The cork oak may be sown, planted or propagate spontaneously, which is often the case in cork oak forests, thanks to the acorns that fall on the ground.

Despite being an evergreen tree, the cork oak does not develop evenly throughout the year. In winter, the tree enters a dormancy period, during which it produces neither wood nor cork, with its vegetal activity reduced to a minimum.

The cork tree grows simultaneously in two directions: vertically and horizontally, resulting in a robust tree of majestic size.

A cork oak has an average lifespan of over 200 years.

The oldest and most productive cork oak in the world is the Whistler Tree, in Águas de Moura, in the Alentejo region (South of Portugal). The cork oak was planted in 1783, stands over 14 metres tall and the diameter of its trunk is 4.15 metres. In 2018, the Whistler Tree, representing Portugal, was voted European Tree of the Year. Its name comes from the noise made by the numerous songbirds that shelter among its branches. Since 1820, it has been harvested over twenty times. Its 1991 harvest produced 1200 kg of cork, more than most cork oaks yield in a lifetime. This single harvest produced over one hundred thousand cork stoppers.

Besides being a very resistant species with extraordinary resilience, the cork tree gives much more than it takes away. As Professor Joaquim Vieira Natividade wrote in 1950: "In the often-ungrateful soil conditions and climate of our Country, the cork oak is a precious tree ... No tree gives more while demanding so little.

Corticeira Amorim has made major investments in partnerships with forestry producers, prestigious national and international academic and scientific institutions and local authorities, in order to shorten the first cycle of extraction of cork from the cork oak tree. Operating since 2013, the objective of the Forestry Intervention Project is to seek answers and solutions to the main challenges faced by the cork oak forest. Through the development and implementation of improved irrigation systems it is possible to reduce the first cycle of extraction of cork from 25 years to 10 years.

An area of 2,000 m2 - the entire exterior area of the Portugal Pavilion - was completely covered with cork, in the largest-ever temporary cork installation, in a project coordinated by the architect Manuel Aires Mateus for the 3rd edition of the Archi Summit , the only trade event for architects, engineers and designers in Portugal.

Cork is stripped from the trunk of the Cork Oak every nine years, without damaging the tree. The largest areas of cork oak forest (montado) are in Western Mediterranean countries: Portugal, Spain, Italy, France, Morocco, Tunisia and Algeria.

In each cork harvest, it is possible to extract an average of 40-60 kg of cork per cork oak tree.

Cork can be compressed up to half its size without losing its flexibility. Then it resumes its original form. This is due to its extraordinary "elastic memory"”.

The total global production of cork is 200,000 tonnes per year, 50% from Portugal.

No. The extraction of cork is a controlled process and does not required the cork oak trees to be felled - on the contrary, it contributes to their regeneration. The cork industry ensures the continuity of the cork oak forest, by contributing to the maintenance of forests and the local populations that depend on them. A recent estimate forecasts that in Portugal alone, that has the world's largest area of cork oak forest, the cork available for harvesting is sufficient in its own right to meet market demand for many years. However, and in observance of new sustainable development paradigms, increasing environmental concerns in society and the countless possible uses within an infinite set of activities, it would be easy to foresee progressive demand from different industries for cork and cork-based products, solutions and applications. As a result, Corticeira Amorim, in close collaboration with forestry producers, is leading a Forestry Intervention Programme, aimed at increasing cork production in Portugal by 35% over the next ten years.

Cells were discovered in 1665 by Robert Hooke. On observing a sliver of cork under a rudimentary microscope, the English scientist discovered that it was made up of multifaceted cavities, which he called cells (from the Latin cellula, small room).

Yes. According to the Life Cycle Assessments by PriceWaterhouseCoopers, in compliance with the environmental management standards ISO 14040 and ISO 14044, natural cork stoppers are the best closure option for wine producers, distributors and retailers who seek to minimise their carbon footprint and adopt best practices in terms of environmental performance. The cork stopper was considered to be the best alternative in six of the seven indicators used in the study, and was rated second in terms of water consumption.

With regard to greenhouse gas emissions, even without taking into consideration the carbon retention of cork oak forests, the study shows that cork stoppers have lower CO₂ emissions than plastic and aluminium closures. According to the study, each plastic stoppers results in around 10 times more CO₂ emissions than a cork stopper, while the emissions caused by an aluminium screwcap are around 24 times greater than those of a cork stopper.

Each tonne of cork can provide, on average, 66 700 cork stoppers.

