or the last few years, a number of long-time wine industry observers, many of them in England, have addressed what they believe to be a great fallacy in the scoring of wines on a rigid, numerical basis. Their criticism is that a small number of mostly American evaluators seem to be smitten by a style of wine that the critics view as antithetical to the classic view of what a great wine ought to be.

Clive Coates, the noted French wine author, recently called to task one American critic (not by name) who loved a particularly controversial red Bordeaux. Wrote Coates, “Anyone who likes [that wine] should have a brain transplant.” It was almost as if the Brits viewed the Americans as being somehow genetically different from Europeans as far as wine tasting is concerned.

And evidence is beginning to emerge that how we taste differs radically from person to person. The latest bit of evidence regarding wine tasting’s connection to a hard-wired status comes from DNA research, and the investigation of the physiology of taste by scientists and amateurs alike.

Some of this research seems to be saying clearly that numerical scores that rate the putative quality of a wine really are little more than opinions, not in any way related to fact, because it is increasingly clear that each individual tastes differently - one man’s greatness is another’s gruel - and what we perceive, or fail to experience, may be related to what we were born with. Or not.

Some of the research seems to indicate that our genetic makeup may well be as much a factor of how and what we smell and taste as any learned experience, certainly with regard to specific aromas and tastes. And, in fact, it is patently clear that some among us cannot sense certain elements, and that others have such an acute sense of the same elements that even a trace is overpoweringly noxious.

Moreover, we’re beginning to see that much of this is beyond our control. It is who we are that determines what we like and dislike. And although learning through a posteriori experience does play a role in our appreciation of certain aspects of wine, a lot of that presumably is limited to what we can sense and how we sense it.

And those who use numbers to persuade us that something is sensational (a score of 99) or wretched (a score of 58) are trying to persuade in a manner that recalls what sociologists call the Big Lie syndrome: the telling of a falsity often enough until it is believed. For instance, people who are told over and over again that red wines with strong aromas of oak (smoke, toast, vanilla, mocha, coffee, chocolate, and other euphemisms) are great wines soon begin to think that any wine is great if it has this component. This tends to follow the concept of pedagogy: an “expert” said it is so it must be true. But it also has the counter effect: Once people learn a specific connection, such as the oak analogy, they then also learn to dislike any wine without the fawned-over character.

Another instance where learning can be compromised by prior experience comes when we learn a basic fact about sound wine and then find one that doesn’t fit the “rules.” For instance, most quality table wines are defined as having a low level of volatility and no oxidation or maderization. So what is one’s reaction to a glass of Château-Chalon, the “famed” white wine of the Jura, also called the yellow wine? This wine is made not unlike Fino Sherry or Manzanilla; it is supposed to have both a volatile component and a certain level of oxidation.

I was served one of these wines blind some years ago. Not knowing what it was, I declared it horrid - spoiled. The person serving it said, “Nope, that’s the way it’s supposed to be.” After a few moments of thought, I identified the wine: No other “fine” wine could be so strange, I thought. And yet I still hated it!

Here, my learning had gotten in the way of any potential appreciation of the wine on any level. I am sensitive to volatile acidity (VA) and have always associated it with bad wine. It’s difficult for me to divorce my academic ability to detect “flaws” from the rest of the wine experience, and thus hard for me to like a Jura wine. But at this stage of my life, I can still detect VA and other similar “spoilage” compounds for what they are. At the same dinner party, one otherwise wine-savvy person couldn’t detect the VA of that particular wine at all! (He had other reasons for detesting it!)

Does It All Come Down to Genetics?

So we get back to the hard-wired-ness of our abilities to sense elements in wine that have nothing to do with experience or learning. Does it come down solely to how each of us is constituted, from a genetic point of view, and in what concentrations can we detect certain common and not-so-common elements in wine?

Some recent stories in the popular press seem to buy into this thesis, concluding that it all comes down to genetics. Alas, this is an inordinately complex thesis that’s still in its scientific infancy. As recently as a decade ago, it would have seemed radical to even propose to do DNA research into wine aroma and taste. In the last few years, though, some sensory evaluation of wine based on DNA has begun.

