Fine writer though he is, you could never claim that Stephen Foster is leading the pack. She Stood There Laughing, his droll account of a dire season supporting Stoke City, adapted the format established by Nick Hornby's Fever Pitch; Walking Ollie, his droll account of life on the leash with a difficult lurcher, coincided with John Grogan's canine memoir, Marley & Me. Now he has produced a droll dissection of the north-south divide which covers much the same territory as Stuart Maconie's Pies and Prejudice

Maconie marvellously summed up his awkward transition to the southern middle classes by recalling how a radio producer first asked him to supper. Delighted as he was to receive the invitation, he was at a loss to understand why a sophisticated BBC type should want him to go round for milky drinks in his dressing gown. Having left Stoke for London to pursue a career in the catering trade, Foster similarly finds that north and south are two nations divided by a common language; this is most forcefully driven home when he turns up for a school reunion carrying a chilled bottle of Sancerre, prompting one of his former classmates to observe: "You're a proper middle-class gayer now, aren't you?"

The comment causes Foster to muse on the meaning of the term "gayer", which is exclusively understood by those native to the Potteries (who, Foster says, you can always spot in restaurants "because they're the ones who check beneath the plate to see the stamp"). The coinage doesn't necessarily imply homosexuality. Rather, Foster's school-friends have come to view him as "the sort of fairy who likes poetry and doesn't have the decency to keep quiet about it".

Just how much this has become the case is confirmed by an episode in which Foster dives into the open-air swimming pool at Eton, and then quotes poetry about how cold it is (Stevie Smith's "Not Waving but Drowning", which he says is one of his favourites). Foster didn't actually swap a rough comprehensive in Stoke for the poshest public school in the country - he's not that much of a gayer - but he did fall in with a mate whose mother was a housekeeper there. And he at least has the decency to admit that the temperature of the pool gave him a grudging respect for Eton scholars: "You needed to be hard to go through this ritual. And no doubt the masters made you do it in winter as well, having first had to break the ice on the surface of the pool."

The best episodes of the book are invariably those in which Foster arrives in a new environment and begins to unpack his bag of prejudices before realising that many members of the landed class are just as hard-up and desperate as people in Stoke. There's a fine account of a country house weekend in a shambolic pile to which the title-holder has brought shame by running up huge debts, then disappearing with an au pair; while his wife consoles herself with gallons of gin and the place is kept solvent by "a fleet of sisters offering riding lessons, practising as (unqualified) vets, concocting flower arrangements from the hedgerow and making bird tables to sell at fetes".

Foster's dawning sense of awareness is admirable: "Here was what I was repeatedly discovering - once I had left my bedroom in the Potteries behind, the rest of the world did not always turn out to be as advertised." Yet there is a problem with the extent to which Foster has begun recycling himself. Walking Ollie virtually mirrors the upwardly mobile course described here, culminating in Foster's emergence as a writer from the University of East Anglia. And there is virtually nothing more that can be said about Stoke - "a disaster of a place with a disaster of a football club" - that has not already been said in the football memoir.

Foster's prose skips along nicely, and the book is never less than an entertaining read; yet the randomness of its episodes, and elisions between them, suggest an author attempting to squeeze out whatever autobiographical details he has left, like the final pressing of a batch of olives. Not that Foster would once have been remotely bothered about pure virgin oil. But it's a distinction any middle-class gayer will understand.

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