Chateau Vignelaure is in Provence, on the road between Jouques and Rians, straddling the border between Bouches-du-Rhone and Var. It's an imposing building; three stories high with double stairs leading up to the piano nobile. Roofed with Roman tiles, the pink blush of its ochre walls glows in the hot autumn sun. The chateau lies in a small plain bounded by wooded hills, and around it are the 150 acres of vines that produce the red and the rose wines of Vignelaure.
It's archetypically French; the gravelled drive is lined with plane trees and is flanked by formal gardens. Persian shutters adorn the upper windows, a fountain is enclosed by the arms of the stairway. But in this chateau the lingua franca is English: it is Irish-owned. Since 1994 it has been the home of David and Catherine O'Brien. David, son of Vincent O'Brien, was himself a trainer throughout the eighties. He always enjoyed good wine, but now he makes it. For David and Catherine it's been a year of change and challenge. An invitation to visit the chateau was impossible to refuse. Warm sun, good wine and provencal food - ingredients for nirvana.

Tuesday.

The trip is confirmed; I leave tomorrow and come home Friday. I start phoning my friends to casually mention where I'm going. Chris de Burgh is lying in bed with a vicious case of tonsillitis. I phone to see how he's doing. 'Anything new with you?' he asks. 'Nah, not much,just off to a vineyard in Provence for a couple of days.' - dead casual. 'A vineyard in Provence?' croaks Ireland's most fanatical oenophile, 'That sounds good, I'd like that, that really sounds like fun, God I'd like to come with you, I probably could, I'm already feeling better, I'm sure I could - see if I can come too.' David and Catherine say they'd be delighted. When I tell Chris that, he asks how I'm getting there. Dublin Paris, Paris Marseille. Depart Marseille 6 a.m. Friday morning. 'No, no,' says Chris, 'that sounds ghastly. Leave the travel arrangements with me.'

Wednesday.

I meet Chris at one o'clock and we drive to the airport. We stop at the door of Parc Aviation, and less than two minutes later we're being driven across the apron to a chartered Citation 2 ten-seater jet on which we will be the only passengers. This is travelling in style. Somewhere over the sea we share a bottle of Piper Heidsieck. After two hours and twenty-five minutes we're in Marseille. Basically this beats hanging around airport departure lounges for hours on end. And it feels so, well, so smart. David O'Brien meets us with a smile and instantly we both know this is going to be a lot of fun. We drive through Aix-en-Provence, through Peyrolles (love that name) through Jouques and by dusk we've arrived. In the fading crepuscular light we see the vineyards stretching across the plains. Stars begin twinkling in a sky devoid of cloud.

David takes us on a tour of the caves, across the courtyard from the chateau. We're nearing the end of the vendange; the only grapes left to pick are cabernet, and the majority of them are already fermenting. The ground floor is where the grapes become wine. The grapes are stripped from the stalks and their skins are burst open before they are pumped into the huge stainless steel fermenting vats. Here, under controlled temperature, the first fermentation takes place. While we're there the first vat of syrah, now two weeks old, is ready for a taste. It's quite unlike a finished wine, but the spicy, peppery taste of the syrah and its fruity bouquet are unmistakable. Vignelaure is matured in new, partially toasted barrels of American oak. Gradually the production will move to these small barrels, rather than the 85 hectolitre monsters that fill one of the subterranean levels. The equivalent of over a million bottles is stored in the caves. It's becoming clearer to me that a vineyard of this size is a major undertaking.

Over dinner in the chateau's dining-room we meet Andrew Thomas, an Australian wine-maker from the Hunter Valley who is supervising the vendange, and his wife Jo; two young men just out of Eton called Henry Cecil and Michael Dunlop, who have been working here for the past two months, and three Irish girls - Janet Hyde, Kate Evans and Sinead O'Sullivan. Kate has cooked a wonderful dinner and now it's time to settle down to some serious research. By two o'clock in the morning we've tasted Chateau Vignelaure from 1982 to 1992, plus the estate's second wine in various vintages and of course the rose. The estate's own marc is pretty good too. A vertical tasting seems an odd name for something that leaves you prostrate. Catherine O'Brien is a hospitable chatelaine who makes everyone feel at ease, but she reminds us that the vendange continues tomorrow at eight, and that we might consider getting some sleep.

