CHAPTER 5
A Nose for the Mouth
Blindfold a person and make him clasp his nose tightly, then put into his mouth successively small pieces of beef, mutton, veal, and pork, and it is safe to predict that he will not be able to tell one morsel from another. The same results will be obtained with chicken, turkey, and duck; with pieces of almond, walnut, and hazelnut….
—HENRY THEOPHILUS FINCK (1886)
WHEN IT COMES TO FOOD, I’M A SMELL CHAUVINIST: taste is boring. The tongue supplies just five channels of information: bitter, sweet, sour, salty, and umami. (My Japanese colleagues insisted for years that monosodium glutamate delivered more than a salty impression. The discovery in 1996 of glutamate receptors on the tongue finally proved their case. The savory taste of umami is now in the official pantheon.) While five taste channels are nothing to sneeze at, they’re rudimentary compared with the 350 different receptors and two dozen perceptual categories available to olfaction.
There is another reason why I think taste is overrated. We are accustomed to experiencing flavor as a singular sensation in the mouth. As a result, we use the words “taste” and “flavor” interchangeably in casual conversation. This makes it easy to forget that flavor is actually a fusion of taste and smell, and that the apparent simplicity of flavor is just an illusion, one that is somtimes reinforced by language. For example, there is only one word for taste and flavor in Spanish (sabor), German (geschmack), and Chinese (wei). I think the tongue gets more credit that it deserves.
That smell makes the far greater contribution to flavor becomes obvious once it is taken out of play. Pinch shut the nostrils, and flavor disappears. What’s left, as the American philosopher and critic Henry T. Finck noted 120 years ago, is bland texture. Caviar tastes like salty oatmeal, and coffee is merely bitter water. This simple, powerful truth is ignored by those who claim the sense of smell is weak and of little importance to modern humans. For example, the pop-science icon Carl Sagan once said “it is clear that smell plays a very minor role in our everyday lives.” Science Digest claimed, “Modern man seldom uses the sense of smell except to detect a burning roast in the oven, or to enjoy a rose bush.” The pioneer sexologist Havelock Ellis had such contempt for smell that he tried to minimize its role in flavor: “If the sense of smell were abolished altogether the life of mankind would continue as before, with little or no sensible modification, though the pleasures of life, and especially of eating and drinking, would be to some extent diminished.” One hesitates to imagine what sort of cramped, joyless inner life could lead a person to write such things, for the reality, made clear by Finck’s demonstration, is that the sense of smell contributes mightily to our enjoyment of food and for this alone deserves to be celebrated.
In his essay on “The Gastronomic Value of Odours,” Finck described a particular type of smelling we use to savor food. He pointed out that aromas released from food in the mouth reach the nasal passages via the back of the throat, and are exhaled through the nostrils. The act of swallowing drives aromas along this reverse path. In effect, we smell our food from the inside out. Today this is known as retronasal olfaction, but I prefer Henry Finck’s name for it: a “second way of smelling,” a phrase that sets it apart from the usual nostrils-first mode. Retronasal olfaction has become a hot topic among sensory scientists, and recent findings confirm Finck’s intuition: the second way of smelling operates by its own set of sensory rules.
THE TWO PHYSICAL paths to the nose—one from the outside world and the other from the mouth—have parallels in the psychology of odor perception. The apparent location of a smell—inside or outside of our body—determines how we perceive it. The psychologist Paul Rozin demonstrated this in a simple experiment. He taught people to recognize the smell of four unusual fruit juices. They sniffed the samples while blindfolded, and quickly learned to tell the them apart with perfect accuracy. When Rozin squirted the same juice samples into their mouths with a syringe, they could not identify them reliably. A smell well-learned when sniffed by the nose is poorly recognized in the mouth. This suggested to Rozin that location has consequences: a food smells one way “out there” and a different way “in here.” The psychological difference between outside-in and inside-out smelling, when combined with taste sensation from the tongue, produces strange contrasts. It makes for foods that smell good but taste bad (coffee, for example), and others that smell bad but taste good (blue cheese).
