What Einstein Kept Under His Hat: Secrets of Science in the Kitchen
Read What Einstein Kept Under His Hat: Secrets of Science in the Kitchen Online
Authors: Robert L. Wolke
Also by Robert L. Wolke
TEXTBOOKS
Impact: Science on Society
Chemistry Explained
TRADE BOOKS
What Einstein Didn’t Know:
Scientific Answers to Everyday Questions
What Einstein Told His Barber:
More Scientific Answers to Everyday Questions
What Einstein Told His Cook:
Kitchen Science Explained
W. W. NORTON & COMPANY
New York London
I dedicate this book, as I have my life, to my wife,
companion, motivator, and most loving critic,
Marlene Parrish, who characterizes
herself as Einstein’s Cook.
| | CONTENTS | |
Chapter One • SOMETHING TO DRINK?
Why does iced tea turn cloudy? • How does green tea differ from other teas? • Are enzymes alive? • Can I make coffee and tea from the same kettle water? • Will coffee stay hotter if I put the cream in right away, or only when I’m ready to drink it? • What are alcohols? • What is a hop? • Why are there sulfites in wine? • What’s so special about Sherry? • Does hanging a spoon handle in the neck of the bottle keep Champagne from going flat? • Why do Champagne corks have that funny shape? • What makes bourbon bourbon? • Why does a mint julep glass turn frosty? • What’s the best way to cool a drink with ice without watering it down? • Is there a formula for telling when I’m getting dangerously drunk? • How can I get a red wine stain out of a tablecloth? . . . and more.
Chapter Two • DOWN ON THE FARM
What ever happened to skim milk? • Why are there so many types of dairy cream? • Does yogurt contain live bacteria? • Why is soft-serve ice cream soft? • Does eating ice cream in hot weather really cool one off? • Why does ice cream shrink when it melts? • Why does all cream cheese come from Philadelphia? • What makes American cheese American? • Does all cheese need to be pasteurized? • Why is string cheese so stringy? • How does a “nut” of butter thicken a pan sauce? • How are eggs graded? • Are brown eggs better than white eggs? • Does a blood spot in an egg mean it’s fertilized? • Would double-yolk eggs hatch twins? • How can I keep boiled eggs from cracking? • Why does a hard-cooked egg spin, but a raw egg won’t? • Why do hard-cooked egg yolks turn green? • What makes an egg rotten? • Why do eggs have dimples? • Can pasteurized eggs be used the same as unpasteurized eggs? • Are thousand-year-old eggs for real? . . . and more.
Chapter Three • WHATSOEVER A MAN SOWETH . . .
What makes the vivid colors in vegetables? • Why do green vegetables turn drab when cooked? • How should fruits and vegetables be washed? • Why do some potatoes have gray patches? • Is rhubarb poisonous? • How do vegetables get their minerals? • Why do onions
really
make me cry? • Why are “sweet” onions sweet? • Why is my cucumber bitter? • Why does heated soy milk boil over? • How do they make tofu? • What is miso made of? • Why do beans and other legumes produce gas? • Must beans be soaked before cooking? . . . and more.
Chapter Four • ABOVE THE FRUITED PLAIN
How can I speed up the ripening of fruits? • Why does a cut apple turn brown? • When a banana ripens and gets sweeter, does it contain more calories? • Why are some oils edible and others not? • Exactly what are trans fats? • Why do fats turn rancid? • What is a free radical? • Does light olive oil contain fewer calories? • What’s “extra” about extra-virgin olive oil? • What is a fatty acid? • What’s the difference between black and green olives? • How does osmosis work? • Why did my strawberry preserves turn out soupy? • Do all fruits float? • What’s the difference between apple juice and apple cider? • Are “raw” cashews raw? . . . and more.
Chapter Five • FOR AMBER WAVES OF GRAIN
What are the different forms of carbohydrates? • What makes mashed potatoes gluey? • Why do leftover starchy foods turn hard in the refrigerator? • Is there an easy way to use chopsticks? • What is converted rice? • Why does unbleached flour cost more than bleached flour? • How does self-rising flour raise itself? • What kind of wheat is buckwheat? • How can I best match a pasta shape with a sauce? • Is the nutritional fiber destroyed when I liquefy fruit in a blender? • Which kinds of fiber contain calories and which don’t? • What is “steel cut” corn meal? • Why do tortillas contain lime? • What are sugar alcohols? • What is stevia? • Why mustn’t babies be fed honey? . . . and more.
