I bet a dog could detect it without even opening the bottle.
Maybe I’ll train one and sell it to a wine retailer. They could then sell their wine as TCA free and dog-approved.
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A Napa winemaker opened a bottle at a tasting for us. He got cork out and said “oh it is corked.” Once you get a whiff you don’t forget. Unfortunately (I guess) I am fairly sensitive to low level TCA. Interesting that some people can’t detect it at all.
Completely disagree. Unless excessively funky, I normally enjoy bretty aromas, but automatically recoil back from moldy aromas.
TCA belongs to haloanisoles, which is a group musty-smelling compounds that common mold and other fungi produce when they turn toxic phenols into nontoxic haloanisoles. TCA is biomethylated by molds from phenols in cork bark with chlorine. TCA is just one of the many musty-smelling compounds molds produce, so I think it’s quite appropriate to say TCA smells moldy. Around here are a few obviously water-damaged buildings and if you walk around them, in some places you get that moldy/mildewy smell (don’t know which one - we don’t differentiate them in Finnish language) that is a dead ringer for TCA.
Other common cork taints (or just musty smells) are tetrachloroanisole (TeCA), pentachloroanisole (PCA) and tribromoanisole (TBA), which - just as TCA can - come from wood preservatives which are biodegraded by certain fungi.
Wet paper or cardboard per se doesn’t smell like TCA. It’s only after it has turned moldy (or mildewy) you can get that smell. You can buy a new cardboard box and soak it all you want, but before it gets infected by certain fungi, it doesn’t smell like corked wine, just wet cardboard. Also moldy bread or fruits don’t smell of TCA either - the aroma comes from compounds in wood, not in, say, grains or fruits.
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Years ago, when I was an excited wine pup, I went to a Beringer tasting in Chicago featuring Ed Srbagia, their head winemaker at the time. I was amused that people seemed nervous interacting with him, so I decided to say hey. A minute after we started chatting he turned to an acquaintance and said, “Hey Jim, pull that last bottle of Chardonnay, it’s corked.” He was about to dump his glass, and i said, “Wait! I want to smell it!” He obliged, and it was total wet newspaper, especially compared to my glass. I’ve never forgotten the smell since, and have experienced it all too often, especially with bottles from the late 90’s - early 00’s.
I now get irrationally excited when I open a corked bottle for novices, especially when I have a duplicate bottle. In my mind, I’m hoping to be their Ed, I guess.
TLDR Ed Srbagia was pretty cool, and not intimidating at all, and I identify corked wines as smelling like wet newspaper.
Someone once asked me if you can buy samples of TCA in different concentrations. I had no answer.
I am right there with you.
I am extremely sensitive to TCA.
I don’t how to describe the smell; to me it just smells like TCA.
I don’t think people are saying that wet cardboard produces TCA; just that the smell of wet cardboard is very similar to the smell of TCA – probably, as Otto suggests, because wet cardboard is a good medium for mold.
I agree that it’s pretty much impossible to describe many smells. But in this case, there is a very close analogy that most people have experience with.
I guess it’s possible if some wet cardboard is left outside, someone sprayed bleach on it, then the right mold attacked it, you could get TCA. Otherwise, just soaking some cardboard doesn’t smell like TCA, even if it sits around for a while. Trust me, I’ve had wet cardboard outside my house, and it does not smell like TCA 
One more time: describe the smell of cinnamon to someone. You cannot. You. Just. Cannot.
Same is true of TCA. People need to STOP trying to describe it to other people.
Good organic chemists can probably identify hundreds of compounds by their odor. I’m a lousy organic chemist, I might have been able to identify maybe 50-100 compounds at one point. But what I can’t do is describe the aroma of a chemical compound to someone who has never smelled it.
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I’ve worked in a couple of labs where we analyze wines and corks for TCA. Quite a few people have come in not knowing what TCA is supposed to smell like and not being wine nerds or even wine drinkers. I’ve never heard anyone, unprompted, describe TCA as smelling like wet cardboard. I’ve always found that descriptor frustrating myself because, as Alan said, most wet cardboard doesn’t smell like TCA, it has to be have a specific type of fungus around and the availability of chlorine to form TCA.
The most common unprompted description I have heard is “carrots”, and “baby carrots” has been my most successful comparison when describing TCA to new people. Also as pointed out earlier, this is because quite a lot of carrots do actually have TCA.
The other places I have smelled TCA are a walk-in refrigerator and on a fallen redwood root structure.
