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. On Wednesday, he examined the age-old stoner's question: Do you taste what I taste? Yesterday, he set out to discover whether or not he's a "supertaster." Today, he'll examine whether being a supertaster helps you evaluate wine.
Being a nontaster, albeit an anomalous one, looked like bad news. What wine writer would want to own up to having a genetically inferior palate? What prudent consumer would take wine tips from a certified nontaster? But after numerous e-mail exchanges with (the very patient) Reed, a follow-up conversation with Tim Hanni, and some additional research, I discovered that maybe I didn't need to curse my ancestors and cut out my tongue, after all. For one thing, being a nontaster was not the career death sentence it appeared to be. For another, being a supertaster turned out to be not nearly as good as it sounded; in fact, to the degree that it matters at all, it is probably more of a liability for a wine critic than an asset.
How so? To begin with, supertasters do not particularly enjoy the flavor of alcohol and often complain that it leaves a burning sensation in their mouths. They are also sensitive to astringency and acidity, which can be equally problematic as wine goes. (Evidently, eating is no joy for them, either; according to Linda Bartoshuk, they can't abide spiciness, they don't like fatty foods, and they tend to find all sorts of vegetables overly bitter. All in all, a fun bunch.) The British wine writer Jamie Goode, in his excellent book The Science of Wine, calls attention to the work of Gary Pickering, a professor of oenology at Canada's Brock University. Pickering has been investigating the relationship between PROP sensitivity and wine appreciation and believes that being a supertaster is no blessing when it comes to wine. "I would speculate that supertasters probably enjoy wine less than the rest of us," Pickering told Goode. "They experience astringency, acidity, bitterness, and heat (from alcohol) more intensely, and this combination may make wine—or some wine styles—relatively unappealing."
As wine writing goes, supertasters may also be at a disadvantage demographically. Researchers believe that just 25 percent of Americans are supertasters; around half are tasters, and the remaining 25 percent are nontasters. The categories also divide along racial and gender lines: It is estimated that 35 percent of Caucasian women are superstars, but only 15 percent of Caucasian men fit that bill.
If, as a wine critic, the aim is to appeal to the biggest possible audience, being a supertaster could be a serious problem. As Bartoshuk tells it, supertasters live in a completely unique world of flavor sensations, which suggests that their opinions about wine wouldn't be of much value to anyone except other supertasters. Even being a taster might not be ideal. By far the biggest consumers of wine criticism are male Caucasians, who according to Bartoshuk are also disproportionately represented among nontasters—35 percent of white males fall into this category. So it could be that, from a purely demographic standpoint, the ideal wine critic would be a low-sensitivity taster. (Hanni suspects that some of the more prominent wine critics are indeed low-sensitivity tasters, given their fondness for heavily extracted, high alcohol wines.)
However, engaging in this kind of speculation gives the supertaster-taster-nontaster trichotomy more weight than it deserves at this point. When it comes to understanding sensory perception, we are literally at the tip of the tongue. Here's what we think we know about supertasters: They show extreme sensitivity to PROP and have high fungiform papillae counts. We also know that fungiform papillae are a reliable indicator of sensitivity to the five basic taste sensations: People with very dense concentrations of these structures are more sensitive to bitter, sour, sweet, salty, and savory flavors than people with average or with sub-average concentrations. But while fungiform papillae have been studied exhaustively, much less is known about the papillae on the side of the tongue (foliate papillae) and those toward the back of it (circumvallate papillae)—except we know they also affect how tastes and textures are perceived.
As for the genetic dimension, TAS2R38 is one of 35 bitter receptor genes that have been identified thus far; there may be others. There appears to be little if any correlation between PROP/PTC sensitivity and sensitivity to other bitter compounds. There is considerable debate about whether the TAS2R38 genotype is indicative of overall taste sensitivity; it might be, and it might not be. Most people who show extreme sensitivity to PROP have the two dominant alleles for TAS2R38, but that is not true in all cases. Meanwhile, scientists have identified receptors for sweetness and umami but have no idea which chemical stimuli, like PROP and PTC with bitterness, can reliably test these receptors. Sourness and saltiness are largely uncharted territory. Reed told me that for all these reasons, and also because the concept has been so often misunderstood and misrepresented in the media, many geneticists are reluctant to even use the term supertaster.
