Oz Clarke is a wine connoisseur and James May a beer-drinking, fast car fanatic who has dubbed his colleague `pretentious'. In their voyages of viticultural discovery around France and California in Series One and Two of `Oz and James's Big Wine Adventures', James learnt a lot about winemaking and O2 learnt that James can't spit. It seemed only right to take a look closer to home and so, in this highly personal account, the odd couple set off on a summer road trip on a quest to find the drink that defines modern Britain.For their latest adventure, James produces a supremely British combination of classic Rolls Royce towing an appallingly kitsch Sprite caravan from the 1970s. The unlikely companions live in this tiny, leaky Sprite as they travel around Britain in one of the wettest summers on record.Their first mission is to find out what goes into a good British beer. The next is to seek out an `honest' drink made and served by an `honest' brewer, pub or winemaker. Oz and James then move on to explore other drinks that might define modern Britain - malt whisky, of course, English wine, Plymouth gin, potato vodka and scrumptious cider and perry, with a sideways glance at Ireland, the ultimate example of a country where one drink defines the whole nation.As part of their `research' O2 and James visit some of Britain's most passionate drinks producers, including a traditional maltster, England's oldest cider maker, a Kent hop farmer, brewers, winemakers and distillers and many others, before drawing their conclusions on the white cliffs of Dover.