For a group intent on nothing less than changing the course of culinary history, the foodophiles gathered in the ancient Sicilian mountain town of Erice are a rather odd crowd. Here's a Michelin one-star chef from Britain who makes ice cream out of foie gras and kickboxes to keep in shape for the kitchen. Over there is a physicist from the University of Bristol who has a penchant for shirts emblazoned with pictures of penguins. A 300-pound restaurateur from Philadelphia stands nearby, his arms a mass of tattoos. At the moment, they and a throng of assorted chemists, food industry scientists, and cookbook writers are huddled together beneath the weathered brick arches of a 15th-century monastery, where they are taking turns prodding soggy slices of eggplant in a frying pan.
They all have the same questions: If you salt and drain eggplant before you fry it, will that prevent it from soaking up oil, as cookbooks sometimes suggest? And will that make the eggplant less bitter, which many cookbooks suggest? The participants agree there's another question that's almost more important, at least in the spirit of this unusual conference: What are the scientific reasons why?
Welcome to the fifth International Workshop on Molecular Gastronomy, dedicated to the proposition that if you teach chefs more about the science of protein strings and hydrogen bonding, they'll be able to take their art to higher levels.
"Most chefs have no scientific background … none," says Jean Matricon. His rebellious white hair, bushy beard, and red suspenders make him look like a cross between a nuclear scientist and an Amish farmer; in fact, he's a noted French physicist who has spent decades trying to develop dramatic new ways of conducting electricity at super-low temperatures. At the moment, though, he's more enthralled with these slabs of eggplant. "Even the great chefs learned to cook by being told what to do, by following tradition, and by trial and error, but they don't understand why things happen," Matricon says. "They're too proud to ask."
One of the impromptu lab assistants, British food writer, broadcaster, and novelist Leslie Forbes, has just finished measuring the olive oil left in the pans after frying. She summarizes the laboratory method: Sliced eggplants half an inch thick. Salted them and drained one hour. Squeezed off beads of liquid. Fried slices in 20 milliliters of olive oil.
The results are striking: The salted slices have absorbed only a fraction of a teaspoon of oil. They taste fresh and light yet almost meaty, with a touch of spring to them and the faintest crackling of a crust. But the unsalted slices are greasy and limp. They've soaked up almost all the olive oil.
"This is pretty much what I expected," says a man who looks as if he might teach Shakespeare in college—and the throng looks to tweedy, bearded Harold McGee for an explanation. Just about everyone at this conference will tell you that McGee profoundly affected their culinary lives back in 1984, when he published his landmark On Food and Cooking: The Science and Lore of the Kitchen. McGee unearthed extensive laboratory evidence, which was essentially hidden away in academic and food industry journals, and used it to demolish some of the cherished myths of the kitchen. He's probably most famous for shattering the axiom that searing meat "seals in the juices"
At the moment, McGee is deconstructing the eggplant—which makes me nervous, since I got a C in chemistry. McGee, though, has a way of turning science into plain English. "Eggplants tend to soak up oil basically because they're constructed like sponges," he says. "Their cells contain water, but there are lots of big air pockets between the cells." And those air pockets are all-important: When you cook the eggplant, the heat squeezes the air out of those pockets, so they become like millions of empty containers—and the oil oozes into them.
When you salt eggplants before you cook them, McGee says, the salt draws water out of the cells, so the cells collapse (it has to do with positive and negative ions, but that's getting too scientific). In turn, the air pockets between the cells collapse—so there are no more empty containers to soak up the oil.
Now you know the answer: Salt works wonders on eggplant. So does any method that punctures the cells and those air pockets—in fact, McGee says he cooks eggplant slices for a few minutes in a microwave before he fries them, and it accomplishes the same thing.
And forget the canard about drawing out the bitterness. If the eggplant is bitter, any water you draw out will contain some of that bitterness, but there's so much water still left inside the eggplant that you won't taste the difference. "If you start with bitter eggplant," McGee says, "you'll end with bitter eggplant." The scientists around him nod and harrumph.
The one-star chef from Britain nudges me and raises his eyebrows toward McGee. "That man changed my life," he says. "And my cooking."
Tomorrow, everyone will regroup for the next workshop topic: Can bakers apply chaos theory—which mathematicians use to study the origins of the universe—to learn how to get better air bubbles in a baba au rhum?
First, let's take a break.
The international workshop on Molecular Gastronomy might never have been organized if it weren't for World War II, the atomic bomb, and a frustrated magazine editor in Paris.
