The Wine Scholars Guild and Master of Wine, Jane Masters, hosted an educational webinar exploring the history and production of natural cork as the wine industry’s preeminent closure. Held on July 5th, the webinar titled, Cork: A Closure for the Ages, focused on the intrinsic qualities of cork and its sustainability. The presentation highlighted cork’s environmental benefits as a renewable natural product, the minimal energy and waste required to produce it, and its positive contribution to the fight against climate change.
Moderated by Mary Kirk, community and membership manager at the Wine Scholar Guild, the webinar was viewed by students from around the world including Chile, the UK, and Latvia. The Wine Scholar Guild provides specialized certification programs that cover the wines of France, Italy and Spain. Spanning more than 30 countries and five continents, the guild is a pioneer in online wine education programs.
Masters, who is the Chairman of the Institute of Masters of Wine and an independent wine consultant, started the webinar by exploring the purpose and importance of wine packaging. She laid out the different functions of packaging from maintaining quality and imparting no off flavors to protecting wine from oxidation and allowing bottles to age. Masters also pointed out that wine packaging has to appeal to the people that are buying the product and consuming it.
She then discussed the advantages of cork as a wine closure. Masters noted cork’s unique cellular, honeycomb structure that creates an airtight, hermetic seal within the neck of a wine bottle making it an ideal closure. Cork resists moisture and gasses, and the seal can last for decades, perfect for aging wine. Masters said that cork has other advantages as well including that it has “a perception from consumers of being a quality product, a quality seal.”
Cork is the bark of the cork oak tree and predominantly grows in the western Mediterranean basin. Cork forests cover nearly 6.6 million acres of land and are part of a natural ecosystem that is a habitat for a wide variety of animals, insects and microorganisms. Supporting the cork industry helps protect the forests. Cork is harvested without damaging or cutting down the trees, which can live for more than 200 years and can be harvested up to 18 times in their lifetime.
The cork forests can also help combat global warming by sequestering carbon. “The cork oak takes Carbon Dioxide from the atmosphere and uses that to photosynthesize in order to produce plant material as it grows,” said Masters, noting that the trees act as a carbon sink. For every ton of cork that is harvested, it helps sequester 73 tons of CO2. A single wine cork has a net negative Carbon footprint of 276 grams of CO2 when the biogenic carbon cycle of the cork forests is taken into account.
Reducing CO2 is a very important aspect of Cork noted Masters, who said that CO2 levels have increased dramatically since the 1950s due to human activity. But sustainability is more than just carbon sequestration, she argues. Master discussed how most industries are looking at moving towards a circular economy. She touched on the basic principles involved, including the elimination of waste and pollution, circulation of products and materials, and the regeneration of nature. Masters noted that cork is a sustainable choice for the wine industry since it comes from a renewable resource. It can also be reground and recycled into a variety of products such as flooring, insulation and shoes. And cork harvesters are some of the most highly paid agricultural workers in Europe.
Masters then went on to describe the harvest and production techniques being used in the cork industry. She touched on the various steps used to produce cork including the seasoning, grading and boiling processes. She also noted that only the highest-grade cork is used to produce wine stoppers and nothing goes to waste in the production process.
The webinar also touched on the elimination of Trichloroanisole (TCA) in natural cork stoppers. Masters said that starting in the 1990s, public and private research facilities came together to figure out what causes TCA and how to reduce the risks. The industry has also developed new processes to eliminate it. Current testing indicates that wine taint from bottles closed with natural cork is down to less than 1%. “The cork industry has continued to move forward,” said Masters, who highlighted other cork studies that are in the works. “There are things we can learn that will allow us to mature wines more consistently.”