Santa Maria de Lamas, Portugal -- A new life-cycle analysis of wine closures concludes that natural cork leads screwcaps and plastic closures in six of seven key environmental indicators, according to research released by cork supplier Corticeira Amorim. The independent study, conducted by Pricewaterhouse Coopers and begun in 2007, found that plastic stoppers result in nearly 10 times greater emissions of CO₂ equivalent (CO₂e) than natural cork during a 100-year period; screwcaps are responsible for 24 times more CO₂e during the same timeframe, it said.

Speaking from his home in Portugal on Jan. 20, Corticeira Amorim marketing director Carlos de Jesus told Wines & Vines that the study highlights areas where his firm is excelling and where it can improve; it also encourages manufacturers of other closures to make their own life-cycle analyses public, he said.

"We didn't have all of the information from our competitors, so we were at least able to raise the disclosure bar," de Jesus said. "I would like to see a life-cycle come out (from other closure manufacturers), so everybody can discuss with fact-based knowledge and not just assumption."

Amorim representatives, who recently presented the findings at an event in London, plan to personally deliver results of the study in North America on Jan. 28. Bruce McIntyre, the leader of Pricewaterhouse Coopers' forest, paper and packaging practice, will give a media briefing at the Unified Wine & Grape Symposium.

Emissions

Pricewaterhouse rated the three closure categories on seven indicators--energy consumption, water consumption, greenhouse gases emissions, atmospheric acidification, contribution to the formation of photochemical oxidants, contribution to eutrophication and solid waste production. Natural cork's performance in the greenhouse gas emissions category was especially notable, as trees cork oak trees convert carbon dioxide into oxygen during photosynthesis, creating a carbon sink.

De Jesus said that unlike electric cars, which still are years away from mass production, the humble cork also marries function with sustainability--and it is available now. "It has been there for centuries, it has a track record," he said. "Each one of these corks has a role in CO₂ retention, so why not leverage that?"

Amorim chairman and CEO António Amorim added: "Many sectors of the global wine industry are working hard to reduce their environmental impact."

Water

One area in which natural cork didn't emerge as the front-running closure was water consumption: Aluminum (screwtop) closures took that honor. Natural cork closures used 88% more water during their life cycles than aluminum closures. Plastic stoppers, meanwhile, used more than three times as much water, most of it expended during the production cycle.

During wine bottling, about 10m³ of water were used by 1,000 cork or plastic closures; bottling using aluminum required virtually no water use at all.

Aluminum and natural cork required similar amounts of water during the production phase. About 30% of harvested cork is used for closures, but regardless of its intended use, all cork is boiled in water.

"It's basic hygiene of the raw material. We have to clean it and make it more pliable--raise the humidity level so it can be worked," de Jesus said, adding that the boiled water that comes out is clean and nutrient-rich, and the company recycles it for fertilizer.

To read the full text of the final report, visit corkfacts.com/.