Why do off-licence forays into food always seem to go off-course? Witness the attempts of market leader Thresher Group, which was forced to abandon its Threshers+Food trial last January after failing to persuade sufficient customers to buy into its ready meals (sold under the Leaping Salmon brand).

It is not the only player that has gone into food. Unwins conducted a small-scale trial in some of its larger stores and Wine Cellar piloted something similar with its Right Choice sub brand, but both were unsuccessful. So, given that food is such a tricky proposition, why is Thresher still pushing ahead with its other food and booze format, The Local? And will other off-licences follow suit?

Thresher is currently trying to attract more franchisees to The Local format, which boasts a 10% to 40% food offer. Chief executive Roger Whiteside is confident that 50 managers will choose to become franchisees - despite the failure of Threshers+Food, which was piloted at the same time as The Local format in 2004.

He believes there is a fundamental difference between the two formats, which predisposed Threshers+Food towards failure. The main issues, he suggests, were store location and target demographics. Threshers+Food stores were located in more affluent areas and tried to tempt customers with premium ready meals.

Unfortunately, the size of the stores meant the food range was not comprehensive enough to present a compelling offer: there was literally no space to put in an offer that supported the ready meal range. "We could get 20% of customers to buy food but they were only existing customers, rather than new ones," adds Whiteside. "Waste was too high."

Had they been larger stores - bigger than the average 750 sq ft of a typical Thresher - a more compelling offer could have been created without compromising the drink offer, says Whiteside. The Local stores on the other hand are targeted at a less affluent customer base that demands a more basic food range and only mainstream drinks brands, making the format more flexible and less reliant on premium ready meals.

The core products remain bread, milk, canned and packet foods. Editing the offer is critical and the company's plans to move The Local to a franchised model should enable the new owners to tailor their offer to a local audience, says Whiteside.

Even so, Thresher has its work cut out, believes Jim McCarthy, chief executive of Poundland and former head of Sainsbury's c-stores. Adding food to off-licences is "in theory a brilliant idea", he says, but it is much more difficult than it looks, especially when space is limited.

"To do food properly you have to have chilled and fresh - which is very capital-intensive. And you need size and range as well as operational controls. The challenges are controlling waste and ensuring full availability," he says.

A possible solution would be for off-licences to join forces with a retail partner such as a supermarket. One director of an off-licence chain predicts that there will be tie-ups but that they will be with independent convenience chains rather than multiple supermarkets. This could result in either a totally new format or an add-on to one of the partners' formats. "They will start marrying up because this will give them a size of range that is credible," he says.

Whether The Local or any similar ventures that follow prove successful - and The Grocer understands that a new tie up between an off-licence and a c-store chain is in the pipeline - remains to be seen.

But Hugh Burkett, chief executive of the Marketing Society, believes that despite the challenges, for many off-licences moves into food are inevitable.

The trick is to make sure the food element is small yet comprehensive - and doesn't compromise the alcohol offer.