Back in the 1930s, a brilliant Jewish physicist named Nicholas Kurti left Europe a step ahead of the Nazis. He ended up in Los Alamos working on the U.S. government's secret project to develop the weapons that destroyed Hiroshima and Nagasaki. People who confront disaster and dying in their work often have an acute zest for living, and Kurti went on to become an irrepressible gourmet. More than that: He became passionate about the idea that scientists spend too much time investigating arcane mysteries at the fringes of the cosmos when they could be using their genius to make life more pleasurable here on earth.
Kurti demonstrated his point in a speech more than 30 years ago to some of the world's leading scientists, at the Royal Institution, in London. He hooked up scientific instruments to a mixture of whipped eggs and sugar and liqueur, and showed how the goo's internal temperature rose and fell as he baked it. "I think it is a sad reflection on our civilization," Kurti told his audience, "that while we can and do measure the temperature in the atmosphere of Venus, we do not know what goes on inside our soufflés."
As Kurti got older, it looked as if he might never realize his dream of getting scientists and cooks to collaborate. But then he met a kindred spirit, a younger man named Hervé This, who tells me his story one evening after we've left the workshop "Parameters That Control the Texture of Gels." "At the time when I met Nicholas, I was like Dr. Jekyll and Mr. Hyde," says This. "During the day, I was editing the French edition of Scientific American, and at night I went home to my kitchen where I have a lab, and I did scientific experiments to improve the way we cook."
As This warms to his topic, the disconnect between science and cooking, he leans across the table to make his points; he's movie-star handsome, in a boyish way, and when he revs up, his eyes go to afterburners. "It's indecent that we cook as people did in the Middle Ages," he says. "They had whisks. They had pans. They had stoves. The microwave is the only really new kitchen tool we've had in the past five hundred years. But in the science laboratory, ooh-laaa … we have many tools that could do wonderful things in the kitchen."
He rattles through a veritable catalog of scientific equipment, which he actually uses to churn out dinners for his family. Forget that obsolete business of straining sauces through wire mesh and clarifying consommé by adding egg whites: This uses a chemist's filter spun from glass, and he produces crystal-clear liquids almost instantly. He would never emulsify homemade mayonnaise with a whisk—or, worse, bruise the ingredients in a processor. "I put the egg yolk and oil and other ingredients in a laboratory ultrasound box," he says, "then press a button, and in two seconds—poof!" The high-frequency sound waves whip the ingredients like millions of miniature beaters. "My mayonnaise is perfect.
"But I was explaining to you about Nicholas," he says. When This, the young, charismatic editor, met Kurti, the old, charismatic physicist, the two men bonded. More importantly, they agreed to launch a crusade to convince chefs that science could lead them into the new millennium. The pair tracked down a group of soul mates in the U.S. and Europe, and in 1992 they all went up to the mountaintop in Erice—and the era of "molecular gastronomy" was born.
Over the next four days, the molecular gastronomists often veer toward the surreal. A British scientist named Robin Heath shows a bizarre film that looks like something out of a 1950s horror movie. His lab, which is funded by the British government and major food companies, has cajoled some poor volunteers into sitting in front of a camera that takes X-ray movies of their heads. So we sit there like voyeurs and peer into some man's skull and jawbones projected up on the screen. We stare right into his mouth as he chews various foods, moistens them with saliva, and tosses the balls of glop around with his tongue, which looks a writhing snake. Until he mercifully swallows.
"We're learning that people perceive flavors differently depending on how they chew their foods," says Eric Dransfield, who's doing similar work at the National Institute for Agricultural Research, in France. His lab, determined not to be outdone by the British, wires electrodes to its victims' faces and jaws, and measures exactly the amount of force the various muscles of the head exert when people chew. When the researchers spike a food with bold flavors—like quinine—the subjects who chew vigorously, with lots of force, rate the foods as much more bitter than do those who chew slowly and with finesse.
Group question: Does this mean that chefs will have to tailor their seasonings to diners' chewing styles?
When you get a few dozen scientists and chefs in the same room, of course, you can't always expect the conversation to go smoothly. Or civilly. The physicists tend to wander off into the stratosphere. One day, they erupt into an argument (which starts to turn bitter) about which principles of physics are at work when you beat egg whites into fluff: Are you exerting shearing forces or extensional flow? (You'll have to look it up in a textbook.)
