There's not a lot I won't do to keep you up to date with the nation's fastest-growing feeding habits. So it was that I spent last Thursday morning standing in pigs' urine. Bloody Liz Hurley, I thought, as I waded through a thick curd of porcine pee'n'poop. Bloody Liz and blooming Nigella and flaming Antony Worrall Thompson.

It was all because the celebrity pack has discovered biodynamics. Roger Moore swears by it. Kate Moss is into it; Martine McCutcheon likes it, and Liz Hurley herself is partial to the odd biodynamic slimmers' sausage, made to a special recipe at Here, the über-organic supermarket at Chelsea Farmers' Market.

Needless to say, this was worth further investigation - particularly since until last week I thought biodynamics was one of those yoghurt drinks that perk up your intestinal flora. Little did I know it's a way of life.

At its most kooky outpost, biodynamics is a method of farming influenced by the cosmos. What you want to look out for, apparently, is spinach sown when Mercury is in the ascendant. And apples planted when the moon is on the wane. Your carrots ought to be put in on a root day, and your leeks harvested only when the zodiac calendar permits.

So far, so much tosh, right? Well, maybe, until you look at the broader picture and realise that Hurley and co might be on to something. Think of biodynamics as 'more organic than organic', as Barry the Butcher at Tablehurst Farm in East Sussex puts it. Tablehurst's small farm shop regularly sells clean out of biodynamic lamb, sausages and finely marbled steaks. When I visited, a tower of leeks, fresh from the top field, were piled by the door. You might have expected Peter Rabbit to skip in holding a basket of carrots.

Instead, I got Peter Brown, manager of Tablehurst. He sighs when I bring up the moon lunacy. 'It's so much more than that,' he says. 'The important thing is that a biodynamic farm is seen as a whole. The idea is that it should be self-sustaining: animal feed and seeds for cultivation are produced on the farm, and the animals provide the fertility for the soil. Herbal preparations [including yarrow, camomile, nettles and the juice from valerian flowers] guide the composting process, in the same way as a homeopathic treatment might work. I suppose people might think it strange that we work with the forces in substances, yet we know that the moon influences the sap in plants, that the planets have their effect.'

Once you've got over the intrinsic weirdness of the ideas, it does make instinctive sense that a farm's livestock produces manure that is right for the soil. It makes perfect sense that the taste of produce is influenced by the soil it's grown in. But most of all, it makes perfect and wholesome sense that the farm's produce is entirely traceable. Little wonder that right-on chefs - from Michel Roux to AWT- are after as much of the stuff as they can get.

At Tablehurst, you can 'meet your meat' should the fancy take you. Piddle notwithstanding, I had a fine old time with the pigs set to be next week's bacon. At the shop, I bought six superb steaks from Sussex cattle which had been born and nurtured on site, and a Jonagold apple from the orchard on the hill. None of it could lay claim to air-miles, or a man-made jacket of preservative. None of it had ever sat glumly in a polystyrene pack waiting to be on special offer.

At a time when we're ever more freaked out about what's on our plates - whether it's flu-ridden poultry, dioxin-wracked salmon or cryogenic apples - it's little surprise that biodynamics appeal. And yet, the idea has been around ever since Rudolf Steiner came up with a holistic take on agriculture in 1924. By 1931, there were over 1,000 biodynamic farms worldwide.

These days, biodynamic produce does not come cheap. As Michelle Smith, owner of Here supermarket, says: 'The biodynamic output is naturally more unstable than organic. Everything comes from small, mixed farms, and it's all properly seasonal. There's nothing mass-produced about it; a lot of personal input goes into it, every day in every way.'

Clearly, if you have a family of five tosupport on benefits, you're hardly in a position to quibble about what Venus was up to during the cultivation of your cornflakes. Though the earth would certainly be better off for it, it's unlikely that biodynamics will go mainstream in the way that organics already has; 'the whole point is its sustainability,' argues Smith. 'It's not the latest fad, but something settled and in tune with nature.'

That's all very well, I hear you scoffers cry, but does it taste any better? Well, you decide. Antony Worrall Thompson and Michelle Smith would argue that you can taste when something has been made with love. Besides, if a banger's good enough for Liz, it's good enough for me.

· Here, 020 7351 4321; Tablehurst Farm Shop, 01342 823173