What Einstein Told His Cook (15 page)

But hey, if you find a bottle of vinegar labeled “balsamic” that you like, no matter how modest the price, stick with it and use it however you like.

HERE’S HOW ALL VINEGAR
“happens,” whether spontaneously in Nature or induced deliberately by humans.

There is a two-step sequence of chemical reactions: (1) sugar is broken down into ethyl alcohol and carbon dioxide gas, and (2) the ethyl alcohol is oxidized to acetic acid. The first transformation, called fermentation, is what makes wine out of grape sugars and innumerable other alcoholic beverages out of innumerable other carbohydrates in the presence of enzymes from yeast or bacteria. In the second transformation, bacteria known as
Acetobacter aceti
help the alcohol to react with oxygen in the air to form acetic acid. Wines can become oxidized, and therefore sour, without
Acetobacter
, but it’s a slower process. The word
vinegar
, in fact, comes from the French
vin aigre
, meaning sour wine.

You can make vinegar at home from wine or other alcoholic liquid by adding a small amount of vinegar containing a mass of vinegar bacteria, called mother of vinegar, to start the reaction. For everything else you need to know about making vinegar, visit Vinegar Connoisseurs International at www.vinegarman.com.

Commercial vinegars range from 4.5 to 9 percent acetic acid, with most of the common ones at 5 percent. At least that strength is necessary for preserving foods by pickling, which is one of vinegar’s most venerable uses, since most bacteria cannot thrive in acids of this strength or stronger.

A few words about acids, while I’m in the neighborhood. People tend to think of the word
acid
as being almost synonymous with
corrosive
. They’re undoubtedly thinking of the mineral acids, such as sulfuric acid and nitric acid, which could indeed dissolve a Volkswagen. But we can eat acetic acid with no ill effects for two reasons: One, it is a weak acid and two, vinegar is a pretty dilute solution of it. One hundred percent acetic acid is quite corrosive, actually, and you wouldn’t want to get any of it on your skin, much less on your salad. Even at 5 percent, vinegar is the second strongest acid in the kitchen, after lemon juice.

What does vinegar do? What
doesn’t
it do, at least ostensibly? Folk medicine abounds with claims that it cures headaches, hiccups, and dandruff; soothes sunburn and bee stings; and, to quote an advertisement that I found on the Internet for a Chinese rice wine vinegar, “is the secret to longevity, tranquility, balance, and strength.” Believers in these and similar folk remedies will zealously inform you that science has been unable to prove that they don’t work. The reason, of course, is simply that scientists have better ways to spend their time than chasing after such will-o’-the-wisps.

BEWARE OF BUDS ON SPUDS

Will a potato with green skin eventually ripen?

N
o, no, no. It’s not green because it’s unripe; potatoes are ready to eat at any stage of growth. And they’re not flaunting the green because they’re a traditionally Irish food. The green color is Mother Nature’s Mr. Yuk sticker, warning us of poison.

Potato plants contain solanine, a bitter-tasting member of the notorious alkaloid family, a group of powerful and toxic plant chemicals that includes nicotine, quinine, cocaine, and morphine. Most of the solanine in potato plants is in the leaves and stems, but smaller amounts are found in and under the skin of the tuber and to a lesser extent in the eyes.

If an underground-dwelling potato is accidentally uncovered during growth, or even if it’s exposed to light after its disinterment, it thinks it’s time to wake up and start photosynthesizing. So it manufactures chlorophyll and becomes tinged with green on the surface. It also manufactures solanine in the same location.

While solanine won’t hurt you unless you eat a lot of it, it’s always prudent to cut away and discard the green parts; the rest of the potato will be perfectly okay. Or, because the solanine is concentrated near the surface, you can get rid of most of it by peeling the potatoes rather heavy-handedly. But don’t buy a bag of potatoes that has more than a few green areas, because it’s a nuisance to cut them all away.

The solanine level goes up when the potato has seen better days and is wrinkled or spongy. So by all means toss out those sad-sack spuds that you’ve been storing too long. As for the sprouted ones, the sprouts are particularly rich in solanine, especially when they start to turn green.

Potatoes keep best in a dark, dry, and cool place, but not too cool. At refrigerator temperatures, they tend to manufacture solanine. They also convert some of their starch into sugar, which produces a peculiar sweetness and makes them turn brown when fried.

GREEN AROUND THE FRILLS

Why do some potato chips have green edges? Are they okay to eat?

T
hose chips were sliced from green-surfaced potatoes, and they therefore contain small amounts of toxic solanine, which is not destroyed by frying. It’s okay to eat them, because in order to experience any ill effects you’d have to eat so many bags of chips that you’d turn greener around the gills than they are around the frills.

Oh, and if you think you can check out the potato chips in the store to see how many green-edged ones there might be in a package before buying it, think again. Have you ever noticed that potato chip bags are always opaque, unlike the bags of pretzels and other snacks that often let you see the contents? That’s not to foil prying eyes, but to keep out ultraviolet light, which speeds up oxidation of the fat in the chips, turning it rancid. All fats and cooking oils, in fact, should be kept out of strong light.