Chapter Six • FROM SEA TO SHINING SEA
Why are wild and farm-raised salmon different colors? • Why do they treat tuna with carbon monoxide? • Do they really make fake scallops by punching out skate wings? • How does lime juice “cook” ceviche? • What do I do with
bottarga
? • What kinds of mussels are there? • Are razor clams good to eat? • How do wet, dry, and diver scallops differ? • Why are shrimp different colors? • Why is shrimp scampi called that? . . . and more.
Chapter Seven • A CARNIVAL FOR CARNIVORES
Is “mechanically separated meat” dangerous? • Why is my supermarket’s hamburger meat red on the outside and brown on the inside? • Does marinating work? • What is souse? • Why are there rainbows on my roast beef? • Why are hot dogs pink? • Are nitrites dangerous? • Exactly what is braising? • What’s the difference between browning and caramelizing? • Why does food turn brown when sautéed? • Why are there so many precautions about making a stock? • Where does simmering end and boiling begin? • Does adding lemon juice to a stock increase its calcium content? • Why do we cook with wine? • Which is better for grilling, charcoal or gas? . . . and more.
Chapter Eight • SPICE IS THE VARIETY OF LIFE
What’s essential about an essential oil? • What makes spices spicy? • Why is cooked garlic so different from raw garlic? • Is garlic powder an invention of the Devil? • Can garlic-infused oil be dangerous? • Should herbs be added near the beginning of cooking or near the end? • How much dried herb shall I use instead of the fresh herb? • What is the average shelf life of an herb or spice? • How do pantry-pest bugs survive in a can of Cayenne pepper? • How do they make liquid smoke? • Is wasabi real? • How can I keep grated horseradish “hot” in the refrigerator? • Why did grinding cloves destroy my spice grinder? • How does a salt pig work? • Why is vanilla so expensive? . . . and more.
Does a box of baking soda in the refrigerator kill odors? • Where should I keep my butter? • Why do foods spoil? • Do airport X-rays sterilize foods? • What’s killing my aluminum cookware? • Exactly what is an emulsion? • Is heat the ultimate form of energy? • Why do broilers give such inconsistent results? • In a microwave oven, why don’t two potatoes take twice as long to cook as one potato? • What’s so special about a brick oven for baking breads and pizzas? • Why do glass and metal baking pans require different baking times? • How do ovens cook food? • What is silicone? • How does the shape of a roast affect roasting time? • Does slow, low-temperature cooking use more or less energy than fast, high-temperature cooking? . . . and more.
What’s the difference between heat and temperature? • What’s the difference between melting and dissolving? • What is a “natural flavor”? • Why can’t I pour all the milk out of a carton in one try? • What are marshmallows made of? • What does the “percent” number mean on a bar of chocolate? • How does tempering chocolate change its properties? • What is that white, moldy-looking coating on my chocolates? • Is carob a form of chocolate? . . . and more.
| | INTRODUCTION | |
T
HIS IS THE SECOND
food-focused book, and the fourth book overall, in what has turned out to be my “Einstein series,” a series I didn’t anticipate when I started it. But then, I have never planned the courses of my careers. I simply followed the advice of Yogi Berra—whenever I came to a fork in the road, I took it. A succession of forks has led me from teaching and research in nuclear chemistry to textbook authorship, university administration, journalism, and trade book authorship, where you now find me. It was some years ago that I left my academic career to spend my full time writing, a love of mine equal to my loves of science and teaching. The “Einstein” books are one result.
But why would a chemistry professor write about food? For one thing, good food has intrigued me ever since I first encountered it—not at my mother’s knee, but some twenty years later in graduate school. Cornell University’s College of Home Economics (now the Division of Nutritional Sciences) operated a cafeteria in which the products of the students’ cooking classes were sold at prices that a graduate assistant could afford. The menus included foods that I had never before seen, prepared with the care and dedication that only a prospective grade of A could inspire. It was perhaps predictable that I should one day marry my loves of science, teaching, writing, and food, and nestle them between the covers of books. The crowning stroke of fortune was my marriage to a fifth love (in order of chronology, not priority): Marlene Parrish, a restaurant reviewer and culinary journalist full of passion for . . . well, everything that I have passion for.
IN 1935,
when Albert Einstein first walked into his kitchen at 112 Mercer Street in Princeton, New Jersey, he of course saw a stove. But in his mind he also saw an apparatus for transforming the chemical energy in wood or gas into thermal energy and for conveying that thermal energy into a chicken. None of which, of course, diminished his subsequent enjoyment of the chicken, but all of which probably added an extra bit of spice to his dinner, a spice undetected by less scientifically tuned intellects.
