What Einstein Kept Under His Hat: Secrets of Science in the Kitchen (2 page)

T
O PARAPHRASE JOHN DONNE,
no writer is an island; he has editors.

It may not be universally realized that every word in a book or newspaper has been scrutinized and checked by at least one, and often as many as a dozen, pairs of eyes, whose invisible fingerprints (to muddle a couple of metaphors) are all over it.

While writing this book and its predecessor, I have benefited greatly from the wisdom, advice, and good judgment of W. W. Norton’s senior editor Maria Guarnaschelli, the personification of “tough love,” who acted not as a mere after-the-fact editor, but as a fond collaborator from the project’s inception to its completion. Without her guiding hand in the tasks of crafting and re-crafting its scope and organization, this book would not have been possible.

My gratitude has been earned also by Maria’s sharp and most capable assistant, Erik Johnson, for coordinating the many elements that go into the publication of a book, including nagging the author about deadlines.

Among the skillful professionals at W. W. Norton who turned my manuscript into a book, led by president Drake McFeely, editor-in-chief Star Lawrence, and managing editor Nancy Palmquist, are designer Barbara Bachman, jacket artist John Fulbrook III, art director Georgia Liebman, publishing director Jeannie Luciano, director of manufacturing Andy Marasia, production manager Anna Oler, sales manager Bill Rusin, and project editor Susan Sanfrey. The illustrations are the products of talented freelance artists Alan Witschonke and Rodney Duran. I thank them all.

My special appreciation goes to ultrameticulous copy editor Katya Rice, whose sharp eye and linguistic expertise (who else would write me an entire paragraph to justify a changed comma?) kept the text either immaculately syntactic or syntactically immaculate, and who would incisively have pointed out the difference.

I remain grateful to my literary agent, Ethan Ellenberg, who long ago encouraged me to write the book that became the first in my “Einstein Series.” The volume you are now holding is the fourth in what I had hoped might some day become a trilogy.

Until now, I have not availed myself of an opportunity to thank in print the people who over the years catalyzed my metamorphosis from chemist to writer.

For launching me on the very first step of my journalistic journey, I am grateful to Nancy Brown, editor of
The University Times,
the University of Pittsburgh’s faculty and staff newspaper, who asked me to write a column when I didn’t know I was capable of writing a column.

I am indebted to Mark Nordenberg, former dean of the School of Law and currently chancellor of the University of Pittsburgh, for perceiving enough of a writer in me to ask that I write profiles of distinguished alumni for the Law School’s alumni magazine.

And I shall always remember the late chancellor of the University of Pittsburgh Wesley Posvar, for recognizing the morale-building value of humor in a university, and for encouraging my satirical monologues at the university’s annual administrative conferences.

For the past seven-plus years,
Washington Post
food editors Nancy McKeown, Jeanne McManus, and Judy Havermann have granted me the privilege of writing for that august newspaper, the bright and curious readers of which have provided the grist for this book. I could never have imagined such an outcome while sitting in a one-semester journalism class at Fort Hamilton High School under the tutelage of the incomparable A. H. Lass.

A special hug goes to Paula Wolfert, who believed in me as a fledgling food writer, who encouraged me, and who gave me valuable advice.

And of course, my wife and coauthor, Marlene Parrish, deserves my admiration not only for the work she did on the recipes but also for enduring the deprivation of my company during my many months of slaving away at the computer.

Chapter One

Something to Drink?

....

W
HAT ARE THE FIRST TWO
things a server says to you as soon as you’ve been seated in a restaurant? (1) “Hello, my name is Bruce/Aimee and I’ll be your server.” (2) “May I bring you something to drink?”

Thus far, I have been successful in repressing the replies: (1) “Glad to meet you. My name is Bob and I’ll be your customer.” Or (2) “Thanks, but I came here primarily to eat.”

