Screwcaps do not eradicate the risk of a wine spoiling, according to experts.

From a blind tasting of 9,000 wines at this year's International Wine Challenge, judges discovered that 4.4% of the corked wine had been tainted in some way, but 2.2% of the screwcapped wine had also been damaged.

The findings will delight many purists, who bemoan the rise of the screwcap at the expense of corks.