CORK VS SCREW CAP: FOUR QUESTIONS ON THE PROS AND CONS

Remember all those moments when uncorking a bottle marked the beginning of a memorable meal? What about the joy of opening a great wine simply by turning an aluminum screw cap? The cork is still fixed in our imagination as theway of sealing a wine despite the growing number of screw caps that make our life a lot easier. Is one better than the other? Let's compare the two. Perhaps they'll both convince us in the end, but at the very least, we'll know the advantages of each.

Which system is best at sealing the bottle?

Cork: A report by Retecork (the European network of cork-producing areas) insists that the elastic structure of the material and the fact that it is 90% air allows it to adapt perfectly to the bottle. In addition, it is practically impervious to liquids and is essentially slip-proof, which guarantees that the bottle stays perfectly sealed.

Screw cap: On this matter, the representatives of EAFA (European Aluminum Foil Association) have no doubts whatsoever. For decades, the screw cap has proven its effectiveness in water bottles and spirits—and in much of the world, wine too. “Screw caps protect against contamination and preserve the aromas, flavors and freshness of wine,” states the association.

Which does more to improve the wine?

Cork: According to Retecork, “The combination of oak barrel and cork, which both originate from trees that share the same botanical genus, Quercus, is unbeatable when it comes to producing wine with the finest qualities.” It is true that cork allows for micro-oxygenation (in other words, it allows minute amounts of oxygen into the bottle), which can have positive effects such as tannin reduction, lower astringency and the elimination of reductive aromas (which diminish the fresh sensation of a wine).

But... When we say a “wine is corked,” doesn't this mean the cork had a negative impact on the wine? It is an unpleasant and immediately recognizable flavor... We won't get overly technical, but rather transcribe part of the answer provided by Retecork: “It is an alteration of the wine's flavor that is mainly caused by the presence of trichloroanisole (TCA). (...) Thanks to on-going studies, we know that TCA is not a molecule exclusively limited to cork or wine. TCA has been found in bottles that were never sealed with a cork and can even present itself in other food products, beverages and materials.” In other words, no sealing system would be immune to TCA contamination.

Screw cap: According to EAFA, the system's biggest advantage is that it does not alter the contents of the bottle. Only the liquid itself improves; the cap simply protects it from undesirable external influences. But let's look at some figures to determine how much more effective a screw cap is vis-à-vis a cork. According to data provided by the association, between 2% and 5% of traditionally bottled wine (worldwide) goes to waste, whereas for screw caps it is only between 0.2% and 0.5%. The screw cap may not improve the wine, but it does offer a better guarantee of keeping it in good condition.

Which system is more sustainable?

Cork: The cork industry has embarked on a true crusade to defend its role in environmental conservation efforts and preserving traditional cork oak landscapes. “Cork harvesting is a sustainable activity, and its profitability is synonymous with the conservation of the cork oak. If there is no demand for cork, these forests lose their economic value and could end up abandoned,” says Retecork. The association adds that “the cork oak has to be protected to maintain an ecosystem that helps mitigate global environmental problems like climate change, loss of biodiversity or desertification, to name a few.” Impressive!

Screw cap: EAFA provides a flood of data to prove that its product is interesting from an environmental standpoint. We like two of the arguments: 75% of the aluminum produced worldwide since it was first manufactured (in the 19th century) is still in use. Recycling is cost effective: the process saves up to 95% of the energy required for initial aluminum production. We'll consider it.

But... Which do we like better?

Cork: The cork is part of a ritual, a tradition of wine drinking; there is a certain magic to it. As an added value, this is priceless. “The cork evokes Mediterranean culture, craftsmanship and good taste,” Retecork explains, “The ceremonial act of opening a bottle of wine loses meaning when the stopper is synthetic. It is no coincidence that the world's finest wines and champagnes are sealed with a cork.”

Screw cap: Enough poetry. EAFA insists that demand for screw caps is rising in the wine market. True, embracing screw caps has been easier for the countries of the so-called New World of winemaking: New Zealand (95% of bottles), Australia (80%), South Africa (60%), Chile (60%)... The screw cap's biggest asset is practicality. “Screw caps are great value for money, easy to open and close with a simple twist, as well as practical in terms of storage and transport,” states EAFA. In 2014, a European survey found that consumers in the continent's big markets already consider the screw cap a more suitable option (68% in the UK and Germany). Even so, it still represents a minority in Spain.

Comparing and contrasting the two, it seems like a tie. Could it be that in the future we'll see even more corks and screw caps existing side by side? Will aluminum seduce premium wines? Will cork lose out among mid-range wines? Will the corkscrew-skilled allow a screw cap to steal their limelight? Will the perennially cork-challenged only order screw capped bottles at restaurants?

What about you? Do you prefer one over the other?