Here's another thing. If you visit Sketch in Mayfair, where the Michelin-starred Library restaurant offers a la carte main courses for upwards of �50, the �7 coffee they produce with your petits fours will also be a product of the same Nestle brand.

That brand goes by a gloriously naff name:

Nespresso. Its products taste perfectly acceptable. Granted, they were not sourced from a top-end, luxury supplier, but in the exacting environment of a well-renowned restaurant, Nestle's mass-market product will certainly pass muster.

Time was, if you wanted a proper cup of coffee you'd need to find a cafe with a machine the size of a Nissan Micra, operated by somone who could trace their genes to Renaissance Florence. It was a problem that came to tax the brightest minds at Nestle, the world's biggest food company. Why, they asked, could it not be possible to make authentic espresso, quickly, in your own kitchen from an affordable, compact machine that worked every time? And, without covering every surface in discarded coffee grounds, and ending up with half an hour's worth of washing-up?

The Nespresso concept . . . simple, efficient, heavily branded machines, fuelled by sleek metal coffee capsules . . . was born. The idea grew and grew. It conquered North America and Europe, even taking off in Italy, spiritual home of luxury coffee. Then, a couple of years back, the brand reached Ireland and Britain.

And today, Nespresso is Nestle's fastest-growing division.

Global revenues topped �500m for the first time last year, and more than one million machines were sold. The brand's annual growth rate has been 30% since 2001, and it is the industry's market leader in Europe.

Not only that, but Nespresso is glamorous, too. George Clooney is its first "brand ambassador", and the star of a global advertising campaign that features in just about any publication you care to open. In Nespresso's TV commercials, the kohl-eyed heart-throb fulfils a role similar to the swarthy male member of the Gold Blend couple of the 1980s and 1990s.

Sophie Marceau loves it, as does Elizabeth Hurley. Elle Macpherson has a machine. The marketing onslaught became even more intense this month when Nespresso launched its latest machine, the Latissima, which can deliver a textbook macchiato in seconds, at the touch of a single button. Put simply, Nespresso is the biggest thing in coffee and one of the biggest things in food; but, behind the scenes, it may also be one of the most controversial.

On the face of it, it's easy to see why Nestle's superficially naff product has become such a success. The Latissima produces the kind of neat espresso, latte and cappuccino one would expect to find in a Neapolitan backstreet. A seductive aroma seeps from the sleek machinery and hits you shortly before the taste.

Like all Nespresso machines, you can fuel the Latissima with capsules filled by 12 different blends, graded from one to 10 in strength, including "hints" of Central African robusta in the (five) capsule Capriccio or the "mildly toasted woody notes" in Roma (six).

The capsules are at the centre of the brand's technical success. They were invented by the research and development department at Nestle as a means "to extract the freshly ground coffee it contains under high pressure". Once inserted into a machine, they are pierced and processed. Water is forced up against a heating element at high pressure, meaning that only the quantity of coffee needed for a single cup is warmed.

Current machines vary from the 149 Slate, which delivers two sizes, right up to a swanky version worth 999 and designed by Porsche.

Other innovations in the pipeline include touch-screen technology and the delivery of espressos instantly. Nespresso has been in discussions with Ferrari; the brand it seems, is more Italian than the Italians.

Driving the exponential growth has been a slick marketing operation. While it was first test-marketed in Japan in 1986, and rolled out in Switzerland, France and Italy the same year, the product was not launched here until 2000, first to consumers, then businesses.

Traditionally, the Irish are a tea-drinking nation, consuming more than any other European country, even the British. But that's certainly changing, and much of that can be attributed to the coffee shop culture, which has mushroomed over the last ten years. "If we go back 15 years, people thought a cappuccino was a luxury thing, and many would not know what they were, " explains Brema Drohan, the Irish-born manager for both here and the UK. "Now nine out of ten people will know. As a culture we have gradually moved more and more to the coffee-drinking habits of Europe."

