Frequently Asked Questions


How is cork harvested?

Why use natural cork?

What is TCA?

What off-aroma compounds are removed in M.A.Silva’s cleaning process?

What are M.A.Silva’s cleaning processes?

Are the finished corks free of residual chemicals?

Why not use alcohol or chlorine in your cleaning solution?

What quality certifications do you meet?


How is cork harvested?

MAS_Quality_TreeCork is harvested using traditional methods that remain virtually unchanged since cork’s value was first discovered. The cork oak bark is first harvested when the tree reaches maturity at approximately twenty years old. It is harvested again (at minimum) every nine years. Regulations determine the legal period of time between each stripping, the ripeness of the bark, and prevailing weather conditions during harvest. Harvesting is a skilled operation that follows a strict code of practice. An incision is made into the bark and the cork is gently removed in sections approximately 1 ft. x 3 ft. No harm is done to the tree during this bark removal process. (top)

Why use natural cork?

Nothing is more ideally suited to sealing a bottle than natural cork. It’s flexible, elastic, and compressible. A typical cork closure is composed of 750 million watertight cells. Each cell contains a gaseous mixture similar to air that becomes compressed when the cork is inserted into the bottleneck. Once decompressed, the cork stopper recovers its initial size, providing a complete seal. A glass bottle will expand and contract with changes in temperature. Cork does too, which ensures a complete seal at all times.??Natural cork is resistant to wear and tear, resists humidity and oxidation, and retains elasticity for a long time. It’s better for the environment, too: natural cork is reusable, renewable and recyclable. Recycled cork is used in products like wall panels, shoe soles, and more. (top)

What is TCA?

TCA (2,4,6-Trichloroanisole) is one of a series of naturally occurring compounds resulting from the growth of many fungal species. TCA was a key contributor to “cork taint.” Although once a concern, our Certified Quality Program has reduced average TCA levels to below the threshold of human sensory capabilities. (top)

What off-aroma compounds are removed in M.A.Silva’s cleaning process?

CozeduraDynavox® reduces off-aroma compounds including TCA (2,4,6-Trichloroanisole), 2,3,4,6 –Tetrachloroanisole (TeCA), Trichlorophenol (TCP), Pentachloroanisole (PCA) and 2,4,6 -Tribromoanisole (TBA) and others. (top)

What are M.A.Silva’s cleaning processes?

Producing the finest natural and technical cork products from raw corkwood requires custom cleaning solutions for each phase of the production cycle. We utilize a comprehensive multi-step process to achieve optimal cleaning. The first stage involves sterilizing the corkwood slabs, while removing off-aroma polyphenols, excess pigments and tannins. We use both intense steam and pressure in our Dynavox® system to unlock unwanted compounds from deep inside the cork matrix. Although this process would damage finished corks and granules, it aggressively reduces TCA in slabs. For cork granules intended for technical and agglomerated corks, our SARA® wash uses steam and pressure, further reducing TCA and other contaminates. Its tumbling action ensures every surface of each granule receives thoroughly cleaning. Once finished, both punched (natural) and formed (technical and agglomerated) corks receive a final Maszone® washing, which uses ozonated water and hydrogen peroxide to disinfect finished corks. This ensures sterilization, while enhancing appearance. No other cork supplier employs such a rigorous, multi-step TCA removal, sterilization, and appearance confirmation program. (top)

• See our informational whitepaper on our Dynavox® process

• See our informational whitepaper on our Maszone® process

• See our informational whitepaper on our SARA® process

Are the finished corks free of residual chemicals?

Yes. Our Dynavox® and SARA® cleaning processes rely solely on a proprietary combination of pressure, heat and purified filtered water. Our Maszone system uses not only ozone but the more powerful Peroxone, a combination of ozone and hydrogen peroxide, to disinfect and clean finished corks. Ozonated water is the same solution regularly used in food processing. (top)

Why not use alcohol or chlorine in your cleaning solution?

TCA and other off-aroma compounds easily volatilize with steam. By using a combination steam and pressure, we achieve deeper contaminate removal without the addition of hazardous chemicals. Washing processes performed at ambient temperature may not thoroughly treat beyond the surface of the cork. Cellared wine remains in contact with the cork for extended periods, inviting migration on interior contaminates. A cork damaged during a subsequent process, like printing or bottling, may expose the wine to an untreated surface. Residual chlorine is also thought to lead to the reformation of TCA. (top)

What quality certifications do you meet?

ISO 9001:2001 – The International Standards Organization (ISO) ISO 9001:2001 standard for quality management systems certification is awarded to companies that globally implement procedures for providing assurance about its ability to satisfy quality requirements and to enhance customer satisfaction in supplier-customer relationships. (top)

ISO 22000:2005 - The International Standards Organization (ISO) 22000:2005 standard specifies requirements for a food safety management system where an organization in the food chain needs to demonstrate its ability to control food safety hazards in order to ensure that food is safe at the time of human consumption.

Systecode – Established by CELIÈGE, SYSTECODE is a quality assurance system for the cork industry. Accredited under the SYSTECODE standard, M.A. Silva guarantees that its products comply with the standards.

Please refer to our certifications download here - M.A.Silva Corticas - Certifications  (top)