The man who mistook his kitchen for a lab

Heston Blumenthal pushes our table with one hand. 'Look at that,' he says, as it sways on its legs. 'Wobbly tables. It's not what you expect of a restaurant with our reputation is it?' No indeed, but then there's a lot about Blumenthal and the Fat Duck, the winner of our restaurant of the year award, which is unexpected.

Blumenthal could, for example, be forgiven if he were a little underwhelmed by the title our readers have bestowed upon him. Last month, just two weeks after the OFM votes had been counted and he had been told the good news, he learnt that he had won his third Michelin star, the ultimate culinary accolade. The Fat Duck, in the Berkshire village of Bray, has achieved the fastest three stars in British Michelin history, having won its first only five years ago. It puts him on a par with the Waterside Inn, also in Bray, and Restaurant Gordon Ramsay in London, the only other three stars in Britain. Not bad for a self-taught chef who only started cooking professionally eight-and-a-half years ago.

And yet, despite this, the OFM award clearly means everything to him. 'This is the first award I've received from the customers,' he says. 'I still worry every time the door opens that they won't understand what I'm doing here. This award means they get it.' There is, to be fair, a lot to get; the menu at the Fat Duck reads like no other.

The current tasting menu, for example, includes both sardine on toast sorbet and snail porridge. There's white chocolate and caviar buttons, or bacon and egg ice cream. He makes basil blancmange and beetroot jellies, pairs salmon with liquorice and cauliflower with chocolate. To a restaurant-going public, grown weary of media-hungry chefs trying to manufacture their 'unique selling points', this could look like just so much innovation for innovation's sake, but it isn't.

Here, I should declare a greedy interest: I am a huge fan, both of Blumenthal and his cooking. There's no doubt his menus read curiously, and the chef is not beyond chal lenging us with language. There would be far fewer raised eyebrows if that snail porridge was listed as a muesli of oats and escargot (even though his description is more accurate) or the mustard ice cream as a frozen mustard cream. But the linguistic tricks are part of the fun, the challenging curtain raiser to the main event, which is the exquisite dishes he cooks. Or, as he puts it, 'Everything has to come down to "does it taste good?" If it doesn't taste good it doesn't go on the menu.' Snail porridge and mustard ice cream both taste very good indeed.

Blumenthal, now 37, was not born to make snail porridge. He was not even born to make dinner. His was, he says, an average childhood, first in London and later, when his dad had made a bit of money, in the home counties, where the taste memories were laid down by nothing more exotic than the synthetic wonders of Angel Delight and banana Nesquik.

It was a family holiday that changed everything. In 1982, when he was 16, the Blumenthals went to France. One day they booked a table for lunch at a famed Provençal two-star restaurant called the L'Oustau de Baumaniere. Blumenthal was transfixed: the sommelier with the handlebar moustache, the lobster sauce poured into soufflés, the gigot of lamb carved tableside. 'That was it,' he says now. 'Gastronomy was for me.'

While still at school he wrote to top restaurants across Britain looking for a job. He received only one reply, from Raymond Blanc's Le Manoir in Oxfordshire. He started work in the kitchen. 'Some bloke was having a go at me one day and, not knowing the etiquette, I threatened to smack him one,' Blumenthal says now. 'I heard this voice shout out "don't stay over there. Come over here by me."' It was a young chef de partie by the name of Marco Pierre White, rescuing him from a confrontation. Blumenthal lasted only one week at Le Manoir, but he and Pierre White remained friends, his one real contact in the restaurant business.

Le Manoir was the only professional training Blumenthal ever received. He earned his living as a trainee architect and a rostrum cameraman, a photocopier salesman and later as a debt collector. (The latter is fully believable; he's a big, stocky man, made chunkier still by a fascination with kick boxing.) But none of these kept his interest. Every penny he earned went on meals in restaurants with his then girlfriend, now wife Susanna, who shared his passion. He likes to joke that they were once so poor they sold their car to pay for food, though admittedly all of that food was eaten in French three-star Michelin restaurants. His mates thought he was mad. Blumenthal saw it as an investment in the future.

And all the time he was reading classical French cookbooks, practising dishes, honing the skills that would take him from amateur to professional chef. It is this which distinguishes him from other chefs. He's book-taught, has no legendary mentors to constrain him, save those he has met on the page; when, in 1986, he picked up a book called On Food and Cooking, by the American writer Harold McGee, he was open to the secrets it contained.

