Blimey. How did this happen? One minute, you're going to the kind of festivals that involve weird hallucinogenic drugs and men with suspect personal habits, the next you're watching a fat Welsh chef de-bone lamb and asking questions like, 'Is it organic?' and 'Do you add the salt before or afterwards?'

Luckily my sister, Sian, is on hand to offer reassuring words. 'You've just got old, love,' she says. But then that's what family's for. 'Look!' I say pointing out a hunchbacked man who's pushing 80 and is wearing a red dragon bobble hat. 'It's your boyfriend.'

My mum's around somewhere, too. Really, I can't help thinking that festivals just aren't what they were. But then, this isn't a festival-festival, it's a food festival, the Abergavenny Food Festival to be precise, and it's already thrown up a whole load of yet-to-be-answered questions. Such as, did I blink or something but when did food start getting its own festivals? And, where did all the posh people spring from?

This is Wales after all. And before you start, I am Welsh, and am therefore allowed to pass comment on Wales, the Welloes and all things Walian. And, let's get this absolutely clear, restaurant critic AA Gill, who's scheduled to speak later in the day, is not. Still, I've already received a Duffers' Guide to Food Festivals during breakfast at my b&b, an event which resembles a high-level food symposium with people batting words like 'provenance' and agro-industrial' across the table.

'Are there a lot of food festivals?' I ask a jolly man in his sixties who introduces himself as 'the Cheese Detective'.

'There's hundreds! All over the country.' His real name is Peter Papprill and it turns out he's the Kate Moss of the food festival circuit. He used to be an exec at BP but jacked it in to become a cheese buyer and now gets to tour more or less full time.

'You can't move for food festivals these days. Nantwich has one. Conwy has one. Manchester has one. But Abergavenny's the biggest. There's a lot of competition with Ludlow, which was the first really, but Abergavenny is the best, believe me.'

I do believe him. Abergavenny is not a big place, and it's not even a particularly foodie place. It's a market town that, over a single weekend, plays host to more than 25,000 people from all over the country. In seven years, it's grown from a single day and a few hundred people, to the present event with dozens of speciality food stalls, a dedicated children's area, various celebrity guests, and a full programme of events - talks, 'tutored tastings', demonstrations, farm visits, mushroom 'forays'... I've studied the brochure and I've already had to make some tough decisions. For my first session, I've foregone 'The Perfect Pepper' - an hour-long session devoted entirely to peppers, and plumped for 'Autumn in Italy - a Masterclass with Ursula Ferrigno' although first I have to deal with a bit of Welsh-style agro from the woman on the door.

'Are you press?' she says. 'I am!' I reply, expecting to be ushered to the best seat in the house and offered a tempting plate of delicious morsels.

'You've got to sit at the back,' she says and gestures to an empty table.

'I'd much rather sit with other people,' I say. 'So, you know, I can talk to them.'

'It's not allowed!' she says and then hisses, 'Some people have paid for their tickets, you know.'

Finally, after a really quite frosty stand-off, she lets me in and I get to see Ursula whip up a loaf of bread, a batch of tortelloni, some tagliatelle, then bake a whole sea bass in salt and, to top it all off, a plum and hazelnut cake. All in the space of an hour. She has a slightly little girl voice and says things like, 'It's so smooth and silky and takes just 20 minutes with no word of a lie,' and her hands move like pistons. It's like watching one of those speeded up nature documentaries you get on the BBC. I enjoy it but have my first inkling that I lack a certain commitment. All around me people are taking careful notes. They follow the printed-out recipes as we go along, and ask complicated questions about fish scales and rock salt and egg sizes.

I talk to one of them afterwards. Sheila Gillard is stylishly dressed in jeans and a white jacket and is down from London for the weekend. She's a devotee of Borough market and had read about the festival in Waitrose magazine. 'I've been wanting to come for ages and I've booked everything I can,' she says. 'Everything.' Which is impressive in itself since the woman at the door had a point about the tickets. Just this one session costs £8 a head. And I'll say it again, this is Wales.

But then, there's an interesting sociological mix going down on Abergavenny's streets. I meet up with Sian and my mum who live just down the road in Cardiff and, with no persuasion at all, from me have come up for the day. They tell me the Londoners are all in the market hall 'deciding what to buy for their cottage meals' and the Welsh grans, who've come for a run out from the Valleys, are all lined up outside the fish and chip shop. My mum rather blows her cover about what she thinks of the two camps though, when she refers to the Londoners as 'refugees'.