In short, there are, to put it in Rumsfeld-ian terms, a lot of unknown unknowns here. Just look at my experience. Based on my reaction to the PROP strip, Wysocki concluded that I was a very sensitive taster and possibly a supertaster. When I described my various taste preferences to Bartoshuk and Hanni, both said I was likely a supertaster. My fungiform papillae count was consistent with my being a medium taster. Then the genotyping pegged me as a nontaster. (So how did I detect the PROP? Reed mentioned one possibility: It is believed that another receptor, TAS2R21, may be related to PROP sensitivity alone, and she said it's conceivable that I have a dominant allele for that.) Like a cartoon road sign, my tongue anatomy, my DNA, and my preferences all seem to point in different directions.
Beyond all this, we know that the nose wields much more influence over our flavor perceptions than the tongue. And beyond all that, we know that our gustatory preferences are determined by a wide variety of factors, most of which have nothing to do with our physiological attributes. The key distinction here is between perceptions and preferences. We may be hard-wired to receive flavor stimuli in a certain way, but that information is immediately relayed to the brain, where it is processed through a variety of filters unrelated to our biological dispositions. Our preferences are formed mostly by experience, expectations, culture, and other intangibles. If biology were determinative, I, as a PROP nontaster, would probably enjoy those sweet, soupy, high-alcohol Australian Shirazes and might not think so kindly of light, acidic red Burgundies. In fact, I generally can't stomach the former and adore the latter. Something happened in my life that dictated these preferences, and it clearly wasn't the genes I was born with.
Viewed from afar, the work being done by Reed, Wysocki, and their colleagues appeared to hold out two conflicting—and, for wine writers at least, equally alarming—possibilities. The research being done into the physiology of taste seemed to carry with it the suggestion that some palates were more naturally gifted than others and that scientists would eventually be able to identify the specific traits that separated the good ones from the not-so-good ones. The insights being gleaned about the psychology of taste appeared to point in a different, but also worrying, direction: namely, that because gustatory preferences were so individualistic and idiosyncratic, no one palate could ever be considered more knowledgeable than another, and any wide-ranging agreement about the merits of a particular wine was more likely the product of groupthink than of true consensus.
Having briefly immersed myself in the emerging science of flavor hedonics, I've come away completely fascinated by the topic—but not especially worried about the implications for my line of work. It is quite possible—in fact, it is more than likely—that there are physiological attributes that are conducive to appraising wines, but we have no idea what they are. We know that the nose is the main conduit through which information about a wine is passed to the brain. Thus, having a "good nose" is helpful. But what anatomical features make for a good nose? We haven't a clue. And as Wysocki pointed out to me, every normally functioning olfactory system has strengths and blind spots. When it comes to judging the bouquet of a Syrah, what are the most desirable strengths and the most debilitating blind spots? We don't have a clue, and because of the aromatic complexity of wine, we'll probably never know.
Moreover, wine connoisseurship involves a lot more than just innate aptitude (if such a thing even exists). It is also a function of motivation, knowledge, experience, memory, and stamina. (You try tasting 60 wines before lunch.) Professionally critiquing a wine involves more than just being able to identify a few aromas. You need to know how the same wine has tasted in previous vintages, how it has tended to evolve, and how it compares to wines that are considered benchmarks in its category—and you need to be able to communicate that information in a way that is meaningful to others.
Some people are better at judging wines than others, but based on what I've learned, the reasons for this are more likely to be found in the brain than in either the nose or the mouth. (And interestingly, researchers have found that for experienced wine tasters, such as sommeliers, more areas of the brain are activated when tasting than is the case for inexperienced tasters.) Moreover, what's striking is how much agreement there is among wine critics. Sure, there is near-universal accord about what attributes a top wine should have—appealing aromatics, ripe fruit, good structure, a sense of harmony in the mouth and a long finish. But given how enormously varied individual palates seem to be, one wouldn't think that there would be much consensus regarding individual wines. However, the critics tend to agree about wines a lot more than they disagree. Taste buds, nasal receptors, and personal tics (my sweetness issue, for example) notwithstanding, wine critics are able to achieve an impressive amount of consensus. Biology is surely a factor when it comes to appraising wines, but it almost certainly isn't destiny.