TCA is an abbreviation for 2,4,6-Trichloroanisole and is the major chemical compound that gives wine an undesirable cork taint. TCA can be formed through the reaction of molds and plant phenols with chlorine. TCA can be formed on the tree bark of cork trees due to the use of certain pesticides. Corks stoppers contaminated with TCA are therefore a problem. However, improvements in the production and quality control reduced the contamination of cork stoppers significantly. An uncontaminated cork stopper or screw cap for that matter does not guarantee the absence of a cork taint. That is, TCA can also originate from chlorine-based cleaning products that come into contact with barrels, wooden pallets or cardboard in the winery. The phenols (or molds) of these wooden materials react with chlorine and form TCA which can be transferred to the wine. A TCA contamination of a winery can only be treated effectively by removing the tainted wooden parts (even if this means reconstructing part of the winery). TCA-taint is one of the most common wine wine faults. Estimates of corked bottles typically range from 1% to 2% of all wine bottles produced, but some studies even report a taint-rate of 7% or more.