
can go either way: as a
crevette
rose
, it’s a prawn, while as a
crevette
grise
, it’s a small, brown shrimp. (Yes,
grise
means gray in French; go figure.) Except, of course, when the chef calls a prawn a
langoustine
, which he or she may do whenever he or she feels like it. Prawns probably became
langoustines
in France when Spanish prawns, or
langostinos
, crossed the Pyrenees. (Not by themselves.)

In our freewheeling United States, alas, any large shrimp might be called a prawn, depending on how hard the chef wants to impress you. If the shrimp are not at least “jumbo” in size (around 20 or fewer to the pound), however, it’s particularly stretching to refer to them as prawns. The only thing you can be pretty sure of is that the critters in “shrimp scampi” on most American menus aren’t either scampi or prawns; they’re whatever plain old shrimp the restaurant has at hand.

Be that as it may, chefs in Venice enjoy covering their scampi with fresh bread crumbs and broiling them in a garlicky butter sauce. Thus, when an American restaurant does that to their shrimp, they call the dish “shrimp scampi” which, when you come right down to it, means “shrimp shrimp.”

That reminds me of when my daughter, Leslie, and I were strapped for something to cook for dinner and came home from the market with, among other things, some good-looking eggplants, known in most places outside North America as
aubergines
. We scooped out the pulp, did a few things to it that I vaguely remember as involving garlic, olive oil, and bread crumbs, stuffed the mixture back in the skins, baked them, and christened the dish “eggplant aubergine.”

Redundancy raises its ugly head. Again.

Chapter Seven

A Carnival
for Carnivores

....

F
ORTY-SIX BILLION
pounds of beef, veal, lamb, and pork, plus 36 billion pounds of poultry, are consumed each year in the United States.

According to USDA statistics for the year 2001, the average American consumed 68.2 pounds of beef; 51.6 pounds of pork; 1.8 pounds of veal, lamb, and mutton; 77.8 pounds of chicken; and 17.9 pounds of turkey, all in terms of trimmed weight at the retail counter. That’s a total of more than 200 pounds of meat for every man, woman, girl, boy, and baby in the country, even counting vegetarians.

Does that make you feel full?

Technically, the word
meat
includes the flesh, or muscle tissue, of any animal, including fish and shellfish. But we went fishing in the preceding chapter and will stick with two- and four-legged creatures in this one—that is, poultry and “red” meat, respectively.

Okay, the pork producers want us to call pork the “other white meat” because it isn’t as red as beef or lamb. The reason is that pigs are lazy. (Nobody ever tried to fall asleep by counting pigs jumping over a fence.) Because they are congenitally inactive, their muscles contain very little of the red, oxygen-storing compound called myoglobin (see “How now, brown cowburger?” on p. 275) that other animals stockpile in their muscles for sudden energy demands.

Along with muscles for movement and locomotion, most animals have bones for support and internal organs for sustaining the processes of life. So besides meat per
se, we’ll talk a bit in this chapter about using bones in stocks, and we’ll delve briefly into the edible but largely unappreciated (in this country) innards.

Differences among the world’s cultures are reflected in their attitudes toward meat—what meats are eaten, and how, and when. In the United States, our red meats come almost exclusively from three mammals: cows, sheep (lambs), and pigs. We may read with fascination and various degrees of dismay about cultures in which other mammals are eaten (including goats, rabbits, camels, horses, whales, and dogs), not to mention amphibians and reptiles (frogs, lizards, alligators, and snakes), or even insects (grasshoppers and grubs).

But at the same time, other cultures may feel repugnance toward at least two of our three favorite meats: beef is forbidden to Hindus, and pork is forbidden to Jews and Muslims. Much of the Catholic world eschews all meats on Fridays, while vegetarians reject them at all times—or, in the current vernacular, 24/7/52.

Nevertheless, meat is valued as the “center of the plate” on tables around the world, with regularity in wealthy countries and whenever possible in poorer ones. Cultures based on raising livestock for their renewable resources, milk and wool, cannot generally afford to kill their “golden calves” for the sake of a hamburger.

Let’s take a highly abbreviated look at the structure of meat and what happens when we cook it.

A mammalian muscle is made up of (surprise!) muscle cells, also known as muscle fibers. These long, skinny cells contain several nuclei apiece, and are packed together in parallel bundles inside an elastic husk (a
sarcolemma
), like a bundle of uncooked spaghetti inside a garden hose. These fiber-filled “hoses,” still largely parallel to one another, are stacked together like a pile of logs to make up the muscle proper. That’s why meat has a fibrous texture, or “grain.”

