The real masterchef: Ferran Adrià is closing El Bulli's doors but has vowed to keep experimenting

I first heard about Ferran Adrià from Gordon Ramsay in 2003. Ramsay is not a man to fling compliments around, but he spoke about the Barcelonan super-chef with something approaching awe. "The man is a genius," he said. "He's got three Michelin stars, and he serves Fisherman's Friend ice cream. It's cooking 20 years ahead of its time."

Tell me more, I said. "Last year he was obsessed with clingfilm," said Ramsay, "But the clingfilm turned out to be the food itself: there was a little sachet of peas, a transparent slice of clingfilm made out of peas, and tasting of peas. Just staggering. The year before, it was cauliflower couscous, which was grated cauliflower, blast-frozen. This guy will go round the dining room with an aerosol can of lemongrass and spray it in front of your mouth before you eat. The last dish I had there was cockles and mussels and oysters with a passion fruit soup – but the passion fruit soup was made with seawater." Going to Adrià's restaurant, El Bulli, was he said, "the trip to the food Mecca of today."

Seven years later, so many people have called Adrià "the world's greatest chef" that it has become a cliché. Millions of wannabe-gourmands have tried and failed to score a table at the restaurant, which is open only for a few months a year. Scratch any award-winning, world-beating chef of the last decade, whether Thomas Keller at the French Laundry, or Heston Blumenthal of The Fat Duck, or René Redzepi at Noma in Copenhagen, and they'll talk about Adrià as their cher maître and El Bulli as the mother ship of their wildest gastro-excursions.

Many people call him the creator of, or mastermind behind, "molecular cuisine" – a phrase he detests. Others hold him responsible for the foams, spumes, frizzes and other ectoplasmic irritations found in so many restaurant dishes today. This is closer to the truth – Adrià, using compressed air rather than cream and egg, has contrived to make beetroot foam, mushroom foam and, indeed, meat foam – but is only a small part of the story.

Closeted with a mystic brotherhood of chefs in El Taller, the laboratory at El Bulli, he has experimented with every food on the planet, umpteen bizarre kitchen appliances (freeze-dryer, Pacojet, liquid nitrogen tank) and a private pharmacology of emulsifiers, acidifiers, galling agents and "spherifiers", to create a kind of parallel universe of food, in which melon is re-imagined as orange caviar balls, warring flavours are pulled into startling alliance (like tobacco-flavoured blackberry crushed ice) and classic dishes are "deconstructed" so that a Spanish omelette, becomes a sherry glass of potato foam, onion purée and egg-white sabayon, topped with deep-fried potato crumbs.

His cuisine has drawn criticism, on grounds both of pretentiousness and health considerations, but an army of admirers has written admiring explanations of his career and modus operandi. The most recent is Reinventing Food - Ferran Adrià: The man who changed the way we eat, by the American food writer, Colman Andrews.

As El Bulli prepares to close for at least two years, Adrià and his Boswell are in London for a rare audience with the press. We met at London's Kensington Hotel, near the Natural History Museum. Clad in a dark sweater and sheeny black jacket, Adrià is a short, stocky, strikingly handsome chap with a wide acreage of forehead, dark-brown marbles for eyes, and a fussily expressive speaking voice. Colman Andrews explains in the book that this is because his tongue has to be unnaturally large to accommodate so many taste buds. I cannot tell if he is kidding.

Adrià was born Fernando Adrià I Acosta in 1962 in the city of L'Hospitalet de Llobregat, south-west of Barcelona. His father, Gines, was a plasterer; his mother worked in a beauty salon. As a child, his favourite food was disappointingly mundane – steak and potatoes, tortillas, liquorice and Twinkie choc bars. Did he recall vivid dishes his parents enjoyed? "You can't remember what you ate when you were six. I have a special memory about my mother's Spanish omelette, but if I had to give her a technical exam, I'm not sure she'd pass. But she's still the best mum in the world." At school he played football to a high level, and considered making a career of it. But when he had to choose between spending Saturdays on the pitch or washing dishes in the kitchen of the Hotel Playafels, he plumped for the latter. There, he was handed a copy of El Práctico, the Spanish bible of international cooking. He still has it: "I learned from it to respect history. And that you cannot move forward if you don't respect the past." At only 22, he took the rocky road to El Bulli, then a respected but scarcely avant-garde Catalan restaurant, to work as a line chef. Among his influences was the French chef, Jacques Maximin, "the Bonaparte of the ovens," whose dishes included duck mousse inside turnip-petal ravioli. Adrià relished his dictum "Creativity means not copying." But hadn't he borrowed some of Maximin's ideas?

