It may be the best olive oil in the world - but it's certainly the oldest

Perhaps it won't be long before we'll be buying litres of finest Cornish extra virgin, but until then we must purchase olive oil from abroad.

Yes, we could restrict our cooking fats to local butter and the new breed of British extra virgin rapeseed oil - but anyone who loves first class Westcountry foods like our vegetables and fish will sooner or later (probably sooner) reach for a slurp of the health-giving, life-reaffirming, juice of the olive.

So, if we keen cooks have to use it, why not set out to find the best? That is what a friend asked the other day when he emailed an invitation for me to join a trip to Puglia in South East Italy, where they claim to make the finest extra virgin olive oil in the world.

No doubt producers in other Mediterranean areas might argue with this - but they would be hard pushed to claim that they've been at the olive oil production game for longer than the Apulians.

As I say, I am now the proud but fleeting owner of a bottle of extra virgin made from olives harvested in one of the oldest groves in the world. The farmer who sold it to me has had some of his trees carbon-dated by scientists, so he knows how astonishingly old they are - but he told me he always suspected the grove was planted in Roman times.

However, the really old tree at the farm known as Masseria Brancati - the one they call The Grand Old Man - is even older than the rest. Agronomists know this because most of the grove is laid out in the strict grid system which the early Romans invented - but the Grand Old Man is not. He stands, or leans, like an ancient anarchist alone in the middle of the rows.

Farmer Corrado Rodio told me: "My family has been here for over 200 years and we've always been in olive oil production. We specialise in only making extra virgin. There are lots of different varieties of olives - in Italy we have over 500 - but in what we call the 'monument' olive grove there are two old varieties.

"If a Roman centurion tasted my olive oil, it would be the same as he knew. But, we have two different ways of making oil - the old way with a mill and a press - and in a modern mill. If we use the mill and the press the oil will be similar to the Romans'. But I prefer the modern mill because the oil is perfect. I love everything that is old, but I must admit that the modern mill does make a nicer taste."

This is a theme you will hear time and again as you tour the olive farms which are located in an almost biblical looking setting between the hills and the Adriatic Sea in the fertile part of central Puglia set between Bari in the north and Brindisi in the south. The area is called Northern Salento and much of it is known as the Monumental Olive Groves Natural Park.

Like farmers all around the world, the producers are equipment junkies. There is, obviously, much art and traditional skill in actually growing the olives, or at least in nurturing the trees, but the harvesting and - even more important - extracting the phil, does call for modern technology. There's not much point in growing the finest olives if your equipment damages the trees or prematurely bruises the fruit - and certainly not if your mills or centrifuges are incapable of effectively separating the good stuff from the olive's watery contents and inedible mush.

Which brings us to those words "extra virgin". Even the lowest budget supermarket will sell bottles of stuff with these words stamped on the label - but the industrially produced oils are an entirely different product compared to the marvel we're talking about here. Many are produced from low quality oil that has been bought in from goodness knows where and which has been subjected to various chemical processes.

What you get in a classic bottle Apulian extra-virgin is nothing but crushed olive, minus the water and solids.

At Corrado's farm we tasted the oil this week and he told me about the harvesting which is done in late October: "There is a mechanical elevator that we use to harvest the olives directly from the branches - and for the extra-virgin they have to be pressed the same day, within a couple of hours.

"We can produce 6000 to 7000 litres of extra virgin olive a year. The olives have got to be a little bit green and a little bit black - in this way we produce much less, but the quality is better."

The hundreds of other farms and groves around his farm combine to create what could be described as a massive olive tree forest - one which, for the most part, is carefully tended so that you can see the rich red earth between the trees after the first spring flush of wild flowers has been been mown or ploughed. This work is more important now than ever because of a bacteria which is killing olive trees all around the Mediterranean area. Carried by a kind of ciccada, the bacteria flourishes in the warm damp undergrowth, which will grow if the groves are not tended properly.

Touch olive-wood, it has yet to reach Northern Salento, but there is a race on as scientists attempt to find a real deterrent or cure.

In the meantime, the extra virgin industry around the town of Ostuni flourishes and you can tour the area enjoying tastings of the greenish liquid gold, rather like you would in a wine growing region. Some of the oil will be delicate, some fruity verging on sweet, and some a little bitter and peppery. Needless to say the Italians are brilliant at utilising each and marrying the oils with ideal partners or dishes.

However, if we are going to all the expense of buying top quality extra-virgin olive oil in this country there is only one way to use it, and that is straight from the bottle and uncooked. Frying a slice of bacon in this stuff would be like using a Rolls Royce to round-up sheep.

Salads are the obvious target zone, but try pouring a little over a sizzling fillet of fish or a chicken breast. It goes particularly well with dishes that do not scream with flavour like, for instance, a fast-made fricassee of quality green or Puy lentils with onions and garlic that you are going to serve with spaghetti. Having completed the cooking of both, mix the lentils with the pasta and, only then, pour on a good few glugs of extra-virgin seconds before serving.

In that way you get the grassy, nutty, fruity kick - and also the application creates an unctuous sauce which lubricates the dryness of the pulses and pasta.

Using quality extra-virgin olive oil like this can make an expensive bottle go a long way. And it will bring extra value to many of those amazing Westcountry ingredients that we love so much.