Wine Faults - Cork Taint and Vinegar

Cork is the traditional closure for a wine bottle. Yet one of its drawbacks is that it can actually cause a wine fault.  And, have you ever had a bottle of wine that "had turned to vinegar?"  Well both of these wine faults can ruin a bottle of wine. So let's explore the causes.

Cork taint is due to some degree by natural chemical compounds found in cork.  Known formally as 2,4,6-Trichloroanisole (or TCA for short), this compound, when combined with chlorine and mold can result in a wine that smells like wet cardboard, wet cement or a wet dog. And you don't want to smell these scents when drinking a wine.  It only takes a few parts per trillion to taint a bottle of wine. The results can also be very subtle. With faint levels of TCA, a wine will be striped of flavor leaving a normally rich, fruity wine tasting quite dull or muted.  Often it is so subtle that after drinking the wine you are simply left disappointed without being able to determine why.  Although the cork industry states that only 1% - 2% of corks may be tainted with TCA, Wine Spectator found in 2012 that 3.7% of the bottle they sampled were tainted, down from 9.5% in 2007.  So maybe this is the reason for so many disappointing bottles of wine.

In addition to cork taint, another wine flaw is finding a bottle of wine that has "turned to vinegar."  But can wine really turn to vinegar? The answer is technically yes. But not really.  Without getting into too many technical details, the reason that vinegar tastes like vinegar is acetic acid.  And acetic acid can form in wine when it gets 'infected' with Acetibacter bacteria. This bacteria occurs naturally in the air and on fruit. But it isn't really fair to call tainted wine 'vinegar' since it tastes really bad. It's not something you'd want to mix with olive oil and pour over your salad.

If you ever encounter a bad bottle of wine, as odd as it sounds, do smell it and learn from it. And especially if a wine server takes back a bottle after opening it without even pouring it, ask to have them explain how and why the wine is bad.  Use it as a learning moment.

A couple final thoughts. First, there are no negative health affects of drinking tainted wine.  But who'd want to? And, second, if you do come across a bottle of wine that has gone bad, know that you can return it to the store where you purchased it or, at a restaurant, send it back for another one. 

May all your wines be fresh and wonderful! Cheers!




What About Twist-Off Caps?

Now that we've explored the natural cork, the technical cork and the synthetic cork, it's time to address the twist-off cap. And don't you think 'twist-off' sounds so much better than 'screw cap?'  The twist-off wine seal has been around for at least 20 years, but it still struggles to gain acceptance.  OK, yes, it got its start on cheap bottles of wines, but does that make it a bad thing?  I think not, and here's why you shouldn't either.

Have you ever been somewhere away from home with a bottle of wine only to realize you don't have a cork screw?  Or, have you ever opened an older bottle of wine and experienced a crumbling cork that either came out in pieces or had to be pushed through into the bottle? These are the situations when I'm sure you'd gladly accept a twist-off cap.  But more than just these occasions, the twist-off wine bottle sealer is one that should be more widely embraced in general.  And leading the way on this front, the twist-off cap has been broadly embraced by greater than 90% of New Zealanders and more than 70% of Australians.  

Twist-offs have gained varying levels of acceptance with the wine-buying public, and actually provide a reasonable alternative to natural cork.

Wine is 'alive' in the bottle and minute levels of oxygen are necessary for it to 'live.' It's just a matter of how much oxygen. Natural cork can and does usually lead to a slow evolution in wines by allowing tiny amounts of oxygen into the bottle.  But a cork can sometimes allow too much oxygen into the bottle leading to oxidization of the wine resulting in an undesirable nutty flavor.  Inside the metal twist-off cap there's an inner plastic liner that provides the seal with the bottle.  This seal can actually be produced to allow a controlled level of 'breathe-ability' for wine makers.  This control would seem superior to the unknowns associated with natural cork.

Others may argue that pulling a natural cork is part of enjoying a bottle of wine or that cork produces richness in texture in a bottle of wine.  Maybe. But statistics show that wine frequently becomes tainted to some degree by chemical compounds found in cork.  Formally known as 2,4,6-Trichloroanisole (or TCA for short), this compound can result in a wine that smells like wet cardboard, or a wet dog. Not a pleasant bouquet when trying to enjoy a glass of wine.

Today, twist-offs are especially gaining acceptance for wines that are typically opened soon after production (whites wines such as Sauvignon Blanc, Riesling and Rosés).  And statistics show that most all wines are consumed very soon after purchase. So embrace the twist-off. It's a good thing. Cheers!

Behind the Cork™ Wine of the Week

Looking for an attainable, affordable wine?  You've come to the right place. Each week I feature just such a wine on the Behind the Cork Wine of the Week page of

Please Note: This feature is being moved to a separate offering that will be posted on Wednesday each week.