originally posted by Levi Dalton:
I think that TCA becomes more apparent with bottle age. This is purely something I've come to think as a result of experience, and I don't recall ever having read it anywhere. I also believe that TCA becomes more apparent with aeration. But back to the original point, you might store a wine for 20 years. You open it. No question, it's definitely corked. Who do you return it to? The shop might not even be around. You may have moved across the country. The winery may be gone, even.
The same bottle opened 2 hours after purchase in an alternate reality: you don't notice it's corked until the last sips. There is hardly any wine left in the bottle.
In either scenario, the wine probably isn't returned.
I have a large amount of trouble returning corked bottles to distributors. It is a major pain in the keister.
Drinking corked wine makes me somewhat sick to my stomach. I feel ill. It is kind if amazing people don't notice TCA, when you think about it.
It depends on where the TCA is in the cork. If it is at the top, as far away from the wine as possible, it is unlikely that the wine will be corked since a study by Australian Wine Research Institute [AWRI] has shown that external TCA will not penetrate a sound cork.
They applied radioactively tagged TCA directly to the top of the corks in bottles of wine.
Of course if there is TCA at the top of a cork which doesn't reach the wine the corkscrew might then introduce it to the wine on opening either directly or by attaching it to the neck on extraction which in turn might contaminate the wine on pouring.
TCA that is 'available' directly to the wine will 'cork' the wine quickly so AFAIK bottle age is unlikely to be highly correlated with the degree of TCA pollution except in those cases where the amount available and placement is marginal.
TCA definitely "becomes more apparent with aeration" particularly where the pollution is low and/or the consumer has a high threshold which varies enormously for individuals; from single parts per trillion right up to those who cannot smell, even that rank odour, at all i.e. true anosmiacs.
TCA in wine is not very volatile at cellar/room temperature so very low levels of TCA infection, temperature increases, aeration and of course time in the glass will encourage the molecules into the sensing zone in sufficient quantity to be smelled when individual thresholds are reached.
The arguments over whether a bottle is corked even amongst wine geeks are primarily a function of very different individual sensitivities and, partially, experience. Experience of the phenomenon affects the ability to recognise it particularly at low levels, occasionally to the point of excessive attribution even when none of those present, even the extreme sensitives, ever smell the dreaded smell but start referring to the 'fruit being stripped' and the wine being 'not quite right'.
At which point, if available, a second bottle [which is apparently better] is used to proclaim the first one corked despite the continuing absence of the smell as though a cork is the only thing that accounts for variability in a wine. And when it does bingo it must be TCA rather than the several other aspects of wine chemistry that can account for such differences.
Nevertheless it is possible for high threshold wine drinkers to experience a diminution in fruit [but not get the smell] while low threshold tasters recoil from what is one of the most powerful, in sensory terms, of wine-related chemicals. The latter obviously become familiar with the taste of such wines but generally that is not confined simply to a diminution of fruit but is altogether more pervasive.
As far as not finding corked bottles of old wine is concerned TCA in cork was only identified as the musty smell/taste in wine in 1981 although the musty corked problem had been identified well before that. TCA is usually formed these days from the methylation of trichlorophenol by a number of common moulds essentially the detoxification of the halophenol by the mould. Halogenated pesticides and wood protection treatments can provide the relevant halophenol although bleach in conjunction with the phenolic components in cork and other wood is also a route.
If very old wines indeed show very much lower [to zero] TCA infection it seems likely that it could be a function of several possibilities: zero to far less halogenated product/pesticide in the cork forests [now banned] or, as later, in their use as cleaning/bleaching agents in cork production [also ceased]. TCA requires a halogen precursor and if one goes back far enough it is possible none were available around corks and wineries. However halophenols are now widely available in the environment which is why TCA can often be smelled where no cork has ever been: in chlorinated drinking water, wood chips used on flower beds and as ground cover generally, where wood and bleach have been in regular contact, in plastic bagged root vegetables etc, etc.
As far as TCA dissipating over time, this would only happen if the chemical either reacted with another wine component or decomposed to something less malodorous or was somehow re-adsorbed/absorbed into the cork.
None of these are likely bearing in mind there are plenty of old [although perhaps not very old] wines that have had strong TCA infections. Interestingly, ullaged bottles of deliberately TCA-infected bottles of wine apparently did lose their TCA to the cork [natural or plastic] closures over a period of weeks which is why the AWRI changed to glass-closed bottles in studies assessing e.g. the stability of TCA and the effect on its perception against background oxidation. However it is highly unlikely that this would explain the apparent absence of TCA from very old wines. It is much more likely that it was never there.
typos