As Harold Mcgee wraps up his talk on better grilling through computer-monitored heat-diffusion techniques (see box at left), one of the participants looks as if he can barely stay in his seat. It's Heston Blumenthal, the 35-year-old kickboxer whose restaurant on the Thames has led British critics to rave about him and led the Automobile Association Restaurant Guide to recently name him Chef's Chef of the Year.
"I think Harold's experiment confirms some of the principles that I've already been working on in my restaurant," Blumenthal says. And as this muscular young man with a blond buzz cut modestly lays out his philosophy—explaining the zany method he's developed to cook his signature tenderloin of lamb, describing how chemists and physicists across Europe are helping him take meat and potatoes where no meat and potatoes have gone before—the molecular gastronomists start to murmur and trade meaningful looks. "Heston's the future of our movement," one of them whispers.
After the Erice conference, I make a pilgrimage to the Thames Valley to taste the future of molecular gastronomy. Blumenthal's restaurant, The Fat Duck, is tucked away in Bray, another lovely village with ancient credentials, and occupies a 460-year-old building that used to be a pub: whitewashed walls, splashy abstract paintings, worm-eaten ceiling timbers.
When Blumenthal took over the restaurant, he says, he served classic French dishes that he learned as a teenager, when he got himself a Larousse Gastronomique and cooked his way through the book. Maybe he would still be cooking that way if he hadn't gone crazy one day over a pot of boiling water and green beans. When he salted the water to fix the color—as cookbooks had taught him—his haricots turned an embarrassing khaki-yellow. He experimented further, deleting the salt and then substituting bottled water for tap. Greener beans were his. But why? He rang up the nearest physicist. Who happened to be Peter Barham, the man with the penguin obsession at the Erice conference.
"I pick up the phone," says Barham, "and I hear, 'Hello, I'm a chef. Is there any good reason why I should add salt when I'm boiling vegetables? And should I use bottled water?'" Barham trekked to The Fat Duck like a doctor making a house call, and he and Blumenthal diagnosed the haricot disease: The restaurant's tap water was loaded with calcium, and the mineral was zapping the vegetable's chlorophyll. Filtering the water solved the problem.
"I'd been rubbish at science in school," Blumenthal says, but now he sensed that chemistry and physics could help him reshape the way he cooked. He started hanging out with Barham in the kitchen, playing around with wild ideas, and the physicist introduced him to a network of European scientists who are intrigued by the notion of helping a real-life chef.
Consider the matter of the mashed potatoes and the artificial nose machine.
Blumenthal had been mulling over a problem that had been floating on the fringes of his culinary consciousness. When he made a potato purée he was never satisfied. Blumenthal flavored it as most American chefs do—with basil or garlic, or infused with truffle oil—but the flavors never seemed to burst through. He tried lime-flavored mashed potatoes, but even then, after a few bites, he could hardly detect the flavoring—it was if the lime and other flavors had simply disappeared.
So Blumenthal turned to his informal science panel for advice. Which is how he found himself sitting in a Geneva laboratory one day with a strange-looking machine hooked up to his nose.
Blumenthal had contacted the Firmenich corporation, which develops and manufactures flavors and fragrances for brand-name products around the world. Firmenich scientists told Blumenthal that if he wanted to perfect his potato purée, he needed to plunge into the latest studies on the physiology of taste and smell, and that meant he would have to learn about the brain.
For instance, scientists have discovered that we taste five basic flavors in our mouths. The taste buds on our tongue and soft palate tell us if something is salty or sour, bitter or sweet—and in the past few years, many scientists in the U.S. and Europe have come to agree with their Japanese counterparts that there's a fifth, an earthy taste known as umami.
But travel up the nose, to the olfactory bulb in the middle of the head: That's where we perceive countless aromas in all their subtle complexity. We "taste" them mainly by smelling aromatic molecules as they waft up our nasal passages (which is why you can barely "taste" anything when you have a cold).
So picture the inside of your mouth as you're chewing mashed potatoes: If a food molecule is as small and light as a molecular feather, and it floats easily up into your head, you'll savor it in its vivid glory. But if the molecule is so big and heavy that it just plops there on your tongue and tumbles down your throat, you'll hardly detect anything at all.
Which brings us back to Blumenthal's problem. Most molecules in potatoes are big lugs, so they sink. Worse, they have a vicious tendency to grab hold of all sorts of lighter molecules and not let go—which means that Blumenthal can add all the ingredients he wants to a pile of potatoes, and the heavier starch molecules will imprison some of them in molecular jail. Fat molecules absorb some lighter molecules in a similarly thuggish way, so when you add butter to flavored potatoes, you're doing double damage.
