You might think that you’re making a more sustainable choice when you choose wine bottles closed with plastic or aluminum, but the truth is that the traditional cork stoppers are by far the best option.
The superiority of alternate closures like aluminum screw caps or plastic "corks" is a myth that developed in the '80s, following two separate but equally important issues.
The first was identification of cork taint in 1981. A “corked” wine takes on an aroma of wet dog or old socks – not terribly palatable.
The second major issue was a widespread blight in the cork forests of Portugal in the '90s, which led to farmers cutting down infected trees. This issue was quickly highlighted by the media and spun into an ecological disaster.
“The spin on that was, 'See, they're cutting the trees down just like they do in the Amazonian rainforest! They're just raping these forests!'” recalls Cork Forest Conservation Alliance founder Patrick Spencer.
While the reality – that about one percent of trees were affected and removed to avoid infecting the rest of the forests – was far from this conflation, the damage was done, and winemakers began to opt for synthetic closures.
But not only was the unsustainability of cork harvest grossly exaggerated, major advances have been made in identifying corks affected with cork taint before they are used, reducing cork taint from five to ten percent of bottles to just one percent. The reasons for choosing synthetically closed wine seem negligible, especially when you consider the true sustainability of the natural cork harvest.
1. Cork is a Renewable Resource
Wine corks are made from the wood from the cork oak. Cork oak forests grow in seven Mediterranean countries: Italy, Spain, France, Algeria, Morocco, Tunisia, and finally Portugal, which produces 60 percent of all harvested cork.
Unlike many other woods, cork is actually fully sustainable to harvest. Because cork is the only tree bark that doesn’t contain lengthwise fibers, it can be removed without chopping down the tree or harming it in any way. The cork tree restores the bark every seven to twelve years, at which point harvesters can return and harvest it once more.
“It’s not like other crops which require replenishing,” explains Peter Weber, Executive Director of the Cork Quality Council. “It’s more like shearing a sheep.”
These trees are only cut down in the instance of blight or when they die naturally – after between 100 and 200 years. In Portugal, where the trade is heavily regulated, it is illegal to cut down a living cork oak.
“People will say, 'Gee, I was buying screw caps because I thought I was saving the cork forest,” says Spencer. “And it's kind of a devastating thing to hear, because it's the antithesis of what's actually happening.”
2. Cork is Good for the Environment
Not only is natural cork sustainable to harvest, but keeping cork oak forests alive is good for the environment.
The trees naturally grow in biodiverse forests: each tree sustains up to 135 different plant species, according to the World Wildlife Fund, not to mention rare animal species like the short-toed eagle or the Iberian lynx.
Spencer also notes that the Portuguese cork forests boast one of the healthiest honeybee populations in the world.
“There is a great desire not to use a lot of pesticides or chemicals in those forests, because there is a really great balance,” he says.
The presence of these cork forests also keep the North African deserts from expanding all the way to the Mediterranean. The forests have been highlighted as important ecosystems by both the United Nations and the World Wildlife Fund.
To top it all off, cork forests are also carbon sinks. Conservative estimates say that cork forests sequester 10 million tons of CO2 annually (4.8 million tons in Portugal alone).
Image: Wine corks background
3. Cork Stoppers are Recyclable
One of the major points highlighted by the aluminum screw cap industry is the recyclability of their product.
“They’ll always say, ‘aluminum is infinitely recyclable,’” explains Spencer. “But then the question always is, ‘Yes, but can those caps be recycled?’”
Spencer notes that for the most part, screw caps are not recycled in the United States, due to their small size. “They fall through the system as particulate matter,” he says.
This means that to make more screw caps, the industry has to partake in active bauxite mining, one of the more devastating mining industries for the health of the planet and for the health of the people in the regions: well water is contaminated up to five miles around bauxite mines, and respiratory disease is rampant. To top it off, turning bauxite to allum and allum into aluminum is one of the most energy-consuming processes in the world, consuming one percent of all electricity used in the United States.
Making cork stoppers for wine, on the other hand, is far less devastating to the planet. Most modern wine cork factories utilize cork dust from the processing plant to co-generate steam, and in some cases electricity. And now, even small wine cork stoppers can be recycled, thanks to an initiative by the Cork Forest Conservation Alliance.
In 2008, the Alliance collaborated with Whole Foods to collect wine corks from individuals, retailers, bottle shops, restaurants, and wineries. While recycled cork cannot be used to make wine stoppers, it can be broken down into granules and used to make other products, including tiles, footpads for shoes, yoga mats, and floor tiles, to name a few.
The collaboration helped to make the program carbon neutral, an important factor for the Alliance.
“If you start shipping corks around the United States, then in fact what you've done is a disservice to the environment," says Spencer. "Yes, we've got the corks out of the landfill, but if we now add more carbon footprint to those corks, it becomes an environmental negative as opposed to a positive.”
Whole Foods Market's preexisting internal distribution network was tapped in order to ship the corks in a carbon neutral way, thus negating this issue entirely.
“I would never tell a winemaker how to close his or her wine,” says Spencer. “That's a choice that they have to make based on what's best for their wine. But what I will say is please don't close your wine with screw cap or plastic because you think there's a cork shortage or they cut the trees down or somehow you're being more environmentally sound, because you're not.”
Even without the environmental benefits of choosing cork stoppers, wine aficionados often prefer them: cork has been used to close wine for centuries (cork wine stoppers were even found at Pompeii), and it does not change the flavor or the nature of the wine itself.
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