Red or white? Full-bodied or fruity? The latest debate in the wine world is something that has nothing to do with the flavor — or does it? What’s better: corks or screw caps?
As early as 6,000 B.C. in the Eurasian Caucasus, wine was stored in earthenware containers sealed with stones. A variety of materials for stoppers were tried and erred by ancient winemakers: wax, oil-soaked rags, leaves, and reeds coated in clay and even glass. All of these methods, however, were imperfect at preventing contamination and oxidation.
While historians find it challenging to pinpoint the first use of cork stoppers, many credit Benedictine monk Dom Pérignon as the founding father. As the story goes, Pérignon saw Spanish travelers using tree bark to plug water gourds and discovered that cork could effectively seal a bottle of Champagne.
With some modifications to bottle shapes and sizes, corks remained the mainstream sealer until screw caps came into play in the 1970s.
“There are whole countries that are dedicating all of their wines to screw-cap closure — all of New Zealand and a majority of Australia, for example,” says winemaker Kasey Wierzba of Shady Lane Cellars. But what about American wineries?
In 2019, Shady Lane Cellars started using the Stelvin cap on their white wines, which are particularly sensitive to oxidation — the process of unwanted oxygen triggering a reaction that alters the original substance and can affect its flavor.
“The caps are engineered to close the line up so that it’s void of oxygen,” Wierzba says. “There might be a tiny bit of oxygen in the space in between the capsule and the liner rather than at the top of the wine, but it’s a very minimal amount, and it doesn’t fluctuate over time.”
Another problem that caps solve is contamination by 2,4,6-trichloroanisole (TCA), the chemical compound that causes cork taint.
“The compound is created when specific fungi and bacteria come into contact with some of the chlorinated compounds used to sterilize wood products,” says sommelier Shelley Bynum, wine director at House of Pure Vin. “The amount of TCA that may be on a cork is not dangerous for us to consume, but it does ruin the wine.”
Cork taint results in a musty, damp smell in the wine, which may create a nutty or sherry-like flavor. It can also turn the wine brown.
Furthermore, according to Bynum, TCA can spread from one cork to another by touch, so if one cork in a box of wines is infected, every cork it comes into contact with will potentially be contaminated as well.
“The occurrence of cork taint is small, but if you drink a lot of wine, you’re definitely going to experience it,” Wierzba says. “It affects about 3 percent (of all bottles) so throughout a year, an average wine drinker could experience two bottles that possibly have cork taint.”
If a cork is working properly, there’s not going to be an exchange of oxygen from outside into the bottle, Wierzba explains. However, when corks get old and start to fail, they create an unintended oxygen exchange.
Cascade Winery owner Bob Bonga is also stepping into screw caps, deciding to use them for his fruit wines in recent years.
“We thought that people who enjoy fruit wines probably don’t use a corkscrew as much. They’re just used to good old twist-offs,” Bonga says.
“It really wasn’t more expensive. It’s kind of a wash — bottles are pretty much the same cost, and the metal screw caps are comparable to putting the cork in it.”
Others, however, prefer the old-school corks. Rob Bowman, wine team member at Plum Market in West Bloomfield, adds his two cents.
“In my opinion, I generally prefer natural cork. It works well for older, more expensive wines, and it helps them age correctly. It’s also a tradition. You go to a restaurant and the wine pull is exciting. Screw caps are a bit less classy.”
Bowman raises another point of interest in the debate — sustainability.
“Screw caps are not as eco-friendly,” Bowman says. “Natural cork is cut from the bark of a tree, which grows back. Aluminum is recyclable, but it isn’t a renewable resource.”
Wierzba argues that both are sustainable. At Shady Lane, they recycle the caps as well as the corks through a company called ReCork. “It can be a bit harder to recycle cork, but both play into different niches of sustainability.”
Bonga concludes: “It ultimately comes down to personal preference. I don’t really have one, but the research is out there, and it’s strong enough to say you shouldn’t be afraid of screw caps.”
As the research shows, each has its pros and cons. Corks risk taint with unwanted oxidation, but their breathability does permit microscopic amounts of oxygen to seep through over time, which creates more complex flavors.
Caps provide an air-tight closure and they’re more easily resealable, but they’re also arguably less sustainable long term. And really, will they ever escape the stigma of tackiness in comparison to the age-old cork?
“The word of advice on closures that I give to my customers is to never judge a bottle by its closure,” Bynum says. “I have had horrible, cheap wine under a cork and elegant, fine wine under a screw cap.”