The psychologist Debra Zellner studies a peculiar sensory illusion involving sight and smell. She pours a clear, scented liquid into two glasses and adds color to one. To a blindfolded person the two samples smell equally strong; with the blindfold removed, the colored version smells stronger. In the classical version of this colorodor illusion, the liquid is sniffed by nose. Zellner wondered what would happen if the smell were delivered by mouth. She had people sip the samples through a straw—the liquid was visible under a clear plastic lid, which prevented through-the-nostril smelling. Under these conditions the illusion was reversed: adding color reduced perceived odor strength.
Because smell and taste are inextricably linked in flavor perception, experience in one modality can affect the other. For example, some odors are commonly described in terms of taste: honey smells “sweet” and vinegar smells “sour.” The Australian psychologist R. J. Stevenson and others have shown that odors acquire taste qualities through associative learning. After a novel odor is paired a few times with the sweet taste of sucrose, the odor is perceived as smelling sweet. If paired with citric acid, it seems to smell sour. This cross-sensory link works in the other direction as well: smells can alter tastes. Strawberry odor, for example makes a weak sugar solution taste sweeter, and a whiff of soy sauce boosts the perceived saltiness of a saline solution. Sensory researchers have just begun to understand the psychological interplay between smell and taste. They are now looking at how these senses are neurologically cross-wired in the brain. To a smell-centric guy like me, the study of taste is about to become much more interesting.
The Pleistocene Barbecue
Carnivores rarely savor their food: they rip, chomp, and swallow. Herbivores chew for hours on end, not for sensory pleasure but to make tough, fibrous plant matter digestible. Humans, in contrast, anticipate, savor, and linger over the aroma of food. We go to great lengths to increase the appeal of food by cooking it and adding spices. The second way of smelling not only provides the pleasure we take in eating, but also may be the key to how the human sense of smell has evolved over time.
Traditionally, researchers in cultural anthropology and sociology have treated food preparation as an expression of culture, as a collection of behaviors driven by custom and creativity only. A new generation of behaviorally oriented evolutionists is now challenging this profoundly unbiological point of view. The Harvard University anthropologist Richard Wrangham, for example, sees cooking not as an optional behavior—a cultural frill—but as a biological requirement for human survival. Surveying the evidence, he finds that “no human populations are known to have lived without regular access to cooked food.” Even the Inuit hunters of the Arctic, famous for their raw diet, occasionally cooked their whale blubber.
Hominids—the near-human species that link us to our common ancestor with the chimps—were definitely cooking with fire 250,000 years ago. Wrangham finds evidence of cooking as far back as 790,000 years, and speculates that it may have begun as far back as 1.7 million years ago. In any case, cooking with fire was well established when our first anatomically modern ancestors emerged in Africa some 100,000 years ago. We’ve grilled a lot of mastodon steaks through the ages.
The invention of cooking had profound consequences for diet and social behavior. Cooking releases nutrients and makes vegetables faster to eat and easier to digest. Wrangham calculates that for a 120-pound woman to take in 2,000 calories a day, she would have to eat eleven pounds of raw fruits and vegetables. That’s a lot of time at the salad bar. Clinical studies show that raw-food cultists in Germany struggle to keep up nutritionally with their countrymen: they suffer from chronic energy deficiency and the women fail to menstruate. If European sophisticates with desk jobs and handy supermarkets can’t thrive on a raw-vegetable diet, how well would a band of hunter-gatherers do?
Adding meat greatly enhances the diet. Chimpanzees in the wild are big fans of monkey meat, but even with their powerful jaws they take hours to gnaw the raw flesh from a bone. Given the effort involved, raw meat isn’t a routine source of nutrition for chimps. Nor would it have been for early hominids. A Homo erectus female (our evolutionary cousin) would have needed six hours a day to get all her calories from raw meat, according to Wrangham’s calculations. Cooked meat, however, is a different story: it is nutrient-dense, easily chewed, and rapidly consumed. The time saved by cooking changes our behavior patterns. Where all other large primates snack throughout the day on raw fruits and leaves, we eat a few discrete meals, leaving more time for other activities. The widespread popularity of cooking among protohumans meant that powerful jaw muscles and large teeth were no longer essential, and as their evolutionary advantage shrank, so did they. In the last 100,000 years our teeth and jaw muscles have become even smaller, making possible finely controlled chewing movements of the tongue and jaw. The more nimble modern mouth makes an easy-to-swallow “bolus” of food and releases more aroma in the process. In the long run, cooking has literally changed the shape of our face.
