What Einstein Told His Cook (6 page)

THE UN-CHOCOLATE CHOCOLATE

Is white chocolate caffeine-free?

Y
es. It’s also chocolate-free.

White chocolate is simply the fat from the cacao bean (the cocoa butter) mixed with milk solids and sugar. It contains none of those wonderful, though inauspiciously brown, cocoa-bean solids that give chocolate its unique character and rich flavor. If you choose a white-chocolate–topped dessert to avoid chocolate’s caffeine, bear in mind that cocoa butter is a highly saturated fat. You can’t win ’em all.

To add insult to perjury, some so-called white-chocolate confections aren’t even made with cacao fat; they’re made with hydrogenated vegetable oils. Be sure to read the ingredient list on the label.

HOW SWEET THEY ARE!

Those little envelopes of artificial sweeteners on restaurant tables: What’s different about the different brands?

I
never use them myself because I don’t view the 15 calories in a teaspoonful of sugar as a serious threat to my existence. But artificial sweeteners are a boon to diabetics and others who want to limit their intake of real sugar.

Artificial sweeteners, also called sugar substitutes, must be approved by the FDA before they can be marketed in the United States. The four that are currently approved for a variety of food uses are aspartame, saccharin, acesulfame potassium, and sucralose. Others are being evaluated. Aspartame is a nutritive sweetener, meaning that it supplies the body with energy in the form of calories, while the others are non-nutritive, that is, devoid of calories.

Aspartame
, which is 100 to 200 times sweeter than sucrose, is the main ingredient in NutraSweet and Equal. It is a combination of two proteins, aspartic acid and phenylalanine, and therefore contains the same four calories per gram as any protein and, for that matter, the same four calories per gram as sugar. But since it’s so much sweeter than sucrose, only a tiny amount does the trick.

Because an estimated one in 16,000 people suffers from the genetic disease phenylketonuria (PKU), in which the body cannot produce the enzyme necessary to digest phenylalanine, sweeteners that contain aspartame must carry a warning label stating: “Phenylketonuric: contains phenylalanine.” Other than for PKU sufferers, and in spite of e-mail and Internet campaigns to link aspartame with a whole flock of serious diseases from multiple sclerosis to brain damage, the FDA gives aspartame its no-strings-attached approval of safety in all but massive doses.

Saccharin
, which has been known for more than 120 years and is about 300 times sweeter than sucrose, is the artificial sweetening agent in Sweet’n Low.

Over the years, saccharin has had an on-again-off-again history of government approvals and bannings. The last round began in 1977, when the FDA proposed banning saccharin because of a Canadian study indicating that it causes bladder cancer in rats. But because saccharin has never been shown to cause cancer in humans, public opposition led the U.S. Congress to pass a moratorium on removing it from the market. The moratorium has been renewed several times, but products containing saccharin still had to carry a warning label saying, “Use of this product may be hazardous to your health. This product contains saccharin, which has been determined to cause cancer in laboratory animals.” Then early in 2001, following extensive studies commissioned by the U.S. Department of Health and Human Services, which found insufficient evidence that saccharin is a human carcinogen, President Bush repealed the warning requirement.

Acesulfame potassium
, sometimes written as
acesulfame K
, 130 to 200 times sweeter than sucrose, is the sweetening ingredient in Sunett and Sweet One. It is used in combination with other sweeteners in thousands of products worldwide. While approved by the FDA since 1988, it has been under attack by consumer watchdogs because it is chemically similar to saccharin.

Sucralose
, known also by its trade name Splenda, is 600 times sweeter than sucrose and was approved by the FDA in 1999 as a general-purpose sweetener for all foods. It is a chlorinated derivative of sucrose itself (Techspeak: Three hydroxyl groups in the sucrose molecule have been replaced by three chlorine atoms), but because it doesn’t break down significantly in the body, it provides no calories. Because tiny amounts are so potently sweet, it is usually bulked up with maltodextrin, a starchy powder.

All of these artificial sweeteners can be deleterious to health if ingested in very large doses. But in spite of the fact that the same statement can be made about every substance on Earth, including all our foods (ten pounds of popcorn, anyone?), each of these sweet chemicals carries as baggage a vociferous group of opponents.

Before we leave sugar substitutes, you may have noticed (if you read labels the way I do) the ingredient
sorbitol
in sugar-free candies and other foods. It’s neither a sugar nor a synthetic substitute, but a sweet-tasting alcohol found naturally in berries and certain fruits. It’s about half as sweet as sucrose.

Sorbitol has the property of holding on to water, and is used to keep many processed foods, cosmetics, and toothpastes moist, stable, and soft-textured. But because of that same property, too much sorbitol can act as a laxative by retaining water in the bowel. People who have overindulged in sugar-free candy have had cause to regret their intemperance.

B
ENEATH THE SURFACE OF
Hutchinson, Kansas, and thousands of square miles of its environs lies an enormous deposit of a precious rock-like mineral called halite. There, several huge mining operations extract almost 1 million tons per year, and that’s less than one-half percent of the world’s annual halite production.

