The next time you open a bottle of wine, take a closer look at the stopper, or maybe even give it a sniff. Whether it’s made of natural cork or a manufactured material, it may have been specially designed to eliminate tainted wine.
Cork taint, most commonly caused by trichloroanisole (TCA), affects a significant percentage of bottles each year. At best, it lessens enjoyment. At worst, it ruins a wine.
Last month, Amorim, a Portuguese company that produces more than 5.5 billion wine stoppers annually, announced it had eliminated cork taint from its production.
“We managed to deliver on an important promise, which is to be able to get rid of TCA and defeat TCA once and for all,” says Carlos de Jesus, director of marketing and communications. Amorim did so by using temperature and pressure to remove TCA and other contaminants during production.
Meanwhile, California-based Cork Supply announced all its natural cork closures will also be TCA-free starting this year. The company is using a two-step process, modified from steam-distillation.
“We honestly think we’re not going to have too many TCA conversations a year from now,” says Jochen Michalski, Cork Supply president and founder. “Hopefully TCA will be a dead topic.”
That topic has long been an embarrassment to the wine industry, which has attempted to address it for decades. Starting in 2015, some suppliers began offering corks individually tested for TCA, using gas chromatography and other methods. Charles Auclair, owner of Auclair Winery in Woodinville, Washington, was an early adopter.
“I said ‘I’m done with cork unless you guys have something else,’” he says. “I was tired of getting corked bottles back, and I was tired of finding them myself.”
Auclair has been satisfied with the one-by-one tested corks with one significant exception: the price.
“They are very expensive,” he says. “There’s a very big difference in cost.”
For his entry level wines, Auclair uses composite corks that cost one-sixth the price of the individually tested natural corks.
“It’s already a low-margin wine,” Auclair says. “Using the [one-by-one tested] corks there just doesn’t pencil out.”
“We honestly think we’re not going to have too many TCA conversations a year from now.” —Jochen Michalski, president and founder, Cork Supply
Compared directly to other natural corks, individually tested ones add a seemingly modest cost of 15 cents extra per cork. However, for a product that can cost anywhere from pennies to a few dollars, that cost adds up quickly. For a 10,000 case winery that otherwise spends 50 cents per cork, that fifteen cents adds an additional $18,000 to annual cork spending. As a result, wineries may relegate their use to more expensive wines to offset the additional cost.
Significantly, Amorim and Cork Supply’s new processes will be applied to all corks during production at no additional cost to wineries.
While eliminating TCA was the main impetus for Amorim and Cork Supply making these changes, another was fending off various cork-like alternatives, which, along with screwcaps, have made significant inroads in the market in recent years. In particular, microagglomerative stoppers, also referred to as technical or composite corks, are surging.
“If you asked me, ‘Of all the closure markets, which is the one that is growing the most?’ It’s technical corks for sure,” says Michalski.
These are made from ground cork granules, and go through a process to remove TCA and other contaminants. In addition to being TCA-free, they offer other advantages.
“We consider that cork is the best way of closing a bottle of wine, but cork is inconsistent. It grows on a tree,” says François Margot, director of North American sales at Diam, a France-based company that has been producing TCA-free microagglomerative corks since 2003. “The density and elasticity and mechanical performance can vary a lot.”
This can lead to significant bottle variation. As a manufactured product, Diam closures are not only highly consistent, but the company also offers fine-tuned control over how much oxygen is released into the wine.
“Winemakers can choose what they need that is best for their wine,” Margot says.
Diam currently produces 2.4 billion closures annually and is growing.
“We consider that cork is the best way of closing a bottle of wine, but cork is inconsistent. It grows on a tree.”—François Margot, director of North American sales, Diam
Mark McNeilly, owner of Mark Ryan Winery in Woodinville, first came across a Diam closure on a high-end Chablis.
“I pulled this cork out, and I had to look at it like six times before I understood that it was a composite cork,” McNeilly says. “It was beautiful and looked like cork.”
After several years of trials, the winery switched production to Diam.
“We’ve never looked back,” McNeilly says. “The wines are aging beautifully the way we would expect wines to age under natural cork, but the consistency in the bottle is what we’re really impressed with.”
Another alternative gaining in popularity is Nomacorc, produced by North Carolina-based Vinventions. A synthetic closure made from sugar cane, Nomacorcs are 100% TCA free, offer customization of oxygen exchange, are recyclable and are carbon negative. Later this year, the company plans to introduce a new line of closures made from recycled plastic.
“We all believe at Vinventions that the sustainability aspect of our wine closures will become increasingly prominent,” says CEO Denis Van Roey.
Marty Clubb, owner of L’Ecole No. 41 in Lowden, Washington, first used Nomacorcs on his white wines before expanding to other parts of the lineup. He’s been impressed, both with their performance and with how much they look like natural cork.
“Literally, we’ve never had a problematic bottle,” Clubb says. “And every time I pull one, I go ‘Wow. This looks great.’”
However, Clubb continues to use natural corks too. He takes the money saved buying the less expensive Nomacorcs and purchases traditional corks for his top-end wines that are individually tested for TCA.
“I’m open-minded,” Clubb says. “We’re not stuck in what we’re doing, and quite frankly, I think all of these cork suppliers now have upped their ante significantly.”
Although alternatives are ascendant, natural cork still dominates the industry. Now, however, winemakers also have an abundance of cork-like options to choose from. Some alternatives can promise fewer cork-tainted bottles, less bottle variation and sustainability, with the latter one of natural cork’s selling points.
And while screwcaps remain popular, these new closures offer something screwcaps cannot.
“Using a corkscrew is not to be underestimated,” says Michalski. “I think it adds a lot to wine.”
Last Updated: May 8, 2023