They start their journey on top of the magnificent and enigmatic White Cliffs and travel north to Yorkshire in a 1982 Rolls Royce Corniche.

Their first pint of the trip is in the Tan Hill Inn in Yorkshire, where James discovers, to his dismay, that Oz knows as much about British beer as he does about wine. Their journey then takes them to the centuries-old Fawcett Maltings in Castleford, and Thornbridge Brewery, a successful micro-brewery in Derbyshire, where they discover exactly what goes into a pint of beer.

Oz is unable to keep away from wine and tracks down one of the most northerly commercial vineyards in the country, where he discovers, to his surprise, that wine has been made in Yorkshire since Roman times.

For the final part of the first leg of their trip, Oz and James leave the car behind and take to the rails, enjoying the beers in a string of real ale pubs located on station platforms. Their tasting notes become as unreliable as the train timetable as the evening proceeds, but despite a spell of beer-fuelled bickering, the evening ends peacefully.

Oz and James travel on to Wigan, home to probably the smallest commercial brewery in the world, run by Patsy Slevin out of her mother-in-law's garage. Stripped down to his red silk boxer shorts, Oz gets down to the dirty business of beer making, while James concentrates on what he does best - beer drinking.

At the opposite extreme, the thirsty pair also visits the famous home of Newcastle Brown Ale. Surrounded by so much beer, James is inspired to create his own, and challenges Oz to a home brewing competition. Sacrifices are made so James can install his high-tech microbrewery in their tiny caravan, and for the rest of the trip he must sleep on the floor.

A disastrous night out in Newcastle's Bigg Market, where Oz and James realise they are too old to party with the youngsters, is quickly forgotten the next day when they head for an idyllic and remote pub on the beautiful Northumberland coast.

Oz and James head for Scotland where they encounter Rachel Barrie, a self-styled high priestess of whisky, who insists that they don blindfolds for a bizarre tasting in order to fully appreciate the complexity of Scotland's national drink.

In Edinburgh's Princes Street Gardens, the pair bump into some radical brewers whose unusual beer and provocative marketing has gotten them into a lot of trouble. After sampling Scotland's national dish - a deep-fried Mars bar - the intrepid pair head for the hills to taste a delicious special beer, brewed according to an ancient recipe.

However, disaster strikes when the most vulnerable member of their party, the ancient, clapped out 1970's caravan, succumbs. Initially reluctant to abandon his precious home brew, James comes up with a plan, while Oz produces a haggis that he always keeps handy in case of emergencies.

The next day, they head for Islay, which is famous for its peaty whiskies. James conducts an unusual experiment using Scottish bio-fuel which scares the pants off Oz. Later, they visit the picturesque Bruichladdich Distillery run by Englishman Mark Reyneir, where they receive a tour of the ancient machinery and learn how whisky is made from beer. The Scottish leg of their trip concludes with the pair bravely accepting the ultimate in tasting challenges.

Oz and James cross the Irish Sea to Dublin in search of the best drinks of modern Ireland. Having had enough of whisky in Scotland, they decide to concentrate on Irish beer. Things take a turn for the worse when they order their first pint of 'the black stuff' and Oz claims that he knows all about the Irish drinking culture because he is, of course, Irish himself.

But before they get into an argument about his claim, the pair head to a Dublin landmark, the Guinness brewery. The problem is this is one drink that James really does not like.

Oz thinks he knows the way to the famous brewery, but they get lost and end up in a tunnel. James challenges Oz to tell him the concise history of stout and porter in the time it takes to walk through the tunnel.

Oz and James then meet brew master Fergal Murray, who teaches a wary James how to sink a pint in true Irish fashion.

The pair are in Burton-on-Trent, and James is particularly excited at being reunited with his home brew. Oz sets to work making his own beer, which is based on an old Elizabethan recipe.

The intrepid pair set out to taste some of the world's most extreme beers, and try their hands at being barmen for an evening at a pub in Stourbridge.

There are many surprises in store for James when Oz takes him to Wales. First they find a 'beverage plant' that makes famous 'foreign beers' from all over the world, and then they visit a farmer who makes 'designer vodka' from potato wine.

Next they meet one of Oz's mates on a farm in Herefordshire and try an ancient British drink known as perry, which is made from pears. They discover that perry had quite a reputation back in the 1970s when it was sold in small bottles and was well known under another name, Babycham.

After weeks of preparation, or hours in Oz's case, it is time for James and Oz's caravan-brewed beers to be judged at the Worcester Beer Festival by a hand-picked panel of 'beer experts'. It is a tense moment. Will the best man, or beer, win?

Following the surprising outcome of the great beer competition, and after so much beer, Oz decides that it is time to visit a vineyard, and where better than Three Choirs in Gloucestershire? What will James's nose make of proper English wine?

Oz and James begin their exploration of south-west England with a trip to a traditional cider farm in Somerset, where they meet 'the Godfather of cider', Frank Naish, who at 84 is still going strong.

Then they head further west to sample some decidedly upmarket cider brandy before visiting the famous Plymouth Gin distillery, where James gets to make his own gin and Oz learns how to be a professional barman. And then disaster strikes the caravan, again. Luckily they break down outside a pub.

The next day finds them at the beautiful Camel Valley vineyard where, despite the typical August weather, rain, they enjoy tasting proper English wine.

Finally they head for a delightful Cornish pub serving delicious Cornish beer. Oz has a surprise in store for James, which unfortunately for Oz backfires in a way he could not have predicted.

icks has gone back to the archives of an extinct local brewery to recreate the beer which was Churchill's favourite, and which cheered the troops after the Normandy landings.

There is another invasion on Oz's mind, however, as he tells James about the rumours that French winemakers have been buying up countryside in the area to plant grapes. This does not go down well.

Finally Oz and James visit a winemaker who has his eyes set firmly on the future. Dermot Sugrue is a young Irishman who is establishing a new winery on the Wiston Estate using amazing equipment he has imported from France, including a vintage Champagne press that is unique in the country.

On the last day of the trip, Oz and James find themselves back on the White Cliffs again, surrounded by the bottles and barrels that tell the story of the journey. But have they come to a conclusion after their three thousand mile expedition? Which is the drink that, according to Mssrs Clarke and May, speaks for modern Britain?