DORKING, England — The damp and cool English terrain hasn't traditionally been known for producing quality wine.
But vineyards are sprouting up all over the countryside as climate change makes England increasingly suitable for making sparkling wines to rival those of France's Champagne region — winning prizes at international competitions.
Last year, the combination of a steadily warm spring, followed by an exceptionally dry and sunny summer that lingered well into autumn, resulted in what's been described by Wines of Great Britain, a trade association, as the "harvest of the century."
The weather has created some logistical challenges, though.
With yields as much as 50% greater than expected, producers were forced to scramble to find enough space to store the unanticipated windfall.
The parking lot at Denbies Wine Estate here was covered with storage tanks containing 53,000 excess gallons of wine.
But it was a nice problem to have.
"The quality across the board is fantastic," said Christopher White, the chief executive of Denbies.
The average temperature in southeast and south-central England has increased by about 1.8 degrees over the last 50 years, according to Alistair Nesbitt, a viticulture and climate consultant.
While it doesn't sound like much, this increase in temperature has brought the average of the region closer in line to the 57.7-degree average temperature in Champagne.
In the 30 years since the sparkling wine industry was established in England, weather has proved to be both a source of opportunity and a disaster for winemakers.
"The whole English industry is being completely changed by climate change," said Chris Foss, the head of the wine department at Plumpton College in Lewes, England.
From stigma to selling point
Until the 1980s, the few English vineyards there were predominantly produced German-style wines such as Bacchus that work well in the short growing season.
White said when his father purchased the Denbies estate in 1984, a friend who was a geologist advised that chalk seams contributing to the soil on the property were the same as in Champagne, France. That inspired him to transform the former cattle farm into a vineyard.
"Whereas it used to be a bit of a stigma to be an English wine, it is now our greatest selling point to be an English wine," White added.
The Americans Stuart and Sandy Moss took over the Nyetimber estate in 1988 and decided to experiment with planting the champagne grapes — pinot meunier, chardonnay and pinot noir, according to spokesman John Franklin.
It worked, and Nyetimber's first sparkling wine received acclaim with its first batch — the 1993 Classic Cuvee, which won an international award for best bottle in 1998.
Foss said while the first chardonnays harvested in England were undrinkable, it's now the country's most widely planted wine grape.
For English winemakers, changing conditions will mean having a flexible rather than fixed formula to grow grapes.
"They'll have to keep very close to what is going on with the weather and adapt things. One year they'll be flooded and one year they'll be irrigating," warned Foss, who has spent decades in the business in France and England.
Nesbitt, the consultant, said the higher temperatures witnessed in recent years aren't entirely cause for celebration for winemakers.
He said that buds bursting earlier in the season would be "at high risk of damage from frost events around April and May."
Although average rainfall has remained largely unchanged, he said, the possibility for more sporadic, extreme downpours due to the changing climate could have mixed results in the future.
'Unthinkable 20 years ago'
England isn't the only place in Europe where climate change is having an impact on wines.
Parts of France have struggled with high alcohol content in the range of 15 to 16% because of hotter summers, said Tom Newham, the vineyard instructor at Plumpton College.
Vines are also being planted for the first time in countries like Denmark, Belgium and Poland, according to Foss, who is involved in a multiyear study monitoring conditions in vineyards across Europe.
Determining which type of wine grows well in a specific area requires a level of experimentation. There are about 400 types of pinot noir alone, Newham said. At the college's vineyard, which in part acts like a living laboratory, they're constantly testing the viability of different varieties and methods.
"Growing grapes here is a really stupid thing to do," Newham said. "There are better places to grow grapes, so if you can do it here you can do it anywhere in the world."
Winemakers are paying attention to what the college is producing while experimenting on their own soils. And the options available to them have expanded. Foss said tests to grow varieties from warmer regions like Spain are underway at many English vineyards, an idea "that was unthinkable 20 years ago."
The English wine industry has grown from roughly 360 vineyards in 2006 to well over 500 vineyards today. Nesbitt's research identified a further 84,000 acres of prime viticulture land — larger than the Champagne region— that could be cultivated.
Many established wineries are also planning to expand. Nyetimber, which surpassed the million-bottle mark with last year's harvest, will see its productive vineyards grow from 444 acres to 716 acres over the next three years. Its bottles are already available as far away as Hong Kong and Singapore, and there are plans to hit East Coast U.S. markets this year.
Denbies is also expanding its operations to add a hotel and restaurant to the existing lodge and two restaurants currently on site just over an hour's drive from London.
Such developments are bound to attract more tourists, Foss said.
"The industry will transform this area of England into the Napa Valley," he predicted.