Does experience increase or decrease our sensitivity to corkiness?

Apologies for banging away at this subject, but the lack of an objective standard for judging TCA levels is very frustrating, and Randy's post this morning brought to mind a number of questions.

Is it possible that wine lovers who have been drinking wine for twenty or thirty years may lose some of their ability to identify TCA in wine?

A few examples:

I've read plenty of criticisms about Parker's growing insensitivity to other aromas and tastes in wine.

The CIA teaches that chefs have to be aware that normally their sensitivity to salt decreases over time, and that they should keep this in mind when tasting food.

Friends who love hot spices tell me that they have to increase the Scoville ratings of peppers as they get older in order to obtain the same enjoyment as they did when they were younger.

It's very common for people to become accustomed to various aromas and tastes, and lose their sensitivity with exposure.

Thomas Jefferson, perhaps the first American wine expert, reported that he found less and less pleasure in wine as he grew older -- was that age or simply a growing lack of sensitivity caused by his exposure to the flavors and aromas

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Or, is there something special about TCA that makes it eternally "fresh" so that an experienced taster can work out accurately and subjectively whether TCA is present in the wine?

Or, do experienced tasters have training in how to continue to be able to accurately identify flaws like TCA in wine? Is that even possible?

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It sure would be helpful if there were an practical objective method of identifying TCA.

Regards, Bob

Bob,
I'm considerably older than most of the posters here and I can state with little doubt that, unlike other stuff, age has not hindered my ability to detect TCA. Does age affect others in their ability to detect TCA? I have no idea.
I'd also submit that some of what is described as bottle variation may well be sub-threshold amounts of TCA that comes across as stripping the wine of fruit/flavor/complexity.
BP

[David M. Bueker]

Increased!!

I used to miss a lot of corked bottles. Now I can spot one from across the room.

I think that there is a lot of suggestability in this matter.

Quite often, I wonder whether the wine is corked on first sniff of the cork and the neck of the bottle but cannot then detect the offending smell with confidence on the nose or palate from a glass; nevertheless my enjoyment is spoilt by doubt. The effect is compounded when my wife sees me taking an extra glass to try the wine and immediately declares it badly corked. Is that because her perception is sharper or because my behaviour has suggested "corkiness" to her? Then often my wife or a friend cries corked when at first I have noticed nothing. Sometimes opening a "clean" bottle makes me see their point but not always.

Undoubtedly perception thresholds for TCA differ from person to person but I sometimes wonder whether the declared contamination is real.

I am certainly more aware of and experienced in TCA than when I started drinking wine about 50 years ago although my physical ability to perceive it may have dulled.

Now I can spot one from across the room.

Does it need to be an open bottle?
BP

[David M. Bueker]

Now I can spot one from across the room.

Does it need to be an open bottle?
BP

Nope. Heck, I have a friend who can spot a corked wine over the phone. Some folks are just more sensitive than others.

I believe sensitivity increases... not only to corked wines but to poorly made wines in general.

Can’t really say if ones sensitivity to a given chemical stimulus decreases or increases, but surely after repeat exposure to a given stimulus one can get accustomed to it. It’s like coming home from a hard day’s work, while walking up the walkway to my front door I can actually smell what I’m eating for dinner. But once in the house and I investigate, eventually my sense of smell actually becomes dull or accustomed to the aromas (and I don’t notice them as much).

Salute

This is put out by the Wine Institute. No mention of age is listed. Anecdotal evidence only -- I have become much more sensitive to TCA over time. Carole used to beat me hands down on finding corked bottles, but I opened one a couple of nights ago that was corked. She did not agree until she tasted it against a fresh bottle.

Trichloroanisole (TCA) Fact Sheet
September 2003

There have been some recent press articles on the presence of TCA in wine which have raised questions regarding the subject. We offer the following facts for consideration:

Trichloroanisole (TCA) is the natural compound that at higher levels can impart "musty" flavors and aromas to wines, other beverages and foods. Wines that contain TCA at a detectable level are described as either being "corked" or having "corkiness."

Cork is a major source of TCA in bottled wine, although experts indicate that TCA in wine may be derived from sources other than cork, such as from barrels or other sources of wood.

TCA does not pose a health risk to consumers. There are no government agencies in any part of the world that have sought to regulate TCA levels in wine.

Wineries in most wine-producing countries, along with the cork industry, continue their research efforts to minimize the presence of TCA in wine. These efforts are under continuous review by the Wine Institute's Technical Committee.

The sensory threshold for TCA of a few individuals can be measured in the parts per trillion. There is no conclusive evidence that wines that exceed any one particular level of TCA will result in detectable negative taste characteristics for any significant portion of the wine-drinking population. Many award-winning wines contain levels of TCA that are detectable by instruments but not by consumers. Therefore, there is no single, fixed level of TCA that distinguishes a "good" wine from "bad."

TCA analyses from a reputable laboratory provide the industry with valuable quality control data. Such data are one of the many tools available to today's winemaker, but cannot, and should not, be a substitute for consumer sensory judgment.

Perception of TCA by consumers is governed by many variables, including alcohol content, wine characteristics, and the sensitivity of the consumer. The consumer threshold of perception of TCA varies dramatically according to experience and inherited genetic capabilities. The research literature indicates that the existence of minute traces of TCA in award-winning wines does not impair product quality.

Bob,
Without being able to directly address your question, I would nonetheless point you to some interrelated phenomena:
1. Our senses grow less acute with age
2. We can habituate to most stimuli if exposed to them frequently enough.

