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Everything you ever wanted to know about cork...ALMOST!


Ready for almost everything you wanted to know about cork in one easy to read article? Well, here we go!

Brief History

No one knows for sure when humans started to realize the differences in the phellem layer of bark of cork oak trees (Quercus suber), but cork has been found in archaeological digs all over the world. The range in the ancient world was vast – cork was used in China, Egypt, Babylon, and Persia as early as 3000 BC. The ancients used cork for flotation (think fishing bobbers and fishing nets), as bottle stoppers, and even to make shoes more comfortable.

Our ancestors knew what was up, but even after all these years companies like Amorim are still finding new applications for this incredible all-natural material. We still use cork for flotation, as bottle stoppers, and in the insoles of nice shoes; however, that is just scratching the surface of the possibilities. We tell people all the time that cork is out of this world. It is empirically true; you might be surprised to know that cork is even used on space bound rockets and the Mars Rover. Cork is an incredible heat and sound insulator and remains very flexible.

Cork forests are so important that there are nearly 5.5 million acres (2.2 million hectares) of cork trees across the Mediterranean and Portugal that have been protected since the 1100s! The Portuguese government declared cork trees endangered (they are not) so they would not be cut down and also imposed a harvest season to further protect the forests. We could go through a list of all the applications of cork like Bubba recounting shrimp recipes in Forrest Gump, but let’s just say it’s practically limited to imagination. What makes cork so special?

Overall Benefits

Cork is one of the few truly zero waste products. Literally no part of the harvest goes to waste and no part in making our products is harmful to the environment. Scraps can be used to make products like cork boards and other composites. Below are some of the benefits of cork trees and cork products:

1. Carbon neutral (in some cases even carbon negative)

2. Thousands of plants and animals rely on cork forests (montados)

3. Is cruelty-free

4. Biodegradable

5. Impermeable to liquids or gas

6. Extremely light weight

7. Fire resistant

8. Soft and pliable

9. UV resistant

10. Does not distort, swell, or shrink

11. Is non-allergenic

12. Is anti-static

13. Will not harbor fungi

14. Is easy to clean and care for

15. Is resistant to wear and tear

16. Is all natural


Because cork is a natural material, unused scraps are not exactly waste because they are biodegradable; however, back in the 1890s a German company invented a process that truly makes cork production zero waste process. They discovered that they could utilize the scraps or waste from other manufacturing processes to create an agglomerated substance that could be molded into any shape necessary. That original process used external binding agents, so it might not have been the best long-term solution, but it did get the ball rolling in a big way. Others like John Smith realized that with heat and pressure the natural resins inside cork particles will be released. Thus, giving rise to the cork composite industry: cork boards, flooring, acoustical panels, so on and so forth. The knowledge of heat and pressure also gave rise to cork fabric, which we will cover in another (much briefer) article at some later point.

Harvesting


The phellem layer (what makes cork…cork) of the cork oaks can be harvested every 9-13 years, and actually benefits the tree. Each tree can be harvested many times throughout its natural 150-to-300-year lifespan. Every time a tree is harvested, the cell structure within the layer gets tighter and smoother. The trees are harvested in the late spring-summer months by hand using specialized small axes much in the same way it has always been done. As many as 35,000 migrant workers are employed in the Iberian Peninsula alone to harvest cork each year and they earn an average of around €135 per day, making cork harvesting one of the most lucrative agricultural jobs in the world. In addition to paying workers well, harvesting creates no water or air pollution, and cork does not require a chemical tanning process. Pretty much a win all the way around.


Environmental Impact

Harvested cork trees absorb 3-5 times more CO2 gas than unharvested trees. Cork forests absorb and eliminate approximately 5.95 tons of CO2 per acre. The cork forests of Portugal are one of the UN’s global biodiversity hotspots, being home to thousands of plants, animal, and mushroom species. Cork oak forests are important for some of the most threatened species in the Mediterranean. According to the World Wildlife Fund, plant diversity can reach as high as 135 species per square meter (for those of you keeping score, that is some of the highest diversity found anywhere in the world). Some of the plants and fungi also have medicinal uses. Montados are also home to many endangered animals such as the Barbary Deer, the Iberian Lynx, the Iberian Imperial Eagle, and the Black Stork. We have to assume you would click the like button on plants and animals or you probably would not have made it this far! Good for you!

The Takeaway

Cork production is one of the most earth friendly processes in the world. Cork is only harvested from trees that can withstand the harvest, which is why each tree is only harvested once every 9-13 years. Why the 4 year window? If a tree is up for harvest, but the harvester determines it is not ready yet, it gets remarked to check the next year. The annual harvest employs many thousands of workers every year. Cork forests are vital to thousands of plant, animal, and fungi species. Harvested cork trees actual absorb more CO2 than non-harvested ones and can live up to 300 years. Due to ingenuity, every part of the cork harvest can be used in some way so there is little to no waste. Remember, there is no such thing as waste in nature…that comes from us. Cork has been harvested and used for thousands of years and even today it remains one of the best materials for countless applications. Those applications are only up to our own imagination to make it happen. When you choose cork, you benefit by owning a beautiful and long-lasting product, but the overall impact is far reaching! This is also why we say at Resonance Cork we are fair trade by nature.

Additional resources:


https://amorimcorkcomposites.com/en-us/about-us/news/cork-thermal-protection-heat-shield-for-mars-spacecraft/

https://www.nasa.gov/exploration/systems/sls/insulation-protects-sls-from-fire-and-ice


https://wineindustryadvisor.com/2021/07/28/studies-confirm-the-unique-co2-balance-of-natural-cork-closures


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990040/


https://wwfeu.awsassets.panda.org/downloads/cork_rev12_print.pdf


https://www.theatlantic.com/technology/archive/2016/02/wine-cork-comeback/470961/

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