You can buy TCA pretty cheaply. That is, 2,4,6-Trichloranisole. Maybe $200 for 25g, or $30 for a small sample. I would never recommend that you purchase some, create a liquid solution, put it into an old bitters bottle and dash it into the wine glasses of people you don’t like at parties. EDIT: This turned out to be a poorly pitched joke. Please do not buy and work with TCA unless you have appropriate materials handling systems in place.
Thank you. I say this kind of thing all the time to people when talking about sensory detection of wine faults. I think it’s even more of an issue in other faults, such as Brett, which can have a range of sensory manifestations and associations, whereas TCA pretty much just smells of TCA.
EDIT: my suggestion to buy TCA and dilute it was supposed to be tongue-in-cheek but I clearly missed the mark. Please don’t do that.
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You could mix a corked wine in a different non-corked bottle (probably fairly cheap) in different quantities say 10% 5% 1% and see at which point it changes from corked to merely dull.
Do NOT do this.
TCA is extremely, intensely pungent. And human detection threshold makes it very difficult to work with. I wouldn’t even try to handle it outside an enclosed fume hood. Spill it somewhere and you’ll never be able to clean it out well enough to get rid of the odor.
I think you can buy dilute solutions that mimic the levels commonly found in wine. That would be the only way I would try to approach a sample of TCA.
Not weird. I’ve had faucets and a toilet that had TCA. Alan, people mention wet cardboard because it’s often tainted.
I’ve had corks some of the TCA but not the wine, that seems weird.
I think you can develop a sensitivity to TCA. I think after exposure to a horrifically tainted wine my sensitivity increased.
I think this comes from wines that have been kept in moldy environments (or in an environment otherwise filled with TCA), where the cork can soak up that moldy-smelling air so that the other end smells like corked, but since the molecules can’t traverse through the cork, the wine stays perfectly fine.
You really can’t smell TCA from corks normally, because you really can’t smell those TCA molecules through the cork when they are residing within the cork. However it takes only a minute amount of TCA in the wine (down to only a few nanograms of TCA per a bottle of wine) to ruin the wine and that stuff gets volatilized easily in a wine (as the wine evaporates), so it doesn’t take much to have the TCA seep into the wine from the cork. However, if the non-wine end of the cork has been in contact with moldy air, those haloanisoles remain on the surface of the cork and once you sniff it, it smells like corked, yet if these compounds haven’t made their way into the wine, the wine is going to be ok.
I think you can develop a sensitivity to TCA. I think after exposure to a horrifically tainted wine my sensitivity increased.
It definitely happens. When I started to work in a wine shop, I could smell faintly corked wines which my colleagues could identify instantly (we had to do olfactory checks for wine faults if they were returned as faulty). Several years later, before I quit working ITB, a tiniest amount of corked wine would smell intensely corked, whereas a newcomer colleague couldn’t even tell if there was anything wrong with the wine. Smelling wines on an almost daily basis for +5 years looking for any faults really does magic tricks for one’s sensitivity in recognizing different compounds (both faults and non-faults) in a wine.
The posts about no acceptable substitute for the real thing got me thinking. This is a reference sample for TCA available from Fisher Scientific. Would a whiff of this educate me?
I didn’t mean weird that they were corked. I meant weird that I invited Jim to come to Philly to sniff my shoes!
I wasn’t thinking clearly at 4 AM.
As Alan said, don’t do it. If you do open it outside. It’s hard to get rid of the TCA taint, so why risk it?
As an intended ‘reference’ sample , would it already be diluted to a relatively low concentration so that it could be safely smelled. Any chemists have an opinion? The concentration is listed in the lower right of the screen shot. Thanks.
I always have 2-3 heavily corked bottles at home - just to show people who don´t know yet how awefully it smells.
A member of our monthly wine-group is a food chemist … he often takes a corked bottle with him to analyze …
The level of TCA that can be clearly dedected varies between
0,001 and 0.005 microgram per litre … easier to smell in white than in red wine.
I personally smell/taste it usually around 0.002-0.003 … sometimes lower (wet moldy cardboard is not a bad description).
At very low levels of TCA we probably won´t smell the TCA directly but the wine tastes unexpressive and muted - certainly different from what it should be … often hard to tell if you don´t know that particular wine …
TCA is so intense that 0.1 gram can spoil a whole sea the size of a football field (just read it online) … nobody should experiment with such a dangerous substance, you maybe won´t get rid of it forever …