That, said the Firmenich scientists, was just the beginning of Blumenthal's potato woes. Many chefs (and gourmands) have known intuitively for centuries that when you eat too much of the same thing, you get palate fatigue, as they call it. So chefs serve sorbets between courses in an attempt to "refresh" the palate. They serve "tasting menus" to try to keep your taste buds on their metaphorical toes. Now, Firmenich researchers have helped develop a remarkable machine that displays the onset and progression of palate fatigue visually. They call it the MS Nose. You can buy one for less than half a million dollars.
And that brings us back to Heston Blumenthal, whom we left sitting in the Firmenich laboratory, hooked up to the MS Nose. "They put a little tube up my nostril," Blumenthal remembers. "The tube was connected to a box. And then they gave me a stick of minty chewing gum, and as I chewed it, I could actually see the mint aroma molecules that were up in my nose projected on a small screen."
The MS Nose is essentially a mass spectrometer, the kind of supersophisticated device that labs use to detect toxic chemicals. As the test subject exhales, the machine analyzes and counts the molecules in his breath, and then portrays them in a series of squiggles on a computer display. "It was strange," says Blumenthal. "After chewing the gum for a few minutes, I couldn't detect the mint anymore. But the screen showed that I still had just as many mint molecules in my nose as I did when I could sense them."
Then the researchers gave Blumenthal a new taste, a sip of sugar water. "It was perfectly amazing," he says. "I got this rush of mint flavor again—even though on the screen the number of mint molecules in my nose hadn't changed." Scientists think that the brain gets bored after it has sampled the same old flavor, and that it turns off the flavor receptors. Jolt the brain with a new sensation, and it switches the sensory circuits back on.
When Blumenthal left the Firmenich lab, he knew that he needed to ignite his customers' circuitry with unexpected flavors and textures, like fireworks that explode into new patterns just when you think they're spent. He decided to start by studding his potato purée with unexpected chunks of lime jelly.
New Problem: Blumenthal quickly realized that gelatin melts at the temperature of warm mashed potatoes, so the lime was oozing into the starch and the flavor was getting diluted. He was almost back where he started.
Next: a quick call to another scientist who's plugged into the molecular gastronomy network. Did he perchance know how to maintain gels at high temperatures? No problem: The chemist sent Blumenthal a bag of agar, a Japanese gelatin made from dried seaweed that allows him to make firm gels that shrug off heat.
Today, a waiter at The Fat Duck holds out a spoon with a dollop of ivory potato purée topped with tiny green slivers like the fins on a fish. You put the spoon in your mouth. The potatoes ooze. They melt. They soothe. And suddenly, pure lime explodes in your mouth like Pop Rocks.
Blumenthal's scientific quest bursts through in almost every dish he creates. A bite of seared foie gras, like warm loam, then the startling, briny-sweet crinkle of crystallized seaweed. A forkful of creamy sweetbreads, heady with the scent of a freshly mown field—Blumenthal bakes the sweetbreads in green hay—then the musty crunch from a dusting of pollen. Your head fills with the vapors of warm roasted crab as you begin his seafood risotto, then you reel as you bite into a cold scoop of ice cream—and reel again when you realize that Blumenthal's ice cream is the pure, cold essence of crab.
Since the erice conference, Blumenthal and some of the other participants have been trading e-mails, trying to figure out a way to broaden the molecular gastronomy movement. Sure, it's fun to meet every few years in Sicily, but they can pack only a few dozen people into the monastery. They dream of flexing the power of the Internet to get chefs and scientists all over the world to talk to each other, to collaborate on experiments, and to come up with new culinary ideas—just as Blumenthal works with his growing network of chemists and physicists. And that's going to require many chefs to become more open-minded—not just about using more science in their cooking but also about sharing their "trade secrets" with their competition.
Here's Blumenthal and Barham's most radical secret. (To do it safely, they employ an arsenal of technical precautions. In other words, don't try this at home.) To prepare a lovely piece of meat so that every bite is a blushing, rosy rare, Blumenthal cooks it the whole time at a shockingly low temperature. According to the laws of physics, says Barham, the meat could never, ever get overcooked.
