Around a million cases a year sold in the UK are corked, a major independent survey has revealed.

The survey, conducted over the last 18 months by the Wine and Spirit Association, an independent UK wine trade body, found that mustiness affected between 0.7% and 1.2% of wines. Around 3.4% in all were found to be defective – as a result of oxidation or other causes. About 100 million cases of wine are sold in the UK annually.

The survey tested 13,780 bottles, one third of which were from France, around 10% each from Italy, Spain and Australia, and the remaining third from the rest of the world. The bottles were ranged equally in the low, medium and high price brackets, 46% were red, 39% white, and 86% were sealed with natural cork. As regards vintages, 58% were from 1990-2000, 23% from 2000 onwards.

The project was run by the WSA with a consortium of companies ranging from major cork manufacturers, food and wine distributors, supermarkets, synthetic stopper manufacturers, bottlers and distillers. Research was coordinated by the Campden and Chorleywood Food Research Association.

If a fault was discovered the bottle was immediately sealed and retasted within two days by independent verifiers. Tasters were briefed to taste for a level of mustiness that might be detected by an average consumer.

Throughout, the WSA has stressed the aim of the project was to find a ‘true’ level of mustiness in wine. Mustiness was only found in wines sealed with corks.

The survey threw up some interesting findings. The incidence of verified mustiness was lowest in Italian wines, and much lower in red wines than white (0.5% of red wines were tainted, against 1% of white wines).

Wines bottled in 2000 or before were far more likely to be tainted than those bottled after that date, or non-vintage wines (1.2% 2000, 0.2% 2001 or NV).

Given that 100m bottles a year are sold in the UK, the figures mean around a million bottles are cork-tainted.

‘I shudder to think what the figure is worldwide,’ Barry Sutton, chairman of the consortium told a London press conference. ‘Our report says how big our problems are. Now let us get on with sorting them out,’

As a result of the survey, the WSA has proposed a ‘cork summit’ in September, with members of the cork industry, members of the UK trade, and key officials from the cork producing countries.

On the agenda for the summit are proposals to revise the cork industry’s code of manufacturing practice, and to institute a universal grading system for natural cork. In early 2003 there will be a seminar to brief the trade on progress.

Written by Adam Lechmere19 July 2002