COOKING HAS ALSO changed our sensory world: it introduced novel aroma molecules and whole new classes of smells. The savory notes of roasted meat, toasted nuts, and carmelized vegetables were rare accidents before we fired up the Pleistocene barbecue. More new smells—baked bread and boiled mush—arose with the cultivation of wheat and other grains about 12,500 years ago. Sheep, goats, pigs, and cattle were all domesticated roughly 10,000 years ago. With them came the smell of butter and the fermented bouquets of yogurt and cheese. As early villagers mastered the art of fermentation, the heady aromas of beer and wine joined the mix.
We are a cooking species, and the smell of an impending meal is woven into our biology. Food aroma is an invitation and a spur to action. Even before the first bite, it triggers an elaborate sequence of physiological events: salivation, insulin release by the pancreas, and the secretion of various digestive juices. The aroma of bacon, at a level so faint it can’t be consciously identified, has been shown to trigger the flow of saliva. This would not have surprised cookbook author James Beard, who once said, “Nothing is quite as intoxicating as the smell of bacon frying in the morning, save perhaps the smell of coffee brewing.” We expect to be stimulated en route to a meal—the anticipatory smells of cooking have become almost a biological requirement. This is a big headache for manufacturers of prepared foods. The physics of microwave heating doesn’t create the toasted, roasted, and caramelized notes that signal impending “doneness.” Food companies spend a lot of time and money on technological work-arounds to restore these missing scents.
IN ADDITION TO cooking food, we spice it. Spice use is a universal human habit, though there are significant regional differences in the spices that are used and how they are combined. What qualifies as a spice? In one definition, it’s “any dried, fragrant, aromatic, or pungent vegetable or plant substance, in the whole, broken, or ground form, that contributes to flavor, whose primary function in food is seasoning rather than nutrition, and that may contribute relish or piquancy to foods or beverages.” Roots, seeds, dried leaves, even aromatic lichens fit this definition; including fresh herbs adds still more materials. There are a lot of spices, and yet, like the huge number of possible smells in the world, the closer one looks, the more this apparent diversity can be simplified. At the core of each of the world’s great culinary traditions is a small group of spices and flavorings. A perfumer would think of these combinations as an accord, the key ingredients that define a style of perfume. The late food expert Elisabeth Rozin called these combinations “flavor principles”: “Every culture tends to combine a small number of flavoring ingredients so frequently and so consistently that they become definitive of that particular cuisine.” Rozin could conjure up an entire culture using two or three key flavorings. She rarely had to use more than four. For example, soy sauce, rice wine, and gingerroot form the Chinese flavor principle, while the Hungarian one consists of paprika, lard, and onions. A beloved and easily recognized flavor principle gives ethnic authenticity to whatever is cooked in it. In the future, Hungarian deep-space explorers eating processed algae paste will find it quite palatable as long as it is seasoned with paprika, lard, and onions.
Some spices are used by many different cultures. What makes a flavor principle distinctive is its specific combination of seasonings. Consider lemon, a widely used flavor source. Add cinnamon, oregano, and tomato and you’ve got a Greek principle. Add fish sauce and chili and you’ve got Vietnamese. The extensive overlap in ingredients across flavor principles means that every traditional cuisine on the planet can be prepared from a very short shopping list. The thirty or so principles Rozin describes in her book require about four dozen ingredients. All the flavors of world food culture can fit into a single grocery bag.
Liz Rozin’s theory of food aroma strikes some people as too minimalist to account for the richness of human cuisine. What they fail to appreciate is the power of combinatorics, which makes it possible to generate huge numbers of flavor variations from a few basic odorous elements. The Chicago chef and restaurateur Charlie Trotter understands this. “You can prepare forty dishes from six ingredients,” says Trotter. He likens creative cooking to jazz improvisation. A chef who has mastered the basic repertoire—the classical flavor combinations—can improvise endless new dishes with only a handful of spices. Thus the cook and the chemist have arrived at the same fundamental truth: sensory diversity is achieved with relatively few ingredients. The chemist can re-create the aroma of any foodstuff with fewer than a thousand odor molecules, and the chef can build any global cuisine with a few dozen spices. The amazing variety of human cuisine, at the chemical as well as the aesthetic level, is a matter of basic themes and endless variations.
