Quality chocolates in the UK? I should coco. Peter Chapman explores the world of high-class confectionery

The world divides into those who love plain chocolate with a passion and those who loathe its bitter intensity, who behave as if they've been poisoned whenthey accidentally slip a square of the dark stuff into their mouth. Me? I was the original Milky Bar kid, tolerant of milk chocolate, but fonder of slabs of white. Something about that sweet creaminess has me hooked. It is childish, I know, but what can I do? My name is Peter Chapman, I remain powerless once I've fought my way past the silver paper.

So it was with some trepidation that I went along to L'Artisan du Chocolat, London's premier purveyor of bespoke chocolates - supplier to Gordon Ramsay's restaurants - for a tasting. Here, surrounded by 20 chocolate gourmets, my preference for the white stuff would surely mark me out as a second-class citizen. I needn't have worried. Gerry Coleman, a gentle Irishman and co-owner of the business with Belgium-born Anne-Françoise Weyns, remained true to their principle, which is to inform and delight.

"Yes, it's true, quite a few people find dark chocolate bitter," said Gerry. "But this is because the cocoa beans have been improperly fermented or force dried. We take great care in finding only the best chocolate. Single-estate chocolate can have a highly distinctive flavour." I tried to conceal my scepticism. Using the language of wine appreciation seemed a touch over the top when talking about chocolate. How wrong could I be?

The Madagascan sample didn't simply taste of oranges, it had a powerful citrus tang, while another sample from New Guinea, made from beans grown on volcanic soil, had a distinctively smoky taste These rich flavours were not added to the chocolate; they come from the cocoa beans and reflect the prevailing conditions (climate and location) that affect the beans. Oh, one other thing, neither was bitter. Powerful, yes, bitter, no.

"A lot of people buy chocolate bars according to the percentage of cocoa solids," continued Gerry. "Unfortunately, some manufacturers use inferior beans and many producers also squeeze the cocoa butter out of the beans, sell it on to cosmetic firms and then replace it with vegetable fat. They can still claim to have a bar with 70 per cent cocoa solids in it, even if it doesn't taste very nice."

As the doors to the kingdom of chocolate opened ever wider, I came clean about my white chocolate habit. Ever the diplomat, Gerry went easy on me. "White chocolate can never be as distinctive as dark because it has a lower cocoa content. Also, producers add milk powder and lots of sugar. Some brands have so little in them that they cannot by law be sold as chocolate. It is, however, very comforting, it reminds us of our childhood."

Only four years old, L'Artisan du Chocolat initially supplied chocolates to high-class restaurants, but public demand was such that they were able to open their own shop 18 months ago and have a stall at Borough market that opens on Saturdays. Their small empire benefits from this country's relative lack of interest in fine chocolates. "In Belgium, every small town has its own chocolatier," said Anne. "Everyone has a fixed idea of what they like. Here, people are much more willing to try something new."

Proof was supplied in the form of a delicious basil chocolate, which had everyone munching contentedly. Clearly, Anne and Gerry are innovators of the first order. It took several months of experimentation before settling on a red Côtes du Rhône for their wine chocolate. It was worth the wait, the intense ruby jelly sitting on a dark ganache (a mix of chocolate and cream) was sensational.

As well as such making idiosyncratic wonders as Banana & Thyme and Passion Fruit & Pear they reinvigorate old favourites. A fan of marzipan, Gerry bought a bar but was disappointed. "It was dry and tasteless. We make our marzipan with at least 70 per cent almonds, and add a little pistachio," he said.

Because of their dedication to fresh ingredients, their chocolates are best eaten in three weeks and have a maximum shelf life of a month. They warn that when you buy a box of chocolates, you should check the sell-by date. If it is a few months away, then the chocs will rely heavily on preservatives. "Sometimes, you will pay more for the fancy wrappings than the chocolates," observed Gerry.

He went on to lovingly detail the labour-intensive methods employed - he talked of mixing up the ganache, of pouring it on to marble slabs, of passing it under showers of chocolate. It was all I could do to stop myself from putting my hand up and offering my services as an unpaid assistant.

By the end of our two-hour tasting we, my fellow tasters and I, existed in a state of happy stupefaction, our palates dazzled by the succession of extraordinary tastes. I had learnt many things, not the least being that Anne and Gerry are at the forefront of an attempt to introduce us to the art involved in making chocolates. We all trooped happily downstairs and through the shop. I handed my Milky Bar badge in at the entrance. I can now exclusively reveal that I am in involved in an ongoing relationship with dark chocolate. Only the best sort, mind.

L'Artisan du Chocolat, 89 Lower Sloane Street, London SW1 (020-7824 8365). Chocolate tastings cost £35 and last two hours. They take place on selected evenings, 7pm-9pm, as well on occasional Saturday afternoons, 5pm-7pm.