Betty's Wine Musings
Cork Wine Stoppers
Cork Wine Stoppers

Cork wine stoppers are a centuries old staple of the wine industry. Yet, more and more, we see plastic wine stoppers and metal screw caps. I think metal screw caps are a great closure for picnic-friendly wines that are meant to be drunk TODAY. But for just about all other wines, I think cork is the ideal closure. There’s just something satisfying about hearing that lovely “pop” when pulling a cork from a dusty red.

I recently did some research on how cork wine stoppers are produced, and I wanted to share what I learned with you. I hope you will reach the same conclusion as I did – that the production of cork wine stoppers offers many environmental benefits, plus a lot of beauty.

Cork is grown in Mediterranean climates – humid and warm, with little rainfall. The most well known regions are Portugal, Spain and Italy. America is the third largest importer of corks, behind France and Germany.

Cork oak forests range in the millions of acres, and are some of the most heavily regulated and treasured resources. They are home to abundant wildlife, including rare bird and animal species such as the black lynx. Due to the rugged terrain, work done on and around the cork trees is manual. The cork forest is truly beautiful.

Cork is stripped the first time at 25 to 27 years, depending upon the girth of the tree and the thickness of the bark. Unless done improperly, stripping cork bark does not kill the tree, and this is very important to understand. A cork tree lives for up to 200 years, producing a cork harvest every nine to 13 years after the first stripping. This is all done manually with a special axe following precise cutting methods.

After cutting, the strips are weathered outdoors six months on concrete. They are then boiled for 90 minutes, killing insects and bacteria. Quickly dried, they’re left to rest three more weeks until smooth. Thereafter, they are graded and bored, either by machine or manually. An intense inspection process occurs, where cork is hand sorted into various quality grades.

Hundreds of hours of manual and automated labor go into creating corks, which overall remain very inexpensive (from 2¢ up to slightly over $1 for the very best ones).

The cork is then coated with paraffin and silicon for ease of extraction from bottles and additional insulation. Voilá—you have a beautiful, compressible, minimally permeable, lightweight bottle stopper that looks lovely.

The remaining cork plant is recycled and used for hundreds of other purposes, from champagne cork tops to flooring, shoes, insulation and clothing. It is truly a minimum waste industry.

From a beautiful cork forest to a beautiful bottle of wine, we hope you appreciate this natural resource and enjoy it even more when you hear that lovely “pop!”

Interesting note: One square inch of cork oak holds millions of tiny 14-sided polyhedron cells, giving it its flexible yet super strong structure.

Cork joke: A cork retriever is not a dog from Ireland ☺

If you have strong thoughts about cork wine stoppers, please share them here.

As an independent wine consultant with WineShop At Home, I absolutely enjoy bringing a taste of the Napa wine country home to you one sip at a time. Whether you simply love to drink wine, seek a special personalized wine gift, or are in search of a new wine jobs opportunity as a wine consultant, feel free to contact me for a truly unique wine tasting experience!

Betty Kaufman, WineShop At Home

As an independent wine consultant with WineShop At Home, I absolutely enjoy bringing a taste of the Napa wine country home to you one sip at a time. Whether you simply love to drink wine, seek a special personalized wine gift, or are in search of a new wine jobs opportunity as a wine consultant, feel free to contact me for a truly unique wine tasting experience!

Cheers, Betty Kaufman
WineShop At Home

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  1. Betty,

    This is an interesting column. Thanks for sharing.

    By way of full disclosure, I work for a closure company in the wine industry called Nomacorc. Our North Carolina based company, although just a little over 10 years old has closed over 10 billion bottles of wine globally with our 21st century closures. We engineer materials to be able to control the way oxygen flows into the wine. Some wines need more and some less oxygen depending on the winemaker’s intentions. Your readers might be interested in learning more about this technology that is different from what you have described in your post. We close almost 45% of all red and white wine (by volume) that is bottled in the United States. Wineries use our closures because unlike tree bark corks, we are engineered to be consistent. You can watch a video of how we make these co-extruded highly engineered closures at

    By the way, our products are fully recyclable too (RIC code #4) and we have programs at retailers like Spec’s in Texas who have recycling bins in their store. Our partnership with TerraCycle has allowed us to upcycle corks into new products too.

    Thanks for the opportunity to comment.


    1. Thank you so much for this information. It’s great to learn more about all the options that are out there. I’m glad to hear that your products are fully recyclable. That’s great.

  2. Dear Betty,
    Thank you for educating your readers about the environmental benefits of natural cork. It’s important that consumers have an understanding of how their purchases affect our planet.

    In response to the reply from Nomacorc, I think it’s important to point out that, though a plastic plug can claim to “control oxygen”, your article was focused on the environmental aspect of natural cork and wine closures.