THE CORNELL UNIVERSITY evolutionary biologist Paul Sherman is another scientist rethinking the assumption that all variation in food habits is cultural. Sherman studies how spice use relates to human survival. He and his collaborator Jennifer Billing were intrigued by the fact that spices often have antimicrobial properties: they contain natural chemicals that kill bacteria and fungi. Could the point of cooking with spices be to reduce spoilage and food-related illness? To test their idea, Sherman and Billing assembled a collection of ninety-three cookbooks from thirty-six countries. From these, they selected 4,578 meat-based recipes and meticulously noted what spices were used in each.
On a worldwide basis, nearly every meat dish (93 percent) had one or more spices. The results varied, however, with a country’s climate: the number of spices per recipe increased with the average annual temperature. In Finland and Norway, for example, one-third of recipes used no spices at all. In contrast, in Ethiopia, Kenya, Greece, India, and Thailand, every recipe called for at least one spice. Sherman and Billing ran other statistical analyses and found that average annual temperature was correlated with the proportion of recipes containing spices, and the total number of spices used. Since unrefrigerated meat goes bad faster in a warm climate, more spices might mean better protection against spoilage. Sherman and Billing examined the antibacterial power of the various spices, and found that the hotter a country, the more bacteria species are inhibited by the local selection of seasonings. They conclude that while spice use is something we do because it tastes good, it also rids food of pathogens and therefore provides a biological advantage in keeping people healthy. (They briefly considered whether spices might be used to mask the bad taste of spoiled food, but dismissed the idea as a nonstarter: there would be little benefit to survival in encouraging people to ingest toxins.)
In their tally of thousands of meat-based recipes, Sherman and Billing found that the most commonly used spices are onion (in 65 percent of all recipes) and pepper (63 percent), followed by garlic (35 percent), hot peppers (24 percent), lemon and lime juice (23 percent), parsley (22 percent), ginger (16 percent), and bay leaf (13 percent). Another thirty-five spices appear only occasionally (in 10 percent or fewer of all recipes). They found that the vast majority of the world’s recipes could be made with about four dozen spices—a number remarkably close to the length of Elisabeth Rozin’s world cuisine shopping list. Further, the average meat recipe calls for 3.9 spices, a number that is consistent with Rozin’s flavor-principle concept.
Sherman returned to his cookbook collection and analyzed another 2,129 recipes, this time looking at only vegetable dishes. Compared with meat recipes, these use fewer spices (2.4 per recipe on average). Still, the results supported the antimicrobial hypothesis: the hotter the climate, the more spices, though this relationship proved somewhat weaker for vegetable dishes. Why? Fruits and vegetables come prepackaged with physical and chemical defenses against microorganisms, which makes the health benefit of adding spices correspondingly smaller.
COOKING AND SPICING are behavioral adaptations with biological consequences. They have shaped our face and made mouth-based smelling a defining human trait. Outlandish as it sounds, spicy cooking may even have altered the core of our biological identity—our DNA.
It is often said that a species’s DNA code can be read like a book. If so, some biologists read it like the sports pages—they add up the number of odor receptor genes and rank us against other species according to the results. Rats lead the Mammalian League with the most functioning receptor genes; dogs and mice are a few games behind, while chimpanzees and humans are looking for a wild-card berth; and dolphins—an aquatic expansion team—own the cellar.
Among primates, humans have the highest proportion of nonfunctional receptor genes; we keep a lot of obsolete junk in our genetic attic. Superficially, it looks like the human nose is weak (relatively few receptors) and getting weaker (losing receptor genes at four times the evolutionary rate of other higher primates). Some, such as the science writer Nicholas Wade, see this as a case of use it or lose it. He says that “the price of civilization is that the faculty of smell is inexorably being degraded.” Wade’s gloomy conclusion may not be justified. Humans continue to evolve, and geneticists have identified hot spots in our genome—areas of biological function in which new genes are being born. Olfaction is one such hot spot. In the last 5,000 to 10,000 years, genes for smell receptors, along with genes related to diet and metabolism, have been evolving faster than those in any other physiological system. One new study finds that “many changes in the human olfactory repertoire may have occurred very recently,” the changes in this case being beneficial genetic mutations that have become fixed traits throughout the population.
