Responsible sourcing

Cork – the sustainable closure?

Simon Mason, our Head of Wine Sustainability, takes a closer look at this traditional wine closure.

Cork forest

For many wine drinkers, cork has always been the closure of choice, particularly for wines needing to mature before drinking. Although alternative closures such as screwcaps continue to grow in popularity, 56% of wines sold by The Wine Society are still closed with a natural cork and a further 20% with cork-based closures. But how do cork’s sustainable credentials stack up? 

Improving quality 

For many years, cork was associated with faults such as TCA, cork taint, which affected its popularity, and in regions such as burgundy, blamed for the premature oxidation of whole vintages of wines. Various ‘technical corks’ such as Diam have helped address and eliminate these issues as have improved processes and quality control in cork factories, meaning the prevalence of cork-related quality issues has never been lower. What’s more, cork could be a big help in reducing the carbon impact of a bottle of wine. 

Supporting the environment 

The cork forests (Montados in Portugal, Dehasas in Spain) themselves are a unique ecosystem and represent a sustainable form of agriculture that both maintains biodiversity as well as a living for the skilled workers that harvest the cork. So skilled are the workers that this is one of the best paid agricultural jobs in the world. Cork trees are slow growing and can only be harvested when 25 years old and then on average every nine years thereafter. Like all trees, they sequester carbon as they grow but the very act of harvesting the cork bark triggers an acceleration in the process. Cork manufacturer Amorim state that a well-managed cork oak forest can sequester 14.7 tons of CO2 per hectare and per year. 

Certified success  

As a result, a life cycle assessment (LCA) by Ernst & Young and commissioned by Amorim has shown that wine corks are carbon positive (at least, as far as the factory gate) and Amorim go so far as to offer a certificate to wineries showing the carbon saving they have made by using cork closures. Of course only like for like LCAs for other closure types will enable producers and retailers to make informed decisions about the relative sustainability credentials – something we hope to achieve with others in the Sustainable Wine Roundtable. 

Recycling – work in progress 

Recycling corks is currently difficult in the UK but gathering our corks up with those from other businesses, they can be returned to Portugal for reprocessing. If you’d like to recycle your non plastic corks, you can bring them in to The Wine Society Showroom in Stevenage or give them to your Society van driver when you get your next delivery. We are working on a solution for those without a Society driver. In the meantime, your corks can be added to compost – ideally grated up first or used on your garden as a mulch. 

Want to find out more? For all the latest sustainability news and articles, visit our hub 

Simon Mason

Head of Wine Sustainability & Due Diligence

Simon Mason

Simon has been at The Society for more than a decade, heading our Tastings Team before moving into our Buying Department. Now Head of Wine Sustainability & Due Diligence, Simon works with our suppliers to encourage and accelerate collaboration and improving sustainability throughout our wine supply chain.

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