She compares the coffee evolution to wine drinking in bars now, as opposed to two decades ago. "First of all, did they serve wine was the question, and the usual option would be a red and white . . . a vin de table red which would be vinegary and a sweet German Liebfraumlich. Now you have these surreal moments when you go into a bar somewhere and you see a see a 23-year-old girl saying 'I'm not crazy about Chardonnay, I much prefer Sauvignon Blanc, " she points out. "It's similar with coffee. We now want our latte, our macchiato and our Americano. The idea that a shot of espresso is something black, bitter and to be gulped like medicine is changing. People realise that if an espresso is made properly, it doesn't taste like a pill."

She describes a typical Nespresso customer as 30, obsessedwith their gastronomy and more likely to entertain at home than splash out on restaurants. In Ireland, coffee aficionados can currently get their fix at the Nespresso boutique in Brown Thomas Dublin, with another one due to open in Brown Thomas Cork in November. The capsules can also be bought online or via mail order.

The product isn't bad value. The price of a 10-pack capsules is 3.30. A coffeeshop regular espresso is around 2. It may still be more expensive than a bag of coffee from your average retailer, but closer in quality to what you would buy in the average coffeeshop.

Nestle's reputation has not always been as admired. Over the years the company has come in for repeated criticism for the circumstances in which it had allegedly marketed baby milk in some of the world's poorer countries. A campaign for an international boycott of Nestle began in the late 1970s.

As you might expect, Nespresso follows suit in the controversy stakes. Clooney clutched for his handbag when questioned at the Venice Film Festival about the apparent hypocrisy inherent in his appearing in Michael Clayton, a film about corruption in multinationals. "I'm not going to apologise to you for trying to make a living every once in a while.I find that an irritating question."

The independent film Black Gold, released earlier this year, questions the ethics of charging 25 times as much for a cup of coffee as the coffee farmers receive from it. "Nestle is trying to sex up coffee, to make it seductive, " says its director, Nick Francis. "But the fact is the coffee farmer is being paid 2p out of every �2 cup of coffee. Nestle has so much purchasing power. But the question is, how much money goes back to the farmers? It's quite staggering.

Nespresso is another reminder of the difference between the owners and buyers in the industry. You can't rely on the likes of them and Starbucks to tell whether that happens."

Black Gold tells the story of Tadesse Meskela, head of an Ethiopian coffee workers' union, and his struggle to get a fair price for his 74,000 farmers. Those behind the film hope it will show that trade, not aid, is the solution. "We need to increase our negotiating power. This film will enable us to be paid more than the current price, " claimed Meskela.

He said the current money his farmers were receiving . . . and note that Nestle use Ethiopian coffee, as do all of the world's major coffee companies . . . was still well short of the mark.

The development of Nespresso's machines has also been touched by controversy. Though the company took out a patent on the process in 1976, Alfred Yoakim, Nespresso research and development director, said that around this time, Nestle was approached with a similar concept by an external technology firm, Batelle, based in Geneva.

Yoakim insists company executives took their incentive from a trip to Italy, where they observed the "effort and skill" with which the baristas prepared their wares. "It took a lot of time to get it right, " he says. "We wanted to replicate that . . . a way of guaranteeing the best quality in the shortest possible time."

And for all the Nestle controversies, Fairtrade is full of praise for Nespresso. Ian Bretman, Fairtrade Foundation deputy director said: "Nestle is the only major coffee brand that's actually using our label."

Nespresso has been at the vanguard of this, instituting its AAA Sustainable Quality Programme to maintain "environmental and social" standards for its growers. It pledges to provide farmers with 75% of the export values of the coffee it buys. And Nespresso aims to get half its coffee through these means by 2010.

For Nespresso, the future is world domination. In Paris, it is set to launch a 1,000sq m flagship store on the Champs-Elysees in December, making it one of the most high-profile elite brands in the city, cosying up to Louis Vuitton's base in the capital.

Whether you like it or not, Clooney's streetspanning smile and favourite coffee machine are coming to a sideboard near you.