Feature Article : Cork: going from stopper to show-stopper

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Cork: going from stopper to show-stopper


'99 Chehalem Pinot Gris and synthetic cork

Ever had a corked wine? Some people know what a corked bottle is, some don't, but everyone's had one.

Sometimes the characters that a bad cork imparts elicits mild "This doesn't taste like it did the last time," or "this wine doesn't have any aroma," or "this is just like my Grandmother's basement or potting soil…," or "boy, you can tell this is a French wine!"

Corked wines are an infection of the cork, caused by the conditions in which corks are harvested, stored, processed and used. The problem is significant, since the compounds that are made by microbes in the cork, TCA (trichloroanisol) and its relatives, mask the wine's real aromas and flavors, at best muting the real wine character, and in extreme, producing aromas and tastes that are reminiscent of cardboard, dirty washcloths, potting soil, musty basements and the like. Estimates are that anywhere from 2 to 10% of purchased bottles are affected by cork taint, whether faintly muting true aromas and flavors or making alarms go off in even the least sensitive or trained taster.

Wine corks are made from the bark of Quercus suber, an oak that thrives in the warm and dry Mediterranean, giving a harvest every 9-12 years for the 150 years a normal tree might live. Portugal, Spain, Sardinia and Northern Africa are prime sources, with rural Portugal and Spain dependent on the industry.

However, this is an industry in jeopardy of going the way of tube radios, horse and buggies, the US Postal Service and pay phones. They will be replaced if they continue to ignore an inexcusable level of faulty product. The "third world" aspect of the growing region is part of the problem. A basic agricultural industry, processes have not been improved over generations in most areas, with cork harvests stacked for aging on the ground, forests uncultivated to remove disease and pest habitat, bark boiled in unsanitary conditions, and cleaning agents like chlorine bleaches used, which have been shown a precursor to TCA. Maybe a little different from the time when Dom Perignon in the late 17th Century replaced a wad of cloth with cork bark, but not by much.

Work has been done by some cork manufacturers who control raw material from the source and who tout better processes that include peroxide washes, microwave sterilization, compression cleaning and other magical solutions. However, most of the industry uses middlemen who trade, process and poorly control the source and contamination of the product. Although not harmful to the consumer physically, the pocketbook part of the anatomy suffers.

It is a totally unacceptable situation for us. How many other operations accept a 5-10% faulty product or service? "Oh, sorry we dropped your baby, but we only do it every twelfth time!" or "Your paycheck is off ? Sorry, but we can't get all of them right!" We are frustrated to spend the effort we spend to gently handle delicate varieties for two to three years in vineyard and winery, only to have the closure to an expensive masterpiece contaminate it!

So frustrated that, although not totally giving up on traditional cork, we have begun using synthetic corks. Our 1999 Estate Pinot Gris uses a bright blue SupremeCorq, a thermoplastic "cork" that we have investigated since the 1993 vintage. Although not without risk itself, it definitely does not impart TCA taints. We are not ready to convert wholesale, with ageability an unknown. The public seems to accept the need to get rid of the problem and either hates or loves the synthetic alternative. Besides early plastic tastes in the development stage six years ago and the jury still being out on ageability, our only reservation is environmental. Consumers have to recycle the plastic the same as milk jugs or polystyrene.

I'd love to see both options viable. To remain our closure of choice, natural cork producers need to focus on understanding the source of infection and investing capital to avoid it, not spending capital to sort out bad from good or, even worse, to seek pretty corks to make wineries feel good. We seek out those suppliers who talk about controlling their processes better and we ignore those who talk more inspection to give us better corks. The problem is the same one other industries have seen (and I worked in Quality and Process Control for over 20 years): depending on inspection you always miss some, plus you never correct the root cause. An emphasis on prevention rather than detection might keep me from asking the gnawing current question: Where do they send the lots of cork they reject as highly tainted? Emerging wine regions?