Because we hold agriculture so close to our hearts, it should come as little surprise that we selected our cork suppliers with the same attention and care that we take with our own estate vineyards. Our sustainability commitments are extensive and ongoing—because each of these efforts is only as sustainable as the willingness to stick with them long term. We do this because, as a company, we want to take responsibility for any impact we have on the environment and strive to have a negative carbon output overall. That’s why we source our corks from a carbon negative company; a single Emeritus cork can represent 300 grams of sequestered carbon.
Cork Oaks & their Forests
The cork that makes up natural wine stoppers comes from the bark of cork oak trees that grow in Mediterranean Europe and North Africa. Like all trees, they use carbon to fuel photosynthesis and new growth. Cork oak is a particularly efficient carbon collector that can live up to 200 years and be harvested fifteen to eighteen times over their lifespan, producing thicker and better-quality cork as they age.
Cork oaks grow in an incredibly diverse ecosystem. By virtue of their height, dense foliage, and extensive root system, cork oaks create a protective microclimate where less hardy species can shelter from extreme heat and cold. They create an effective wind-block and catch lot of rainfall in their thick canopy, which minimizes soil erosion from both elements. The lack of soil erosion leaves habitats for healthy microbes and insects undisturbed, keeping the soil healthy and fertile. The fact that these trees can be harvested without being cut down also aids in the preservation of environment for hundreds of species, both flora and fauna.
Cork bark is harvested by hand from these living oak trees in much the same way wool is shorn from sheep. The level of skill required to do this without harming the living tree is why it’s some of the highest-skilled agricultural work in the world, and often handed down from generation to generation.
At twenty years old, a cork oak tree is ready for its first harvest. This first harvest best suited for agglomerated cork products such as shoe insoles, dartboards, and bulletin boards. It’s later, after at least nine years of regrowth (which is when most of the Co2 absorption happens), that the bark has grown to an inch or two thick, when the wine cork magic happens. Slabs of bark are harvested using a specially designed hatchet, then cured, cleaned, trimmed, and sorted by quality. Only the best selections are reserved to make wine bottle stoppers; these strips of bark are punched through with hollow metal tubes, removing cylinders of cork.
Bottling with Cork
During bottling, the filled bottles (which are designed not only with the wine in mind but the cork as well) roll down the bottling line. The corker pulls any extra air out from the bottle before inserting the cork. Just below the lip the glass widens just enough to allow the cork to expand slightly before narrowing again as it gets closer to the wine.
This expansion in the glass helps keep the cork in place and efficiently stops any wine from getting out. Once the cap is put on over the cork, the full bottles are packed into boxes and aged for the next 3+ years until it’s ready to be in your glass.
The structure of cork bark resembles honeycomb, or layers and layers of bubble wrap. When cork stoppers are punched out of the bark, many of the outside edge cells are cut open to form a tiny suction cup that creates a non-slip surface. That’s why getting it out of the bottle is sometimes difficult—but on the other hand, that’s what creates such an effective, leak-proof seal!
Other Fun Facts about Cork
- Cork does not absorb dust or moisture.
- Cork is resistant to both rot and insects.
- Cork is fire retardant, and if lit on fire will only char on the outer surface without releasing any toxic fumes.
- Cork is so resistant to wear that it’s also used to polish diamonds, which are one of the hardest naturally occurring substances on earth.
- Cork has been used for bottle stoppers since antiquity because of its impressive resilience; you can squash it under a 14,000lb weight and it pop back up to most of its original size within 24 hours.
- Because cork is about 1/4 as dense as water and the honeycomb structure contains a lot of dead-air space, it’s an effective insulator when it comes to noise and temperature.
- Rather than being wasted, extra cork left over from the manufacturing process can be ground down and used to make more agglomerated cork products (shoe insoles, dartboards, bulletin boards, etc.).