A cork, made from a piece of cork oak, traditionally seals wine bottles. Some winemakers are using plastic bottle stoppers or metal caps. There is a tradeoff here. Cork can grow mold and it can be difficult for some people to open the corked bottle, although this is part of the ritual of enjoying wine. A plastic stopper doesn’t have mold problems and petroleum based plastics are cheap, for now, so some winemakers use these as an alternative. A new campaign, reported by Triple Pundit, has started at 100 Percent Cork to convince winemakers to continue corking wine bottles with real cork.
Cork has many environmental advantages. Cork trees, which are a type of oak, produce shade and oxygen while removing carbon dioxide from the air. According to 100 Percent Cork, it is not necessary to chop down a cork tree to produce corks for wine bottles, the cork only uses part of the bark. The cork trees have a long lifespan, several hundred years, even when winemakers harvest their bark. It is also possible to grow the cork trees organically. Organic wines are popular so it would be nice to know that the stopper for the wine bottle is an organic product as well. Cork farmers are also backing this campaign, since they lose their jobs if winemakers switch to plastic. Many of the cork farmers live in Portugal which has been hit very hard by financial turmoil.
One of the Big 4 accounting firms, PriceWaterhouseCoopers, performed a study comparing natural cork to plastic and metal stoppers. Natural cork produces much less carbon emissions by far, with plastics producing 10 times as many emissions and metal producing as much as 24 times greater emissions. This is a complete lifestyle study so it also includes mining expenses, plastic manufacturing, and disposal costs.
Cork also receives some unfair blame for causing wine taint. Researchers at Virginia Tech have found an alternate explanation for the cause of the taint. The chemical tribromophenol, often found in wood cleaners, is used in many wineries since it prevents fires as well as kills fungi. Tribromophenol has similar chemistry to trichloroanisole, which does cause cork related taint problems in wine. Both of these compounds are halogenated benzene rings, so telling them apart without performing chemical tests may be difficult.
Protecting the cork industry helps protect wildlife habitat in Portugal and Spain. According to the Smithsonian Zoogoer, cork trees grow in a region known as the dehesa, where many animals live in a grassland which is the home of many oaks. If winemakers switch to using plastic or metal stoppers, cork farmers will not earn any money and may have to sell the dehesa land to developers. The Smithsonian states that half of the world’s cork is grown in the dehesa in Portugal, and another quarter is grown in the Spanish dehesa.