Wine Features

Last October, an argument broke out on the Internet between two wine experts: What matters more, nature or nurture? Wine journalist and author Jamie Goode and Tim Hanni, MW, entered a debate about how influential genetics are for wine preference. Hanni contended that we’re programmed to like certain flavors. Goode agreed to an extent, but he said it was a more complex mix of genetics and acquired taste. Although the term didn’t come up, in a way the disagreement was over so-called “supertasters,” defined as people who are more sensitive than average when it comes to taste. Scientists have been studying supertasters for decades, and estimate that roughly 25 percent of the population falls into this category. Most of the research on supertasters has focused on bitterness—in part because of an accidental discovery that some people can taste certain bitter chemicals while others can’t detect these same chemicals at all. (More on this in a moment.) Folks who can detect these bitter chemicals often dislike cruciferous vegetables, black coffee, dark chocolate, hot peppers and the sting of alcohol. In wine, supertasters are thought to prefer something sweet, and some research supports this idea. One large study of 1,010 American wine drinkers found that supertasters, broadly speaking, preferred sweet and fortified wines over dry table wines. To understand whether being a supertaster really makes that much of a difference when it comes to wine, I ran an experiment on myself and nine family and friends using a simple supertaster test that you can buy online. I also interviewed half-a-dozen scientists—including the woman who coined the term “supertaster”—and pored over the scientific literature. It turns out that I’m a supertaster, despite the fact that I loathe sweet wine and once hated, but now love, Brussels sprouts. I have to agree with Goode: It’s complicated. The History of Supertasters To really understand the term “supertaster,” we need to jump back to the 1930s, when Arthur Fox, a chemist at DuPont, spilled a white powder called phenylthiocarbamide (PTC) in the lab. His lab mate, as the story goes, complained that the powder got into his mouth and tasted bitter. Fox couldn’t taste a thing. So the two took turns to sample the PTC. (As one does, I suppose.) This set off formal research. It turned out that both Fox and his colleague were both right. Some people are genetically predisposed to taste the bitterness of the PTC, while others aren’t. The scientists then labeled these people, respectively, tasters and nontasters. In the 1990s, Linda Bartoshuk, an experimental psychologist at the University of Florida, delved into the intensity that tasters experience. She used a different bitter chemical thought to be a little safer to ingest, 6-n-propylthiouracil, or PROP. Bartoshuk grouped test subjects into three categories: nontasters, medium tasters and supertasters. Eventually, researchers linked PROP detection to specific genes, one group of which helps build taste buds. Scientists continue to use PROP tests in taste research. The tests use small strips or discs of paper laced with PROP that are placed on a subject’s tongue. Nontasters won’t taste anything. Medium tasters detect a little bitterness. Supertasters may gag. But Bartoshuk says that PROP tests don’t prove you’re a supertaster in the modern sense of the word. “ ‘Supertaster’ refers far more generally to people who perceive taste as very intense,” she says. While her original experiments focused on PROP, “long ago we realized it was way too narrow.” Still, the term is misused. “The problem is when people extrapolate PROP supertasting and go too far,” says Gary Pickering, professor of biological sciences and psychology/wine science at Brock University. “There are many other genes that explain other aspects of taste.” Scientists have identified around 25 bitterness genes, and there are yet other genes related to sweet, sour, salty and umami flavors. If you’re a supertaster on a PROP test, you might not have the genetic makeup for heightened taste across the board. And just because you can’t taste PROP, that doesn’t mean you’re a nontaster, only that you can’t taste that single bitter compound. Two Friend and Family Supertaster Wine Tastings The genetic complexity of supertasting helps explain the results of experiments I conducted on my friends and family. In the first experiment, I tested friends with PROP strips from Supertaster Labs and then gave them a flight of wine with the labels hidden: a Chardonnay (Chablis), Sauvignon Blanc, Riesling, Pinot Noir, Shiraz and Tempranillo. In the second experiment, I took leftover bottles of Riesling and Shiraz to an eight-person Thanksgiving dinner. I gave everyone a PROP test, and then took informal notes through the meal as they ate and drank as normal. The Brooklyn results were mixed. I was a PROP supertaster and vastly preferred the Chablis and the Pinot Noir. I hated the Riesling. Another friend was also a supertaster. She preferred the Chablis and the Tempranillo, the latter she described as medicinal: “It smells like a hospital, but I like it.” The third was a medium taster who said the test strip gave off “strong notes of Band-Aid.” She liked the Shiraz the most, followed by Sauvignon Blanc. My Thanksgiving dinner experiment wasn’t any clearer. My test subjects included four supertasters, three medium tasters and one nontaster. Two of the supertasters (including me) disliked the Riesling, but had no major reaction to the Shiraz. One medium taster hated the Shiraz, but found the Riesling okay. The nontaster liked the Riesling. The rest either didn’t drink wine or didn’t report a preference. The results from these experiments surprised exactly none of the experts. Most obviously, these experiments didn’t have enough people. You’d need at least hundreds of subjects to identify any real trends. But there’s more at play. When it comes to genetics, what applies to a population doesn’t predict the characteristics of an individual. “Biology is not predeterministic; it’s probabilistic,” says John Hayes, a food and sensory scientist at Penn State. In other words, if you have the genetic makeup of a PROP supertaster, it increases the odds that you’ll prefer sweet wine. But you can easily have other preferences, thanks to a complex interaction of your genes, socialization and more. “The fact is, there is variability in taste perception, smell perception, bitter perception and sweetness perception,” says Hayes. “When you add these together, it’s difficult to predict an individual’s wine preference. “We might be able to get there, but we aren’t there yet,” he says. One important factor may be what sensory scientists call “wine adventurous,” says Pickering. This personality trait may help supertasters overcome an initial aversion to an intense flavor, and even learn to enjoy it. Does Your Biology Even Matter, Then? While being a supertaster may not predict your wine preferences, your personal biology plays a role in what you like. This understanding can enhance your wine selections. Research from Pickering and Hayes, for example, suggests that wine experts are more likely to be supertasters than consumers. This may mean that the average consumer’s tastes don’t always align with a wine reviewer or sommelier. If you can’t detect a particular note in an award-winner, or if you don’t really like the bottle that a restaurant paired with your meal—that’s okay. You may just have a different genetic profile from whoever recommended it. Because of these differences, some experts promote a more individualized approach to assessing wines. Rather than to rely on standard wine benchmarks, Anna Katharine Mansfield, associate professor of enology at Cornell University, says: “I want to teach people how to know their own equipment, to understand how their sensory equipment is allowing them to perceive the world.” After hearing about the two above experiments, Mansfield suggested a better test might be an orange wine, a white wine that is made with an extended period of skin contact. “There are some white wine skin components that can be transferred to the wine that are quite bitter,” she says. “So that’s always been one I thought might have more potential to be pushed one way or another because of inborn preference.” It was possible that a supertaster wouldn’t like a trendy orange wine. So I bought a bottle. To me, it wasn't particularly bitter, rather it was smooth. I liked it just fine. Discover more about how science is leading drinks into the future in our Wine & Tech issue.