Do you taste what I taste?

Wine, beer, and other potent potables.
June 20 2007 1:03 PM

Do You Taste What I Taste?

The physiology of the wine critic.

Illustration by Mark Alan Stamaty. Click image to expand.

Do certain physiological traits make some wine critics better than others? In a three-part series this week, Mike Steinberger examines the physiology of the oenophile. In this part, he examines the age-old stoner's question: Do you taste what I taste? In Part II, he set out to discover whether he's a "supertaster." And in Part III, he examined whether being a supertaster helps you evaluate wine.

Contrary to the oft-cited aphorism, there actually is some accounting for taste. We know, for instance, that the vast majority of flavors that we perceive when eating and drinking are actually aromas, filtered up to our noses through a tube called the retronasal passage. Our taste buds, on the other hand, detect just five basic flavor sensations: sweet, salty, sour, bitter, and savory. It is also known that some tongues have a higher degree of sensitivity to flavors and textures than others. As for the nose, while it is a more perceptive instrument than the tongue, and thus a more useful one at the dinner table, it is pretty limited in its own right; research has shown that human beings have remarkably poor olfactory abilities, both in the aggregate (dogs and cats can detect many more odors than we do) and episodically (we can sniff out at most four aromas at any one time).

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The tongue and the nose do not, of course, tell us what we think about the things we smell, taste, and feel; it is the brain that draws the conclusions. How the brain translates and interprets the information collected by the tongue and the nose is a dauntingly complex transaction—"higher-order processing" is the term of art—that is only just beginning to be understood. This much, at least, is clear: Memory, experience, and expectations play an enormous part in how individuals react to aromas and flavors, and may even be determinative. Why we notice some flavors and aromas but not others, and why we enjoy some but not others, results from the interplay of visual cues, genetic endowments, physical attributes, and personality features. Because these traits vary dramatically from one individual to the next, flavor and aroma perceptions vary dramatically from one individual to the next.

All of which raises, for wine writers, a truly buzz-killing possibility: Is there a grand fallacy at the heart of what we do? Those of us who review wines do so in the belief that our evaluations, while obviously subjective, are of some value to consumers. But a growing body of scientific evidence suggests that taste perceptions may be even more individualistic and idiosyncratic than previously imagined—and if our noses and tongues all operate on such different wavelengths, then who's to say what's good or bad? Is it really possible to agree about the attributes and virtues of, say, a Napa Cabernet, or are we—wine writers and wine consumers—just conning ourselves into consensus?

Admittedly, this kind of superheavy metaphysical question is perhaps better pondered over a bong than a bottle of wine. It is certainly not a topic that generates much discussion among wine folk. That's probably because the wine industry's critic-consumer apparatus seems to function reasonably well: Critics offer recommendations, and it appears that consumers are, by and large, satisfied with the advice. (Robert Parker didn't get rich steering people to wines they hated.) But it could also be that the physiology of taste is a discomfiting subject. Wine writing is an enterprise with few barriers to entry; a guy trying to make a buck off his presumed wine expertise probably doesn't wish to entertain the possibility that some people may be naturally better suited to evaluating Rieslings and Syrahs than others—or, alternatively, that no one is better equipped to judge wines than anyone else.

However, with scientists gaining ever-greater insights into the mechanics of taste, it is becoming harder for us wine hacks to ignore the biological dimensions of what we do. So, in the spirit of somewhat wary inquiry, I paid several visits to the Monell Chemical Senses Center in Philadelphia, hoping to learn more about the blossoming field of flavor hedonics—the study of gustatory pleasure—and to perhaps glean some insights into my own sense of taste. I first met with Dr. Charles Wysocki, an expert on olfaction.