The human genome responds rapidly to cultural changes. For example, in ancient populations the gene for lactose absorption ceased to function shortly after weaning. With the emergence of dairy farming, natural selection favored individuals in whom the gene stayed active into adulthood. The selective advantage of being able to eat milk products was so great that adult lactose absorption became a widespread trait within 5,000 years, a mere blink of the eye in evolutionary time. I suspect there has been ample time for the aromas of cooked food to influence our odor receptor repertoire in a similar way. If our gut evolved to digest dairy products, why wouldn’t our nose evolve to appreciate the smells of cheese, butter, and yogurt?
In the recent evolutionary past we have evolved entire subfamiles of odor receptors not shared by the chimpanzee—our closest living relative. An intriguing possibility is that these new receptors are tuned to detect new smells—ones that only recently became important to human survival. It’s speculation on my part, but I’d bet these receptors pick up the nuances of grilled meat—salmon filets and mastodon steaks—along with the volatiles of fermentation: not only milk products, but alcoholic drinks from beer to wine. On a daily basis we season food to please our palate, but over the long run our palate is evolving to match our menu.
I also suspect that dogs are part of the whole story. Dogs were first domesticated by man somewhere in Siberia about 15,000 years ago, just as human populations were shifting from a hunter-gatherer existence to sedentary village life. Increasingly preoccupied with the complex man-made aromas of the cooking pot, our ancestors began to rely on hunting dogs to locate the telltale scent of game. Having co-opted the canine nose, our own scent-tracking ability began to fade. Dogs became, in effect, our long-distance noses, while we specialized in the close-in smelling of food in the mouth.
Dog and humans have complementary nose skills: dogs have little retronasal ability but great distance detection; humans vice versa. (I’m unable to find a single scientific paper on canine retronasal smell. According to pet-food manufacturers, dogs sniff first and gulp later; they don’t spend a whole lot of time savoring food in the mouth.) The Yale University neurobiologist Gordon Shepherd suggests that retronasal smelling “has delivered a richer repertoire of smells in humans than in nonhuman primates and other mammals.” I would go further and claim that humans are a retronasal species; our best olfactory skills are reserved for appreciating food aromas at the point of eating. Our talent is smelling food in the mouth, not food on the hoof. When it comes to tracking the scent of a gazelle on the savannah, we can’t compete with our hounds; but once we drag it back to the campfire we can sure season the hell out of it.
CULTURES ALL OVER the world may choose from the same selection of spices, but that doesn’t guarantee that we all find each other’s cuisines equally appealing. Aromas mark differences between cultures, along with all the moral baggage that entails. On a field trip to Costa Rica, when Miss Stevens admonishes him to “respect other cultures this instant!” Eric Cartman replies, “I wasn’t saying anything about their culture, I’m just saying their city smells like ass.” Offhand dismissals of cultural differences aren’t limited to the fourth graders of South Park. Before he became the president of France, Jacques Chirac was mayor of Paris, and made himself notorious for observing that “the noise and the odor” of freeloading immigrant families would reasonably push a hardworking Frenchman over the edge. He hastened to add, in Cartman fashion, “It is not racist to say this.”
Smell prejudice is not just a Eurocentric trait. Wang Lung, the fictional hero of Pearl Buck’s The Good Earth, moves to another region of China where his scent marks him as a outsider: “[W]hen an honest man came by smelling of yesterday’s garlic, they lifted their noses and cried out, ‘Now here is a reeking, pig-tailed northerner.’ The smell of the garlic would make the very shopkeepers in the cloth shops raise the price of blue cotton cloth as they might raise the price for a foreigner.”
