NOBODY can accuse Tim Mason, the head of Tesco’s fledgling American business, of lacking commitment.

Since he was given the project of taking the group into America two years ago, Mason has driven his blue hybrid Lexus over almost every inch of the West Coast. He and a hand-picked team of 20 have spent thousands of hours trying to discover what the American consumer wants.

His team includes John Burry, one of Tesco’s top buyers, and Simon Uwins, one of its top marketing executives. Mason, in London last week for a whirlwind 48-hour pit-stop, now has to prove all the homework will pay off.

The preparation has involved hiring researchers to probe the fridge contents and lifestyles of 60 American families, checking the time they got up, what they ate for breakfast and when they shopped. The retailer even prepared meals for them.

A prototype store was built in a warehouse tucked away in the gritty industrial district of Hawthorne in Los Angeles, its walls sealed with blinds and reflective material to foil snoopers. Tesco has flown in people from San Francisco, Las Vegas and Phoenix to test new ideas and products.

At the group’s head office in El Segundo near LAX airport in Los Angeles, staff try out different products each week to hone and refine the product range. Fresh juice, yes – Twiglets, no (apparently too disgusting for the American palate).

The stores are about 10,000 sq ft – similar in size to a Tesco Metro shop in Britain, and they will be branded Fresh & Easy.

They will stock about 3,000 products, focusing on fresh meat, vegetables, packaged goods, wine and beer. Products will be split half and half between Tesco own-brand and other companies’ products.

Most importantly the format will be fresh – an acceptance that it is impossible simply to transfer the Tesco format from Britain to America. “It is an American store designed for American consumers,” said Mason.

Already Tesco has more than 100 sites in the pipeline, with the first opening in late autumn. Mason said the aim was to have 50 sites by the end of February 2008 – on average, one new store opening every two and half days. More than 2,500 jobs will be created within a year.

The stores will be aimed at everyone from health-conscious middle-class shoppers in Santa Monica to families living in some of the most deprived inner-city areas of south central LA.

The scale of Mason’s ambition is immediately apparent. “There is no point going to America to be a small business. If you want to be a small business you want to be in a small country like Guernsey,” he said.

It has not been easy. “A year makes a tremendous difference. Back then we could not even lease cars easily – people would say ‘are Tesco good for the money?’.”

Some of Tesco’s British suppliers have moved to America, hoping to piggyback on what they hope will be a successful debut.

Mason pledges that Fresh and Easy will pay higher wages than its competitor Wal-Mart, but the retailer has not made a firm commitment on whether its workers will be unionised. Mason said that by law the workers have the right to be unionised if they want to be, so it will not necessarily be Tesco’s choice.

Falling out with America’s tough unions would not be pretty and the company has already had skirmishes in Arizona where a low-key campaign tried to prevent the company getting liquor licences.

Every week Mason and Uwins hold a “Magic Monday” induction session for new employees explaining the culture of the business and its beliefs.

“One woman said she felt like she had won job lotto when she got a position here,” said Mason. “If your boss doesn’t make your working life fun that is a dereliction of duty.”

Failure is not an idea Mason will countenance. “It would be deeply embarrassing for me - but I am sure Tesco would survive it even if my career wouldn’t.”