When we sat down to talk, Wysocki emphasized that science is just beginning to understand the connection between the nose and taste. That said, it is clear the nose does most of the heavy lifting, a fact he demonstrated by having me plug my nose and chew on a blindly selected jelly bean. All I could taste was sweetness and texture; it was only when I released my nose that I was able to identify the flavor of the jelly bean—bubble gum. Wysocki went on to explain that while the human olfactory system is capable of identifying thousands of smells, roughly two-thirds of the potential sensory receptors in our noses are, for genetic reasons, defunct, which creates certain aromatic blind spots in all of us—specific anosmias, as they are known. We quickly found one of mine. Wysocki handed me a plastic tube holding a clear liquid and asked me to take a whiff; I couldn't smell a thing. The liquid contained andostenone, a mammalian pheromone found in boar saliva. In a random sampling of 100 people, around half will detect nothing, 15 or so will smell an inoffensive musky-floral-woody aroma, and the rest will be thoroughly repulsed by a liquid that, to them, reeks of stale urine or particularly nasty body odor.

My faith in my nose was quickly restored by the next plastic tube he handed me; I opened it and took in a very pleasant floral scent. This was Galaxolide, a chemical used primarily in cosmetics; according to Wysocki, around 60 percent of us can smell Galaxolide, and the rest cannot. With enough time, Wysocki told me, he could find anyone's olfactory blind spots. But he also said that studies have shown that specific anosmias can be at least partially overcome—that with repeated, heavy exposure to, say, andostenone, someone previously incapable of detecting its aroma might begin to sniff it out. (And who would want to miss out on the pleasure of smelling stale urine?) It was reassuring to learn that biology isn't necessarily destiny when it comes to the sense of smell.

It was less encouraging to discover how easily the nose can be led astray by the eyes. For his next stupid human trick, Wysocki produced two jars, one labeled "Food," the other "Body." I was told to sniff each. I actually was one of the few people not fooled by the experiment: I said both jars smelled like vomit. In fact, both jars contained the same chemical compound, butyric acid, which can be perceived as vomit but also as perspiration or Parmesan cheese. Wysocki told me he often conducts this test at seminars and that, on average, 60 percent of the people in the room will claim they enjoy the aroma in the "Food" jar, with most saying it's redolent of Parmesan cheese; but when he asks if anyone found the "Body" jar pleasant, no hands go up—the participants invariably claim that it smells of puke or body odor. He mentioned similar work done with wine by Frederic Brochet, a French cognitive psychologist. Brochet has shown that people given a white wine that has been dyed red will describe it exactly as they would a red wine. He has also found that if he serves the same wine in two different bottles, one labeled a cheap vin de table and the other a pricey grand cru, people invariably lavish praise on the latter and scorn the former. Brochet has dubbed this phenomenon "perceptive expectation."

Wysocki expressed admiration for the stamina, aroma-identification skills, and descriptive abilities of wine critics, but he was skeptical about some aspects of the trade. He said it's impossible to taste dozens of wines in rapid succession and not suffer olfactory fatigue and that anyone who claims otherwise is claiming to "defy biology," as he put it. Although a critic might think that his sense of smell is still acute after sampling 40 Cabernets, his impressions at that point are being formed less by the nose than by past experience, visual cues (such as the color of the wines), and perhaps also tactile sensations. I asked Wysocki if he thought that we might eventually be able to determine conclusively that some noses are more capable of evaluating wines than others and to identify those superior beaks. He said there is no question that some noses are more naturally gifted than others. But he quickly reiterated that the nose is an educable instrument and that people can be trained to detect odors that previously eluded them. More importantly, Wysocki said, wine is so aromatically complex that it would be pretty much impossible to devise the kind of rigorous, reliable test required to do such screening.

At my request, we then turned, briefly, to the issue of my tongue. Wysocki went to a lab down the hall and returned with what looked like a long, thin strip of white construction paper. It was actually blotting paper dipped in propylthiouracil, a thyroid medication known more commonly as PROP. He instructed me to place the paper on my tongue. I did so and felt a wave of bitterness roll across my mouth. Rather than subsiding, the bitter flavor seemed to build in intensity (in fact, it would linger for nearly an hour, disappearing only after I guzzled a sweetened latte). As my tongue thrashed around my mouth like a hooked fish convulsing on the deck of a boat, Wysocki explained that my ability to perceive the bitterness classified me as a "taster" and that my strong reaction to the PROP suggested I might be a "supertaster." Suddenly the PROP didn't taste so bad.