Duh: Natural Corks Greener than Synthetics

I’ve never been a big fan of synthetic corks. Even after just a couple of years, they seem to be more difficult to remove than natural corks and they’re just one step away from screw-top closures in my book. I never believed that the potential faults of synthetic closures—oxidation in synthetic corks and reduction in screw caps and glass stoppers—where significantly less than TCA faults with natural cork. Those were reasons enough against synthetic closures. Now I have even more reason to dislike them.

A new Italian study conducted by the Milan Politecnico and funded by Labrenta, an Italian producer of beverage closures, has found that natural corks have less of an environmental impact than their synthetic counterparts. Using data from 2010, the study conducted in November 2011 has made it possible to estimate the amount of CO2 emissions generated by the production of synthetic closures versus natural cork closures. By comparing the entire product life cycle of both types of closures—from obtaining raw materials to its eventual disposal—researchers found that synthetic cork production produces more CO2 emissions than natural cork production. That doesn’t really surprise me. An older study made by PriceWaterhouseCoopers in 2008, comparing the full life cycle environmental impact of natural cork, aluminum screw tops, and plastic corks, also shows that natural corks have significantly less overall negative effects.

What was surprising were the actual numbers in terms of grams of CO2 produced per gram of product. A synthetic enclosure generates 14.8g while a natural cork produced -15.6g. The negative figure accounts for the growth of cork trees and the CO2 that they absorb. Yes, for Labrenta, producing natural cork closures actually offsets the emissions produced by synthetic cork production. Labrenta also points out that their production processes, specifically their use of renewable energy and recycling of materials can lead to reductions greater than 90% in CO2 emissions. All of these studies compare natural to synthetic closures. I wonder if an environmental study comparing natural whole corks versus agglomerated corks (formed granulated cork) versus colmated natural corks (natural cork core coated with fine cork particles) has ever been conducted.

While I’m often skeptical of studies funded by private industry, especially when it’s in their favor and widely publicized, sometimes these outcomes can change public awareness and, hopefully, improve wine industry efficiencies. If you’re a winemaker, especially one touting environmental consciousness, wouldn’t you want to use natural corks given all this data? What are your thoughts on wine closures? Do you have a preference and why?