In a report published in the May/June 2009 edition of Vineyard & Winery Management, Dr Christian Butzke said TCA was no longer a major issue from both a consumer and winemaker perspective.
Considered one of the leading wine experts in the US, Dr Butzke is a professor of enology at Indiana's Purdue University and is president-elect of the American Society for Enology and Viticulture.
The director of winemaking at Sakonnet Vineyards from 2002 to 2005, Butzke is also a member of the LLC managing committee of the Unified Wine & Grape Symposium and chairman and chief judge for the Indy International Wine Competition - one of the largest wine competitions in the US.
From his experience reviewing the thousands of international and US wines submitted to the Indy International Wine Competition, Dr Butzke says he believes cork has achieved a performance rate exceeding 99 per cent.
Amorim's director of marketing and communications, Carlos de Jesus, said it was refreshing to hear industry leaders acknowledging the progress that has been ma de by the cork industry in recent years.
"As Dr Butzke's assessment suggests, the problems associated with TCA contamination are now a rarity and this is evident in both scientific analysis and anecdotally," he said.
"As with any other product or service, promises of perfection are difficult to deliver, but Amorim will continue aiming higher and higher when it comes to the performance of our products. We look at strong figures such as those presented by Dr Butzke as a great departure point, never as the limit of natural cork's performance capabilities.
"While some commentators continue to live in the past when talking about natural cork, we know from our discussions with winemakers on all continents that the industry recognises the progress that has been made."
A number of independent analyses provide scientific evidence of the improvement in cork's performance and particularly the drop in the incidence of 2,4,6 trichloroanisole (TCA) contamination.
The US-based Cork Quality Council, for example, shows a dramatic reduction in TCA levels in bulk cork imports since 2001. The average TCA count has dropped from 4.0 nanograms (parts per trillion) several years ago to less than 1.0 nanogram - well below human sensory thresholds.
Meanwhile, Decanter.com has reported that one of Australia's leading wine brands, Penfolds, is in the very early stages of trialing a glass stopper that might imitate the oxygen exchange provided by natural cork. Chief winemaker at Penfolds Peter Gago maintains that oxygen exchange is essential for the development of fine wine and he told Decanter.com that if you can neutralize the problem of TCA, cork "can't be beaten" as a wine closure.
Dr Butzke's report in Vineyard & Winery Management coincides with the recent release of two studies underlining the preference for natural cork as a wine closure in the United States.
In its '2009 Closure Report', leading US trade publication Wine Business Monthly said natural cork remains the highest rated closure among US wineries in terms of 'overall perceptions'. The ranking, from a survey of 229 wineries, was achieved by natural cork's top rating in several categories including consumer acceptance, performance on the bottling line and product performance.
Nelson Barber, Christopher Taylor and Tim Dodd of the Texas Tech University also found strong US consumer preference for cork in their consumer perceptions study titled Twisting Tradition: Consumers' Behavior Toward Alternative Closures. The study suggests that 71 per cent of US consumers prefer natural cork closures.
