After learning all about wine in the first two series of Oz and James' Big Wine Adventure, James finally gets to drink a pint (or two) on home soil. The improbable duo travels the length and breadth of the UK, sampling the broad range of booze on offer, in an attempt to find the drink that defines Britain. For their latest adventure, James produces the wonderful combination of a classic Rolls Royce and an appallingly kitsch Sprite caravan from the 1970s. Living in cramped, leaky conditions, the bickering reaches new heights as James discovers that Oz is as knowledgeable about beer, stout, cider, whisky and lager as he is about wine. As James tries to air his knowledge, Oz struggles to keep the upper hand. In their quest, the pair tries extreme beers from the worlds strongest to the worlds most expensive pint; they pit the best in German technology against the best of Ozs know-how in a brewing competition; James discovers Ozs Irish ancestry; and they even drink some wine much to Jamess horror! But will Oz be able to convince James to try cider after more than 30 years of not letting a drop past his lips? Will the pair manage to overcome their fear of Morris dancers? And more importantly will they find the drink that defines Britain?