The cork is one of the most important materials used to create our BIRKENSTOCK footbed. The cork is acquired from the bark of the Cork Oak which reproduces its outer layer. The bark harvest only occurs when the tree reaches 25 years of life and every nine years following to ensure that the tree is fully protected. Cork Oak’s can reach an age of 250 years and provide up to 200 kilograms of cork during their life.
The bark is first harvested for wine bottle stoppers. It is cut into strips and the bottle stoppers punched out. The leftovers, which would otherwise go to waste, are collected and processed into finer cork granules. These granules are bound with latex and jute and our iconic footbed is created.
ENVIRONMENTALLY FRIENDLY ADHESIVE
Did you know? BIRKENSTOCK was one of the first manufacturers in the world to use eco-friendly adhesives in mass-production processes. As of today, 98% of our adhesives are water-based, with a considerable portion of these solvent-free. Another naturally sourced material is latex - a primary binding agent in the production of our footbed. Natural Latex is collected from the resin of rubber trees. Like the Cork Oak and its bark, the Rubber tree also reproduces its latex milk.
The latex milk is collected in small buckets from the trees that have matured to six years old. It will then provide about 80grams of latex every day for the next 25 years. Natural Latex sourced from rubber trees is free from pollutants such as solvents and CFCs (Chlorofluorocarbon), which could lead to serious health concerns. It also o ers beneficial natural properties such as high elasticity and superior breathability, which is passed into our footbed.
Jute adds stability to the cork and latex core of the original BIRKENSTOCK Footbed. Like the cork and latex, jute is also a renewable resource which is generally grown in humid tropical regions. Jute bushes can grow up to 20 centimetres before they are harvested. In four months, they grow back again for another harvest.
The harvested jute fibres are roasted, peeled, combed and cleaned so they can be spun. After this process, they are then softened and adhered onto the top and the underside of the footbed to stabilise the form.