Can a wine be fine with a plastic cork?

Future Tense for May. 21, 2007

By Steve Welker

I’m not really a wine snob, but I play one in real life.

When I tell old friends about the joys of living in North Carolina, I often rhapsodize about our area’s wines. They think I’m knowledgeable. Truth is, I’m a rank amateur, but the turnip truck that dumped me seems to be receding in the distance while I become oriented to the Yadkin Valley Viticultural Area and its products.

Many years ago, my dad often traveled abroad and picked up the European tradition of serving wine with meals. Not every night, but often enough, my parents would have a glass with supper. Sometimes they would give me a sip to educate my palate, but it was years until I developed a taste for wine.

Living in Iowa for 30 years didn’t add to my oenological education. When Hawkeyes reach for a fermented beverage, the label probably says Budweiser, Miller or Pabst. Iowans care less about what year their beer was made than what month. “Did you try the January Icehouse?” “Yes, but I much prefer the February Blatz.”

Iowa claims to have about two-dozen wineries, all seemingly devoted to making “wine” out of anything except grapes. Iowa wines have scents of cranberries, apricots and plums because that’s what’s in them. Also dandelions and roses. The Amanas’ dangerously delicious rhubarb wine, Piestengel, will blow the top off your head.

In school, I studied Spanish and German. Neither equipped me for ordering wines with French names. My education has come at the price of my dignity, lost through a long series of embarrassments. Memorable is the time I tried to impress an executive secretary by taking her to a high-class Davenport restaurant (an oxymoron, I know). “I’ll have the ‘sal-aid nick-oh-ease’ and a glass of ‘sow-vig-none blank,’” said I. “I believe that’s ‘sa-laud nee-schwaa’ (salade Nicoise) and ‘saw-veen-yawn blonk (sauvignon blanc),’’’ said she. If the floor hadn’t been in my way, I would have slid under the table all the way to the wine cellar.

Moving to North Carolina’s wine country has improved both my pronunciation and palate. I know that viognier, chardonnay and cabernet rhyme, never mind how they’re spelled. And when I open a bottle and the wine smells like wet dog or eau de basement, I no longer drink it, because I know it’s “corked.”

We amateur wine snobs all believe the only good wines come in a bottle with a natural cork. Screw-topped bottles and boxed wines are for cheapskates and winos. Synthetic corks might be all right — reputable vintners such as Kendall-Jackson and Clos du Bois (“cloh-doo-bwaa”) use plastic corks — but only for wines to be consumed now. In our received wisdom, we wine snobs believe natural cork, preferably from Portugal, defines a good wine.

We might be right. Science has had a hard time producing viable alternatives to cork.

Cork is bark from a cork tree, a kind of oak. Workers peel the bark every nine years or so, but the process doesn’t harm the tree, so it’s a naturally renewable resource. The oldest and largest known cork tree, called The Whistler, has produced cork in Portugal since 1820.

Beginning with a tree’s third cutting, usually when it’s about 52 years old, an average tree will provide 12 to 18 harvests. In each cutting, an average tree produces enough cork for 4,000 bottles. Like any wood, the cork varies in quality. The cheapest corks cost about 7 cents a piece; the best about 27.

Cork works so well as a stopper because, after being compressed into a bottle’s neck, its cells expand to fill even the most microscopic imperfections in the glass. Those cells also act like little suction cups, grabbing the neck and holding the cork in place (corks didn’t become popular closures until someone invented the cork screw around 1680). And although it is very resistant to absorbing water, natural cork allows a small amount of gas exchange as a wine matures, which helps it “age” and mellow.

As a natural product, cork has only two problems. Cork trees cannot be planted and grown fast enough to meet the rapidly rising worldwide demand for wine. And corks can carry microscopic bacteria and fungi, including one that produces TCA.

If you open a bottle of wine and it smells musty or moldy — like wet cardboard — it’s probably tainted with 2, 4, 6 trichloroanisole. TCA stinks so bad that you could smell an eighth of a teaspoon dissolved in a YMCA swimming pool. TCA is not harmful — except that it ruins the pleasure of drinking any wine it contaminates. And by some industry estimates, it ruins one bottle in every 20.

Bleaching the corks doesn’t work; the fungi thrive on chlorine. Chopping up cork, washing out any TCA and then binding the pieces is one solution, but it’s costly and those corks don’t seal or hold as tightly.

Synthetic corks, in contrast, hold almost too well. Introduced about 20 years ago, synthetic corks made from plastics and resins have names like Neocork, Nucork, Nomacorc and Supreme Corq. Most are manufactured with a honeycomb-like interior (so they can be compressed) and a smooth exterior surface. They’re easily sterilized and the makers claim they add no plastic aroma to the wine (a subject much debated among wine experts). However, the synthetics can be tough to extract and you can pretty much forget about cramming one back into the bottle. They also cost more than natural cork.

However, science has come up with a new (old) solution for replacing corks: screw-top caps.

An Englishman, Dan Rylands, invented the screw cap in 1889, but it never caught on with makers of fine wines. Aside from their aesthetic deficiencies, screw caps posed a problem for winemakers because they’re made of metal that wine’s acid corrodes, producing a distinctly metallic taste. Putting a piece of cork or plastic in the cap hasn’t worked either.

However, French engineers have invented a high-tech screw cap, called a Stelvin, whose surface is sintered with a fine glass coating. It costs more, but it produces no flavors and it is sterile, so winemakers don’t lose money on tainted product.

Stelvin-capped wines have proved popular in Australia and you’ll soon see more on shelves in the United States.

Which gives me one problem.

If the bottle doesn’t have a cork, how will I know the wine is really good ... in the future?

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