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What is cork?

Cork is the outer bark of the cork oak (Quercus Suber L), an endemic tree of the Mediterranean basin that occupies more than two million hectares throughout the world. It is also the name by which the cork oak is known. The cork oak is a very long-lived tree and its productive life lasts between 150 and 200 years. Thanks to its regenerative capacity, the bark can be removed at intervals of between 9 and 14 years.

What are the main characteristics of cork?

Low density and lightness, impermeability, low heat transmission and good thermal insulation, acoustic insulation and low sound transmission, high resistance to movement or high coefficient of friction, damping capacity, compressibility, flexibility, elasticity, durability, rigidity, hygroscopic, biosorbent and natural. It’s recyclable and renewable.

Can cork be used to produce energy?

Yes, cork powder can be used as biomass and thus contributes to generate energies that reduce carbon dioxide emissions. In fact, it is common practice in stopper manufacturing companies when it comes to taking advantage of the cork dust generated in the stopper manufacturing process.


What is a cork oak?

The cork oak (or Quercus Suber L) is a perennial tree of the Fagaceae family native to the Western Mediterranean. Its outer bark is cork, which has favoured the exploitation of cork oak forests.

How long does it last a cork oak productive life?

A cork oak productive life lasts between 170 and 250 years.

How and where do cork oaks grow?

Cork oaks grow at an altitude between 0 and 800 meters above sea level and rarely appear at higher altitudes. They require a mild oceanic climate, with average annual rainfall between 600 and 1000 mm, with average annual temperatures around 15 ° C and a relative humidity between 65 and 80%.


Did you know that cork production is environmentally sustainable?

The cork sector has a negative carbon footprint (it means that the balance between CO2 emissions and CO2 capture is negative, more CO2 is captured than is emitted) and contributes to the mitigation of climate change due to the fixation of carbon dioxide from the atmosphere. It contributes to maintaining the biodiversity of the protected habitat of the cork oak, its management facilitates fire prevention, prevents erosion, regulates the water cycle and offers many other environmental services: ecotourism, hunting, collecting mushrooms, truffles…

Do you think cork is a natural resource in danger?

No, since the cork extractive industry is regenerative, extinction of the trees or the material is not in danger. Furthermore, the exploitation of cork oak forests generates economic activity and jobs in rural areas, the survival of which depends to a large extent on the demand for cork material. The current prospectives are good because the great global trends are the bioeconomy, the circular economy and the promotion of an economy based on natural capital.

What is the carbon dioxide retention volume associated with the cork oak forest?

Cork is a natural product that retains carbon dioxide from the atmosphere and therefore contributes to reducing greenhouse gases, the main cause of climate change. It is estimated that cork oak forests retain up to 14.7 million tons of CO2 annually (Cork Information Bureau | 2019).

What is the value of the environmental services that the cork oak forest provides?

Cork oak forests provide direct and indirect environmental benefits for society, since the well-being of humanity depends on ecosystems and the multiple goods and services they provide, such as food, water, fuel or protection. It is estimated that the real value of cork oak forests in Catalonia is 4,500 euros per hectare each year, of which forest products and foods represent 13%, cultural services 14% and regulation services 73% (“El valor dels serveis ambientals de les suredes a Catalunya”, Fundació Institut Català del Suro 2013).


Is the cork stopper the only closure with a positive environmental impact?

Yes, because it is the only closure that is made with a 100% natural material. Furthermore, cork is the only material used in the manufacture of stoppers that retains more carbon dioxide than it emits. In fact, in Catalonia it has been recorded that a natural cork stopper retains 234 grams of CO2 (Rives, J., et al., Integratedenvironmentalanalysis of themaincorkproducts in southern Europe (Catalonia) 2013) and there are studies that show an increase of CO2 fixation by above 500g per cap.

Can cork stoppers be recycled?

Yes. Cork stoppers are fully recyclable, biodegradable and reusable. Although new caps cannot be made, other applications can be found in areas such as construction, design, fashion, cosmetics and gardening. Currently, cork stoppers are managed as compostable organic material (brown container) but there are appearing more and more initiatives for their recycling.