What do we do with all that halite? Among other things, we eat it; it is the only natural rock consumed by humans. The other name for this crystalline mineral is rock salt. And unlike the crystals that some people carry around for their supposed healing powers, this is one crystal that really does keep us alive and healthy.

Common salt—sodium chloride—is probably our most precious food. Not only are its sodium and chloride parts (Techspeak: ions) nutrients that we can’t live without, but saltiness is one of our fundamental taste sensations. In addition to its own flavor, salt has the seemingly magical ability to enhance other flavors.

The word
salt
doesn’t describe a single substance. In chemistry, it is a generic term for a whole family of chemicals. (Techspeak: A salt is the product of reaction between an acid and a base. Sodium chloride, for example, results from the reaction of hydrochloric acid with the base sodium hydroxide.) Some other salts of gastronomical importance are potassium chloride, used as a salt substitute in low-sodium diets; potassium iodide, added to common salt to supply iodine in the diet; and sodium nitrate and sodium nitrite, used in curing meats. In this book, unless I indicate otherwise, I’ll do what everyone else does outside of the chemistry lab: use the word
salt
to mean sodium chloride.

In the face of so many different salts, can what we call “salty” really be the unique flavor of sodium chloride? Undoubtedly not. Taste one of the potassium chloride “salt substitutes” and you’ll describe it as salty, but it’s a different saltiness from the familiar flavor of sodium chloride, just as the sensation of sweetness is slightly different among different sugars and artificial sweeteners.

In addition to its roles as a nutrient and a condiment, salt has been used for thousands of years to preserve meats, fish and vegetables for consumption long after the hunt or the harvest was over.

In this chapter, while I can’t solve the mysteries of salt’s nutritional or savory qualities, I
can
tell you about the physical and chemical roles it plays in our foods, including preservation.

SALT STICKS

What’s so special about those expensive “popcorn salts” and “margarita salts” sold in my supermarket?

C
hemically speaking, absolutely nothing. They’re plain old salt: sodium chloride. But physically speaking, they’re either finer-grained or coarser-grained than ordinary table salt. And that’s all.

The number of specialty salts on the wholesale market is astounding. Cargill Salt, Inc., one of the world’s largest salt producers, makes about sixty kinds of food-grade salt for food manufacturing and consumer use, including flake, fine-flake, coarse, extra-fine, super-fine, fine-flour and at least two grades of pretzel. Chemically, all are 99-plus percent pure sodium chloride, but they possess special physical characteristics designed for use in everything from potato chips, popcorn, and roasted nuts to cakes, breads, cheeses, crackers, margarine, peanut butter, and pickles.

For margaritas, you want coarse crystals that will stick to the lime juice on the rim of the glass. (You do wet the rim with lime juice, don’t you? Not, Heaven forbid, with water?) Finer grains of salt would just dissolve in the juice. On the other hand, for popcorn you want exactly the opposite: fine, almost powdered particles that will nestle into the kernel crannies and stay put. Grains of ordinary salt-shaker salt don’t stick to dry foods; they bounce off like the fake boulders in an Indiana Jones avalanche.

But why pay a high price for ordinary sodium chloride with a come-hither label? Kosher salt is quite coarse enough to coat a margarita rim and works very well despite the ethnic mismatch. And for popcorn, I grind kosher salt into a powder with a mortar and pestle.

I get a particular kick out of the label on one brand of “popcorn salt” that sells for nearly $5 a pound. (Table salt sells for about 30 cents a pound). The label forthrightly declares: “Ingredients: Salt.” Well, that’s fair enough. But then it goes on to boast that it “also enhances the flavor of French fries and corn on the cob.” Big surprise.

A LITTLE TENDERNESS

I read the label on a jar of meat tenderizer and it was mostly salt. Does salt tenderize meat?

O
nly to a slight extent. But if you read further down the ingredient list, you’ll find papain, an enzyme found in unripe papayas. That’s what really does the job. All that salt is there primarily to dilute and spread out the relatively small amount of papain in the product on the assumption, I suppose, that it would be more welcome than sand.

Meat can be tenderized in several ways. A piece of fresh meat becomes more tender in the weeks following the moment at which it was transformed into fresh meat—to put it as delicately as possible. That’s why meat is aged—hung at controlled humidity for two to four weeks at a temperature of about 36ºF. Some meats are quick-aged at 68ºF for only 48 hours. But all aging, obviously, takes time, and time is money, so not all meats are even quick-aged before being shipped from the packing company. That’s a shame because aging not only tenderizes the meat but improves its flavor.

There are various enzymes in fruits, however, that have the property of breaking down protein and can be used to tenderize meat. They include bromelain from pineapples, ficin from fig trees, and papain from papayas. But they don’t penetrate the meat very far and mainly tenderize the surface, which isn’t much help to a steak. Also, they are destroyed by temperatures over 180ºF, so are effective only before cooking.