Anthropologists tell us that olfactory stereotyping is central to tribal identity. The Desana people of Colombia’s Amazonian rain forest, for example, believe each tribe has a characteristic odor due partly to heredity and partly to what it eats: “Thus, the Desana, who are hunters, are said to exude the musky smell of the game which they eat. Their neighbours, the Tapuya, on the other hand, live by fishing and are thought to smell of fish. The nearby Tukano are agriculturalists and they, in turn, are said to smell of the roots, tubers and vegetables which they grow in their fields.” Traditional Scottish clans put a different spin on it. Before the invention of woven tartans, each clan was associated with a plant, worn by its members as an aromatic badge of identity. An enterprising smell scientist is attempting to reintroduce the concept by marketing clan-based perfumes. Eau de Whortleberry, anyone?
At cultural boundaries the smell of food become an invisible, fragrant fence. One study went to the trouble to prove that bonito flakes smell like food to Japanese people but not to Germans; the opposite is true for marzipan. You eat what you were raised on. The most unsettling result of this study was that nearly 40 percent of the German ladies interviewed found the smell of Vicks VapoRub to be edible.
Does the fragrant fence limit us to the food aromas of our birth culture? Not necessarily; but there are hazards in jumping the fence. These are nicely depicted in Radhika Jha’s novel Smell. Leela, a young Indian woman born in Kenya, is sent to live with relatives who run an Indian grocery in Paris. Aromatic crosscurrents are present from the opening sentence: “When the wind blew hard, as it did very often that spring, the smell of fresh baguette would fight its way into the Epicerie Madras to do battle with the prickly smell of pickles and masalas.” Leela has a fine awareness of scent and is skilled at cooking with traditional Indian spices. As she learns the ways of Paris she improvises new dishes and creates new possibilities for her love life and career. (She takes a French lover and becomes the darling of the Parisian fusion cuisine scene.) Eventually, Leela realizes that the scents that make her exotic and attractive also make her an outsider. As an author, Radhika Jha has an extraordinary feel for the boundary-creating power of scent, perhaps because she herself lived in Paris as an exchange student. By showing how one woman used scent to redefine her relation to two cultures, she proves it is possible to cross the fragrant fence.
SOME FOOD AROMAS raise the fence to unscalable heights. For example, if you are not Swedish it is unlikely that you can be persuaded to try Surströmming. Surströmming is fermented herring, and is horrifically foul-smelling even to those who consider it a national delicacy. Another Scandinavian specialty is lutefisk. To make it, one soaks air-dried codfish in water for several days, then in a solution of caustic lye for another couple of days, and ends with a few more days in plain water. The result is a swollen, jellylike mass of smelly fish flesh that is popular in Norway and the Norwegian-heavy precincts of Minnesota and Wisconsin. Garrison Keillor recalls lutefisk as “a repulsive gelatinous fishlike dish that tasted of soap and gave off an odor that would gag a goat.” But people who consider themselves true Sons of Knut eat it at least once a year. Norwegians are not insane; they know lutefisk smells bad. But they have carved out a special exemption for it—they’ve made it a badge of belonging.
The psychologist Donald E. Brown compiled a list of cultural universals that includes things like music, proverbs, incest avoidance, and death rituals. I would like to propose an addition to the list of universals: every culture has a foul-smelling food for membership. You are not really Taiwanese unless you eat “stinky tofu” (chunks of fermented soybean curd). You are not really Icelandic unless you eat harkarl (rotten shark meat). Real Japanese eat natto (a gluey mass of fermented soybeans that smells like creosote). Then there is the fabulously stinky durian, or jackfruit, of southeast Asia. Singapore being Singapore, one is allowed to eat its sweet, custardy innards, but it is illegal to carry it on public transportation. I’m personally a big fan of kimchi, the national condiment of Korea. It’s made from fermented Chinese cabbage, vinegar, garlic, fish sauce, and lots of red pepper. It packs a punch—a bottle of it once exploded in my refrigerator. Its postingestive consequences are spectacular: the humorist P. J. O’Rourke described them as “a miasma of eyeglass-fogging kimchi breath, throat-searing kimchi burps, and terrible, pants-splitting kimchi farts.”