Environmental motivation is one of the most important factors in recycling. Cork stoppers absorb CO₂ particles that have been retained by the bark of the cork oak. If they are decomposed or incinerated, they release the CO₂ into the atmosphere, thus contributing to global warming. Recycling not only prevents the release of CO₂ into the atmosphere, but enables the ability of cork to retain CO₂ to be extended. In each tonne of cork stoppers, around 1.07 tonnes of CO₂ is retained, in an endless process, since the reuse of this raw material is unlimited.

On the other hand, by recycling used cork stoppers you are also contributing to enabling the reuse of a raw material and the decrease of the costs associated with the production of other high added-value products.

Corticeira Amorim is a pioneer in promoting the recycling of cork stoppers, by developing collection programmes in Portugal, the USA and Canada, France, Italy, the United Kingdom, South Africa and Australia.

Learn about the cork stopper collection projects in:

Portugal: http://www.greencork.org/

France: http://www.ecobouchon.com/

The USA and Canada: http://recork.org/

Italy: http://amorimcorkitalia.com/campagna-etico

Lightness
Cork is a very light raw material, weighing just 0.16 grams per cubic centimetre, and can float.

Flexibility/compressibility
Each cork stopper is made up of around 800 million airtight cells. Among them is a gaseous mixture which allows it to be compressed to around half its thickness, without losing any flexibility, and to be decompressed and return to its original shape. This is what is called an elastic memory. Cork is the only solid which when compressed on one side, does not increase in volume on the other. This feature enables it to adapt to variations in temperature and pressure, without compromising its integrity as a stopper.

Impermeability
Thanks to suberin and ceroids, it is practically impermeable to liquids and gases.

Decay resistant
Cork is highly resistant to moisture, and therefore to subsequent oxidation and decay.

Insulation
Cork is an excellent thermal, acoustic and vibration insulator. When transformed into stoppers, its insulation properties contribute to making it the best protection for wine and spirits against temperature variations or contamination and possible negative effects from storage and transport conditions.

In construction, it has clear advantages in regard to the quality of buildings, indoor air and comfort, and may be used in the waterproofing of infrastructures, foundations and underlays, in acoustic and thermal insulation and the final coverings for floors, walls, ceilings, facades and roofs.  

Biodegradable, recyclable and renewable
Cork is a natural raw material which is 100% biodegradable, recyclable and renewable.

Cork consists of suberin cells in the shape of tiny pentagonal or hexagonal honeycombs, a complex fatty acid and filled with an air-like gas, which makes up 90% of its volume. It possesses an average density of around 200 kg/m3 and low thermal conductivity.

Each cubic centimetre of cork may contain around 40 million cells. There are around 800 million cells in a single cork stopper.

There is evidence of cork being used by the people of Ancient Egypt and in Roman civilisation. In France, amphorae from the 3rd century BC were found full of wine considered to still be in good condition. The use of cork at pre-industrial level dates back to the end of the 17th century.

The first stripping, or «desboia», takes place when the cork oak is 25 years old and the trunk has reached a diameter of 70 centimetres, measured 1.3 metres from the ground. Subsequent stripping take place with an interval of at least nine years.

Over the course of its lifetime, the cork oak may be stripped around 17 times, at intervals of at least nine years, which means that the harvesting of the cork will last 150 years, on average.

The first stripping is called "desboia" from which the virgin cork is obtained, which has a highly irregular structure and hardness that make it difficult to process.

Nine years later, when the second stripping takes place, the cork, known as "secundeira", has a regular structure which is not as hard. 

The cork from these first two harvests is not fit for the manufacture of stoppers and thus used in other applications for insulation, flooring, decorative items, among others.

From the third and following  strippings the "amadia" or reproduction cork is obtained. Only this cork has a regular structure, with a flat front and back and the ideal characteristics for the production of natural, quality cork stoppers.

No. After stripping, the planks are stacked into piles in appropriate structures and shall remain outdoors for at least six months for the cork to stabilise. This process is governed by the strict compliance of the Code of Cork Manufacturer Practices.

More than 60% of Corticeira Amorim's energy needs are met from biomass, a CO₂ neutral energy source.

No. Stripping is carried out manually and the trees are never cut down. After each stripping, the cork oak undergoes an original process of self-regeneration of the bark, which gives the activity of cork harvesting a uniquely sustainable nature.