Science is a sort of intellectual spice that adds depth and allure to everyday things, not the least of which is food. Food, of course, gives us pleasure and nourishment. But
understanding
our food—where it came from, what it is made of, what happens when we cook it, all in the contexts of the many experiences and circumstances that make up the world of gastronomy—nourishes our minds and adds immensely to our enjoyment of cooking and eating.
The cliché has it that cooking is chemistry. True, but other sciences bear equally on what goes on in our kitchens. There is the physics of heat transmission, the mechanics of whipping and emulsifying, the microbiology of fermentation, the anatomy of meats, the engineering of utensils and equipment, and the technology of producing and packaging prepared foods—all preceded by the agronomy and animal husbandry that take place on our farms. Kitchen science is not the mere chemistry of cooking. It involves a lot of what I call thinking outside the pot.
This book, then, is a truth-seeking exploration of the farm, the market, and the kitchen by a scientist—not, most assuredly, an Einstein, but a scientist with a congenital curiosity about everything he sees and an urge to share the joy of knowing with others.
THE ENTHUSIASTIC RECEPTION
accorded the first volume of
What Einstein Told His Cook
, together with the limitless number of opportunities for scientific scrutiny in the world of food, has inspired the present sequel. Unlike its predecessor, which focused mainly on specific foods such as sugar, salt, and fats, the present volume is organized into eight major food categories: beverages, dairy and eggs, vegetables, fruits, grains and carbohydrates, seafoods, meats, and herbs and spices. There is also a chapter on kitchen tools and equipment and a concluding chapter offering a handful of lagniappes to please not the diner’s palate but the reader’s inquiring mind.
As she did for the previous book, my wife, Marlene, has wrought and thoroughly tested (on me) about three dozen tempting and accessible recipes that put the scientific principles to work in the home “laboratory.”
And as in the earlier volume, the questions come mainly from readers of my
Washington Post
column, “Food 101,” and thus represent the concerns of real cooks and consumers, who are often bewildered by the products and labels vying for their attention in today’s multifarious food markets. It is a rare privilege for an author to be in direct correspondence with a cross section of his readers, so that he can tailor his writing to their specific needs and concerns.
One of the most difficult decisions to be made in writing a popular science book is at what level to pitch the scientific explanations. Too high a level will of course lose the less scientifically sophisticated readers. But I see no corresponding danger in writing for those who have studied no science beyond the bare minimum required in most school curricula, and who will readily admit that even that much “didn’t stick.” I therefore write for the latter type of reader without apology, having been told by scientists, engineers, and chefs that even they have learned from my previous books. For that segment of my audience, I dig into my bag of teaching tricks to employ novel explanatory approaches that can generate fresh insights.
Teaching in a book (and that’s what I’m doing) is different from teaching in a classroom. Each Q&A unit in this book, which can be read independently, launches a new issue requiring a new explanation. But science is a continuum; it doesn’t come in discrete pieces, like M&M’s. Hence, when explaining one concept I have often found it necessary to restate, very briefly, a closely related one that had been covered earlier. Otherwise, the unit would be incomplete and unsatisfying. So please note that I do this intentionally. It’s one of my teaching tricks.
I have explained all concepts in nontechnical language, using similes and metaphors related to everyday life whenever possible. Nevertheless, I do present the pertinent scientific terminology in italics within parentheses, so that the reader can relate it to his or her other readings and, if desired, follow up on it in more technical references.
I believe that words, which of course are only symbols for concepts, are often more easily understood if their origins are known. For that reason I have included the etymologies (and occasionally the pronunciations) of some of the scientific terms that might otherwise intimidate the uninitiated.
The current volume is somewhat deeper and richer in science than the previous one, in recognition of the growing appetite for science among foodies, both avocational and professional. I have set aside the more technical details, however, in sections that I call “Sidebar Science,” which each reader may choose to read or skip, depending on the depth of his or her scientific interests. Skipping them will not interrupt the continuity of the text, especially since the Q&A units are designed to be read independently, wherever one may chance to open the book.
If, as Miguel de Cervantes wrote in
Don Quijote de la Mancha
, hunger is the best sauce in the world, then humor is the best
digestif
. In my opinion, there are few subjects or circumstances that cannot be made more palatable and digestible by being seasoned with humor. As food and cooking can be fun, so can—and should—science. In this vein I have not restrained myself (very much) from injecting a wry observation wherever I deemed it appropriate. At the risk of disaffecting pun haters, I have also scattered “Foodie’s Fictionary” definitions throughout the book like truffles (or nettles?) in a forest.
After all, one cannot enjoy food without at times putting one’s tongue in one’s cheek.
NOTE:
This book is all-natural and has not been tested on animals
.