AMERICA IS IN the midst of a great sensory reawakening; we are more open to new foods and flavors and smells than at any point in our history. In a country where quiche was once considered exotic, we are no longer surprised to find pad thai in Peoria or moussaka in Muskogee. Kraft Foods, an outfit best known for serving up millions of pounds of macaroni and cheese, recently introduced a Mango Chipotle seafood marinade. Yet in contrast to this growing abundance of sensory options, the regional differences that once characterized the national smellscape are fading. In 1947 The Saturday Evening Post asserted confidently that “West Coast doughnut flour has a predominant lemon flavor, whereas in New England, doughnuts have a strong nutmeg flavoring, with little lemon.” Traces of these regional preferences linger on the contemporary American scene, as evidenced by variation in air-freshener sales. Food-inspired scents such as vanilla and cinnamon have a 39-percent market share in the North Central states, compared to only 28 to 29 percent in the Northeastern, Western, and Southern regions. Citrus and fruity scents (lemon, orange, grapefruit, mandarin, and green apple) show the reverse pattern: they are only 16 percent of sales in the North Central states, but 22 to 23 percent elsewhere.
Beer brewing used to be a strictly local operation, but today’s American beer market is dominated by national brands like Miller and Budweiser. It is no coincidence that in the last fifty years the amount of malt in the average American brew has declined more than 25 percent and the amount of hops more than 50 percent. In other words, beer is less bitter and less aromatic than ever. Big brands expanded through a strategy of making inoffensive beer. They traded character for market share. The good news is that the microbrewery movement is thriving. Small producers have created distinctive beers with greater flavor and more interesting aromas. These so-called “craft” beers are on the rise, while overall domestic beer sales are flat or declining.
It is tempting to think of odor blanding as a typical expression of American mass-market consumerism. Yet it’s a truly global phenomenon. France, a country not known for its welcoming attitude toward American culture, is home to some of the world’s stinkiest cheeses: St.-Nectaire, Ami du Chambertin, and Epoisses. (The last is said to smell simultaneously of “socks, wet dog, and manure.”) France has more varieties of cheese on sale today than ever before; roughly a hundred new varieties hit the market annually. Paradoxically, these products are tasting more and more alike. Traditional mold-ripened cheeses, made from unpasteurized milk, change in texture, smell, and taste as they age. The new versions are made from pasteurized and ultrafiltered milk; they are built for a long and consistent shelf life. Industrial brie—rubbery, flavorless, and never-aging—is taking over the market.
French manufacturers go to great lengths to create an aura of authenticity for the new fromage-blah; they package it in a wooden box, wrap it in plastic straw, and give it an impressively historical name. In trade jargon, these impostors are known as vrai-faux produit traditionnel; think of it as cheese that is “fake but accurate.”
Coffee Beans and Other Bad Memes
Joel Lloyd Bellenson places a little ceramic bowl in front of me and lifts its lid. “Before we begin,” he says, “you need to clear your nasal palate.” I peer into the bowl. “Coffee beans,” explains Bellenson’s partner, Dexster Smith. “This is what they use in perfume stores. It’s like the reset button.” Dutifully, I reinitialize my nose by sniffing the beans.
—CHARLES PLATT, Wired magazine, 1999
Charles Platt began his Wired cover story with this vignette about the two founders of DigiScents, Inc. Joel and Dexster had come up with a small unit that could release innumerable combinations of scent when activated by a digital signal from a personal computer. Stanford graduates, with degrees in bioscience and engineering, respectively, they had previously started a successful genomics company. Neither of them knew beans about smell. That’s why I had been hired a few months earlier—to bring a working knowledge of sensory science and the fragrance industry to the new venture. I thought their coffee stunt was silly. I’d seen beans at a trade show, but had never heard of a perfumer using them. Still, Joel and Dexster had an unerring sense of publicity—a useful talent for founders of a Silicon Valley startup. So I sat back and watched with inward eye-rolling as the meme of a “reset button for your nose” was launched into digital culture.
The bean meme is now a fixture in perfume retailing. I toured the Mall at Short Hills, New Jersey, recently and marveled at how thoroughly it has taken root. At the Angel counter in Nordstrom a glass cone full of coffee beans was held aloft on a brushed metal stand. In Bloomingdale’s the beans were in a cocktail glass. The Jo Malone display in Saks had them in an apothecary jar with a metal lid. It’s all good fun and marketing, but there is not a jot of science behind it. (There are twenty-seven aroma impact molecules in roasted arabica coffee—how could smelling all these help clear the nose?) I don’t make an issue of it when I’m shopping, but a perfumer of my acquaintance was once ejected from a Nordstrom in Seattle for disputing the bean meme a little too persistently with the lady behind the counter.