I concede that it would be useful to know the server’s name if it were permissible to summon him/her in time of need by yelling across the room, “Hey, Bruce/Aimee, over here!” But that would be boorish.

(When I lived in Puerto Rico, I found that it is perfectly acceptable to summon a server with a brisk “Sssst!,” which carries across the room but isn’t unduly disturbing to other patrons. It is quite effective and not considered the least bit vulgar. I highly recommend that we obtain Miss Manners’ permission to adopt that practice here in the States.)

I have often suspected that many people respond to the “Something to drink?” question by naming whatever liquid first comes to mind, from an apéritif or cocktail to iced tea and the ubiquitous Diet Coke, simply because they feel it’s expected of them. Or maybe they’re afraid to answer “Just water, please” because they dread the question that often follows, “Bottled or tap?,” which demands to be answered in a way that wards off the label “cheapskate,” like a priest brandishing a crucifix against a vampire.

When thinking about drinking, we must sidestep the all-too-common meaning of “a drink” in our society. “Let’s have a drink” is rarely an invitation to share a glass of carrot juice; it strongly implies the consumption of an alcoholic beverage. And a person who is said to “drink too much” certainly isn’t hooked on milkshakes. Drinking liquor has even captured its own verb,
imbibe
, which in reality has several other contexts that you’ll virtually never hear.

Look. You don’t need me to tell you the difference between eating and drinking, between solid food and liquid beverage. But let’s lay it all out on the table for detached and objective scrutiny, as if we were aliens just off the saucer from a planet where all food is gaseous and consumed by inhalation.

Drinking is the mechanism by which we “eat” liquids, as opposed to solids and semisolids. We take solid food into our mouths by biting it off or shoveling it in, if you’ll pardon the metaphor. On the other hand, we take liquids into our mouths by sucking—even from a glass. (Think about it.) Before solid food can be swallowed, it must be chewed and mixed with saliva to make it supple enough to slide “down the hatch.” Liquids, however, can go directly down the hatch without any pretreatment.

When we talk about drinks, we are talking primarily about water. All beverages that we consume are about 90 percent water, the universal liquid on Earth without which we cannot live.

Coke and Pepsi are 89 percent water by weight; milk and orange juice are 88 percent water; coffee and tea, more than 99 percent. Wines average around 87 percent, while 80-proof whiskey, because of its significant content of another liquid, ethyl alcohol, comes in at only about 67 percent water.

How does our physiology handle the ingestion of all these liquids?

Just behind the mouth in a region called the pharynx lie the openings of two tubes: the trachea for breathing and the esophagus, or gullet, for eating and drinking. Thus, swallowing, whether liquids or semisolids, can be a bit of a risky business lest they go down “the wrong pipe” and choke off our air supply. Nature has therefore provided us with a complex series of muscular reflexes, with valves or sphincters that open and close to propel our food and drink down the esophagus to the stomach, rather than into the trachea or up into the nasal cavity (except when children burst into laughter while drinking milk).

Having thus belabored the obvious for the benefit of any visiting aliens, let us begin our shared literary repast with a variety of “somethings to drink.”

Someone in my household (I have my suspicions) put a half-empty plastic bottle of cola in the freezing compartment of the refrigerator. When I discovered it a couple of days later, I was surprised to see that it had frozen into lacy crystals of pure white ice against a background of unfrozen brown. Why wasn’t the frozen cola brown, like the original liquid?

....

L
et’s follow the fate of the soda from the time that rascal put it in the freezer, probably with the misguided intention of keeping it nice and fizzy till the next attack of thirst.

All liquids turn into solids—that is, they freeze—when they get cold enough. Pure water freezes at 32°F (0°C), but your soda isn’t pure water. Far from it. It contains flavorings, phosphoric acid, coloring, and sweeteners—sugar, corn syrup, or artificial sweeteners.