We sweep off to the market hall where there are stalls selling - and more excitingly giving samples of - dozens of different cheeses as well as Welsh whisky and chocolate and bread and olive oil and smoked salmon. All farmed by local producers, all delicious. We despise the lone cake stand in the corner that's offering nothing at all and try but fail to get near the sausage stall where we're elbowed out of the way by a group of elderly Welsh ladies with a determined manner and done hair.

But then that's the thing about a food festival, I discover. It brings out you inner hunter-gatherer. It's a dog-eat-dog world out there, or at least cheese-samplist-eat-cheese-samplist one. Sian and I see a sign for scotch eggs and hotfoot it over but horror! The fridge is bare. It's only 1pm but Neil Chambers who makes nothing but speciality scotch eggs has already sold out.

'How many do you think I brought?' he says.

'Five hundred?' I say. He shakes his head.

'A thousand?' He nods. 'Who could have predicted I'd sell 1,000 scotch eggs in three hours? The last one went an hour ago. And that was meat-free and egg-free.'

We hustle back out through to the crowds to the Angel Hotel. 'Look!' says Sian. 'It's Anthony Bourdain!'

'I know,' I say, nonchalantly. 'I've already met him.' Karen, The Observer photographer, had taken his photo earlier and I'd gone and introduced myself to him and Fergus Henderson, the head chef at St John, the Clerkenwell restaurant famous for offal.

They're drinking pints in the courtyard and smoking and just hanging out, looking cool. Bourdain is tall and handsome with a pierced ear, a T-shirt beneath his jacket and that kind of New York voice that is bred to utter suave urbanities. Fergus has little round glasses and a vaguely old-fashioned air. It's only later, after meeting them both properly, that I realise that Bourdain is Abergavenny's Jagger. And Fergus its Lennon.

In fact despite the hordes of middle-class folk with bulging shopping bags heatedly agreeing with one other about the moral superiority of locally-farmed produce, there is something just a tiny bit rock'n'roll about the place. It's not Glastonbury, it's true, but it's not Hay either, where the authors tend towards tweed jackets and nervous dispositions. The chefs, and there are a whole load of them hanging out at the bar, are all drinkers and faggers and they might not sing, but you don't get the impression they would flinch if you made a sudden movement.

Half an hour and five slices of bread later, I'm beginning to flag. I'm at a 'tutored bread tasting' where a nice man called Dan Lepard says things like, 'It's all in the aeration of the crumb' and rather more complex things I'm not quite following like, 'When the ascorbic acid oxidises it inhibits the action of two proteins.' I think I might be about to slip into a carbohydrate coma while the man sitting next to me, who's in his fifties and is wearing what looks to me like specialist fishing wear - a beige sleeveless jacket with a lot of useful-looking pockets - asks really quite technical questions about crusts.

He tells me he's 'an accidental foodie'. He was laid off work with stress and the doctor told him to pick up his diet.

'It's a hobby, then?' I ask him.

'Oh yes,' he says. 'When I retired it was either this or hanging out down the pub.'

But then, food festivals, or at least the hard-core element of food festivals - the talks and the demos - are a hobbyist's dream. There's all the gadgets to buy, the equipment, the new cookbooks, the expensive ingredients, and the kind of specialist knowledge and vocabulary that marks you out from the amateurs.

I bump into John Mitchinson, a book person I know, who's in high spirits. 'I've just been thrown out of a pub for "language",' he says. He used to publish certain food writers when he was head of Cassell and claims the reason food is so popular is 'because it's become an acceptable leisure activity for men'. I suspect he's right but I'm starting to suffer a certain confusion. The sessions are beginning to blur in my mind. They all proceed roughly the same way, there's the vaguely educational bit, then there's the moment when the speaker says how much they adore and worship Fergus Henderson, and then they slag off the supermarkets.

I'm starting to wish that there was a McDonald's executive around; a Heinz beans manufacturer. For all the Welsh grans, there's a certain middle-class smuggery in the air. I'm beginning to tire of hearing of the importance of seasonality. I'm beginning to suspect the whole it-was-better-in-the-old-days-when-people-knew-how-to-cook argument is a subtle piece of woman-bashing. And I can't help thinking there's something peculiarly British about building an entire festival around what's essentially a good lunch.