Now that scientists are learning about how humans and other living things operate based on their genetic structure, we may well be within a few years of coming up with a DNA “picture” or chart of each individual that could be used to pre-select the styles of wine that he or she should prefer, and exclude the styles that won’t be preferred. (We already know that some people cannot stand the idea of dry wine; they prefer wine with some sugar. Is this learned or related to DNA?)

There are at least two elements to this research: smell and taste. Although these topics are linked, the research into one often excludes research into the other. Smell seems to be a bit harder to research, but anecdotal examples abound. For instance, when the Australian Wine Research Institute (AWRI) was in the process of attempting to identify the origin of black pepper aroma in certain red wines, it discovered that between 10 percent and 20 percent of all tasters - including the lead researcher! - could not detect the black pepper smell in red wines. Also, one U.S. Master of Wine has widely acknowledged to colleagues that he cannot detect trichloroanisole-2-4-6 (the famed TCA compound that leaves a wine “corked”) at all. Even so, both of these examples are still anecdotal; neither has been measured in a scientific way.

The Sense of Smell Institute based in New York has created a strategic alliance that includes the Association for Chemoreception Sciences in Minneapolis, the Monell Chemical Senses Center in Philadelphia, and UC San Diego. Dr. Charles Wysocki, a behavioral neuroscientist at Monell, said, “You can quantify aroma. It’s called psychophysical methodology; in wine, it’s called organoleptic evaluation.” He said the sensory abilities of tasters as well as instrument analysis both play a role in determining how people smell.

Such research “allows you to generate real numbers that people can agree on, and when you see outliers, you can identify them.”

This means, for instance, that if a wine should score 100 points on someone’s personal list of top wines, and then that wine is served to many skilled tasters in a double-blind study, and the wine rates lower by a statistically significant margin, then the 100-point score might be seen as meaningless.

Doing such a test would be meaningful only if the wine is served without any clues as to its origin other than the most basic of facts. But what happens when a wine evaluator sees the label before tasting? Well, all bets are off. Objectivity is what research is all about, and being told anything about a wine before a supposedly objective test obviates the meaning of the evaluator’s comments on the wine.

A Taste-y Problem of Smell

From my reading of the research into smell, it seems a bit trickier than research into taste because it entails levels of aroma that cannot be accurately measured (at least from the standpoint of what the individual senses), and the sense receptors from person to person are different, and difficult to monitor. Brain scans have been used in some research, but they are of less use when the subjects know something about the wines, such as price.

Moreover, for various reasons, the amount of research into wine aromas seems to be significantly less than that into taste. Part of the reason is that the Smell Institute’s board of directors is primarily composed of companies that are aroma companies, such as perfume producers or food producers, and sensory work obviously is their lifeblood. From what I can tell, most of the recent work in aroma research is in their areas of specialty, not into wine. Wine companies have sponsored very little aroma research.

Taste is another story, but again wine companies don’t seem to sponsor much scientific research here. The Canadian and Australian governments have sponsored two major wine taste investigations in the last year alone and much of that work continues. Taste research seems to be an area of interest because we taste with parts of the anatomy (what’s in the mouth and the nasal cavity) that are a little easier to analyze.

At last year’s Wine Industry Technical Conference in Australia, a paper was presented entitled “Genetic Basis for Individual Differences in Wine Flavor Perception”, in which the researchers looked at the long-held theory that there are levels of taste perceptibility based on factors related to individuals’ DNA. The research was funded by the Australian government and carried out by the Australian Wine Research Institute (AWRI).

The paper by Dr. Gary Pickering, chairman and professor of biological sciences and wine science at Brock University in Canada, was a step forward in attempting to determine the meaning of the super-taster/non-taster phenomenon. The paper stated, “Significant variability exists between people in their perception of wine flavor. . .” The paper looked at the “variation in the sensitivity of individuals to bitter compounds [based on] numerous studies dating back to [1931].”