Bags of potato chips are also usually filled with nitrogen gas to displace oxygen-containing air. That’s why they are puffed out like balloons. Of course, cynic that I am, I must point out that opaque, ballooned-out packages take up more display space and prevent us from realizing that they may be only about half full.

AVOIDING THE EVIL EYE

Whenever I peel potatoes I feel I’m flirting with death, ever since a well-meaning friend told me that the eyes are poisonous and that I’d better be careful to get them all out. How dangerous are they?

N
ot as dangerous as some well-meaning friends who spread scary stories. But there is a small grain of truth to the story.

When potatoes were introduced into Europe in the second half of the sixteenth century, they were suspected of being either poisonous or aphrodisiac or—an intriguing thought—both. (What a way to die!) Europeans tended to think the same of any exotic food from the New World, including tomatoes. (Their scarlet color no doubt helped to provoke the French into calling them
pommes d’amour
, or love apples.)

But we must let the suspicious Old Worlders off lightly, because both potatoes and tomatoes are indeed members of the same family, the nightshade, whose most infamous and deadly poisonous member is the belladonna plant.

I can’t help pointing out here that in Italian,
bella donna
means “sweetheart” or “good-looking woman.” Why was the plant so-named? Because it contains atropine, an alkaloid that dilates the pupils of the eyes. It was used (the story goes) by sixteenth-century Italian women as a cosmetic to simulate sexual arousal.

Fast-forward to the twenty-first century and your well-meaning friend. The toxic alkaloid solanine, normally present in small amounts in potatoes, does build up in the eyes when they sprout. So eyes that are beginning to sprout should certainly be excised, and most especially if they have started to turn green. But even then, the solanine doesn’t lie very deep, and an ordinary gouge with the paring knife will take care of it.

HOMINY GRITS DOES IT TAKE TO EDUCATE A YANKEE?

Here in the South, the starch on our plates is often hominy grits instead of potatoes or rice. But I understand that they’re made with lye. Isn’t lye a very corrosive chemical used in drain cleaners?

Y
es, but it has been thoroughly washed out before the grits ever get near your breakfast plate.

The word
lye
is related to the Latin for
wash
, and originally referred to the strong alkaline solution obtained by soaking, or washing, wood ashes in water. (The alkaline material in wood ashes is potassium carbonate, and because alkalis and fats react to form chemicals called soaps, early soaps were made from wood ashes plus animal fat.)

Today, lye refers most often to caustic soda, which chemists call sodium hydroxide. It certainly is nasty stuff. Not only is it poisonous, but if given the chance will dissolve your skin. It opens drains both by converting grease into soap and by dissolving hair.

If you soak corn kernels in a weak solution of lye, it loosens the tough cellulose hulls. It also separates the oil-containing germ, leaving only the starchy part or endosperm, which is then washed and dried and christened hominy. The anxiety-alleviating step in all of this is the thorough washing, which removes all the excess lye. The dried hominy is then coarsely ground into hominy grits, which are boiled and consumed below the Mason-Dixon Line.

A less powerful alkali than caustic soda is lime (calcium oxide), which also can be turned loose upon corn kernels to break them down, such as in making hominy. Lime is so easy to make by heating limestone or seashells (calcium carbonate) that it has been known and used for thousands of years. Natives of the Americas used it for centuries to treat or cook corn. In Mexico and Central America today, corn is boiled in lime water, then washed, drained, dried, and ground into masa, the flour from which tortillas are made.

Unknowingly, the early Americans were improving both the flavor and the nutritional value of corn by treating it with lime. Corn is deficient in certain essential amino acids, and the alkali makes them more available. Lime reacts with the amino acid tryptophan, producing a very flavorful chemical (2-aminoacetophenone) that gives tortillas their unique flavor. Lime also adds calcium to the diet, and perhaps most importantly, increases our absorption of niacin, an essential B vitamin.

A deficiency of niacin in the diet causes pellagra, a debilitating disease characterized by three D’s: dermatitis, diarrhea, and dementia. Pellagra was rampant in societies whose diets consisted primarily of corn, such as in polenta-consuming Italy and the rural American South, until 1937, when the disease was recognized as being caused by a deficiency of niacin. Because of their lime treatment, Mexicans and Central Americans have always been quite free of pellagra.

But back to the gritty details: Having been raised in the grits-deprived North, but being acutely aware of the fact that this book is being offered for sale also in the South, I hasten to praise a memorable brunch that I once enjoyed in the Cajun country west of New Orleans. It consisted of mimosas, fried eggs, grits, andouille sausage, grits, biscuits, grits, and
café au lait
. I was converted.

Want to know more about grits? Go to (where else?) www.grits.com. And that’s no lye.