The lovely taste of extra virgin

There was another million pound question in Fulham on Monday, and it had nothing to do with Judith Keppel or Eleanor of Aquitaine's marriage to Henry II.

It was an Italian query: was the Fattoria Selvapiana Estate Label more oily than the Fattoria di Felsina? The answer will eventually be worth considerably more than a million quid and it is not in Chris Tarrant's gift.

In fact, if the former disc jockey opened his mouth, the steely gaze of Rose Gray and Ruth Rogers would have shut it. The founders of the The River Cafe and authors of the River Café cookbooks were, at exactly 11am on 20 November, about to sup on the true sacrament of west London - the new century's first cold pressing of extra virgin olive oil from Tuscany.

In the stainless steel church of Italian gastronomy, just off the Fulham Palace Road, half a dozen olive oils had been rushed in from northern Italy and were now lined up on the altar that is the River Café bar.

In the solemn surroundings of the colourless canteen I pulled on my chef's whites and joined Rose and Ruth and Chef Peter Begg. We were each given a sheet of paper for our tasting notes and took it in turns to sniff the oils from nosing glasses and then to try them by dipping a teaspoon into plastic chemistry dishes. My notes were not extensive. (Rose Gray, by contrast, managed a paragraph on each.)

The arrival of the new olive oil in November has much in common with the celebration of the newly pressed wine grape, although it would be considered sacrilege to compare the event to the arrival of beaujolais nouveau. The cold pressed extra virgin oil is made from the best hand-picked olives and pressed in small mills on single estates. Every year Rose and Ruth and their favoured foodie friars from the River Café take two minibuses to Italy to find the oil that will be served in the restaurant for the coming year.

For a fortnight the W6 epicureans tour the olive oil estates supping and tasting before returning to Fulham with six or seven oils. One or two of these will ultimately bear the River Café's own label - but which one? The tasting was held to find out, and I had been invited to witness this exclusive mid-morning matins.

First pressed olive oils are not the sort you mix with vinegar or lemon. It is not the oil of supermarket shelves and Greek delicatessens that comes in large cans. In fact when you splash out a fiver on a bottle of olive oil, rather than a plastic container of Mazola, you have taken a step towards gastronomic nirvana. A River Café Tuscan oil will tell you that the gormandising road ahead is very long indeed.

When I suggested to the tasters that the first oil, the Fattoria di Felsina, would be delicious with balsamic vinegar, I was told in no uncertain terms that it was not the way to make sauce vinaigrette. The oil is too good. It would have been less heretical had I suggested mixing Coca-Cola with a Ch?teau d'Yquem. First pressed oils are used only for drizzling on salads and cooked foods or as a dip for bread. They taste of autumn mists and damp grass with a peppery tang - a sort of oleaginous Tabasco sauce with class. "I like to think I know some of the olive trees personally," said Ruth Rogers, who talks of the oils with a missionary zeal. "I sometimes bring back a branch of the olive tree and put it somewhere in the restaurant as decoration after a tasting trip to Tuscany."

Rose Gray is equally passionate about the River Café oil which comes in wine bottles and retails for about £15 to £18. "I left a bottle in the sun in my flat and each day the taste was slightly different," she said. "When the oil is young, at this time of year, it is ideal for winter salads and as it gets older it is perfect for the summer salads. After a year, if we have any left, then and only then do we use it for cooking."