The Bitter Truth about Super Tasters

A chemical compound called PROP has long been used to determine individual sensitivities to bitterness. Using PROP as a factor, it has long been estimated that about a quarter of the population are non-tasters, half are moderate tasters, and another quarter are super-tasters. Super-tasters, it has been assumed, can detect bitterness more readily than members of either of the other two groups. “Super-tasters experience bitterness more intensely,” said Pickering in a telephone interview. “But that’s the least interesting result of the research. What is really fascinating is that we have shown time and again that PROP is a good general proxy for all taste sensitivity, for an entire universe of oral sensations.”

Moreover, he said, it is not appropriate to make the assumption that super-tasters are automatically those who have a great number of “taste buds” (fungiform pappilae). “It’s a tempting thing to do, but it may not be accurate,” he said. And he added that it appears that different ethnic groups may have differing levels of super-tasters from the 25%-50%-25% divisions normally believed to exist in society.

Using funds from the Natural Sciences and Engineering Research Council of Canada, Pickering’s on-going research into taste profiled 400 different wine consumers using a huge questionnaire. The most fascinating result, he said, is that “PROP status isn’t the only evidence that a person is a super-taster. I think the most important aspect of this work is the interaction between PROP status and food adventurousness towards different alcoholic products.

“I think we’ll find among super-tasters those who are near-phobic to food and booze, and from that group, we will find those that are really adventurous to a wide variety of foods and beverages.”

He added, “The psychological constructs explain some of our behavior regarding our wine choices. It’s very easy to overstate one’s PROP status,” which I took to mean that it’s easy to assume that a person who can easily and acutely detect PROP might or might not have any sort of advantage in taste detection over a person who cannot. “This field is far too complicated to make such simplistic conclusions,” he added.

As an example, he suggested that it would seem that those who are super-tasters and thus taste bitterness more acutely would dislike bitter beverages and foods. And yet, he noted, many people who are super-tasters love India Pale Ales (IPAs), most of which have a significantly high level of bittering units.

He said our upbringing and exposure to a wide (or narrow) variety of products is as great a determining factor as genetics in what we detect and whether we like or dislike such elements. And it’s not just that: The acculturation that occurs with greater contact with peoples from other cultures also can have a significant impact on what we detect and how we like and dislike certain tastes.

Pickering said super-tasters “do tend to have a higher number of ‘taste buds,’ but other than that, broad generalizations are inappropriate and (we) must wait for science to test a series of hypotheses.”

One interesting side note here is that two different recently published scientific papers show that being a super-taster does have a protective effect against the risk of alcoholism!

“This may be related to an aversion to alcohol, or a sensitivity to high-alcohol products,” he said. It may well be that “the increased acuity of super-tasters for higher-alcohol products” may be off-putting to such a degree that these people simply unconsciously self-regulate themselves into consuming far less than those who are tolerant of high alcohol.

A Crock of Spit

Also at the Australian Wine Industry Technical Conference last August was an interesting paper published by lead researcher Caroline Payne of the University of Adelaide. It spoke of astringency and its inter-reaction with saliva. A key finding: Tannins bind to the human palate in different ways depending on the source of the tannins, whether from seeds or skins for instance.

This is also true depending on whether the tannins came from one grape or another. And apparently there is a big difference between the kinds of tannin we get from Cabernet and the kinds we get from Merlot. So making Merlot and Cabernet by identical methods would seem to be silly if a wine maker wants to make a Merlot that has a lower astringency than a Cabernet.

As a kind of conclusion to this first look into the genetics of taste, we can say that it is true that we all taste quite differently from one another and that each individual’s DNA plays a major role in our ability to detect some of the near-trivial elements in wine, both in aroma and taste (which are inexorably linked anyhow).

Moreover, we know that some aromatic compounds appear in wine at astounding low levels, so it’s logical some people may not be able to detect them. Rotundone, for example, can be measured in nanograms and AWRI says that a teaspoon of the stuff would turn an Olympic-sized swimming pool into a pepper pot!

Furthermore, it also appears that external factors such as our upbringing, our wine training (formal or informal), exposure to a wide (or narrow) range of wine types, connection to skilled (or unskilled) mentors and various ethnic, social, and acculturative influences all play as much as, if not a greater role than, genetic makeup.

It is the totality of it all that ultimately determines whether you like a particular element in a wine, hate it, or are incapable of sensing it.