"One has to be honest with creativity," said Adrià. "Because everybody is susceptible to influence. The most important thing is creating that first omelette, not making 10,000 different kinds of omelette. Maximin's character influenced me, especially conceptually. His recipes weren't actual recipes, they were conceptual. For example, in his book there was asparagus ice cream. But it was a concept. He didn't see it as a dessert. He thought: this is an ice-cream made with vegetables." Adrià's first great period of experimentation dates from this period when, with El Bulli shut for six months, he closeted himself away with a battery of machines and processes.

He would try anything. There's a charming vignette in the biography, about him standing in the kitchen with a bowl of almond-milk gelatin in his hand, and looking at a pot of boiling oil on the stove. One by one his comrades realised what he was planning and shouted, "No, Ferran, don't!" But he did. He spooned the gelatine into the boiling oil and it exploded all over the kitchen.

Among the 1,200-plus dishes with which he has amazed diners over the years, some have failed to find an appreciative audience.Even Adrià's biographer draws the line at his "Sea Anemone 2008", which combines sea anemone, raw rabbit brains, and oysters in a lukewarm dill broth. "I found it so utterly unpleasant that I wondered whether Ferran had gone off the rails," writes Antony. Did Adrià believe he had a faultless palate?

"It's a very good question. If we like our meat medium-rare or practically raw, is this right? Does that mean that people who prefer their meat well done are incorrect? If I create a dish, I love it – otherwise I wouldn't cook it. But I know some dishes will create a debate or be challenging."

Was it his intention to combine flavours in a divine harmony? Or to stun people, by putting together completely alien flavours? Adrià thought about it: "It depends. A menu is like the script of a film. There are moments of love. And there are moments when you want to kill someone."

Do his lunchers and diners ever want to kill him? He smiled. "People who come to El Bulli sometimes find it difficult to say there's something that they don't like. They usually say such-and-such a dish was 'strange'. But if you eat 40 things and don't like three, that's not a bad strike rate."

His main devotion is to the utmost enhancement of flavour. His gazpacho ajo blanco comes as a white, shaved-ice granite but gives you the purest belt of summer gazpacho, garlic and almonds you'll ever taste. "His spherical olives," says Andrews, "taste more like olives than olives do. Because he's taken out the pith – which, if you isolated it in the laboratory, wouldn't have much olive flavour."

Some might say Ferran Adrià has been taking the pith out of the gastronomic world for years; but he's robust in rejecting criticism that his experiments put diners' health at risk. "In November, I will be presenting a book about health and nutrition with one of the world's leading cardio-logists," he said, with indignation. "Do you think if my cooking wasn't healthy I would be asked to collaborate? Do you think Harvard would invite me to lecture? Would I have a laureateship in chemistry [actually an honorary degree from Aberdeen University] if I didn't know about all these things?"

One doesn't want to tangle with the maestro. One just wants to try his food. Regrettably, El Bulli is about to shut up shop for at least a couple of years, while Adrià and his team take stock and consider the future. The restaurant laboratory will meanwhile become "a centre for creativity", and its experiments will be monitored by a science foundation, which will post its findings online.

The actual restaurant may not be open for business again until 2014. I'm already trying to book a table for two on the first night. "The mission," says Ferran Adrià, "is to be creative. It's like investigating new material for chairs. Asking who's going to sit on them isn't important. What's important is to keep on researching."

'Reinventing Food – Ferran Adrià: The man who changed the way we eat' by Colman Andrews, £19.95, published by Phaidon Press

El Bulli – surrealism ina Catalan kitchen

El Bulli is indisputably the most controv-ersial and experimental restaurant in the world. Each year it receives a colossal 1m requests for a reservation, but a mere 8,000 lucky people get the chance to dine here.

Ferran Adrià is widely regarded as the best chef in the world, and has a "scientific" approach to cuisine. He joined El Bulli in1984 and was put sole in charge of the kitchen in 1987.

The restaurant, in the resort of Roses on Spain's north-eastern coast, has a limited season, which doesn't help ease the pressure on reservations. The 2010 season runs from mid-June to 20 December, and the restaurant then closes for at least a couple of years.

Restaurant Magazine voted El Bulli number one on its list of the world's 50 best restaurants a record-breaking five times: in 2002, 2006, 2007, 2008, and 2009. This year, though, René Redzepi's Noma restaurant in Copenhagen pipped it to the post.

Dishes served at El Bulli include deep-fried rabbit ears, a caramel made of virgin olive oil in the form of a coiled spring, an orange "caviar" made from melon juice, and white asparagus with hot mayonnaise.

The average cost of a meal at this three-Michelin-star restaurant is €50 (£44).

El Bulli serves only dinner, and has fewer than 50 seats. The tasting menu consists of around 30 dishes eaten with fingers, forks and spoons (no knives).

Racquel Stewart