Word of mouth: Caroline Stacey spends a happy hour with the new cocktail kings
Only a few years past the legal age of drinking in bars, Andres Masso and Jamie Terrell, at 22 and 24, are the uncrowned kings of London's cocktail scene. Having come respectively first and second in the UK heat of this year's Beefeater International Bartenders Competition, their ambition is to replace cocktail umbrellas and lurid syrups with fresh juices and pure spirits combined in their own inventions: the Fresca - lemon vodka, orange bitters and kumquats; Winogrono - red and white grapes, crushed and shaked with vodka and lemon oils, and Loretto Lemonade - Maker's Mark bourbon, Japanese melon liqueur, Washington red apple juice and ginger beer. And they don't need to have alcohol in them - Jamie's Passionart has passion fruit juice, strawberry puree, lime, orange and apple juice - but it helps. "Cocktails should seriously kick ass. Balance is important, a good one should be well disguised but strong."

Andres and Jamie don't just invent juicy cocktails. As company trainers for Gruppo, the group of trend-setting bars and restaurants that consists of the Atlantic Bar, Mash and Coast in London, and Mash and Air in Manchester, they are responsible for instructing 50 other bartenders in the ways of the contemporary cocktail. "A barman should be knowledgeable enough to assess someone's aura," Jamie says. And have the skill to knock up a concoction so quickly there isn't time for a beer to seem like a better idea. "They look feminine but you've got to get over that," he adds, surveying a line-up of pinkish drinks.

They describe their base at the Atlantic as the Wembley Stadium of bars (it serves 150 cocktails a night), and mean it as a compliment. "We're the blueprint for today's drinking environment," says Andres, an ex-photography student, whose studies gradually took second place to bartending.

So, when Seabreezes and Cosmpolitans seem old hat, how will cocktails develop? "Our tip at the moment is playing about with champagne cocktails. People have gone Martini crazy, but why call it a Martini just because it's in that glass?"

Incidentally, how do you serve the perfect Martini? "However the person wants it, though you should never really shake a Martini."

Jamie and Andres' JA'Moro

"Like heaven," says Andres. "I want to die with this drink," says Jamie.

1 measure fresh orange juice

1 measure fresh Washington red apple juice (or red apple juice at least)

1 measure of vodka

1 measure Chambord or raspberry liqueur

Dry champagne

Give the first four a quick shake to mix together, strain into a champagne flute to half way, top off with a layer of the champagne by pouring it down the thread of the twisted handle of a bar spoon, if possible