English wines have collected a record number of medals at the world's biggest blind-tasting competition, enhancing the reputation of vineyards in the Home Counties for producing sparkling wine that can rival - and in some cases outclass - champagne.

Better technique and a warmer climate have been credited with transforming the once faintly comical English wine production into a serious, if small, industry. Yesterday the International Wine Challenge announced that England had been awarded 21 medals, compared with 16 in 2006 and 10 in 2005.

One sparkling white made 25 miles from central London was awarded a gold medal, despite a fall in the number of top awards bestowed in the competition, which tested thousands of wines.

France retained its position as the country making the finest wine, with 635 medals, followed by Australia and Italy. Chile was the most improved country, increasing its medal haul from five to 13 this year. The judges said that English wine, and sparkling wine in particular, had performed particularly strongly. Tim Atkin, a master of wine and a chairman of the awards, said: "English wine is finally showing that it should no longer be regarded as a cottage industry but as an industry which can produce world-class wines."

The gold and silver medals came from four vineyards. Greenfields, from the 265-acre Denbies estate in Surrey, won the gold, while Chapel Down winery in Kent, Ridgeview in East Sussex and Camel Valley in Cornwall picked up silver.

In recent years, British wine production has increased its acreage and concentrated on sparkling wine following the discovery that the chalklands of Sussex and Kent share almost identical weather with the Champagne region in north-eastern France.

Many are now sold in supermarkets, as well as from the vineyards which are visited by hundreds of thousands of people in summer.

Wine from 35 countries was entered into the International Wine Challenge and tasted - with only a brief description of country and grape. Announcing the results at the London International Wine and Spirits Fair at Docklands, the 400 judges, from 19 countries, said they had detected an improvement in the quality and quantity of organic wine. Of the entries overall, 2 per cent won gold, 12 per cent silver and 19 per cent a bronze.

Charles Metcalfe, one of the chairmen, said: "We have got over 9,000 wines judged but there aren't many gold medals so there will be some countries out of the 35 which have not got a gold medal at all. The fact that English wine has won a gold medal is a big thumbs up for what's been happening in English wine.

"English wine has really found its niche, which is making sparkling wines. And in the context of where we are in Europe, not that far from Champagne, it makes good sense.

"We have got at least four vineyards which are making sparkling wines that are quite frankly better than a lot of champagne."

Marcus Sharp, winemaker at Denbies, welcomed the gold medal as "fantastic". "To win a gold medal sends out a signal to the English wine-buying public that English wine is up there with the best from across the world."

English gold-medallist

Denbies Wine Estate Greenfields 2003

Made from the classic champagne grapes pinot noir, pinot meunier and chardonnay, the Greenfields 2003 vintage has all the elegance of a good champagne.

Perhaps the weather gave Denbies in Surrey a hand when these grapes were growing; the heatwave of 2003 broke the UK temperature record. "We really got the ripeness of the fruit and I think that shows through in the wine," says Marcus Sharp, the wine-maker.

Unlike many wines, the grapes were whole bunch-pressed, including their stems. Like most English wines, though, the scale of production was small. The award-winning 2003 vintage has now sold out; the 2004 is available from Denbies, independent wine merchants and selected Waitrose stores.