The corktree (Quercus Suber),the tree that produces cork, is typical from the Mediterranean region and is particularly abundant in its western part. Portugal is known to be the country that has its biggest implantation and exploration.
Appreciated for the wood, the cork bark covering it and the fruits, the cork tree, which resisted everything, including fire, has long become an exceptional tree. The ancients adored it and the young have been in charge of its protection. It was consecrated to Jupiter by the Greeks and Romans as a symbol of value (liberty and honour).
It’s the most protected tree in Portugal (almost since the foundation of the country). Portugal is also pioneer and main legislator in this matter. The most ancient fossil that is known in Portugal has about 10 million years.
The cork, which has also been used for utensils during the Roman period, is used once again only later, in the XII century.
According to several authors, due to the Earth’s since a remote past, the area of cork trees plantations is estimated in about 8 millions of hectares, has decreased to less than one third – the actual area.
It is during the reign of king D. Dinis, beginnings of the XIV century, when it’s registered the exportation of cork to the United Kingdom. Later it becomes also known the exportation to Flandres.
Around 1450 the interest in cork as a fishing accessory (floater) is notorious. It is then that the Portuguese king, D. Afonso V, gives the monopoly of national cork’s exportation to a merchant from Bruges, for a decade, which originated complaints from the people’s representatives, due to that privilege.
In 1488, D. João II forbids the cut down of cork trees and, a short time later, edits a letter over the rights of farmers, so they can sell the cork freely.
With the Age of Discovery the use of wood and cork in all of the ships was great.
But with the excessive use of cork trees, it becomes more and more clear its disappearance. In 1602, the king, Filipe I, has even dictated the punishment of being 4 years in Africa, for those who cut own cork trees or removed the cork from it. Unfortunately, despite of these several efforts, a great part of these cork trees had been disappearing.
Only after the mid XVIII century, with the setting of population, the cork tree is recognized as a replaceable value, also appreciated then for feeding the cattle, especially the suine.
By the ends of the XIX century, there’s a large annual exportation of cork, (especially to the U.K) of about 30.000 tones that has immediately arisen to over 50% in less than a decade.
It is also by then that the plagues attack the cork trees the most. The attack of the cobrilha and the diseases that lasted for over a half century are the most referred episodes.
Later, lepidoptera stopped being the most important source of plagues, because it has been gradually replaced by the green lizard (himenoptera) and after by the small coleoptera.
The deaths of cork trees concur a lot with the hardest periods of draught. One should stress that around 1950, in a period of 7 years, over a million cork trees were cut down.
Henry Bucknall & Sons, Ltd, (the most ancient company), established in Portugal in 1750, was eporting to the U.K. where the cork was transformed. By then there were other foreign companies working in Portugal, namely: Mundet, Wicander, Robinson (still manufacturing), Rankins, Avern and Armstrong in Spain which prepared the cork in boards to be transformed throughout all Europe, United States, South America, Japan and Australia.
Between the end of the XVIII century and the beginning of the XIX century there was a decrease of interest in this sector, since the using of cork was destined almost exclusively to wine sealers, which meant the using of only one fourth, due to the quality demanded for that purpose.
With the use of cork leftovers (unappreciated until then) for the making of agglomerated, by the end of the XIX century, there was a new expansion in cork production.
Around 1874, with the collaboration of specialized personnel from Alentejo, a factory for the making of cork stoppers was installed in Romeu, Mirandela.
The cork (bark of the oak’s trunk) is removed for the first time after about 25 years, for what is called “virgin” cork. During a second extraction, in which the cork is known as “secundeira”, a period of recess of at least 9 years has to be followed, as well as during the following strippings. Only at this phase, after the third stripping, the best cork is removed, called “amadia”, for the manufacturing of cork stoppers.
The best wine sealer
Since remote times that cork is being used as the most convenient sealer for wine containers. Egyptian, greek and roman vases have testified for thousands of years its efficiency regarding the preservation of the best wines in the Mediterranean region.
It’s a light product, impermeable to liquids and gases, resistant to use and extreme temperatures, that never becomes putrid, and that fits perfectly to the bottleneck of the container due to its flexibility and compressibility.
In a universe of 340.000 tones of annual average production, we can observe that this number is distributed in the following way:
Other applications of cork
Due to its numerous qualities and unique characteristics, cork is being requested, since ancient times, for many purposes. In fact, its first uses are related to the making of floaters for fishing, shoes, urns, ornaments and house coverings. Nowadays, there’s a great variety of cork products, especially as a resource in the making of floors and isolators for the house construction industry.