The Portuguese Cork Association (APCOR) and the California-based Cork Quality Council announced results from a joint study conducted by U.S. wine market research company, Wine Opinions (, to understand the attitudes and purchase behaviors of American wine consumers toward wine closures. In addition to cork being seen as an indicator of wine quality by as much as 97% of respondents, findings also revealed that natural cork is the closure of choice for wine purchased at a restaurant (91%), wine purchased as a gift (93%), and wine purchased to bring to a dinner party (86%). 

Reasons respondents stated for preferring cork were led by the notion that natural cork evokes an important sense of heritage, while the enjoyment of opening wine sealed with a cork, the “pop” and the “ritual” creating a unique distinctiveness at the moment of consumption were also cited. Importantly, respondents also found cork to be conducive to wine aging, a marker to check the quality of the brand before purchasing, and an indicator of overall quality. 

A total of 1,549 consumers participated in the study and questions asked were cross-tabulated by gender, age, frequency of consumption, price bracket of purchases, importance of closure type, and those who age their wine. 

One surprising finding from the survey, according to executive director Peter Weber of the Cork Quality Council, was that consumers still need help understanding and appreciating the environmental and social benefits of natural cork over plastic stoppers and screwcaps. 

“The fact is that cork is a 100 percent renewable and sustainable natural resource, harvested every nine years without damaging the tree. It not only provides important CO2 retention, a crucial tool to fight climate change, it also provides one of the world’s 36 most important biodiversity hotspots. In the era of climate change, education about natural cork’s environmental and social benefits is becoming more and more of a focus, and we still have work to do to fully engage the public on this topic,” notes Weber. 

The positive environmental attributes of natural cork have also been recognized by the International Organisation of Vine and Wine (OIV), the world’s governing body for global wine production. In the 2011 "General Principles of the OIV Greenhouse Gas Accounting Protocol for the Vine and Wine Sector," OIV’s resolution to help address the harmful effects of climate change encouraged wineries around the world to consider each individual cork’s ability to retain as much as 3.95 ounces when calculating the carbon footprint of bottled wine.