I would argue that the first accounts for chefs' growing insensitivity to salt with time and that the second accounts for the chili pepper phenomenon (in support of the latter idea, I can note that my wife eats less hot food now than formerly owing to some stomach problems and now finds herself more sensitive, not less, to chili peppers)

TCA is a different kettle of fish, I think. We probably do gradually lose some sensitivity to it, as our sense of smell as a whole becomes less acute, but since we can detect TCA at low ppb levels, I'd guess that even the elderly can still detect it at low ppm/high ppb level. And, with luck, no one is exposed often enough to TCA to habituate to it, not even RMP.

Mark Lipton

The phenomenon I’m trying to describe is “adaptation”; basically all our senses do this. After experiencing a given stimulus (first at low concentrations, possible increasing concentration levels over a period of time) our senses almost immediately try to “re-adjust” so that they are as ‘acute” as they were before the stimulus was experienced and we are once again “aware of our surrounding” Basically by doing this however we don’t recognize or become consciously aware of certain things. Unless of course one has a “reaction” to certain exposures, let’s say your checks, throat and neck swells up or you break out in hives. (Our mind definitely knows its there but doesn’t tell us- the difference between “drinking and ‘tasting”). So I guess, especially at a social event (dinner with family and friends- non wine geeks) after drinking a wine that with the first sip might of seemed slightly tainted with TCA or corked, or just slightly ‘funky”(just at or slightly above ones personal perception threshold) by the end of the evening ones sense of smell might of ‘adapted” to the TCA.or corkiness It’s unfortunate, that the majority of people just “drink” wine and they really don’t “taste” it.

Salute

It sure would be helpful if there were an practical objective method of identifying TCA.

This is impossible, Bob, due to varying sensitivities. Did you know the threshold concentration difference between the most sensitive 5 percent of people and the least sensitive 5 percent is nearly 2000-fold? This clearly demonstrates why most complaints about cork taint arise from only a small proportion of people, and why there are disagreements about whether a wine is really corked.

Randy, thanks very much. That information helps me understand the effect of TCA much better.

I put down Parker's growing insensitivity to aromas and flavors to age. I've seen this in my own wine perception as I go into the 50s.

I think TCA is kind of like phenolphthalein. There are genetic "tasters" and "non-tasters". I've encountered non-tasters occasionally pouring wine in tasting rooms in wine country. On one occasion, I was served a sample that positively reeked of corkiness, but when I pointed this out to the server, he adamantly denied there was any problem. I asked him to have a companion behind the counter try the wine. The second server exclaimed, "phew!" at first sniff, poured the rest of the bottle down the drain, and served me a new (and untainted) sample. Ability to detect TCA seems to be all over the map. I know of people far more sensitive than I am to it, and also, as mentioned, those seemingly totally unable to taste or smell it (lucky them!).

-Paul W.

As long as TCA is the exception rather than the rule, experience will enhance one's ability to discern it.

Great topic, Bob, lots of interesting answers. I think there's a few key things to keep in mind.

First, it is key to keep separate two different variables (that, alas) covary. There is first the effect of age (where folks have suggested either a general negative effect with sensory decline or no effect). There is second the effect of experience where two different effects have been hypothesized. First, experience may decrease the ability to detect TCA (as Victor has suggested) due to the subject adapting to the stimuli over time. Second, experience may increase the ability to detect TCA as David and Ryan has suggested. Resolving whether ability to detect TCA increases or decreases with exposure to TCA is, as they say, an empirical question. But my guess would be that Ryan and David are correct that the ability increases with exposure. I don't expect this is because our sensory organs actually become more adept at picking up the sensory elements of TCA. Rather, I think our brains become more adept at putting together fragmentary pieces of sensory information to categorize and identify what a given combination of sensations represents. So it isn't only the exposure to TCA, but the exposure to TCA knowing that it is TCA that builds a template of memory and experience in our brains. Then when we are exposed to indicators of TCA our brain needs less and less information to correctly identify the mix of sensations as TCA.

I have noticed this with regards to other senses. After an unfortunate incident on a bicycle, I noticed that I was much more conscious of my peripheral vision. Presumably the ability of my eyes to see did not increase, but the priority of those signals within my brain had likely increased. Similarly, they just had an article in the Economist on the acoustics of Greek theaters where they found that they were effective for conveying sound as the surfaces did not reflect sounds at a certain frequency--which left out non-useful sounds such as the wind, but also eliminated some frequencies of human speech. But it didn't matter because the theater patrons received enough sensory input from human speech to have their brains fill in the rest (without even noticing it). I have certainly noted this when learning foreign languages when I get frustrated because I think I need to 'hear' every word, when we often don't 'hear' every word in our native languages, our brains just fill in the gaps. If our brains are filling in the gaps for TCA, the association with past negative TCA experiences could actually increase the negative sensory experience with TCA--making you not only more acute to TCA but making each accumulating experience with TCA increasingly unpleasant.

So I think the thing that keeps TCA fresh is that powerful learned negative association with it.

As someone who has low sensitivity to TCA and rarely identifies it, I think this is a rousing call for TCA ignorance for people like myself. The more I learn how to experience TCA, the more likely I will be able to identify it and turn those marginal cases of TCA from what right now might be forgettable wines into undrinkable ones!

Is it possible that wine lovers who have been drinking wine for twenty or thirty years may lose some of their ability to identify TCA in wine?

I've read plenty of criticisms about Parker's growing insensitivity to other aromas and tastes in wine.

Bob,

I'm 63 years old and I would say my ability to identify corked wine has increased with experience.

Parker is so controversial that it is hard to put any stock in anything anybody says about him. To your point, I don't know of any factor from over consumption that deadens one's ability to taste. However, if one's liver has been partially knocked out, s/he could become intoxicated more easily and thus less perceptive about everything, including flavors.

Covert