Still, the vast majority of the molecules in the bottle are good old H
2
O. And when they are cold enough to freeze, they join together into a rigid network—a geometrically regular, three-dimensional arrangement of H
2
O molecules that we call ice. The molecules in ice are in fact so rigidly fixed in their places that they are hard to break apart from one another. Ice is therefore (surprise!) a much harder substance than liquid water.

With all those other non-H
2
O molecules cluttering up the place, however, the water molecules have a harder time finding one another so they can join together and form ice crystals. So the soda had to be cooled down past its normal 32-degree temperature before it was able to freeze.

But freeze it eventually did. The water molecules eventually slowed down enough to settle comfortably into their places. As they did, they were able to elbow aside all those foreign molecules, so the ice they formed was relatively pure. That’s the white ice you saw. All the “brown molecules” had been left behind.

Ice floes in the Arctic are made of relatively salt-free ice for the same reason, in spite of the fact that they were frozen from salty seawater.

When I make tea, it’s always beautifully clear when freshly made. But when refrigerated, it often turns cloudy. What causes that, and can I prevent it from happening?

....

T
ea leaves contain tannins, a loose collection of chemicals that give tea much of its flavor and body, and especially that astringent, puckering effect in the mouth. They dissolve in water to form a clear solution, as long as the water isn’t too cold or slightly alkaline.
*
Your cloudiness occurs when some of the tannins in the hot tea fall out of solution (
precipitate
) as tiny solid particles when the tea is cooled. Cloudiness can also form when certain tannins react with the caffeine in the tea.

Tannins are present to some extent in most plant materials but are particularly abundant in oak galls (abnormal growths on oak trees); certain barks, woods, and roots; and nut shells.

All tannins are soluble in water, but how much of them can dissolve in a given amount of water (their
solubilities
) depends on the temperature of the water and upon its acidity or alkalinity. When hot water is used to make strong tea (the usual first step in making iced tea), it extracts most of the tannins from the leaves. Then, when the solution is cooled down with ice cubes, all those tannins cannot stay dissolved, and they fall back out as fine, suspended solid particles that give the tea a cloudy appearance.

Tannins are more soluble in acidic solutions, so that when an acid such as lemon juice is added to tea, any solid particles of tannin will dissolve and the cloudiness will clear up.

Also, if the tea is initially brewed with hard water—that is, with water containing dissolved calcium or magnesium salts—these minerals can react with the tannins to form relatively insoluble complex chemicals that show up as flotsam and jetsam.

If your water is hard, then, try adding a little lemon juice to clear up any cloudiness. Or switch to a different tea, because some teas, such as Assam and Darjeeling, are richer in tannins and thus more prone to cloudiness than others, such as Ceylon.

There’s a lot of talk about green tea these days. But isn’t all tea green to begin with? Are there other tea plants with other-colored leaves, or are other teas picked after the green is gone? I bought some green tea the other day and it looks pretty black to me, not green at all.

....

A
ll tea comes from the same, one-and-only tea plant,
Camellia sinensis
, whose leaves certainly were chlorophyll-green on the living plant. But based upon how the leaves are processed, there are three types of tea: green, which is consumed mostly in the Far East; black, the favorite of the British and other Westerners; and oolong (“black dragon” in Chinese dialect), which is intermediate in flavor between the green and the black.

Beyond this, there are a bewildering number of names for dozens of kinds of tea based on their places of origin, the sizes of their leaves, or added flavorings such as jasmine, bergamot (in Earl Grey), and orange blossoms.

In all cases, the leaves are first plucked from the plant and encouraged to wither and lose moisture, usually by means of hot air or, more traditionally, by being exposed to the sun. After that, the green, black, and oolong teas take different paths.

Leaves destined to be sold as green tea are blasted with steam or roasted on iron pans in order to deactivate enzymes in the plant cells (see “What’s an enzyme?” on p. 12) and prevent the so-called fermentation that black and oolong teas undergo. The leaves for green tea are dried until the moisture content is about 3 percent, and then are crushed or powdered.