What makes a great chocolate? Is it 70% cocoa content? Is it using organically grown, fairly traded cocoa beans? Or is it the man or woman who takes the base ingredient, warms it, seasons it, "tempers" it as it cools, then coats a caramel with it, stuffs a fig with it, bakes a tart with it?

The now-overused criterion for buying chocolate--that it must have no less than 70% cocoa content--was once a useful way of alerting consumers to how inferior most existing chocolate products were; but in fact it cannot define the quality of the final product. That would be like saying a wine is only worth drinking if it has a 15% alcohol content. No, it is cooks who truly define a great chocolate.

Historically the best chocolate confectioners have been based in only two countries: Belgium and Switzerland. Tiny Belgium boasts more than 2,100 chocolate shops, while Zurich is home to the closest thing the real world has to Willy Wonka: Barry Callebaut, a company with an annual chocolate-related turnover of more than $3.5 billion.

But there are minnows nipping at the tails of these behemoths. The lobbying of specialist groups such as the London-based Academy of Chocolate has done much to increase a now global belief that dark, high cocoa-content chocolate is good for our health. (In America, consumer outrage at a so-far unsuccessful attempt by industrial confectioners to call their products "chocolate" even if they've chosen to replace cocoa butter-an increasingly expensive ingredient-wholesale with vegetable fat, shows how far even the land of the cardboard-textured Hershey Bar has bought into this belief.) So what consumers want is handmade, high-quality chocolate-and they're not necessarily going to Belgium, or Zurich, to get it.

Instead, across America and Europe, individual patissiers with absolutely nothing Belgian about them are opening shops selling their own artisan products. Not just in the big cities, either-in Britain you can find independent chocolate shops of the highest quality everywhere from Brighton in the south to the Isle of Mull in the north.

The capital meanwhile, crams ever more chocolatiers into its greedy maw. Three new arrivals are typical of the breed: William Curley, Paul Young and Keith Hurdman. All are highly trained, having worked--between them--everywhere from France to, yes, Belgium, and alongside chefs as feted as Marco Pierre White, Raymond Blanc or Pierre Koffmann. All three operate out of small shops in characterful London locations (Notting Hill in the west, Shepherd Market in Mayfair, and Camden Passage in the north) and all sell their own stuff, made fresh every day.

Perhaps the newest boy on the chocolate block is William Curley, who has just opened London's first chocolate dessert bar in a narrow passage in Shepherd Market. The shop's entrance is dominated by shelves of hand-crafted chocolates, while at the other end is a workmanlike bar where custom-made pralines, tarts and confections show how, in Curley's own words, he lets "chocolate be the hero of the dish".

Surprisingly, neither Curley, Young or Hurdman rely on base chocolate from Belgium or Switzerland ("too fatty and sugary", they say). Instead Curley mainly sources his base chocolate from the world's two finest producers--Valrhona in the Rhone Valley and Amedei in Tuscany. Typically, he uses Amedei's gold-standard Chuao chocolate (made with beans from Venezuela) in a rich, dark tart, served with raspberry compote and a Kyoto green-tea ice cream--a clear sign of the influence of his Japanese patissier wife and co-worker, Suzue. I tried one: the complexity and chocolate intensity was like hearing opera after a month of musicals.

To the north and east, in Camden Passage and his new outlet in the City, is Paul Young, potentially the Heston Blumenthal of the chocolate world. Young's creations include a Marmite Guinness ganache, a port and Stilton chocolate, and a sea-salt caramel. He also sells a selection of huge "artisan" chocolate bars: 1kg-slabs of milk, white and dark chocolates blended with a spectrum of flavours including stem ginger, cranberry and pecan, prune and macadamia nut. When I visited recently, his shop was packed with customers as happy to experiment with tastes as Young himself.

Young has much in common with Keith Hurdman. He is the Swiss-trained chocolatier at Melt, Notting Hill's purveyor of edible chocolate name-plaques to London's media and banking elite--though Hurdman perhaps allows non-chocolate ingredients to do more of the speaking than either Young or the Curleys. He is especially proud of his highly flavoured vanilla and tonka-bean ganache on sesame praline, his crunchy salted pralines, and passion-fruit caramel with orange ganache.

Could Marmite or tonka-bean ganaches ever dent the established market for continental-style chocolate? It's hardly likely, given their makers' homemade, hands-on approach. Still, for my money, William Curley's profoundly complex and exciting flavours are a better buy than any Belgian selection box. And as Curley said: "Independent chocolatiers can take on the Belgians or the Swiss when it comes to a more cosmopolitan approach--you don't see them using Japanese flavours the way we do. Besides, success is really down to how you deal with the best raw materials--and the last time I looked there were no cocoa plantations in Brussels."

William Curley 32 Shepard Market, London W1 and branches; www.williamcurley.co.uk
Melt 59 Ledbury Rd, London W11; www.meltchocolates.com
Paul Young 33 Camden Passage, London N1 and branches; www.payoung.net