Demonstrating this, Blumenthal turns one end of his stove down low, then sets a battered aluminum pan on top—the temperature's so low that you can touch it without wincing. He drizzles in a bit of oil, and then he props a few lamb tenderloins, with the bone and fat still cradling them, at weird angles all around the pan so only a small amount of meat touches the metal. Then, for the next hour and a half Blumenthal lets the tenderloins just sit there … and sit there … except every couple of minutes, he gives the hunks a quarter turn. The oil in the pan never spits or shimmers. You never see any juices oozing from the lamb or hear it dance and sizzle. After that hour and a half, the outer surface of the lamb looks so red and moist that it seems almost raw. But when Blumenthal's probe tells him the entire chunk is an even 135 degrees, the lamb is ready to serve.
Blumenthal is about to send an order to a customer, sliced, draped with reduced lamb roasting juices along with a crispy, caramelized lamb onglet (diaphragm). Before the plate is ready, though, he hands me a slice and I dangle it in my mouth. Revelation: This is what lamb should be. Ridiculously juicy. Exquisitely tender. Not a hint of tension or distress. And every bite is perfect.
Eggplant: To Salt or Not to Salt?
Eggplants are filled with cells (a) that contain water and are surrounded by tiny air pockets (b). The presence of heat will squeeze the air out of the pockets (c). If the eggplant has not been salted, oil is then free to seep into them (d) and the eggplant becomes soggy.
But when salt is sprinkled on an eggplant (e), it draws the water out of the cells. The cells then collapse (f), which in turn makes the air pockets collapse. As a result, no oil can seep into the tiny pockets during the frying process (g).
Fifteen Seconds of Flame—a Steak's Own Story
Every cook knows that when you cook a good steak, you have to make painful compromises. You learn to blast it at high temperatures (a) because you need more than 300 degrees Fahrenheit to produce a crust with those rich, caramelized flavors that form like magic from the meat's natural sugars and amino acids. (Scientists call this process the Maillard reaction, named for the French physician who almost a century ago was the first to investigate similar reactions between proteins and sugars in the human body.) But you don't want the steak's interior to go much above 135 degrees, because that's the temperature at which it stays juicy and rare. Above that, the strands of proteins in the muscle fibers contract so much that they start to squeeze out their juices (b)—and beef has tons of juices before you cook it; it's more than 60 percent water. Renowned food science author Harold McGee shocked the cooking world in 1984 when he used these principles to demonstrate that searing meat at high heat does precisely the opposite of "sealing in" those juices—it starts to dry them out.
So what usually happens when you throw your steak on the fire? You end up with a great Maillard crust, a juicy rare or rosy center—and then there's a dry, chewy "gray zone" in between.
McGee had a hunch that computers could figure out a satisfactory solution. He knew that Silicon Valley scientists had used mathematical simulation software to help them study how electrons move through silicon chips, so he figured they could modify the software to study how heat moves through meat. They could. McGee ran hundreds of simulations, in effect asking the computer: What's the best way to get the heat to diffuse through the meat so it cooks as fast and evenly as possible?
The computer told them that chefs are cooking their steaks, well, wrong. McGee aims a laser pointer at his computer's simulation of beef, up there on the screen: The computer shows a simulation of the inside of the cooking steaks as sedimentary layers of purple and green and yellow, each color representing a different amount of accumulated heat (c). And they show that when you throw a steak on the fire and just let it sit there, sizzling away, and then you flip the meat only once before you serve it, you're messing with the heat diffusion. There's such a huge difference between the temperatures on the side that's facing the fire and the side that's turned away that the heat inside your steak fluxes all over the place. (This applies only to beef.)
"But," McGee says, "the computer model shows that if you keep flipping the meat as you cook it, the heat diffuses through the meat much more evenly, so it cooks much more evenly. Our study suggests that the optimum flipping time is every fifteen seconds."
Every 15 seconds? Can McGee be serious? "Maybe that's a little extreme; it might be inconvenient," McGee says, laughing. "The computer model shows that flipping the meat every thirty seconds will work almost as well." And it's nice to know that another recent study, at Lawrence Livermore National Laboratory, shows that frequent flipping makes steaks more healthful, too: It reduces the amount of carcinogenic compounds that can be generated when you cook over high heat by as much as 75 percent.
Which means that short-order cooks have been doing things right all along. —D.Z.
The Flavor Formula
Flavor = taste + aroma. On our tongue and soft palate, taste buds indicate salty, sour, bitter, sweet, or earthy (umami) (a). But flavor happens when the aromatic molecules in our nasal passages come into play. All foods contain light, volatile molecules, which easily float up our nasal passages (b), and large, heavy molecules that tumble down the throat (c). To maximize the flavor of a predominantly heavy-molecule food like starchy mashed potatoes, it should be spiked with predominantly lighter-molecule foods, like lime.