Does the wine industry take into account the added value of the cork stopper?

Yes, it has been proven that the most important oenological attribute that the cork stopper provides is micro-oxygenation. The cork stoppers provide a stable transfer of oxygen to the bottled wine (OTR – Oxygen Transfer Rate) favouring a good maturation of the wines. In addition, it is the only closure that has a positive impact on the environment. Currently, 7 out of 10 bottles are sealed with cork and 95% of consumers in Spain prefer the cork stopper for still and sparkling wines (Cork Initiative, 2017).

Is the production of cork stoppers less polluting than that of alternative closures?

Yes, because cork stoppers emit 10 times less carbon dioxide than plastic stoppers and 24 times less than screw stoppers (PricewaterhouseCoopers/ECOBILAN, “Evaluation of the environmental impact of cork stoppers compared to aluminum closures and plastic ” (2008)).

Did you know that consumers associate cork with moments of celebration?

Cork is synonymous with quality wine or cava and that is how most consumers perceive it. In fact, 88% of the best quality wines from around the world are sealed with cork (Wine Spectator’s Top 100 List) and 93% of consumers perceive that a wine with a cork stopper is of a higher quality (Cork Quality Council).

Did you know that using cork contributes to an increase in the value of a bottle of wine?

According to the Nielsen Report (2017), wines sealed with cork have an added value of € 2.27 more than wines that use other closures. In reference to exports, wines sealed with cork are valued at $ 3.87 more in the United States, $ 5.15 more in China and 2.00 in the case of the United Kingdom.

Why is it important for oenology and sommelier schools to train in cork stoppers?

Because the cork stopper contributes to the positive aging of the wine and its aromas can also influence the finish of the bottled product. In addition, the cork stopper offers many possibilities to complement the marketing of the wine itself, not only because of what the images printed on the stopper itself tell us, but because it allows us to know and preserve a sector with a lot of history. In addition, the cork stopper is the perfect choice for those who want to use natural materials, make organic or ecologic wines.

What quality controls are done on cork stoppers?

Cork stoppers are the only closures that have their own standards with test methods and specifications related to sensory, physical, chemical and microbiological aspects. There are currently 27 quality control standards for cork stoppers drawn up by the Technical Committee for Standardization 56 / SC5 of UNE, which is coordinated by the Catalan Cork Institute Foundation.

Why are cork stoppers the only closures that are regulated by national and international standards?

Because the cork and wine sector decided to work together to standardize the specifications of cork stoppers in order to offer the maximum guarantees for the end consumer. In the case of other types of closures, these standards do not exist and apart from internal specifications, they must comply with other regulations related to the contact of plastics with food material.

Can I seal my wines with proximity cork?

Yes, a clear example is the Taps de Finca initiative (“Estate cork stoppers”) promoted by the Regulatory Council of the Empordà Designation of Origin and the Catalan Cork Institute Foundation, with the support of AECORK. The Taps de Finca brand identifies corks and bottles that have been covered with local cork stoppers.
This seal is adopted by the wineries participating in the project and which have bottled their wines with cork stoppers made with cork extracted from cork oaks located in the same Empordà wineries or on farms located in the territory of the DO. In addition, all the estate cork stoppers have been made by Catalan cork companies.
We can identify the wines sealed with Tap de Finca because we find its logo on the label and the cap. Check out the companies that are part of Taps de Finca.


Did you know that cork stoppers are subjected to quality controls typical of the medical and pharmaceutical industry?

Some quality controls require analysis for the presence of odours only detectable at very low concentrations. To detect these odours, quantify and identify them, very high precision and sensitivity equipment is needed, such as gas-mass chromatographs, which are more common in the pharmaceutical industry.

Where can I expand my knowledge about cork stoppers?

As part of the Intercork international communication campaign, in 2015 the Cork Stopper Technical Manual was published, which includes everything you need to know about the cork stopper, from the forest to industry to the time of opening the bottle.