PERFORMANCE / Right off her trolley: Bobby Baker's latest daffy domestic drama checks out the supermarket. Georgina Brown helps her take stock

Supermarkets make the performance artist Bobby Baker's pulse race. 'Visually I'm beside myself with the possibilities. All these ideas. All this packaging - it makes me shriek with laughter. For years I've wanted to shout, 'Stop a minute, just look at this,' and get everyone joining in.'

Pushing through the barriers of the Barbican Safeway, Baker pauses to gasp at the spaciousness of the aisles. Then she sets sail. 'I'm a very careful shopper,' she says, steering purposefully up the aisle and reaching for two packets of camomile tea. Sweeping on, she lunges at a non-stick cake-tray that has a cardboard slice of cake as part of its inspirational packaging. 'Don't you just love it?' Mid-gallop, she picks up some Persil washing-up liquid and stops to caress the container. 'I always buy this. The phallic shape is deliberate.' Fighting herself for a moment, but finally unable to resist, she succumbs to the temptation of a limited edition Persil powder tin which she admits she doesn't need at all. Next she seizes some medicated shampoo - phallic, naturally - and places it carefully in her trolley. (Baker's purchases arrive home uncrushed and smelling only of themselves.) At the patisserie counter, she chooses two anaemic custard slices, for her husband and son ('to make up for not being at home'). Finally she tears over to the tinned fish, grabs some anchovies and shoves the rectangular tin crossways inside her mouth. Her eyes smart with tears. Later, having removed the tin, she explains, a tad obscurely, that 'The Anchovy Sequence' symbolises obedience in her new show How to Shop.

As ever, Bobby Baker is wearing her costume of a white overall, the uniform of a faceless, female domestic. But closer inspection reveals a subtle parody of the stereotype. The overall is a wrap-over shortie, some six teasing inches above the knee; the shoes are clacking high white plastic slingbacks with an embroidery motif running down the side ('I like the sex and glamour aspect of these shoes. pounds 6.99 in Leicester. I've a gift for shopping,' she explains); finally, one fake-tanned leg is embellished with a gold ankle chain on which hangs a tiny crucifix. This tall, angular, self-deprecating woman may introduce herself as '42, mother of two and an expert shopper', but her new show will do more than teach the audience to manoeuvre a trolley with a nifty hip flick. How to Shop, beams Baker, with disingenuous daffiness, is 'a complete guide to shopping for the well-nourished spirit'.

Home is always where the art is in Bobby Baker's shows. In an early piece she made a life-size edible family that included a fruit-cake father and a son made of Garibaldi biscuits and invited the appalled audience to devour the exhibits. It was a wry comment on people's demands upon each other. Years later, after childbearing had intervened, in Drawing on a Mother's Experience, she poured treacle (to represent post-natal depression) and skimmed milk (to symbolise her problems with breast-feeding) on to a white sheet. The drawing with carefully chosen 'paints' - egg yolk, blackberries, yoghurt, Guinness - was as significant as the experience of the mess and mystery of motherhood that she was illustrating. In Cook Dems, Baker baked food for thought. People expecting a cookery demonstration took their notebooks. Baker enjoyed their disorientation as she prepared a pair of enormous dough antlers and attached them to her head with a ribbon. 'Wear them to improve your status,' she said. Her most recent piece, Kitchen Show, took place in her own kitchen. To each of the 25 members of the audience she offered a hot drink, milking, sugaring and stirring herself. It was the first of a 'Baker's dozen' of actions which she then marked with a physical reminder - in this case by bandaging the spoon to her hand.

None of the shows are as bonkers, nor as artless, as they sound. While extraordinarily funny and often strangely moving, each, in its peculiar way, is also a calculated, public examination of the invisible, unacknowledged and despised domestic chores that daily threaten to erode a housewife's identity. Baker's witty deconstruction transforms these tasks into something comical and complex; indeed, her scrutiny celebrates and makes precious the skills involved.

'What Kitchen Show is trying to convey is the whole range of associations and experiences of being in a kitchen doing routine tasks. It makes you think about why you do things - out of habit, upbringing, indoctrination. It's not a simple thing. Women often find it very sad. So do young men, thinking of their mums. Some cry - which pleases me. I feel deeply harrowed by a lot of it myself.'

Certainly, the contemplation of small actions provokes questions on a bigger scale, both personal and political. Bobby Baker believes that our domestic relationships influence world affairs, albeit indirectly. 'How we treat each other in supermarkets, how we care for our children, are symbolic of something much larger, international relations - war and peace.'

She is concerned, however, that the intimate kitchen setting and the comforting hot drink that plays a large part in Kitchen Show might have obscured its more serious purpose. Determined to avoid that, Baker has given How to Shop the form of a lecture, incorporating slides, fantasy film sequences (by Carole Lamond) in which Baker turns into a corkscrew and jumps into a glass of wine, and some distinctly theatrical surprises, and has found a lecture hall in which to perform it. This is a new departure into theatricality. Baker's roots are in art (St Martin's), rather than performance. Until recently, she confesses, she saw theatre as 'a sham. I can't make that leap and suspend disbelief. I'm beginning to understand what is possible through theatre but I prefer to be in a space which has its own set of associations - like a lecture hall'.

Her intention, yet again, is to transform the banal into the sublime. She introduces her shopping lecture as a spiritual journey. 'Like Pilgrim's Progress. And you can do this by going down the road with my set of instructions.' These instructions lead to the purchase of seven virtues - 'joy' in a toffee apple, 'humility' in a posy of parsley, and 'compassion' in a glass of wine. 'It's a straightforward search for values that are very important for a successful, happy society. Of course the juxtaposition of a spiritual search with shopping is ridiculous, but all the more powerful for that.'

The supermarket dash has never been more consuming.

Bobby Baker's 'How to Shop' is part of the London International Festival of Theatre: see 'Festival Highlights', facing page.

(Photograph omitted)