Cork Versus Screw Cap. Eco-friendly or ease of use?
As a wine lover, you'll undoubtedly have had your fair share of wines bottled under a Stelvin closure aka the screw cap, as well as those which use cork. Both are prolific globally in the wine industry with Australian winemakers and many consumers having a strong preference for screw cap.
When you think Australian white and red wine, screw cap comes to mind. For French Bordeaux, Burgundy and Champagne, Italian Barolo or Brunello, Spanish Rioja and Priorat one tends to think cork. Wines from other New World regions of California, South Africa, Chile and Argentina sit closer to the fence with use of both closures for entry and premium wines.
There's an ongoing debate amongst winemakers, wine professionals, and consumers as to which enclosure trumps the other. And several prominent Australian wineries are using cork increasingly in their mid-level wines. So which is better?
While from a winemaker's perspective screw caps offer a more inexpensive option for sealing wines, the fact of the matter is that screw caps are nowhere near as eco-friendly as the traditional natural cork. Cork, which comes from Quercus suber or cork oak tree, is a one hundred per cent natural product with every tree consuming CO2 and producing oxygen. This means cork can be recycled, or if left to its own devices, will eventually decompose the same as most other organic materials out there. Feel free to chuck your wine cork into your compost pile without a second thought. On top of this, natural cork stoppers have the lowest CO2 emissions out of all the wine enclosures available on the market. Whilst shipping cork from Portugal offsets part of cork's eco-friendly credentials, the largest Southern Hemisphere cork oak tree forest sits in Canberra suggesting there is a viable local industry waiting to be unearthed.
Compare this with the screw cap, which boasts the highest level of CO2 emissions and has the largest impact on the environment with its use of plastic and aluminium. Even the increasing popular artificial corks don't hold a candle to natural cork. These synthetic corks are typically made of plastic and like screw caps, take a greater toll on the environment in order to produce them. Both Stelvin closures and some synthetic corks can be recycled but tend to end up in the bin, ultimately winding up as landfill – a poor result if we're working towards making the world a greener place.
Taste and Ageing
Natural cork enclosures have long been associated with quality wine while, outside of Australia, screw caps have tended to be linked with more cheap and cheerful bottlings. Champagne and Port remain steadfast in the use of natural cork for closures of their wines. In Champagne, despite steel caps actually being the closures on the sparkling wine bottles during their production and maturation right up to dosage and labelling. Such significant wine regions, dependent upon premium product quality, putting their multi-billion dollar faith in cork is interesting.
In truth, the belief that all wines bottled under screw cap are lower quality is false. There are plenty of outstanding screw cap wines. Some screw cap wines are sought-after collectables and command a high price, including many premium Australian red wines able to be cellared for decades.
If it's a matter of taste, cork stoppers and screw caps measure up fairly equally. As for ageing, natural cork is a tried and true method for long-term cellaring. When stored properly, wine bottled with a cork stopper can age beautifully for many years. On the other side, recent studies have shown that wine can also age very well under screw cap. This is especially true thanks to recent advances in screw cap technology which allow minuscule amounts of oxygen into the wine, allowing the wine to breathe just like cork.
While cork taint may be a concern for some wine lovers, the reality is that it has a relatively low rate of cropping up and millions of dollars of investment by the cork industry is trying to eradicate this problem. The occurrence of cork taint is thought to range between one and three per cent, with some producers today claiming they produce 100% problem free corks. Of course, the screw cap virtually eliminates this issue.
So what's the verdict?
It all comes down to how you want to define 'better'. Natural cork stoppers beat out the competition for their low impact on the environment. If you're looking to reduce your carbon footprint, try to stick to wine bottles which use natural cork stoppers when possible. If ageing wine is your major concern, the jury is still out but recent technological advances mean you can rely on both classic cork and screw cap to satisfy your cellaring needs. If it's a quick open of a bottle, then screw cap wins hands down.