The solution? Find a butcher who sells well-aged meat (very hard to find these days) or buy the naturally more tender cuts. Of course, they’re more expensive.

And while you’re in the spices and seasonings aisle of the supermarket, check the labels on all those “seasoning mixes,” the Cajun seasonings, hamburger seasonings, pork seasonings, and the like. You’ll find that the primary ingredient, the first-named ingredient on the labels, is salt. Read down the list, buy one or two of the spices listed, and season the food yourself while cooking. No need to pay spice prices for what is mainly salt.

WHEN IS SALT NOT SALT?

What are all those salt substitutes that I see in the market? Are they safer than real salt?

“R
eal” salt is sodium chloride. The issue of safety revolves around its sodium content; no one has ever blamed the chloride for anything. The aim of all the substitutes is to lower or eliminate the sodium.

Sodium in the diet has long been suspected as a possible cause of high blood pressure, but there appears to be little consensus among medical researchers. Some believe that sodium contributes to high blood pressure and some don’t. While no smoking gun evidence has yet been uncovered, opinion seems to be swinging toward the sodium–is-bad side of the fence.

As in all health research, the worst that can be said of a dietary practice is that it increases the risk of something or other. That doesn’t mean “eat it and die.” Risk is only a probability, not a certainty. Nevertheless, cutting down on sodium may well be a prudent thing to do.

The medical uncertainties haven’t stopped our vast national food mill from grinding out fear-of-sodium products. Salt substitutes are usually potassium chloride, a chemical fraternal twin of sodium chloride. It tastes salty, but with a different kind of saltiness. Both are members of a large chemical family called salts; we call sodium chloride “salt” as if it were the only one because it’s by far the most common. But you can hear chemists laughing as they pass the supermarket shelf where NoSalt is sold; it is potassium chloride, an honest-to-god chemical salt, but its label claims that it is “salt-free.” That’s only because the FDA allows labels to use the word
salt
to mean sodium chloride and nothing else.

Morton’s Lite Salt Mixture is a 50-50 mixture of sodium and potassium chlorides, for those who want to cut down on sodium but retain some of sodium chloride’s unique flavor.

And finally, there is Salt Sense, which claims to be 100 percent “real salt” (meaning real sodium chloride), yet also purports to contain “33 percent less sodium per teaspoon.” That statement is disconcerting to a chemist, because sodium chloride is made of one atom of sodium plus one atom of chlorine, which means that sodium chloride must always contain the same percentage of sodium by weight: 39.3 percent. (It’s less than 50 percent because the chlorine atom is heavier than the sodium atom.) So there’s just no monkeying around with how much or how little sodium “real salt” contains. It would be like claiming that a certain dollar contains less than 100 cents.

So what’s the trick? It’s in the word
teaspoon
. A teaspoon of Salt Sense does indeed contain 33 percent less sodium, because a teaspoon of Salt Sense contains 33 percent less salt. Salt Sense consists of salt crystals that are flaky and fluffy, so they don’t settle down into the spoon as much as ordinary granulated table salt does. So if you use the same volume, or bulk, of Salt Sense that you do of ordinary salt, it’s actually less weight and, hence, less sodium. It’s just as if a brand of ice cream claimed to have 33 percent fewer calories per mouthful because it’s frothed up with more air (yes, they do that) and there is therefore less ice cream in a mouthful.

In tiny print at the bottom of the Salt Sense label, there’s a footnote: “*100 grams of either product [Salt Sense or regular salt] contains 39,100 milligrams of sodium.” Right. When you take equal weights, rather than an equal number of teaspoonfuls, Salt Sense is nothing but salt with an additive: creative marketing. (Okay, you nitpickers, you’ve noticed that 39.1 isn’t exactly 39.3. That’s because Salt Sense is only about 99.5 percent pure.)

FASTA PASTA

Why do we have to put salt in the water before boiling pasta in it? Does it make the pasta cook faster?

V
irtually every cookbook instructs us to salt the water in which we cook pasta or potatoes, and we dutifully comply without asking any questions.

There is a very simple reason for adding the salt: It boosts the flavor of the food, just as it does when used in any other kind of cooking. And that’s all there is to it.

At this point, every reader who has ever paid the slightest attention in chemistry class will object. “But adding salt to the water raises its boiling point, so the water will boil hotter and cook the food faster.”

To these readers I award an A in chemistry but a D in Food 101. It’s true that dissolving salt—or really anything else, for that matter (I’ll explain)—in water will indeed make it boil at a higher temperature than 212°F at sea level. But in cooking, the rise is nowhere near enough to make any difference, unless you throw in so much salt that you could use the water to melt ice on your driveway.

As any chemist will be happy to calculate for you, adding a tablespoon (20 grams) of table salt to five quarts of boiling water for cooking a pound of pasta will raise the boiling point by seven hundredths of 1ºF. That might shorten the cooking time by half a second or so. Anyone who is in that much of a hurry to get the spaghetti onto the table may also want to consider rollerblading it from the kitchen to the dining room.