The art of the mix

Cocktails are back in fashion, and the fashionable are doing it for themselves. John Walsh goes to bartender school, and stays sober enough to tell the tale

REMEMBER THE Hampshire brewery that was recently upbraided by the Advertising Standards Authority for claiming their beer was "an all-round food containing a balanced package of nutrients and minerals"? There's a kindred spirit in the Zeta Bar of the Hilton Hotel on London's Park Lane. Sit in the retro-Fifties plush of the Zeta – with its downbeat yellow lighting and twisted-wire sculptures – and flick through the bar's cool grey cocktails menu, and you'll discover the place has a "Philosophy of Drinking". It's not exactly (despite his fondness for the bottle) Aristotle. "It is our philosophy at Zeta to highlight the benefit of natural fruit and vegetable juices on our menus wherever possible," they state severely. They are, it seems, a shrine to "a healthier approach to alcohol". Their cocktail recipes are "accompanied by an analysis of the important nutrients and valuable minerals", not to mention "the suggested benefits for certain ailments".

Remember the Hampshire brewery that was recently upbraided by the Advertising Standards Authority for claiming their beer was "an all-round food containing a balanced package of nutrients and minerals"? There's a kindred spirit in the Zeta Bar of the Hilton Hotel on London's Park Lane. Sit in the retro-Fifties plush of the Zeta – with its downbeat yellow lighting and twisted-wire sculptures – and flick through the bar's cool grey cocktails menu, and you'll discover the place has a "Philosophy of Drinking". It's not exactly (despite his fondness for the bottle) Aristotle. "It is our philosophy at Zeta to highlight the benefit of natural fruit and vegetable juices on our menus wherever possible," they state severely. They are, it seems, a shrine to "a healthier approach to alcohol". Their cocktail recipes are "accompanied by an analysis of the important nutrients and valuable minerals", not to mention "the suggested benefits for certain ailments".

Thus their Russian Spring Punch, a blend of vodka and Champagne with a few blackcurrants thrown in, is "a good remedy for circulatory and respiratory problems". Snivelling wretches will enjoy a Guava Palava ("an excellent boost if you feel like you're getting a cold"), topers who've had too many Guava Palavas will benefit from a Ginger Martini ("unexpectedly useful against nausea"), while those who believe cocktails are a vital tool of sexual foreplay will embrace the challenge of a Ms Collins ("helps improve fertility in men") and the assistance of a Ketel Grass Martini, ("has a certain Viagra feel about it").

The cocktail hour as therapy session is a new one on me, but there's no doubt that cocktails are cool once more. In the last decade they've moved from being quaint Thirties-flapper drinks (Tom Collins, Horse's Neck, Rusty Nail) to becoming the drink-of-choice of Delboy Trotter and his associates, to being rebranded as fruity alcopops with additional smut (Slow Comfortable Screw Against the Wall, Sex on the Beach, Slippery Nipple) to being thought hopelessly provincial. By the turn of the millennium, only very dumb young City brokers fancied blowing £7.50 on a Strawberry Homicide on a Friday night.

But look around now, and you'll see there's a whole new cocktail generation. At the Cinnamon Club in Westminster, made famous by the gourmandising Andy Gilchrist, they do a zingy line in Indian lassi cocktails (try the mango-and-vanilla). Fans of Nippon culture will lap up the Saketinis, Long Dragons and Chinese lychee liqueurs in the Ling Ling bar at Hakkasan in the West End, and the shochu (Japanese barley-spirit) cocktails at Zuma in Raphael Street, Knightsbridge. Ian Schrager's hotels, a reliable index of what's cool and trendy in expensive-nighthawk circles, shift a lot of cocktails: the Sanderson hotel offers the classiest martinis in town (but they should be pretty good, at £10 each) while its exclusive, guests-only Purple Bar is promoting their chocolate martinis (like the Divinitini, with two kinds of vodka, Grand Marnier, crème de cacao and melted milk chocolate).

And now you too, dear reader, can learn how to do it yourself. Since January, the Zeta Bar has been offering a "masterclass" in the black arts of blending, crushing, shaking and stirring, "mudding" and "layering", for aspirant smoothies and Tom Cruises everywhere. The classes last an hour and take up to six people who have paid £20 a head and who get to sample a dizzy-making succession of strong drinks.

Running the operation with South African panache is Justin Smyth, an athletic-looking Cape Towner who came to the Hilton by way of the Beach Blanket Babylon bar-restaurant in west London. His passing resemblance to Mel Gibson is not lost on the ladies in our little group. I met Rebecca, a plump and pretty lawyer who has been inspired to attend the class because of the hoard of "so many unused bottles of spirits" from forgotten holidays that are silting up her fashionable home. "Doing the course is no more expensive than buying a couple of cocktails," she reasons. "I'll be just fine as long as they don't give me tequila. The last time I had some, I was locked in the bathroom for four hours." Beside her sat Nancy, a striking blonde with enormous eyelashes and moon boots, who works for Arcadia (the retail company that owns TopShop). Nancy is anxious to show off her bottle-twirling skills at a friend's birthday party. Neither woman seems unduly intimidated by the "masterclass" schtick. They are here for a good time.

