Corks and Screwcaps – How Important Are They For Wine?

One of the age old questions in the wine industry is just how important are caps when it comes to determining the quality of a bottle of wine? Some people will forever argue the virtues of the traditional cork, with a few often going so far as to believe that no wine can attain a high level of quality if it uses a screw cap. Others go in the opposite direction, noting that a screw cap not only prevents wine from being contaminated by a cork, but also allows for easier storage of the wine should you not consume it in one night. Yet others don’t really mind either way, preferring to judge the wine on its own merits once they have completed a taste test.

So what is the truth about all of this? Does the cap that a wine bottle uses actually have an effect on the quality of the wine? How important are there to the wine industry?

Before we can start answering those questions, let’s first take a slightly closer look at each type of cap to see what each has to offer on its own merits.

The Cork

Used throughout Europe since the Middle Ages, the cork clearly has something going for it to have survived as a method of capping wine bottles for over 600 years. A completely natural product, it is one of the few materials capable of holding wine in a bottle without allowing it to seep through, explaining its popularity in an age before humanity was capable of creating alternative methods of capping. Interestingly, the rise of the cork cap also coincided with the rise of glass bottles for wine storage, lending further credence that the two going hand in hand is crucial to the quality of the wine.

Beyond being a natural resource that is also completely renewable, corks have been proven to allow wines to age properly over the long term, without causing any issues. Couple that with the historic preference towards this type of cap, which again comes from the centuries during which it has been used, and it’s easy to see why so many people equate cork caps with quality wines.

However, corks are not without their downfalls. For a start, the cost of using cork is much higher than creating screwcaps, which is a cost that gets passed onto the consumer in more cases than not. Of course, many will argue that they are happier paying higher prices if it means that they get a better quality product, but that won’t always be the case.

You see, the thing that always needs to be considered when using cork as a bottle cap is that cork is not a uniform material. No two corks will ever be exactly the same, as natural corks breather at a variety of rates and offer different levels of quality. The use of the wrong type of cork will create issues over time.

Further, we now know that cork can end up affecting the quality of the wine, with some estimates claiming that between one and three percent of bottles are affected by cork taint. Cork taint leads to the presence of 2, 4, 6-trichloroanisole, otherwise referred to as TCA, in the wine. TCA creates a mouldy odour that is clearly not desirable in a product that places such a high importance on scent, plus even a small amount of TCA can result on actual mould developing on the cork, all of which damages the wine inside the bottle.

The Screwcap

So as you can see, there are positives and negatives to using cork to cap wines, but the same can be said of screwcaps. Since their introduction in 1964, screwcaps have encompassed the market to the point where the vast majority of wines use them instead of corks. Part of this is due to the fact that the 1980s saw a reduction in the quality of cork production, but screwcaps have plenty going for them in their own right.

For one, the issue of TCA cork taint is completely eradicated, meaning that you know the wine in the bottle has not been affected by an outside substance, unless you consider the materials used to make a screwcap as an outside substance in their own right.

Further, screwcaps make access to the wine much easier as you don’t run the risk of breaking up a cork and contaminating the wine during the opening process. Beyond this, screwcaps offer a more affordable alternative to corks, which generally creates savings that wine producers can pass onto the consumer.

A key concern for cork supporters is that screwcaps and cork alternatives don’t offer the breathability of cork, but even that is less of an issue thanks to modern technology, with numerous studies demonstrating positive results when it comes to wine ageing using caps other than cork. Having said that, not all screwcaps and cork alternatives breathe, which means you need to do a little research to make sure.

As for the downsides, the chief issue is actually an environmental one. Screwcaps are typically made using non-natural, non-renewable resources, which means the argument can be made that bottles using them contribute to higher carbon emissions. Further, screwcaps don’t biodegrade as cork does, though this issue is somewhat mitigated by the fact that you can at least recycle a screw cap.

Beyond the environmental, screwcaps suffer the same issues when it comes to variances in manufacturing quality, as we hinted at when we spoke about breathability, plus this type of cap has a longstanding association with cheap wine, which means it has an in-built, and frankly underserved, prejudice to fight against.

The Final Word

So how important is the type of cap used for a bottle of wine. The simple answer is that it plays a role, but perhaps not as large a one as many people believe. Each type of cap has positives and negatives, but as a general rule we would recommend placing the type of cap used fairly low down on your priority list when choosing a wine.