Muscle tissue is made largely of protein. In a sirloin steak, for example, 57 percent of the dry weight is protein and, depending on how the steak is trimmed, about 41 percent is fat. The tiniest filaments within the muscle cells, called
myofilaments
, contain the actual protein molecules, which are mostly
actin
and
myosin
. When set off by chemical and electrical “move” signals from the nervous system, these protein molecules bond (
cross-bridge
) with one another to form tighter, shorter protein molecules, thereby making the myofilaments, and hence the whole muscle, contract.

But now, into the kitchen.

When we cook meat, the primary effect is that the protein molecules become
denatured
or reconfigured. That is, upon agitation by the heat, their convoluted structures unwind and then, generally, clump together by forming cohesive bonds. Known as
coagulation
, this clumping has several effects.

For one thing, the coagulation scrambles the neatly lined-up bundles of fibers in the muscle tissue, making the structures more tangled, random, and rigid. Second, the tighter structure of the reconfigured proteins squeezes out juices (muscle is 65 to 75 percent water) and dries out the meat. Thus, a steak becomes both tough and dry if cooked too long. Moderate cooking, however, has many virtues: it tenderizes meat, improves its flavor, improves its appearance, and makes it safer by killing microorganisms.

Now it’s time to eat. Meat is a valuable source of high-quality protein containing essential amino acids, and fats containing valuable fatty acids. That’s not to mention its abundance of iron and vitamins A and B. So grab that steak knife and let’s dig in.

I’m an inveterate food label reader. In the past, I used to see “mechanically separated chicken” or “mechanically separated beef” on franks and other manufactured meat products. I wondered about it at the time, but now that I want to ask about it I can’t find it on labels. What is (or was) mechanically separated meat, and why don’t they do it anymore?

....

T
he Food Safety and Inspection Service (FSIS) of the USDA won’t let them. It’s a reaction to “mad cow” disease.

Mechanically separated meat is meat that has been separated from the bone by a machine, rather than by knife-brandishing humans. The first time I saw the words
mechanically separated beef
on a label I said to myself, “Well, what did you expect, Dummy?” (I hate it when I talk to myself disrespectfully like that.) “Did you think all the meat we buy is cut by blood-spattered slaughterhouse workers hacking meat off the carcasses, much as our prehistoric ancestors did after a successful mastodon hunt?”

Truth be told, yes. That is indeed the way most of the job is done. But these days, machines supplement those blood-spattered slaughterhouse workers by removing the remaining meat from the bones after the humans have done their best with their knives.

Although most of us would rather not think about it very much, meat begins with slaughtering at a packing plant, which might better be called a hacking plant. (The euphemism “packing” originated in colonial times, when pork was salted and packed in barrels for shipping overseas.) As soon as the animal has been killed and its blood drained out—procedures that the meat industry delicately refers to as “immobilization” and “exsanguination,” respectively—what had previously been skeletal muscle has officially become meat. (Skeletal muscle is muscle attached to the skeleton rather than the muscular parts of the circulatory system, such as the heart.) But a carcass is not all meat; it contains internal organs, bones, cartilage, tendons, ligaments, fat, and skin, all of which need to be excised during the subsequent stages of “disassembly.” That job is done mostly by saws and sharp knives, hand-wielded by packing-house workers.

After the carcass is split into two “sides” by a power saw, workers with knives cut it into eight so-called
primal
cuts
: chuck, rib, short loin, sirloin, round, brisket and shank, short plate, and flank. The primal cuts may then be packed and shipped as is or reduced to smaller cuts (
subprimals
) or even down to display-case cuts, depending on how much subsequent butchering, if any, the buyer wants to do at the retail level. In either case, there is still a lot of unrecovered meat left in the trimmings, and that’s where the machines come in. They can separate almost all of the remaining meat from the bones.

There are two types of so-called meat recovery machines, depending on whether the bones are first crushed: the mechanically separated meat (MSM) systems, used since the 1970s, and the newer advanced meat recovery (AMR) systems.

In MSM machines, the bones are first ground or crushed, after which the soft tissues (muscle and fat) are forced at high pressure through a kind of sieve, separating them from the bone fragments, cartilage, ligaments, and tendons. What comes out is in the form of a paste or batter that can be thrown directly into the mixing vat for hot dogs, sausages, hamburgers, pizza toppings, taco fillings, and similar manufactured meat products, which have to be labeled as containing “mechanically separated meat.”

