From Pop to Flop?

Why some wineries are making the shift to synthetic corks or twist-of caps, while others stay loyal to the traditional ways

News | Caitlin Spencer | February 2009

The evolution of the wine stopper: some vintners are making the switch (Photo: Lauren Brassaw)

The reassuring "vvwopp" of a cork being pulled from a wine bottle has long been music to the ears of wine lovers.

Now, after almost three centuries, the wine industry may be changing its tune. Almost all the producers of the prestigious wine in Austria have started topping their bottles with synthetic stoppers instead of corks. Why the change?

Rumor had it that the world was running out of cork. Not true. More than enough cork is produced each year, mostly in Portugal, to more than meet the world’s demand. No, the driving force behind screw caps (Stelvins, as the most common ones are called) is a flaw in cork itself. Although cork is miraculous enough – almost impermeable to air and water, resistant to rot, and elastic enough to be compressed into the neck of a wine bottle – it is susceptible to a contamination known as cork taint, which causes some wines to develop a musty aroma similar to wet cardboard.

Drinking a wine that’s been "corked" isn’t harmful, but it is very unpleasant and frustrating, especially when you paid €28 for that Chardonnay now languishing in the fridge. Needless to say, the Chardonnay’s producer isn’t happy either, since you now associate his or her wines with wet cardboard. Some experts put the value of ruined wine at $10 billion annually.

But the real test is in the tasting. Heuriger Sommerbauer, a traditional wine restaurant, is tucked into a row of 18th century houses along the main street in Perchtoldsdorf, in Lower Austria, lining the streets like Christmas markets under cheery greens and fairy lights. Sommerbauer is a local celebrity hang-out, frequented by an assembly of TV hosts, comedians, singers, actors who live nearby. The Heuriger offers an excellent and seasonal cold and warm buffet in a genuine Austrian ambience, with roughly 26 different house wine specialties. One of them is a fresh white wine called Steinwein, meaning "stone wine," made from the Morillon grape popular amongst locals. A large garden with plenty of seating during the summer months, Sommerbauer is known for regular Heurigen-music and Jazznights. Some evenings, the owner, Erwin Sommerbauer, himself steps out on stage as entertainer, telling stories and jokes until the wee hours with a glass of his own wine in hand, of course. If anyone understood what was at stake here with synthetic stoppers, I decided, he would. Surprisingly, perhaps, he saw advantages on both sides.

"One real advantage of plastic corks is that they don’t produce any ‘corky’ aftertaste that can affect a wine’s quality." Since the 1970s, the dominance of cork seals for wine has come under attack by alternatives like screw caps, plastic, and glass stoppers. And this is no small skirmish: wine stoppers are a $4 billion business world-wide; each year, some 20 billion stoppers go into wine bottles and, increasingly, they are not corks.

The emergence of these alternatives has grown in response to quality control efforts by winemakers to protect against "cork taint" caused by the presence of the chemical Trichloroanisole or (TCA). Cork taint is a term that refers to a set of undesirable smells or tastes found in a bottle of wine, especially spoilage that can only be detected after bottling, aging, and opening. The cork-industry group APCOR cites a study showing a 0.7-1.2% taint rate. In a 2005 study of 2800 bottles tasted at the Wine Spectator blind-tasting facilities in Napa, California, 7% of the bottles were found to be tainted.

"Although plastic corks aren’t suitable for storing wine, this is not an importing criterion when we talk about white wines because they are usually consumed quite young, and don’t need to maturate like red wine." Sommerbauer is not alone – Swiss winemakers have been sealing their white wines with screw caps since the 1920’s, and, more recently, their neighbors in Germany, Austria, France, as well as the United States, South Africa, Canada, New Zealand, and Australia have also begun to replace the tradition-bound cork stopper with screw caps.

"Screw caps are gaining more and more acceptance among wine producers and wine drinkers. But in the end, also the cost factor of the diverse products is impacting the choice whether to use the one or the other."

Research shows that light, fruity white wines with a high acid content are more sensitive to TCA contamination than huge, heavy oak aged wines, or red wines in general. Since Austria, Switzerland, and Germany mainly produce such fragile wines, problems of taste modification occur more readily, even when the cork quality is similar to that of other markets. The wine producers in the German speaking territory have reacted accordingly. In Austria, over 50% of the white wine production is bottled using synthetic stoppers. This is the largest usage of such stoppers worldwide.

And his personal choice?

"Recently we have also taken the plunge into plastic stoppers for our white wine. With the two liter white and red wine bottles, we use metal pop caps, similar to beer caps. For our red wine we have stuck by the original cork, especially since this region of Austria is known mostly for its white wine."

In other German speaking regions, Switzerland has sided with screw caps for white wines (80%). German wineries use both screw caps and synthetic stoppers.

As a product, the cork itself has never been so good. Better technology and more emphasis is being made on cleanliness –washing with peroxide instead of chlorine has increased control quality and led to the lowest incidence of cork deterioration ever.

With the development of global markets, standards are on the rise. While the quality of cork has improved, the demands of both vintners and consumers for clean, clear, reliable wines have also increased disproportionately. Consequently, the cork industry is encouraged to catch up.

Jan Hoedl, a wine buyer for Wein Orgel, a cozy Viennese wine bar in the heart of the city commented that, "customers prefer real corks when it comes to red wine. Red wine needs to breathe, and the cork allows for that process to happen. Especially since we carry a wide variety of high-end red wines, customers expect the real cork.

Plus, a place like this [Wein Orgel] embodies a certain romantic timeless feeling. We have a mature crowd who really know their wines and come regularly in small groups or even alone to enjoy some of our best bottles. Personally, I am a fan of them as well, even though almost ten percent of them have to be returned because of their poor quality – there is a certain aroma and feeling that classic cork has exclusively to offer.

While natural corks are not going to be replaced completely, each type of stopper has its advantages and disadvantages. Synthetic corks store only up to three years. Screw caps are unromantic and also unsuitable for long-term storage.

While real cork is nice, practical, traditional and ecologically unobjectionable, it also comes with known deficiencies. The estimation for the future seems to be that metal screw caps and to a certain limit, plastic corks will be used more often. Hopefully it will be possible to develop a system by which every natural cork is tested for TCA. This will allow the supplier to provide a guarantee of the cork’s neutral taste.

The cork will nonetheless maintain its significance for noble, storable wines as a high quality and stylish stopper, due to its many advantages and inimitable characteristics.

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