Inaugurated in 2018, the new Lisbon Cruise Terminal, designed by the Portuguese architect, João Luís Carrilho da Graça, presented a revolutionary solution that combines cork with concrete. "White concrete" reduces the building structure’s weight by about 40%, creating an architectonic effect of extraordinary beauty.

Nothing is wasted from the cork oak, all its components have a useful ecological or economic purpose:

• The acorn, which is the fruit of the cork oak, is used to propagate the species, as animal fodder and in the manufacture of cooking oils;
• The leaves are used as fodder and a natural fertiliser;
• The material from tree pruning and decrepit trees provide firewood and charcoal;
• The tannins and natural acids contained within the wood from the tree are used in chemical and beauty products.

It is estimated that there are over 2.1 million hectares of cork oak forests. About one third (approximately 730,000 hectares) is situated in Portugal, which represents 22% of the national forest area. Half of the world’s cork production comes from Portugal. The rest comes from Spain, Italy, France, Morocco, Tunisia and Algeria.

The cork oak forest offers a set of economic and environmental goods and services that are related to agroforestry and other systems, such as ecotourism, generating a range of products that make a significant contribution to the economic importance of this ecosystem. The various productive systems in this ecosystem, in addition to cork, are: providing wood, animal products, plants and medicinal and aromatic herbs, mushrooms, honey; climate regulation, preventing fires, hydrological regulation and soil protection, maintaining habitats and biodiversity, pollination, and various cultural services such as recreation and tourism activities, scientific and educational activities and cultural and landscape identity. EY study estimated an average amount of over 1300 €/ha/year for the ecosystems services associated with a well-run cork oak forest.

(Source: Assessment of the services of the ecosystem of the cork oak forest EY 2019)

This ecosystem is extremely fire-resistant. Cork oak trees, in addition to being less flammable, are also a species that more easily repopulates burnt areas, which should be considered in replanting initiatives after forest fires.

(Source: Assessment of the services of the ecosystem of the cork oak forest EY 2019)

The cork oak forest plays an important role in promoting certain ecological functions, such as soil conservation, carbon storage and water retention, due to the vast existing biodiversity and the multifunctional exploitation that characterises it. Cork oak trees have long lives (about 200 years) providing the raw material, cork, which is known for its high elasticity, good thermal insulation and impermeability.

Cork products are the most valued items in the ecosystem, especially cork stoppers. Due to its varied characteristics, cork is also used in different sectors. As a result, cork has an enormous economic and social significance, in terms of job creation and local development of rural areas. It is estimated that over 100,000 people depend on these ecosystems for their livelihoods.

Cork oak forests are a biodiversity hotspot, protected by the EU Habitats Directive (habitat 6310 - cork oak forest and habitat 9330 - Quercus suber forests) and a priority shelter habitat 6220 (grass sub-strains (Thero-Brachypodietea)). As part of the Mediterranean Basin, the cork oak forest is integrated within one of the world’s 36 biodiversity hotspots, as stipulated in the Critical Ecosystem Partnership Fund in partnership with Conservation International (CEPF, 2017). The Mediterranean Basin has 0.9% of all vertebrates and 4.3% of all plants, which translates to around 770 species of vertebrates and over 25,000 species of plants, more than half of which are indigenous.

The environmental and physical characteristics of the cork oak forest are the main reasons for its ecological value. Perennial trees with long life spans, along with the verticality and density of the shrub stratum, promote the coexistence of indigenous fauna and flora. Since it is an agroforestry ecosystem, there is an essential relationship between maintaining habitats with extensive farming practices and more traditional extraction methods, such as the one used for the extraction of cork.

The cork oak forest is a habitat for more than 130 species of vertebrates, including 75 birds, 28 mammals, 10-15 reptiles and 5-7 amphibians. Around 95% of all terrestrial mammals in Portugal can be found in the cork oak forest. The endangered Iberian Lynx (Lynx pardinus) is one of the species that historically lives and hunts in the cork oak forest, but which is currently only found in very limited numbers. One of the main reasons for this absence of lynx population is the decline in the population of the European rabbit (Oryctolaguscuniculus). In total, more than 28 cork oak forest fauna species are classified as protected. In terms of flora, there are more than 1,350/ha of vascular plants in this ecosystem, many classified as rare species or with protection status.

(Source: Assessment of the services of the ecosystem of the cork oak forest EY 2019)

In Ancient Greece, cork oaks were revered as the symbol of Freedom and Honour. Thus, only priests had permission to cut them down.

It is due to the high level of expertise necessary to harvest the cork without damaging this precious resource.