The vast majority of chefs learn technique first and only then, and only if they can be bothered (most can't), find out why things happen the way they do in the kitchen: why meat browns, why if you boil bones in stock you get jelly. Courtesy of McGee and his clear explanations, Blumenthal became fascinated by this stuff.

In 1995, by now a father of two, Blumenthal scraped together enough money to open the Fat Duck in a 450-year-old tumbledown pub in Bray. Today the restaurant is a discreetly elegant affair, all subtle greys and white. Back then, the toilet was outside and there was a massive bar running through the middle. The menu was very different too: it was all classical French dishes like steak bordelaise and chips and petit salé of duck. But already the science of the kitchen was influencing his method. His duck legs were cooked at low temperature for up to 60 hours; his chips went through multiple processes to get the best, most luscious chip, soft and fluffy on the inside, crisp on the outside.

'What gets me excited is the original principle,' Blumenthal says now. 'And the dish is always the end result of that principle.' For example his famed bacon and egg ice cream came about through his interest in 'flavour encapsulation': the principle of which means a single coffee bean crushed in your teeth while drinking hot water will taste much more of coffee than the same crushed bean dissolved in the water. One day, using that principle, he over-cooked the egg custard for an ice cream, so that it practically became scrambled. He puréed that and made an ice cream from it, that had an immense eggy flavour because of the single egg molecules. But egg by itself was not particularly pleasant. Which was when he decided to see if he could incorporate the sweet tones of smoked bacon into an egg ice cream. Boy, did it work.

Blumenthal has a massive puppyish enthusiasm for what has become known as molecular gastronomy. He insists we go to a shed at the end of the back garden. (The Fat Duck's kitchen is so small that a lot of the storage is in garden sheds, lined up in serried rows outside.) Inside he has jars of flavour essences and refined acids, the chemical versions of tastes we know so well. He has one that smells of cut grass, another of oak, a third of leather. He is working with Gerard Coleman, winner of our producer of the year award, to incorporate some of these into chocolates. He likes the idea of a chocolate with the deep tones of leather that we all recall from chewing satchel straps in school. 'There are 3,500 of these essences,' he says. 'They are the building blocks. I want to learn them all.'

He gets me to sniff some Benzaldehyde. 'I was shocked by how pure an almond kick it is,' he says, and he's right. Benzaldehyde is almonds. It is also present in cherries, so he put cherries and almonds together with a roasted foie gras dish. He used the same principle to pair caviar and white chocolate. All well and good, I say, but chemistry can't make things taste nice. 'No,' he says, 'it can't. I detach myself from that when I put the food in my mouth.' And that's what makes the Fat Duck work. It's not the science; it's the dishes, which prove that the appliance of those principles by someone with extraordinary taste makes a difference.

Later, I stand in the tiny kitchen through lunch service, watching his brigade of intense young men and women, cooking and plating his food. The most striking thing is how normal, how much like other top-flight kitchens, it is. This is not a chemistry lab. Sauces are being reduced in copper pans. Scallops are being seared. Yes, there's a bath of liquid nitrogen working its way round the dining room, used to freeze a quenelle of green tea and lime foam served as a palate cleanser. (It explodes to nothing the moment it hits the tongue.) And yes, there are thermometers and low temperature baths for cooking fish. But it's still cooking.

The only real wonder is that they are able to work in this space at all. It's like performing ballet in a broom cupboard. Over the years Blumenthal has discussed, quietly with friends, the possibility of being able to attain three Michelin stars. But he has always said the same thing: not in that building, however smart the makeover. 'The thought didn't even occur to me,' he says now. 'It was an impossibility.' So he simply continued doing the things he wanted to do. Is having won the stars worrying? He nods furiously. 'I flip between cloud nine and panic.'

But this is what he's been working so hard for. He regrets not seeing his three kids more, he says, and gives thanks that Susanna is so understanding. 'I'm terrible domestically,' he says. 'I'm a disaster.' These days he tries to make sure he's home for roast dinner on Sundays. And on Monday nights he and Susanna always share an Indian takeaway, which is a pleasing image. The man who makes sardine sorbet is also partial to a curry.

Will the Fat Duck change? 'We want to improve things,' he says. 'And the menu is always evolving.' Very soon he will put versions of Escoffier-era classics like sole Veronique and lamb en cocotte on the à la carte menu. His more outré dishes will then be on the tasting menu. 'The food here will always keep moving on,' he says, 'because that's what I'm like.' But for now the real challenge is not to let this moment pass him by. He says he wants to enjoy the recent honours that The Observer's readers - and Michelin - have bestowed upon him. After that, it's back to the stove. And the chemistry set.