The idea of a reset button for the nose goes back a long way. At nineteenth-century Japanese incense parties (which were part guessing game and part poetry contest), it was customary for participants to rinse occasionally with a mouthful of vinegar to keep the sense of smell sharp. American perfumers in the 1920s sniffed camphor to restore sensitivity after a hard day at the office. The pioneering odor classifiers E. C. Crocker and L. F. Henderson routinely sniffed camphor or ammonia to “refresh the nose” during long smelling sessions. It’s not clear if these practices worked as intended, or if they are just testimony to the olfactory placebo effect. Similarly, contemporary food companies require taste-test panelists to rinse between samples. The rationale—that it minimizes flavor carryover—seems so commonsensical that no one bothered to test it until 2002. When a sensory lab finally got around to it, the results were surprising. In the study, trained tasters rated the bitterness of cream cheese samples mixed with different amounts of caffeine. (Caffeine is notorious for the delayed onset and lingering aftertaste of its bitterness.) Between samples the tasters tried all sorts of lab-standard palate-cleansing techniques: they rinsed with water or with sparkling water (up to six times); they ate carrots or crackers or plain cream cheese. The results were all the same—cleansing the palate made no difference to subsequent judgments of bitterness. Caffeine leaves a bitter taste, but panelists can compensate for it as they move from sample to sample. So go ahead—serve bread and crackers at your wine tasting, and enjoy the between-course sorbet at your fancy French restaurant. Just don’t expect either habit to make your palate sharper.
According to discriminating foodies, red wine should be paired with only certain kinds of cheese. Aged Gouda, Dry Jack, and Manchego enhance the flavor of red wine, while blue cheese and triple cream varieties interfere with it. At least that’s the dogma. Like many rules of cuisine, the logic behind wine and cheese pairings has seldom been put to a scientific test. The sensory specialist Hildegaarde Heymann and a graduate student addressed the question head-on. They trained panelists to rate red wines along a number of sensory dimensions. When wines were paired with eight different cheeses, the tasters’ perception did indeed change, but not for the better. The flavor of the cheese accentuated the butteriness of the wines, but it blunted every other sensory characteristic—probably not what one wants when uncorking a valuable vintage.
Wine-tasting tradition holds that a wine must be drunk from the correct glass: reds from a large, bulb-shaped one that tapers at the mouth, whites from a smaller version of this, or perhaps from one that isn’t tapered. The idea is that the size and shape of the glass determine how the aroma is collected and delivered to the nose, and that there is an optimal glass for each type of wine. Do these rules have a basis in fact, or are they simply the pretension of wine snobs? Only three studies have addressed the question, and the results are mixed. In one, a Mondavi cabernet smelled less intense in the traditional big-bulb Bordeaux glass than in other shapes; other sensory measures (fruitiness, oakiness, etc.) were unaffected by glass shape. Another study served red and white wines in five different glasses and found that shape altered the perception of the wines on nearly every rating scale. Why such different results? For one thing, the first study was done with blindfolded subjects and the second one was not. A judge’s expectations about the wine change when the glass can be seen. A third study found that tapered, bulb-shaped glasses produced a stronger impression of wine aroma than a tulipshaped or a nontapered bulb. This effect disappeared, however, when the odor sensitivity of individual judges was taken into account. Only people with superior noses could appreciate the subtle effects of glass shape. While this will no doubt reinforce the self-regard of wine snobs, the final joke is on them. The study presented a single wine in glasses of various shapes; afterward most judges thought they had been served two or three different wines. Another triumph of the visual over the aromatic. In the final analysis, glass preferences may be nothing more than a tradition. In a similar way, I have heard French perfumers insist that their style of smelling blotter (folded lengthwise into a V-shape, and cut to a point on the end) is superior to the thin, rectangular version used by Americans. Why? Because it allows the perfume to evaporate more precisely. The world of olfaction is filled with irrational beliefs, and sometimes that’s just part of the fun.