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CL OSURE S cork until the advent of synthetic corks in the late 1990s (and from 2000 onwards the widespread adoption of screwcaps, particularly in New Zealand and Austra- lia), the pressure on the cork producers to do something about taint issues wasn't all that strong. But since the loss of significant market share to alternative closures, the cork industry has invested a lot of money in searching for remedies. There are two ways of addressing taint. The first is by curative measures, attempt- ing to remove TCA from products during the production process. The second is by improved quality-control steps. Both approaches have been adopted by cork companies in their attempts increase the reliability of technical corks, and especially so since the disaster of Altec. Because of the averaging process of using many small granules, it is imperative that agglomerates and microagglomerates are made from cork that has been cleaned in some way. Amorim was the first to use steam- based methods for cleaning cork granules. Their technology, called ROSA, involves suspending the granules in steam under pressure, which removes a good portion of any TCA present. It's not as effective as using critical-point carbon dioxide, but it is much cheaper and takes out around 70%-80% of TCA. "Steam works," says de Jesus. "It's natural, it's inexpensive, and it's not highly invasive." Unsurpris- ingly, other companies are now using variations of ROSA for their products as well. "Our SARA process is similar to the Amorim ROSA process," says MA Silva's Hernandez, "and gives an 80% reduction in TCA." Cork Supply's steam-cleaning process is named Vapex. De Jesus points out that techniques such as ROSA are much more effective when they are coupled with preventive processes that seek to reduce any TCA present in cork in the first place. After all, an 80% reduc- tion in TCA is only effective if this brings the total level down below the perception threshold; 20% of a large initial TCA level is still a huge problem. The leading cork companies have made significant improvements in the way they deal with cork bark during the production process. One is that most cork is now stored on concrete, not bare earth, while it is waiting to be processed. Another is the boiling stage: It's important that the water used to boil the planks, necessary to clean and soften The makers of Diam put cork particles through a supercritical carbon dioxide treatment. 36 Wines & Vines AUGUsT 201 1