Wine 101 TM_W1_CLOSE_FI_001

Closing the Case

Natural cork, screw cap, synthetic cork — is there an ideal wine closure?


“Oh no!” I heard my friend shriek from her kitchen. Had a mouse just run across her foot? Was an oven mitt on fire? Did someone put too much soap in the dishwasher? I couldn’t quite tell, but the loud slamming drawers and cabinet doors sounded rather serious.

“I can’t find it anywhere!” She came running back into the room, her hands full of various utensils. “What about a knife? Or maybe scissors?” she asked with a puzzled expression. “Do you know how to uncork a bottle with a fork?”

It’s happened to all of us before — that awful moment when you realize you’re missing one very essential item — a corkscrew. The lack of one usually leads to a panicky dilemma, but I couldn’t help but laugh at our situation. After all, we were in no real danger. There was no crisis to be dealt with. An easy solution was just one twist away.

“Relax,” I said as I held up the bottle of Australian wine I had brought to her apartment, “It has a screw cap. There’s no need to panic.”

Her face didn’t show any immediate signs of relief. Instead, she looked rather turned off by the sight. “Aren’t those for cheap wines? Or, like, sodas?”

I’m often surprised when someone reacts this way to a bottle of wine that isn’t closed with a traditional cork. I mean, surely you’ve opened a bottle that wasn’t sealed with one before. And chances are, you even liked what was inside. Yet, the stigma remains that screw caps should never be used on real quality wines.

Anybody who drinks wine knows that bottles have customarily been sealed with a cork, and we’ve all been told they are the best type of closure. But over the past decade, trends have grown away from tradition and focus has shifted to exploring other methods. Plenty of newer, alternative options have been introduced — screw caps, synthetic corks, glass stoppers, even crown caps you’d normally find on beers. Is one necessarily better than the other? Well, that depends on who you ask.

Cork has been the default wine closure since the 17th century for good reasons. Natural wine corks come from the bark of cork trees, which are grown mostly in Portugal. The living organic material works well under pressure, which makes it easy to plug a bottle with one. And there’s something extremely romantic about a cork — the way it pops when it’s pulled from the bottle, a sound that represents history and culture, a sound that evokes both nostalgia and excitement when it’s heard.

Even more important, though, is the unique cellular structure cork has, which allows minuscule amounts of oxygen from outside the bottle to interact with the wine inside. Most winemakers argue this “breathing” plays a vital role in how a wine develops inside the bottle and is necessary in order for it to age. It’s this small interaction with oxygen that helps bring the wine’s aromas, flavors, tannins and acidity together over time.

When I visit wineries, it’s not uncommon for a winemaker to open an older vintage to taste in order to illustrate how well the wine will age. I’ve tried amazing wines that were far older than me, ones from a different time and era, which still remain as alive and elegant as ever. Never are they ever closed with anything but natural cork. Every prestigious wine in the world is stopped with one — including Bordeaux, Barolo, Champagne, as well as big Spanish reds — so surely there are grounds for its use. But cork also has its downsides.

If you’ve ever tasted a wine with aromas and flavors that reminded you of musty, wet cardboard or soggy newspapers, you’ve met cork’s fatal imperfection: its vulnerability to 2,4,6-tricholoanisole, a chemical better known as TCA. It’s an incredibly potent substance, and a big problem for anybody who makes wine or enjoys drinking it. When a natural cork is contaminated with TCA and then used to seal a bottle, it can ruin the wine inside. Wines tainted with TCA are called “corked” and can be rather undesirable.

Not long ago, “corked” wines were a major problem. In 2002, the Cork Quality Council found over 4% of natural corks were contaminated by TCA, and in 2005, at an infamous Wine Spectator blind tasting, 7% of bottles were found to be tainted. Experiencing a corked wine is a lot like opening a flat soda — you open the bottle expecting something great, but are met with disappointment. Of course, it seems like a very minor portion of all wine, but the small amount of error was enough to cause a backlash reaction against natural cork stoppers in the wine industry.

In the early 2000’s, several countries pioneered an initiative to promote the benefits of using screw caps — what people in the industry call Stelvin closures, which get their name from the company who makes them. At the time, 80% of wines from New Zealand were closed with them, and numerous Australian producers had been experimenting with screw caps since the 1970’s. Then in 2002, the largest British supermarket, Tesco, lead the way in the revolution when they began to demand certain bottles of Beaujolais, Burgundy, Bordeaux and other wines from France they carried be closed with screw caps. In every case, people were tired of dealing with cork taint.

The problem was so bad that Randall Grahm, owner and winemaker at Bonny Doon Vineyard in California, held a controversial mock “funeral for cork” in New York’s Grand Central Station later in 2002. “Corks at that point were unspeakably bad,” said Grahm, who is well known in the industry for taking oppositional stances on all sorts of customary wine traditions. “Cork manufacturers were in total denial about the problem, and were seemingly unwilling (or incapable) of making any real improvement to their product. Corks were truly untenable.”

After many years of dissatisfaction with “corked” wines, Grahm took the plunge and shifted to an alternative method of closure for his wines. “With no real possibility of going back to cork at least at the time, the opening was there for screw caps.” All of Boony Doon’s wines still remain cork-free today.