Not necessarily. The Quercus suber L genome is the same, therefore there are no significant differences according to origin. There are, however, individual differences from tree to tree.

Yes. The environmental and economic advantages of cork stoppers are increasingly recognised by organisations, the wine industry and consumers. Surveys conducted in several countries confirm that at a global level, cork stoppers are the preferred choice - not just because of the connection to the protection of the environment, but also as a result of the association of cork with high quality wines.

According to the prestigious Wine Spectator magazine, 89% of the world's best wines are sealed with cork. In China and the United States, 97% of consumers associate cork with wine quality. Throughout the world, in traditional and emerging markets, consumer satisfaction with cork stoppers exceeds 80%.

Yes. At Corticeira Amorim, over 60% of energy needs are met by using cork dust (biomass), which is a CO₂ neutral source of energy.

Due to the lightness and acoustic and thermal insulation capacity of cork, it is also used in wind turbines.

The name Quercus suber L. stems from the fact that the cork oak belongs to the oak family - «Quercus (oak) suber», because it is a subspecies of the oak tree - and L. derives from Linnaeus, who was the first botanist to describe the species.

If we compare the production of a plastic closure with cork stoppers, CO₂ emissions are 10 times higher than the cork stopper and this emission increases to 24 times higher when it comes to aluminium stoppers.

No. The first stripping of the cork oak takes place when it reaches 25 years of age, but it is only from the third stripping, at around 40 years of age, that the cork reaches the standard of quality required to produce stoppers.

Yes, all beverages can be sealed with a cork stopper. For example, the world's most expensive beer is bottled with a cork stopper and the best whiskies in the world too.

In 2008 the Albanian artist Saimir Strati entered the famous Guinness Book of Records for making the largest cork stopper mosaic in the world. The work depicts Romeo playing the guitar and is 7.1 m tall and 12.9 m wide. 229 675 cork stoppers in different shapes and colours and glued together were used. The mosaic was shown at the Sheraton Tirana Hotel, in Albania's capital.

Prior to that, in 2006, the Frenchman Gerald Malou had entered the Guinness Book of Records with the largest cork sculpture. The work, 2.35 m in height, was shown in Gaillac, a city in southwest France, renowned for its wine.

The largest collection of cork stoppers in the world can be found in Spain. It belongs to Antonio Fontela Blanco and Rosa Maria Valdes Diaz, who began collecting corks in 1995. They entered the Guinness Book of Records in 2002 with 744 different cork stoppers, from 284 brands of cider from the Asturias. The oldest cork stopper was 60 years old at the time.

In 1678, the Benedictine monk Pierre Pérignon was the first person to use cork stoppers as a sealant for his sparkling wine produced in the Abbey of Hautvilliers in the Champagne region.

The production of cork coverings releases low rates of CO₂ - contrary, for example, to the production of wood coverings, which release 2.5 to 4 times more CO₂ than a cork flooring. Furthermore, cork coverings are produced from a raw material whose production does not require the trees to be felled.

C₁₂₃H₁₈₂O₅₆N

The chemical formula of cork was first recorded by the Italian chemist Brugnatelli in 1787.

The Portuguese Post Office (CTT) and the Portuguese Parliament issued the world's first cork postage stamp in 2007, in a single print run of 230 000 stamps. Designed by the engraver João Machado, the stamp pays tribute to the national cork industry, a sector that has placed Portugal as the global leader.

Thanks to its lightness, cork granules are used in special effects scenes to simulate explosions. This technique was used in films such as Total Recall, with the actor Colin Farrell, and Gangster Squad, with Sean Penn, Mission Impossible, with Tom Cruise, and, more recently, Tomb Raider. In turn, expanded regranulated cork was used in Ghostbusters to simulate debris falling from buildings, in Volcano and in Dante's Peak to recreate volcanic rocks. As a general rule, in films when bullets are shown hitting something, the particles projected after impact are made of cork.

Yes. Research carried out by University of Porto reveal that cork has antioxidant and anti-carcinogenic properties. The University of Bordeaux II also discovered that cork stoppers pass those health-giving properties to the wine. Furthermore, when it is applied to flooring and footwear, cork contributes to improve posture and reduce physical effort.

No. Only 30% of the cork extracted from Montado has the quality levels required to produce natural corks.

