Nicholas Wroe finds evolution, and revolution, in his local vineyards

So you've seen Sideways, yes? The film featuring Miles and Jack ambling through mid-life crises and Californian vineyards "in search of wine and in search of themselves". And you might also remember The Darling Buds of May, in which strait-laced taxman Charley was lured into the bucolic postwar Kentish idyll of the Larkin family - and more particularly into the arms of the young Catherine Zeta-Jones - via a few bottles of local hooch. Great stories, set 6,000 miles and half a century apart, yet, in a manner of speaking, you can have a walk-on part in both just an hour's drive from London.

Let's start in Larkin territory. Not far from Pluckley in Kent, where the TV series was filmed, is Biddenden. These vineyards were founded in 1969 when, in what might have been a Darling Buds plotline, the mother of current owner Julian Barnes (no, not that one) heard an item about wine on Woman's Hour and persuaded her husband to give over a few acres of their apple orchards to vine. Wine might have been produced in England since before the Norman conquest, but this was the ground floor of the modern English wine industry and Biddenden reflects where it came from and, just maybe, where it's heading.

Biddenden still specialises in the ortega grape, which produces fruitily off-dry Germanic-style wine, which is presented in bottles with gothic script on the labels. The longstanding lack of interest from the wine trade in this style means that 80% of this wine is sold at the farm gate. But Biddenden is adapting to modern tastes. It has retained some orchard and produces increasingly sought-after apple juice as well as cider. The vineyards - quite spectacularly beautiful - attract 30,000 visitors a year, who can walk among the vines as well as taste the products at the farm shop. There is even a self-catering converted loft - complete with incongruously hi-tech flat screen TV - where guests can stay. But perhaps most interesting is that Biddenden has begun to introduce the more fashionable French variety grapes, and sparkling wine and light pinot noir are coming on stream. "You work with what you've got," explains Barnes. "But that doesn't mean you can't change things as you go along."

If David Jason as Pop Larkin might have raised an eyebrow at the advances at Biddenden, he would have apoplexy at Chapel Down. This stock market listed company (englishwinesgroup.com) sees itself very much as the future, and its approach has been more revolution than evolution. It has made a commitment to French varietal grapes - in particular the champagne holy trinity of pinot noir, chardonnay and pinot meunier - and has approached the problem of high prices and variable quality of English wines by going unashamedly upmarket. Chapel Down was the first English winemaker to win a gold medal at the International Wine Challenge, it supplies Gordon Ramsay and Gary Rhodes restaurants, the Dorchester and Mandarin Oriental hotels, and it exports. Just like the state-of-the-art California wineries visited by Miles and Jack in Sideways - and as is the norm in other wine tourist hotspots round the world - Chapel Down also boasts a newly opened high-quality restaurant.

A visit can range from some fairly lavish all-day corporate entertainment to wandering round the vineyard and tasting the entire range of wines for free. There are plenty of other options in between - comparative tasting of identical wine aged in either French or American oak barrels is a particularly enlightening part of one tour - and this combination of high-quality product and visitor access appears to be the new model for the English wine industry. A few miles away at the Gusbourne Estate, one of the many new vineyards cropping up all over England and Wales, they have been planting vines since 2004, but won't have any wine (sparkling only, competing directly with some of the best-known Champagnes) until 2009. But already the vineyards are picture-book pretty, with a rose bush bookending every line of vines, and a visitor and tasting centre will be ready as soon as the wines are.

Looking out over the Gusborne vines to the newly constructed windfarm dominating the skyline over Romney marsh, you might be reminded that everything changes. The Darling Buds of May landscape is now inhabited by Sideways viticulture and increasingly sophisticated wine culture. But in a sense, that's nothing new. An ice age or two ago, Kent and Champagne were part of the same landmass. And, as the winemakers enthusiastically point out, every one degree of global warming pushes the "wine-growing envelope" 200km north. So raise a glass of English sparkling now, and maybe prepare your grandchildren for the possibility of a glass of English claret.