Cork vs. Plastic vs. Screw Tops: What’s the Greenest Way to Seal a Wine Bottle?
By Christa
Who hasn’t popped the cork on one bottle of wine, only to unscrew a second, and wondered what’s the greenest way to seal a wine bottle? There’s nothing quite like the pop of a cork, of course – though nowadays it’s quite likely that the cork that pops out won’t be cork at all, but rather a plastic cork. And even some nicer wines are showing up on the shelves wearing screw tops instead of the more traditional corks. Now I’m not about to get into a debate about which method of sealing works best – cork lovers will mention bottles coming unscrewed and brettanomyces, while cap lovers will bring up the percentage of “corked” wines, ease of use, and it being the least expensive option – but I would like to talk about which method is the most eco-friendly. I thought the best way to do that would be to highlight the green pros and/or cons of corks, plastic corks, and screw tops.
Natural Cork: Cork is a renewable resource – in fact, cork oaks are the backbone (and protector) of unique and bio-diverse Spanish and Portuguese ecosystems. Cork is harvested from cork trees every nine years by hand – part of what makes it the most expensive option – in a process that leaves the tree alive and able to continue absorbing CO2. It also has the smallest carbon footprint. The main con of natural cork is that its failure rate is higher than that of the other options – some say as high as 5% – and that means waste.
Plastic Cork: Plastic corks are made of, well, plastic, and manufacturing that plastic is as environmentally unfriendly as producing any other plastic. Plastic corks are furthermore not recycleable – or at least, many of them aren’t and there are usually no numbers on the bottom or sides to tell the consumer that is can or can’t be tossed in the recycling bin.
Screw Tops: Often cited as the most environmentally friendly wine bottle closure, screw tops have the highest carbon footprint of the three options thanks to how they’re prpduced and are many times non-recyclable because the screw tops contain both plastic and metal. The main pro of screw tops is that, according to some wine bottlers, they have a failure rate of close to 0% which means less wine is poured down the drain.
I think the winner is pretty clear. So why aren’t wine producers everywhere clamoring for natural cork? For one, it’s expensive – or at least more expensive that a plastic cork. Two, demand is starting to outpace supply, which is driving prices up even further. Three, plastic corks and screw tops offer branding opportunities because they come in colors other than cork. And four, the makers of plastic corks and screw tops launched an aggressive marketing campaign a while back that had the effect of decreasing the use of natural cork (90% to 70% of bottles over a shortish period of time).
As for me? I’ll take a nice organic wine with a real cork from a reliable producer that doesn’t let a lot of corked wine make it out into the world. Seems like the greenest way to get a tipple on, no?
December 22nd, 2010 at 12:50 pm
The real carbon footprint story for wine, however, is the glass bottle. By weight or volume, a case of 12 750ml bottles is only half wine! And even if people recycle the bottles (which most don’t), re-manufacturing glass is energy-intensive. Some producers and retailers are starting to “light-weight” bottles, and there’s even startups investigating bottle recapture and reuse, as is more prevalent in Europe. But the best container for mass-shipped wine is a BOX. That settles the cork issue, too.
Yeah, in case you are wondering, I do research in this area. Don’t even get me started on the whole food-miles oversimplification.