A report published in 1928 in the book entitled Cork Insulation, by Pearl Edwin Thomas, revealed that expanded cork agglomerate withstood an immersion test in boiling water for three hours without suffering significant changes. The Navy Test, conducted by the USA Navy Department, had the aim of concentrating into a short period of time the destructive forces that a refrigeration room is subject to during its operation. Immersed and boiled for three hours at atmospheric pressure, the insulation materials being studied would have to avoid disintegration and could not expand more than 2%. The «pure cork board» (the name that distinguished it from the cork materials where filler products were applied) passed the test with flying colours. It thus proved to be an option with the clear capacity to withstand deterioration caused by humidity in cold storage environments.

According to a recent scientific study conducted by the University of Oxford, consumers associate cork with a positive experience and better wine quality. The experience tested the same wine, served in a bottle sealed with cork and another sealed with an artificial seal, wherein the former was classified as 15% better.

Due to the fact that it is an excellent thermal insulator. When a rocket or spacecraft is launched into space, its structure is subjected to temperatures exceeding one thousand degrees centigrade. The same occurs on the return to Earth, as soon as the spacecraft enters the atmosphere. Just a coating of a cork compound between 1.6 cm and 2.5 cm thick, depending on the heat load it shall have to withstand (always above one thousand degrees centigrade) is needed to protect the spacecraft from the spread of flames. The cork is applied to critical components for the spacecraft's safety - usually the nose cone and other parts of the propulsion rockets coupled to the spacecraft.

Cork began to be incorporated in aerospace projects as part of the North American space programme, with the Apollo 11 mission to the Moon, in the late 1960s. Since then Corticeira Amorim has continued to produce compounds for the aerospace industry. One of the most recent projects is use of cork in the European Space Agency's IXV mission and integration of this material into a probe that will be sent to Mars.

Thanks to its large-scale research investments, Corticeira Amorim has developed quality control and analysis methods that deliver cork stoppers with unique guarantees in the market. NDtech is a sophisticated screening technology that monitors each cork individually, eliminating the risk of "contamination" with TCA, a chemical compound responsible for cork taint in wines. This state-of-the-art technology can detect TCA levels above the threshold of 0.5 grams per litre, equivalent to finding a drop of water in 800 Olympic swimming pools.

It is the Convent of the Capuchos, in Sintra, whose small cells, formerly used by Franciscan monks, are completely lined with cork. Founded in 1560, this place is known as the "Cork Convent". In addition to creating comfort, cork provided the ideal conditions for spiritual contemplation, in communion with nature.

The start of cork being integrated into aerospace projects is associated with the North American space programme, with the Apollo 11 mission to the Moon, in the late 1960s. To this day, Corticeira Amorim continues to produce compounds for the aerospace industry. One of the most recent projects is the VEGA rocket, by the European Space Agency.

As a result of technological advances and strong investment in R&D+I, the applications of cork are increasingly surprising, from its use in construction and architecture, in design, in the manufacture of clothing, jewellery and footwear, in furniture, decoration, health and cosmetics, in energy production, pollution control, among many other original applications, and those still undiscovered.

At the end of 2011, the cork oak was unanimously established as Portugal's National Tree. This classification is directly related to the economic, social and environmental performance that it represents to the country. Around 23% of Portugal's forest area is made up of cork oaks, which support the country's main industry, besides providing a fundamental contribution against social desertification and making an unparalleled contribution to the preservation of the biodiversity associated with the cork oak forest. 

The cork oak's importance in Portugal has been recognised since the 13th century, a time when the first laws arose for the protection of the species.

In Portugal the felling of cork oak trees is prohibited by law and each cork oak is individually identified, in order to ensure its absolute traceability.

The Alentejo region, the largest cork forest area in Portugal, shall propose UNESCO to classify the cork oak forest as a World Heritage Site. The reasons underpinning the application are those related to tourist interest, to the fact that the montado is a unique ecosystem in the world and that it may be advertised as a destination with an identity.

Cork is the option of some of the most renowned contemporary architects in the world. E.g. from among those awarded with the Pritzker Prize, considered the Nobel Prize of Architecture, various architects have already chosen cork for their projects. Such is the case of Eduardo Souto Moura and Siza Vieira (for example in the joint project for the Portuguese Pavilion at Expo Hanover 2000) and the Jacques Herzog and Pierre de Meuron team (Serpentine Gallery Pavilion 2012).

When in contact with wine, the cork stopper forms antioxidant and anti-carcinogenic compounds that may reduce the risk of heart and degenerative diseases. Furthermore, waste from the cork industry gives rise to composites which are used in vaccine adjuvants to enhance immune system response.