When screw caps are used in place of natural cork, the risk of wines being “corked” is eliminated. The airtight seal keeps aromas and flavors fresh, and you don’t need to hunt down a special gadget to open a bottle closed with one. You’ll often find crisp whites, fresh and fruity reds, and rosés popularly sealed with screw caps, which should be consumed while they are still very young.

Winemakers not only choose to use Stelvin closures to reduce the risk of cork taint, but often also to reduce the price of their wine. Screw caps are cheap — much less expensive than natural cork. A lot of the wines I write about and recommend are in the $8-15 range, and a good majority of them are stopped with screw caps. But that doesn’t mean it’s a practical type of closure for all types and ages of wines.

The use of screw caps is still hotly debated all over the world. In 2006, Spain established a cork-only law for 11 of its wine regions — it’s illegal to use any type of alternative closure. And it wasn’t until recently, in October 2012, that Italy finally allowed the use of screw caps, though it didn’t happen without blowback from producers and their traditions. The change came with compromises — wines from specific sub-regions or certain vineyards still must use natural cork stoppers.

The real issue at hand in the discussion is aging: No other material has proven to be as beneficial for the process as natural cork. The truth is, screw caps haven’t been used for long enough to really know how the development of wine over many years is affected, though screw cap advocates disagree.

“There are many misperceptions about screw caps, and one of them is that screw caps are most appropriate for wines that are not meant to age,” said Grahm, a huge advocate of screw caps. “In fact, if you really want to keep a bottle of wine for a long period of time, screw caps will enable the wine to age more slowly and gracefully.”

I’ve found that even the producers that do use Stelvin closures for some don’t close all of their wines with them, especially the high-end bottles they make. Clearly, natural cork is far from dead in the wine world. There’s been great improvement in quality within the cork industry over the past decade and rates of TCA contamination have dropped to less than 1%.

“When cork works, nothing really beats it,” said Carlos de Jesus, Head of Marketing and Communication for Amorim, one of the largest producers of cork worldwide. “It has a unique cell system that cannot easily be replicated.”

Of course, there are companies that do indeed try to duplicate it. Advances in technology have created the possibility of an alternative cork that provides consistent quality without the chance of cork taint. Synthetic corks — alternative closures made from plastic compounds — are designed to look, sound, and function like a real cork, though some are better than others.

“Synthetics have been defined by the lowest common denominator,” said Katie Myers, who works for the leading synthetic cork company, Nomacorc. “People think of synthetic as really hard injection-molded plastic plugs.”

Like the natural cork industry, producers of synthetic cork don’t always share the same standards of quality. Recently, I opened a $6.99 bottle of bonarda from Argentina that was sealed with a black plastic plug. The wine inside had totally suffered, and tasted like chemicals, the way water does when you’ve left it in a plastic bottle in your car for several hot summer days. But I’ve also uncorked wines with more sophisticated synthetic corks made by a company like Nomacorc, and the wine inside was fresh and elegant. Even better, it was TCA-free.

“Ultimately, what consumers have to understand, is that there are different qualities of synthetic closures,” said Myers. “Not all companies are using patented technologies.”

When it comes time to definitively decide which kind of closure is best for all wine, there really is no clear winner. Natural cork, screw cap, and synthetic cork all have their place in the wine world. Every wine is different — a closure that works well for one type isn’t necessarily good for another. But instead of making a huge fuss over the ideal stopper, I suggest you just uncork, unscrew, whatever you have to do, and enjoy the wine inside.


I’ve selected the bottles below to illustrate that good wines can be stopped with a range of closure types.

Quinta do Crasto ‘Crasto’ 2010

Douro, Portugal, 13.5% ABV, $14.99
Vibrant and purple in the glass with raspberry and smoky aromas. Herbal and dark fruit flavors are well supported by silky tannins that should only get better with time. Natural cork closure.

XYZin 10 Year Old Vines Zinfandel 2010

California, 14.2% ABV, $14.99
Deep ruby in color and perfumed with sweet raspberry and baking spice aromas. Fruity and bold, but quite easygoing and easy drinking for a California zinfandel. Closed with Nomacorc Synthetic Cork.

Tora Bay Single Vineyard Sauvignon Blanc 2012

Martinborough, New Zealand, 12.0% ABV, $13.99
Brightly aromatic with hints of grapefruit, green apple and wet stones on the nose. A white wine that is as fresh and juicy as it gets, with mouthwatering acidity and crisp lemon flavors. Screw-cap closure.

Heinrich Zweigelt 2008

Burgenland, Austria, 12.5% ABV, $16.99
An elegant, textbook example of Austrian zweigelt, with ripe cherries and dried green tea aromas. Young and fruity in the mouth, with a lasting spicy finish. Glass closure.

Illustration by Claire Jelly

Shelby Vittek is an award-winning food, wine, and travel writer. Her food writing has twice won awards from the Association of Food Journalists. Her writing has appeared in the Washington Post, The Smart Set, the Philadelphia Daily News, The Triangle and on and She is currently an MFA candidate at Rutgers. Follow her on Twitter: @bigboldreds.


  1. gabe says:

    one last thing about cork – it is natural, renewable, compostable, and bio-degradable. synthetic closures and screw caps may work as a wine seal, but once they’re done with that use, they become trash.

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