Consider the cork

It’s no wonder Phillip Mollet, a fifth-generation cork farmer in Alentejo, Portugal, is a champion of the product responsible for wine’s celebrated “pop!” In recent years, screw tops and plastic corks have come into fashion, partly because people fear cork taint, in which chemicals in the cork — the naturally occurring compound trichloroanisole (TCA), to be exact — give wine a spoiled taste. But cork taint is extremely rare, according to Mollet and other experts, and has become one of the most misunderstood issues in the wine world.

Four years ago, I strolled through the cork forests in Alentejo with my Slow Food class. In keeping with our Italian-based school’s tradition, this trip to south-central Portugal was a combination of education and pleasure. Slow Food, founded in northern Italy in 1989 by Italian activist and wine lover Carlo Petrini, is an international organization dedicated to promoting awareness about and protecting the biodiversity of the world’s food supply. Its relatively new school, the University of Gastronomic Sciences, aims to educate young people about various food traditions and how they are surviving in the fast-paced global economy. The principle of good, clean, fair food lies at the heart of the Slow Food curriculum, and my class was visiting Portugal to learn about food- and wine-related products that are facing extinction. Cork, the venerable wine stopper, is one of those products.

Mollet, who owns a cork farm and vineyard near Alentejo, was our host and guide. During our tour, he explained the complexity of cork trees, how cork is harvested and the pressures facing cork producers like him.

Cork is harvested from the cork oak’s bark, which is waterproof, odorless and spongy. The trees are not cut down; rather, the bark is carefully stripped about once a decade, which allows the bark to regenerate. The process is slow and time-consuming but necessary in order to ensure the survival of the cork trees and their surrounding habitat.

Ten years ago, cork producers faced increasing demand for cork from the wine industry. This forced cork farmers and producers to exceed the limits of optimal production, which resulted in subpar corks and a series of tainted wines in the early 2000s. This blackened cork’s reputation and enabled synthetic stoppers and screw caps to enter the market. Since then, cork has become the scapegoat for TCA.

Although TCA can come from natural cork, it can originate elsewhere. A winery is a perfect place for phenols — the organic compounds that constitute TCA — to emerge, whether it’s from a damp floor, unclean bottling equipment, cleaning supplies containing chlorine or improperly stored cardboard cases. Specifically, TCA forms through the interaction of plant phenol, mold and chlorine. The word “corked” describe wines whose chemical compounds have changed, producing a wet mold or wet newspaper smell; this usually stems from TCA. It is also why sniffing the cork is an important and not just pretentious ritual.

Wine experts insist that cork is still the best seal for wine. Josh Adler, a former wine buyer for Bi-Rite Market, an organic grocery store in San Francisco and now the owner of the Paris Wine Co., works intimately with wine producers throughout France. “Any decent producer would never use a synthetic cork,” he told me.

In a country where eating and drinking is practically a birthright, France may seem like the exception when it comes to cork loyalty. This loyalty to the cork is more a matter of quality than tradition. Natural cork is the better match for a bottle of wine because cork is 90 percent air, making it spongy, light and pliable, allowing the wine to breathe while protecting it from external elements.

Cork appeals to environmentally conscious consumers because it is completely biodegradable and the harvest-to-production process entirely sustainable. Natural cork’s carbon footprint is much smaller than its synthetic rivals’, and cork forests sequester 10 million tons of carbon dioxide annually. Known as montados, these forests are some of the most biodiverse ecosystems in Europe, home to rare birds such as the imperial eagle and tens of thousands of plant species. Cork harvest, which takes place only every nine to 10 years, hardly disrupts the existing wildlife in the montados. Most cork farmers like Mollet use their montados to raise livestock, which only enriches the cork forest.

Although cork taint incidents and rumors have damaged cork’s reputation, Adler, Mollet and other experts argue that such cases are rare. Adler pointed out that although he considers TCA a potential danger, he is confident that he and most good wine producers have enough experience to identify it right away.

“The real scare and threat to the cork industry is that people may now think a certain wine will be bad because it has a cork,” he said.

Meanwhile, producers have adopted stricter measures to ensure quality cork, by investing in better machinery and tighter production, despite the added expense. Mollet claims that he still faces sharp competition from screw tops and plastic corks but is hesitant to push production past its limits. It is a tricky balance: Producing high-quality cork requires time and patience, while his competitors can quickly manufacture agglomerate corks and screw tops, making them easily available and generally cheap. Consumers should realize that to dismiss cork is to put at risk not only a long tradition but also an entire ecosystem and economy — something worth considering when you find yourself perusing a wine shop for your next tipple.