Site logo

The Curse of the Cork

by Zoe Patterson Ross

The day my brother was born, my parents put a 6-litre bottle of 1982 Hunter Valley Wood Matured Hermitage from The Rothbury Estate under our house. It aged in peace, nestled in a bed of straw and tucked in a pinewood box, as my brother grew up in the hustle and bustle of the world outside.

On my brother's twenty-first birthday, my father emerged grimy but grinning from the tiny door leading to the underbelly of our house. He was pulling behind him a pinewood box now adorned with spiderwebs and dust.

The small gathering of close friends and family in our backyard smiled when the bottle was brought out. Tastebuds tingling in anticipation, we watched the standard corkscrew take on that giant cork, a vinophiles version of David and Goliath.

But we got a rude shock when the first glass was poured. Without even having to lean closer for a sniff it was obvious there was something wrong. A smell I can only describe as moldy
wet cat came spilling out along with the red liquid, and a hesitant taste test (read: drinking while trying not to breathe) revealed a substance unrecognizable as wine – all the natural aromas and flavours that you expect every time you raise a wine glass to your lips gone, and replaced by a stagnant swill. The disappointment was almost as tangible as the smell.

So, what villain had snuck into our precious wine? Well, any quick Google search for “off wine”, “tainted wine” or “faulty wine” will lead you to a site describing the wine as being “corked” or having “cork taint”. But what the hell is that?
People have been struggling with cork taint for a while, as it turns out. Without at first being entirely sure what caused it, the wine industry has been suffering the effects of cork taint in up to 1 in 10 bottles sealed with a cork. And don’t think that cork taint always produces horrible smells. It’s actually the milder cases that can be the most damaging to wineries. When cork taint doesn’t produce a terrible smell, but just masks the natural flavor of the wine, this makes consumers think the winery produces poor quality vino and not that the particular bottle has a fault.

Faced with the terrors of faulty wine, scientists began to investigate. In 1982, three such heroes–
Hans-Rudolf Buser, Carla Zanier and Hans Tanner – used high-resolution gas chromatography with direct odour characterization and mass spectrometry to identify the corking culprit. Basically, this means that they turned the wine into a gas and then looked at the different chemicals present once they’d been separated out from the bunch. They concluded that a chemical called 2,4,6-trichloroanisole (TCA) was responsible for the weird smell and loss of flavor. Further research has found that the villainous TCA in wine is produced by airborne fungi (several different varieties, in fact). This fungi can either already be in the cork – having infected it at some point after sterilising treatment of the cork – or if the cork is of low quality then it will not provide a good seal, and fungi on the outside of the cork will contaminate the wine on the inside with TCA.

Although TCA and infected or poor quality corks are the most common way for a wine to become contaminated, other studies have shown that other chemicals can be responsible and any part of the wine making process can be affected – hoses, tanks and barrels. Since some of these chemicals (for example,
2,4,6-Tribromoanisole [TBA] and 2,3,4,6-Tetrachloroanisole [TeCA]) can be present because of wood treatment methods, pesticides, or other chemicals used, there have been cases where entire cellars have had to be rebuilt because the origin of contamination hasn’t been identified.

So, TCA…TBA…TeCA…huh. I’ll be honest with you – I get REALLY disappointed when I feel like a scientist has missed a brilliant opportunity to make the lives of all those following in the field a little bit happier. Chemical names are great because they give us so much information about a molecule – things like what elements are present, how they are connected and what shapes they form.  But names like ‘salt’ instead of ‘sodium chloride’ are better for common usage. In my opinion though, the best names will always be those that entertain. Surely we could have nicknamed any of these molecules something along the lines of “The Masked Corksader”, “Cruella de Cork” or “Dr. Corkero”? Or even, considering there are a number of them, my personal favourite: “The Cork Musketeers”! (See how I did that? It’s got both “cork” and “musk” in it. They didn’t give me a degree for nothing.)
But from my experience in labs I am sad to admit that not all scientists are as enamoured of cartoon supervillains as “The Big Bang Theory” would have us believe. Shame. Though, this doesn’t mean that everyone passes by fun nomenclature opportunities – some are starting to head in the right direction. Just check out the Sonic Hedgehog. That one certainly made me smile back in Protein Biochemistry classes at uni. (Any readers know of other great names in the scientific literature?)

I’d love to hear back from readers about this topic – how many of you have experienced the dreaded cork taint? And how many of you have done something about it? Sent a bottle of wine back at a restaurant? Returned a purchase to a bottlestore? Tried the trick of soaking clingwrap in your wine? (Apparently polyethylene – a common type of plastic used to make things like cling wrap and milk bottles – has a high affinity for TCA and can be used to extract and remove TCA from wine. Next time I find a corked bottle of wine I’m definitely experimenting with this.)

Let me know.  Experiences, questions, anecdotes vaguely related to wine….I’ll read them all. Meanwhile, enjoy every last drop of that delicious wine you’re planning to have with dinner – ‘cause you never know when The Cork Musketeers might strike!
© Lloyd Spencer Davis Contact Us