    Using the figures posted on Nomacorcs website, of the 2 billion plastic plugs they produce each year, only 5% of them have gone to TerraCycles recycling program which leaves 95% of them to end up in landfills, our oceans or to be burned. Just because something can be recycled, doesn’t mean it is being recycled. If anyone wants to, they can do a Google search for recycling rates, nationwide and see the reality of recycling in the US.

    It’s also important to state, that plastic is not biodegradable and that every plastic plug, (produced from petrochemicals) will still be affecting our planet for thousands of years.

    With the current widespread medical and environmental concerns over plastics effect on the health of our planet and its inhabitants, it would seem that choosing a wine closure, should be based on its over all environmental impact, not merely the control of oxygen.

    1. Hi Patrick. I agree with you that the environmental issues are huge and that cork is without a doubt the most environmentally friendly wine stopper. Of course, I wish that cork didn’t have all the “quality” problems associated with it.

  3. Hi Betty,

    I must congratulate you for the nice description that you made of the cork stoppers production as well as for the light approach on this matter. Just to support what you wrote before with some interesting thoughts, cork stoppers are the truly tridimensional sustainable closure for the wines closed all around the world:
    1 – It is a natural resource which is truly green – is grows on trees which live in averae over 200 years and you can strip each tree every 9 years. No resources are wasted to grow them, only the contribution of Mother Nature anc climate. It is biodegradable, fully recyclable, converting old used corks in granules used in building industry, cork flooring, thermal or acoustic insulation
    2 – It’s extraction promotes jobs and the fixation of people working on the forests either pruning trees, cleaning forests or harvesting cork. Let us not forget all the remaining 100.000 jobs which directly or indirectly are connedted with the cork production. In about 1 hectare of forets live upto 102 species, some of them endangered. If there were no cork groves in South Portugal and Spain, I wonder how the influence of the African desert could progress in south Europe as well, so it is quite positive that there is life here, living and working in harmony.
    3 – The usage of cork stoppers adds value to this raw material – first, the industry transforming it into stoppers, which account for about 70% of the raw material’s value, and the leftovers converted in a myriad of products ranging from technical wine corks or champagne corks, and also building materials, insulation materials, high fashion design objects, even surfboards! So, wealth is created with the usage of this material

    Last, but not the least, cork creates value. It is widely known that different studies conducted recently analysing the behaviour of consumers while buying wines is different and they are willing to pay moe (and they do so) for wines closed with cork, because indeed this is a synonim of quality and of a deep bond with Nature.

    Man can try its utmost to dissociate Nature and Man, in some cases more successfully than others, but this is a clear case, for a number of technical, but also objective and subjective reasons, where that is simply not happening.

    Wine (sealed with a good cork) for thought!

    1. Hugo, thank you so much for your beautiful write up. I fully agree with you on the many lives, both human and animal, that are benefited by our use of corks as wine stoppers. I especially love your last line: Wine (sealed with a good cork) for thought!

  4. Betty,
    I think one of the biggest problems the cork industry faces is the kind of perception you worry about, “Of course, I wish that cork didn’t have all the “quality” problems associated with it”.
    Worry no more! All the most recent tests and studies, on TCA and cork taint, have proven that wines, sealed with natural cork have a failure rate of 1%, ( screwcaps have a failure rate of 2.5%) Peter Gago, head winemaker at Penfolds just said the failure rate of their wines, sealed with natural cork is down to 1%, the same failure rate of their wines closed with screwcap. Christian Butzke, an enology professor at Purdue University conducted a study that showed that the issues of TCA taint from natural cork have been virtually eliminated.

    Quality cork and quality wine closed with natural cork is not a problem, the problem is with those who would benefit from continuing the fallacy that there is a problem.

    Once again I thank you for your willingness to open this discussion to your readers.

    1. I’m thrilled to hear that TCA and cork taint problems have gone way down. That’s fantastic. I’m really curious how they made the improvements. Can you shed any light?

  5. I am very glad you appreciate this product. I live in a region which focus its efforts on producing skilled cork stoppers, and I do believe it is in this way.
    A few year ago, There were very controversial inputs and outputs about the fault of cork, sometimes behind of economical interest lobbies and its disloyal competences, although this false statements are being disassembled with tecnical and scientific arguments.
    Concerning organic problems due to contamination, Have you heard something about the good practices in the cork stoppers manufactures or the new processes which focus on deleting this kind of compounds?.
    Read the paper you can download in this site
    Sorry by the mistake in the english lenguage, because I am not an expert (you can see), although I do believe it is easy to understand what is the message.
    This is maybe rather divulgative than technic. If you want more specific information I could send you lot of them.
    Best Regards.

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