In the more modern AMR machines, the bones are not crushed. They enter the machine whole and emerge essentially intact after the meat has been scraped, shaved, pushed, or pulled off in small pieces. The USDA allows this meat to be labeled simply as “meat.” It may contain tiny pieces of bone the size of grains of table salt. This bone contributes most of the calcium listed in the Nutrition Facts tables on many processed meat products that you wouldn’t expect to contain much calcium.

As a result of the outbreak of mad cow disease, or BSE (
bovine spongiform encephalopathy
), in the 1980s in Britain and subsequent incidents in North America, the USDA since March 3, 2003, has required the routine sampling and inspection of AMR-produced beef for the presence of any spinal cord or brain tissue. That’s where the disease-transmitting prions (PREE-ons) are located in sick animals. Prions are rather mystifying proteinaceous particles. They have no DNA or genes with which to replicate themselves and are therefore not alive, but they can cause disease in animals and humans. They can’t be inactivated by extreme conditions such as acids or heat that normally affect the nucleic acids in microbes and viruses. In humans, the mad-cow-transmitted disease is called Creutzfeldt-Jakob (KROYTS-felt YOK-ob) Disease, or CJD.

On December 30, 2003, the USDA announced that (a) all central nervous system parts (such as nerve cells along the vertebrae), not just brain and spinal cord tissue, must be absent in AMR meats, and (b) the use of mechanically separated meat (MSM) in human food is prohibited, because it is more likely to contain fragments of central nervous system tissue.

And that’s why you no longer see the MSM words on labels.

Of course, the machines enable the meatpackers to sell more meat, and that’s why they use them. But on its website (http://www.amif.org/FactSheetAdvancedMeatRecovery.pdf), the American Meat Institute explains the virtues of using the machines: “Hand trimming requires repetitive cuts with a knife, which can result in repetitive motion injuries to employees. Reducing hand trimming [by using AMR] protects employees.”

It’s nice to know that the meatpacking companies are so concerned about their employees’ hands.

While you’re perusing labels in the meat case, you may see some hot dogs labeled as containing “variety meats.” This is a euphemism for any or all of the animals’ non-skeletal-muscle parts: hearts, brains (except beef brains), large intestines (chitterlings or chitlins), spleens (melts), pancreas and thymus glands (sweetbreads), kidneys, livers, lips, and tongues.

Other parts of animals that may find their way into wieners, sausages, and other mystery-meat products are blood, marrow, cheeks and other head trimmings, feet (trotters), tails (oxtails), stomachs (hog maw), lungs (lights), small intestines (sausage casings), skins (pork rinds), stomach linings (tripe), and testicles (fries, prairie oysters, or mountain oysters). Notice how the number of euphemisms multiplies along with the indecorousness of the organs.

As my father once told me when I was a little boy, “They use every part of the pig but the grunts.” For years I wondered which part of the pig was its gruntz.

Isn’t that offal?

My supermarket has a sign at the meat case assuring us shoppers that if we open a package of ground beef and find that the meat on the outside, visible through the plastic wrapping, is red while the meat on the inside is brown, there is nothing to worry about. They go on to say that once the hamburger is formed, all of the meat will return to its red color. Why does that interior meat turn brown? And why does it return to its red color, if in fact it does?

....

I
wrote briefly about this topic beneath the same corny heading in a previous book,
What Einstein Told His Cook: Kitchen Science Explained
. But I continue to receive letters from worried purchasers of prison-pallor hamburger meat. So permit me to address this question again, but in more detail than I did before.

The brown-meat syndrome has been a concern of consumers ever since the neighborhood butcher, who ground the meat before our very eyes, went the way of his sawdust-covered floors. In today’s supermarkets, the meat is ground somewhere “in the back,” or even at another location, and then packed into plastic trays and covered with plastic film. In some markets, it may languish in the cooler for a day or two, then sit even longer in your refrigerator before you get around to opening it and discovering that the inner meat is an unappetizing gray-brown.

Are they spraying the top meat with some sort of red dye? No. Is the brownish meat spoiled? No, not unless it smells bad, which indicates either spoilage by microbes or that the fat is becoming rancid. So brownish meat is okay to eat unless it smells bad.

The chemistry of meat color—any meat—is a bit complicated, and what we call “red meat” could give a chameleon a run for its money. But in a nutshell, the color of meat depends largely on the relative amounts of three colored proteins, just as when an artist mixes three pigments on the palette to achieve a desired hue. The three proteins are
deoxymyoglobin
, the deep purplish-red color of freshly cut beef;
oxymyoglobin
, a bright pinkish-red; and
metmyoglobin,
a grayish-brown color. (There are other forms of myoglobin, but these are the main ones.)