What is cork taint? Why Are Some Wines Corked? Top 5 Facts About This Sneaky Subject

We talk about serious stuff here, people. When a wine is corked there is not a lot you can do, except crying.

But why is a wine corked? And where does the cork taint come from? Keep reading to find out in our special top 5 list about cork taint.


1. Cork taint can be given by a family of molecules, not just 1

Where does cork taint come from? Cork taint can have a different origin than the cork itself. Cork taint comes from a molecule called Anisole. On top of that molecule are going to be glued some atoms of chlorine. The most common is that 3 atoms of chlorine are glued on top of the anisole and that’s why we attribute cork taint to TCA or Tri Chloro Anisole. But sometimes only 2 atoms of chlorine are stuck on the anisole and that’s called Di Chloro Anisole (DBA). Sometimes 4 atoms of chlorine are bounded to it, that’s Tetra Chloro Anisole. Bromine can also be chemically bounded with anisole, with 2, 4, or 6 atoms of it, forming Di Brom Anisole (DBA), TriBromoAnisole (TBA), and TetraBromoAnisole. Cork taking in wine is not related only to TCA, but rather to this family of 6 molecules.

Where do these molecules come from?

Essentially, the anisole and the gluing of chlorine atoms on it are made by microorganisms that are present in wood including cork. Cork taint can come from a large variety of contamination sources. Virtually any wood that is a little bit humid, and in an environment where there could be a little bit of chlorine or bromine floating around.Let’s remind everyone that chlorine, including the chlorine in tap water, is volatile so it flies and it evaporates into the air, especially when using chlorine-based cleaning products.And this starts at the winery. Many wineries, many old wineries, that had wood structures or wood pallets or any source of bad, humid, rotten wood into them can have entire wine tanks contaminated by cork taint.

Then of course the cork itself can be contaminated.But your wine could be contaminated in your own cellar. If you’re ageing wine in an old dusty or moldy cellar that somehow contains wood treated with chlorine, or a paint that contains chlorine, over time, the chlorine in the atmosphere of your cellar may be converted into TCA and end up contaminating your wine.In the end, it is believed that 1% to 7% of all wines may be affected by cork to some level.


2. If you can’t identify the taint, it doesn’t mean that the wine isn’t tainted!

Cork taint fades the perception of the wine’s aromas and makes wine taste/smell flat and dull. Essentially, cork taint smells like wet cardboard, fungus, rotten wood, old moldy dust.

But that’s if the concentration of TCA in your wine is high enough that you can actually smell and identify the TCA. In many cases the concentration of TCA is very low, so it doesn’t really smell bad or smell like cardboard. But TCA fades out all the other aromas of your wine, the fruit, the oak, the spices, even at a very low concentration. It flattens the aromatic profile, at least your perception of it! So sometimes when you open a bottle of wine that you know and love, you may find it a little tamed, a little shy, and you don’t understand why. It may be caused by cork tainted, even though it may not smell or feel really bad. But TCA does that!


3. Cork taint not only smells bad, but it tastes bad too.

Cork taint smells horribly bad and sticks to you taste buds because it’s a very powerful and pungent aroma, a very dominant fault. But cork taint also destroys the palate structure, the palate textures, all the balance of the wine. It makes the wine taste really harsh. This also why cork taint is so horrible: because it not only smells horrible, but it also tastes horrible. There is no escaping corked wine!


4. We’re not equals at smelling cork taint

And, it gets even worse. Cork taint and the family of molecules that cause it can be smelt and perceived by our nose and our senses at a very low concentration. Sometimes a wine affected by TCA at a concentration as low as one part per million (1ppm) can still taste dull or smell bad. Some people can smell cork taint at 1ppm, not everyone! Some people cannot smell it below 20 parts per million. Others below 50 parts per million. It is said that some untrained palates can not even detect it below a 100 parts per million. So, you could be smelling it really really well because you start detecting it as low 1 part per million, but someone else may not be able to notice it even at 50 parts per million. Meaning the sensitivity to cork taint can vary by a factor 100 between several human individuals! This is why sometimes YOU smell cork, but your friends, your sommelier or your wine shop "expert" don’t. It may not be because they do not know their wine very well, it may simply be that they do not smell TCA really well, or at least as well as you do. Which leads us to the following point…


5. You can reject or return a wine that is tainted

You can reject a wine at a restaurant if it is corked, or you can return it to a wine shop. The producer (the winery) is responsible for reimbursing the shop or providing a new bottle to a shop if a corked wine bottle was returned. It’s the producer’s responsibility also to get back to the cork manufacturer and get compensated for the loss. This is a bit of a controversial topic obviously, in the retail and the restaurant/hospitality industries, because wine shops don’t want to be dealing with returning bottles and sommeliers don’t want to be getting back to the producer trying to get a replacement bottle. But it is your right as a consumer to return or reject a bottle of corked wine.


Bonus: How to avoid cork taint?

Well unfortunately for a wine that is corked under natural cork, or even agglomerated cork, there’s not a whole lot of solutions for us. Many cork manufacturers test the cork for faults, and they’re getting a lot and a lot better at it with modern techniques. But it is never 100%. The only way to avoid completely cork contamination (or almost entirely because it may have originated at the winery itself prior to bottling) is to buy wines bottled under plastic cork or screw cap. This is why countries like New Zealand and Australia are leading the way towards more and more screw caps. Many markets though, especially in Europe, are not ready to accept screwcaps, loving the traditional gesture of uncorking a bottle and hearing the cork pop too much!




Source: http://socialvignerons.com/2019/01/19/what-is-cork-taint-why-are-so-many-wines-corked-top-5-facts/

Image credits: Damian Konietzny