Oak barrels linked to source of TCA

New research by Excell in France suggests there are several sources of TCA contamination of oak wood - although so far nobody seems to know where it comes from.

TCA contamination usually comes from corks but can also come from barrels, other cooperage or even from wood within the cellar including walls or beams. The term 'corked wine' is applied to all wines with TCA contamination because corks are the souce of most of the problems. The wine industry estimates that as many as 3% to 7% of all wines have TCA contamination at levels that can be detected by consumers.

Excell said it believed that infection occurred while the wood was being naturally dried and seasoned, but could not pinpoint how the contamination happened, despite having several theories on the subject.

This research has upset the French coopers association Tonneliers de France, which described them as ‘inaccurate and insulting’. They argued that only 0.04% of barrels produced in the last three years were suspected of being infected with TCA – fewer than 100 barrels out of about half a million.

‘The extent of the problem is still severely under-estimatedby coopers and barrel-users, due to the extremely unpredictable, localised contamination of the staves,’ the laboratory said.