Quoting a study conducted by the Bordeaux Wine Council (CIVB) since 2001, Wine Business Monthly reports that the incidence of wine contaminated by cork taint and TCA has diminished. The drop is the result, it appears, of “the improved quality of natural corks as well as the use of synthetic closures.”
 
From 2008 to 2011, the CIVB selected 9,143 bottles of Bordeaux wine at random from retail stores and wholesalers in France and other countries. In the full eleven years of the study, 2.38% of all wines “were identified by tasters as tainted by cork or mold.” Chemical analysis confirmed that the tasters were correct in 95% of the cases.
 
Agglomerated corks were found to have the highest rate of overall contamination, partly owing to “a polluted environment,” whereas natural corks contained the highest levels of TCA. “The analyses revealed a definite decrease in the levels of TCA found in wines” over the past decade, WBM writes.