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Unveiling the Mystery of Cork Taint

3 minute read
updated 18 May 2023

When it comes to the world of wine, there’s one wine fault that wine lovers dread: cork taint. Scientifically known as trichloroanisole (TCA), cork taint has the power to alter the flavours and aromas of wines. It creates a musty or mouldy odour – think of a dishcloth that someone hasn’t wrung out & has left scrunched up on the side … or wet cardboard.

Let’s take a look at the science behind cork taint. We’ll explore its causes, and discover how the industry is working to combat this phenomenon.

Understanding Cork Taint

Cork taint is caused primarily by the presence of TCA, a chemical compound that can contaminate cork. Unfortunately it then affects the wine. TCA is formed when certain fungi interact with naturally occurring compounds, such as airborne mould spores or chlorinated phenolic compounds that are used in the production of cork.

However, it’s not JUST about the cork – TCA can be found throughout a winery (for example, contaminated barrels, cardboard boxes). The North West Wine Report (US based) attempted to crunch the numbers around how much cork taint comes from sources other than the cork. Their estimate? Roughly 6%. Although it wasn’t a massive sample size, it suggests that using something other than cork to seal a wine goes a long way to reduce the risk of cork taint.

The Impact on Wine

When TCA contaminates a wine, it can lead to a range of negative effects on its sensory profile. The most common is a musty or mouldy aroma. Think damp cardboard or wet newspaper. At low concentrations, TCA strips a wine of its (delicious) fruity aromas and flavours. This often causes more problems for producers than a really obviously faulty wine – because the wine just tastes ‘meh’, consumers can take this on board as “well, wines from XYZ brand are all just a bit boring”.

Industry Response

The wine industry has not turned a blind eye to the issue of cork taint – it’s a BIG problem after all.

In Australia, we’re very lucky to have had parts of the industry pioneer the use of alternative closures. In the early 2000s, Clare Valley producers banded together to produce whole vintages of wines under screwcap and today, well over 90% of Australian wines are sealed with a screwcap. This goes a very very long way to eliminating cork taint.

But there are plenty of consumers who love the pop of the cork and associate it with fine wine. And there are plenty of producers around the world still using it … so what can they do?

  • Quality Control: Stringent quality control measures are implemented during cork production to identify and eliminate tainted corks before they reach the wineries.
  • Improved Cork Production: Cork manufacturers are continuously investing in research and technological advancements to reduce the risk of TCA contamination in their products. Innovations such as steam cleaning, supercritical carbon dioxide treatment, and individual cork testing are being implemented to improve the quality of natural corks.
  • And, of course, hyper-vigilance in the winery to eliminate the small percentage of cork taint issues that aren’t cork based.

And what to do if you find a wine affected by cork taint? Well, if you’re in a restaurant you should be offered a new bottle. If it’s a wine you’ve purchased retail, take it back to the bottle shop and they should replace it for you. Of course, this only really works if it’s a recent purchase (and you still have the receipt!). If it’s a wine you’ve cellared for years or bought at auction, then unfortunately you just have to to chalk it up as a (disappointing) experience.

Want a wine NOT sealed with cork? Even super premium producers avoid cork in Australia … for example, Henschke wines, such as the Mount Edelstone, often come under both screw cap and Vinolok.

  • Henschke Mount Edelstone Shiraz 2016

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