It's vaguely cheering, then, to arrive at the Borough Theatre just in time to hear Anthony Bourdain and AA Gill discussing the relative gastronomic merits of puppies versus monkeys. The auditorium is packed and Bourdain is charming and funny and articulate and there's a bit of talk about anal seepage and rotted shark's fins and then he and Gill get on to sex. Food, says Bourdain, is these days roughly on a level with pornography. 'People are reading cookbooks and watching people on TV doing things that they're not going to be doing themselves any time soon.'

Which in a way goes to the heart of the mystery of the Abergavenny food festival, that we're obsessed enough with food to watch all the TV programmes and buy all the books and go to the festivals, and yet leave the cities and there's still a Challenge Anneka element to trying to get a decent cup of coffee, let alone a meal.

Outside, smoking a cigarette, is Fergus. He's rather shy and thoughtful and seems bemused by the hero worship and the whole food festival thing. 'There is something a bit strange about it,' he says. 'It's all very jolly and jovial...but you do wonder why you should have a festival about something that should just be the norm. If you go to France and Italy, after all, people just buy food ...'

AA Gill appears next to us. 'Which Observer?' he asks when I tell him where I'm from. And then, 'Is that shorthand? Good God! Nicola look at this, she's writing shorthand. How quaint.'

'Yes,' I say. 'That's "AA Gill", right there, although transcribing it back, it could easily be mistaken for "A Girl".'

We eye each other for a moment and then I tell him I'm Welsh.

'What was it you said again?' I ask. 'I've forgotten.' But he just shakes his head. (It was, for the record, 'Despicable little trolls'.) But then I'm taller than him, so I'm not sure he'd really pull it off.

Still, he's entertaining and my notes go something like, A Girl: 'What do I think of food festivals? They're better than armament festivals ... is it an interest in food? Or is it a metaphor?'

Me: 'A metaphor?'

A Girl: 'Food is the great metaphor.'

Me: 'Is this a metaphorical festival, then?'

A Girl: 'Interest in food is a displacement for other things but I think the idea of festivalitis is rather nice. I mean there's a dressing-up cars festival, why not a food festival?'

Why not a food festival? It's a good question and I skip off to a wine-tasting with Malcolm Gluck although I skip straight out again after he suggests that 'you should be getting apricots' when all I can taste is wine and I hang around a launch for a new book on Welsh food just long enough to scarf some more cheese and meet a TV producer from Llanelli who says 'I saw you talking to AA Gill,' with a slight hint of menace in his voice.

'I'm an imported Welshman so I get a bit defensive,' he says. He's called Adam and tells me that, 'I buy all the cookbooks. And I read them, but I'll probably only ever cook one recipe out of them.'

'You're the type of person they're all banging on about!' I say. And then I realise that I am too! I've got a stack of cookbooks on my shelf and yet I tend to eat houmous or, if I'm really pushing the boat out, pasta.

Ah well. I'm quite happy in my new role - food porno fan - although I discover there are other potential bit-parts to play. Bourdain, when I finally pluck up the courage to talk to him, tells me about 'food groupies'. At the South Beach Festival, there's a whole subculture of women who come to lust after chefs. 'There are people around who collect them,' he says.

And then there are what he calls 'the serious food nerds who are just like Star Trek fans'. But the common factor is that 'there's a buzz that surrounds the whole industry at the moment and I think the people who come to events like this are picking up on that.'

He's right. Food as porn, food as metaphor, food as food. It's all right here in Abergavenny. What's not to like? It could be just a middle-class smugfest but at the festival party on the Saturday night, there's a funny mix of Welsh cheese producers and London chefs and local sheep farmers and WI ladies and, oddly, a roomful of Waitrose execs who seem to have managed to escape the all-supermarkets-are-evil tag. Bourdain's doing his Jagger impression. Fergus is looking faintly perplexed. And I spend most of the evening performing my new party trick: transcribing rude words into shorthand for Tim, who was one of Jamie Oliver's reality TV teenagers from Fifteen, and Lee, a chef from St John, who's an ex-removals driver from south London and is very proud of the fact that he's just drunk 12 pints of cider. He demands that I interview him and, reluctantly, I pick up my pen.

'OK,' I say. 'Why do people come to food festivals?'

'Because people are taking food seriously in Britain these days. Because ... Do I sound pretentious? Why aren't you writing it down?'

'Because I've been hearing it all day.'

'All right I'll tell you why people are here. Because there's loads of free food and you'll get fantastic award-fucking-winning cider for a quid but you're not going to write that in the fucking Observer are you?'

Oh no?