Thursday.

Rather surprisingly I awake at quarter to eight. Half an hour later as I walk across the gravelled courtyard to the kitchen I stop and look, soaking in the warm sun. Not a cloud is in the sky, tractors and trailers are already arriving with the first loads of grapes for the caves. Forty-five pickers are at work in the huge seventy-acre field that abuts the main gates.

After a breakfast of coffee, croissants and brioches David takes us to see the estate. Vignelaure is big: 150 acres of vine, mostly cabernet-sauvignon plus grenache and syrah. The canal de Provence runs through it, taking mountain water to the coast. The lower land has deep sandstone top-soil with a beautiful russet colour, while the rising land becomes progressively stonier and well drained; perfect for vines. Although it rained heavily in September, the weather has settled to days of continuous warm sun. On the vines the small, thick-skinned cabernet grapes are ripe. The syrah and grenache, already picked, are fermenting in the caves. We watch the pickers moving slowly and inexorably along the rows of vines.

Over lunch we learn a little of the history of Vignelaure. The property was bought in 1965 by George Brunet, the innovative wine-maker who brought Chateau Lagune to prominence. He was the first man to plant cabernet in Provence, and the wine of Vignelaure has a high proportion of it in its blend - sixty per cent. After lunch Catherine takes us to see an extraordinary archaeological find about a kilometre away. A huge Roman winery lies partly excavated, forty amphorae so far, each holding about three hundred litres. Dated to the third century BC, it's hard evidence of wine-making in this area for well over two thousand years.

She tells us that their venture has its problems. Apart from adjusting to so big an undertaking, they are now faced with an embargo on French wine by people who have a point to make about nuclear testing. They've lost big orders to Denmark, Finland and Germany - it's a boycott they could well live without. It began in Australia and America, two countries whose wine industries are benefitting enormously from the fall in sales of French wines. It's a moral crusade, but the commercial benefit to the perpetrators is large. As an Australian herself Catherine can see that the protesters have a point, but the motives seem tainted with plain old commercial jostling for markets. Besides, she adds, Vignelaure is almost an Irish wine.

There's a long tradition of Irish people setting up in the wine trade in France - Irish connections to Bordeaux go back to Edward III. Back in Ireland some of us in Annamoe indulge in the forgivable pretension of referring to Leoville or Langoa Barton as our 'local wine'. Annamoe's Glendalough House was one of the Barton estates, the same family that has made its mark in Bordeaux.

Over another wonderful dinner of good food and more wine research David reads me a description of Vignelaure '85. 'young, exuberant, muscular, excellent length, full-bodied, good legs, may reach maturity in 1996, can be drunk anytime.' Could be a description of me.

Friday.

After breakfast we make a last tour of the vineyards. The pickers have left the secondary fruiting of the cabernet on the vines. David looks at the perfectly blue sky. 'Who knows, if this weather keeps up, these bunches could ripen as well.' Hand-picking ensures that only ripe bunches and grapes free of rot get vinified. It's more expensive than indiscriminate mechanical picking, but that's the price you pay for quality.

At mid-day David and Catherine drive us to Marseille airport, but there is time for a leisurely lunch in Aix. Les Deux Garcons is where we eat, its long list of famous patrons includes Cezanne. We decide to do a little more wine research. Over lunch we select three different local roses, all good, but none matching Vignelaure's La Source, which won the gold medal at this year's Concours General in Paris. Some excellent Armagnac rounds off my rognons de veau au moutarde and it's time to leave. I'm sorry to be going, but I think I'll take up the O'Briens rash invitation to visit them again.

Oddly, I sleep most of way home to Dublin. It's been a hard week, but there's the week-end ahead for some recreation.