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 Part I, he examined the age-old stoner's question: Do you taste what I taste? In this part, he set out to discover whether or not he's a "supertaster." And in Part III, he examined whether being a supertaster helps you evaluate wine.
At a Masters of Wine symposium held in Napa last year, attendees were given the same bitterness taste test that the Monell Chemical Senses Center's Dr. Charles Wysocki would later give to me. The British wine writer and Master of Wine Jancis Robinson found the PROP-soaked blotting paper to be oppressively bitter, which suggested she might be a supertaster. She subsequently reported this finding on her Web site; one e-mailed link led to another, and within days, the critic Robert Parker, though dismissive of the notion that biology can account for differences in taste, was trumpeting his dislike of spicy foods (supposedly a common trait in supertasters), and New York Sun columnist Matt Kramer was skewering the whole idea. Oenophiles were left wondering what all this talk of supertasters and nontasters was about. I was certainly curious. Had science finally proved that some people were more naturally gifted at tasting wine than others? More importantly, was I among the chosen?
The term supertaster was coined in 1991 by Linda Bartoshuk, then a professor of otolaryngology and psychology at the Yale School of Medicine. (She is now at the University of Florida.) Some 60 years earlier, Arthur L. Fox, a scientist for DuPont, had discovered that the chemical compound phenylthiocarbamide, or PTC, tasted unpleasantly bitter to some people but elicited no response in others; the former were dubbed tasters, the latter nontasters, and the differences were put down to genetic variation. In the 1970s, concerns about the toxicity of PTC led Bartoshuk and other scientists to begin using PROP instead to test for sensitivity to bitterness. During the course of her research, Bartoshuk noticed that not all tasters reacted the same way to PROP; all of them found it bitter, but a minority found it excruciatingly so. Intrigued, she began studying the tongue anatomy of these individuals and discovered that they tended to have much denser concentrations of fungiform papillae—the structures at the end of the tongue that house our taste buds—than other tasters and nontasters. Nor were they sensitive only to bitterness; they seemed to experience much more heightened taste sensations in general. Bartoshuk and her Yale colleagues began to refer to these individuals as supertasters, a name that clearly implied that these people possessed not just sensitive palates, but superior ones.
As a result, when Wysocki gave me my PROP test, I was actually quite pleased when I felt that nauseating wave of bitterness wash across my tongue. It seemed to indicate that I too might be a supertaster, which sounded like a nice credential for a wine writer. But extreme PROP sensitivity is just one part of the supertaster equation, and I was curious to find out how I measured up in the fungiform papillae department.
I was also hoping to learn more about what I had come to regard as my Achilles' heel as a wine writer/critic: my aversion to sweetness. I like dessert wines well enough, but I find the sweetness in many nominally dry New World wines off-putting. More generally, I was curious to find out if my wine preferences—I am a Burgundy fan, with a strong predilection for wines that sit at the lighter, more delicate end of the spectrum—could somehow be accounted for biologically.
Wysocki's colleague, the geneticist Danielle Reed, agreed to inspect my tongue. Not only that: She told me that she actually could test my genotype to determine if I had one or both of the dominant alleles associated with supertasting. Three years ago, researchers at long last confirmed Arthur Fox's hunch and identified the gene responsible for PROP/PTC sensitivity. It is believed that most supertasters possess the two dominant alleles for the gene, known as TAS2R38, but it is also known that some people who are highly PROP-sensitive have only one. Tasters are thought to possess at least one dominant allele, while people with two recessive alleles are categorized as nontasters. Given my strong reaction to the PROP, Reed and I took it as a given that I would have at least one dominant allele and very possibly two.
Before meeting with Reed, I had a brief chat over the phone with Bartoshuk herself. I told her about my reaction to the PROP and my low tolerance for sweetness. She said the latter was also consistent with being a supertaster; while humans, for evolutionary reasons, are disposed to like sweetness and abhor bitterness, supertasters tend to have much lower thresholds for sweetness. She told me that for nontasters—and she happens to be one—there is no such thing as too sweet; in fact, she said that she regularly adds sugar to her wine to sweeten it up. I also had a conversation with Tim Hanni, a Napa-based master of wine who has done extensive research into the science of taste—research that has convinced him that wine criticism is pretty much worthless, given how much individual palates vary. I told Hanni about my experience with the PROP, my aversion to sweetness, and my preference for lighter wines. He then asked me several rapid-fire questions: Did I like Scotch? Did I take my coffee black? Did artificial sweeteners taste different to me than regular sugar? Was I a heavy salter? Did my mother suffer a lot of morning sickness when she was pregnant with me? I didn't know the answer to the last question, but the (emphatic) answers to the other four were no, no, yes, and yes, all of which indicated to Hanni that I was either a very sensitive taster or a supertaster.