Justin runs through a brisk tour d'horizon of cocktail history: they began, it seems, in the days of Prohibition in America, when bars had to deliver their libations of illegal grog by concealing them inside fruity punches. The name dates from the American War of Independence, when innkeepers decorated their drinks with the feathers of fighting cocks – hence "cocktails".

We were introduced to the barman's vital batterie de cuisine: one measure, one long spoon, one Hawthorn strainer, and one "Boston shaker" – the wide-brimmed metal container which slots into a half-litre glass without getting it stuck (the occupational hazard of the classic all-metal shaker that's theatrically agitated, as if to a samba rhythm, by all cocktail barmen in Hollywood movies).

Justin took us through a classic "Manhattan", the drink created in 1874 at the Manhattan Club, New York, for Lady Randolph Churchill – and riotously prepared by the all-girl band on the train in Some Like It Hot. Canadian Club rye whisky for preference, Angostura bitters, sweet vermouth, lots of ice. Justin poured the 25ml of vermouth on his tiny measuring spoon in little 5ml dribbles, flicked into the shaker with infinitesimal twitches of the wrist, and added a glacé cherry (so much for the bar's zealotry about fresh fruit). The Manhattan tasted slightly sour, then slightly marmalade-y, but we kept coming back to try it again and again – one example of each drink is passed along the line of students for a cautious appraising sip, then returned to the counter.

Sober, pro tempore, as kirk elders, we watched the boss build a classic dry martini. I thought that I'd perfected the no-vermouth-if-you-can-help-it approach, in which you just flavour the ice with vermouth, then throw the liquid away and pour the gin (or vodka) over the scented cubes. At the Zeta Bar, Justin is more hardcore: he throws the ice away as well, leaving bare traces of vermouth in the shaker. The result is 100 per cent pure gin (or vodka) with a fugitive ghost of vermouth somewhere at the back of the tongue. Justin wouldn't use Gordon's gin, by the way: Bombay Sapphire is more alcoholic, he said, while Plymouth gin – his favourite – has a more herby, juniper-scented, ginny authenticity.

I was starting to appreciate Justin's little signature touches that made all the difference to his cocktails, and his insistence on doing things the right way. James Bond, he said, was wrong about vodka martinis: they should be stirred, not shaken, otherwise the ice gets broken up and the drink too diluted. Be sure, he said, to try the "dirty martini" – that is, a martini zhooshed up by the addition of olive juice. Try pouring a whisper of dry sherry over the very top of a Bloody Mary. And use green, not red, Tabasco. And garnish it with halved cherry tomatoes, not celery. And wipe the glass rim with a lemon, then roll it in a spilt circle of ground black pepper.

A top secret of advanced cocktail-making was revealed: the spirit marinades. The Zeta Bar has a dozen bottles of specially decanted gin and vodka into which they've crammed a score of peeled lychees, blueberries, vanilla pods, strips of ginger and other less identifiable ingredients. The bottles look fantastically rustic, the kind of thing you'd find at a sinister backwoods auberge in Perigord. But the alcohol-saturated fruit packs a real wallop.

We sailed onwards, through Cosmopolitans ("so much part of the Eighties gay scene in New York and now of Sex and the City") which are mostly lime and cranberries behind the Dutch citron vodka; the result is powder-puff pink but tastes decidedly bitter – despite what Delia Smith says, I've never gone for cranberries. More fun was the Mojito, Cuba's national drink and Hemingway's favourite, as a written declaration on the wall of a Havana bar attests. It's a citric dream of crushed lime wedges, rum, brown sugar and mint leaves, and needs a lot of strong wrist action with a rolling pin. Cocktail snobs can have fun with this one, because there's a wide range of fancy rum labels from Central and South America, each with its adherents – like Matusalem, the clásico rum of Chile, or the grandly titled Ron Zacapa Centenario from Guatemala.

By the end of the hour, a whole platoon of half-drunk cocktails in nursery hues lined the bar. From the lightest (Champagne cocktail) to the heaviest (the Buzz Lightyear, crammed with bananas, passionfruit and mango purée), we'd cocktailed not wisely but too well. And there were more to come. Rebecca was anxious to find a recipe which would use up her stocks of holiday limoncello, but sadly, none seems to exist. Nancy, the bottle-blonde with the hairy boots, went behind the bar and tried to make a cocktail of her own devising. "I only like pink drinks," she said, looking for the crushed strawberries. She added a dash of lychee gin and fraises de bois, thought for a minute and topped it up with Champagne.

"According to Richard Gere in Pretty Woman," she said, "strawberries bring out the flavour of Champagne."

"Does that make you a prostitute?" asked Rebecca cattily.

"No, darling, just a film buff," said Nancy. The atmosphere was getting a little rackety. Natasha, the PR lady, tried to interest everyone in the exciting vodka masterpieces to be had at the Russian Bar in the Langham Hilton beside the BBC, but we were trying to concentrate on Nancy's new gin-strawberry-fizz creation. I tried a sip. It was disgusting.

"Nancy," I said. "I mean, c'mon – gin and Champagne together? What were you thinking?"

She tossed her head. "Oh please. Someone must once have said, 'What, vodka and tomatoes? What are you, crazy?' "

She had a point. At least she didn't pretend it would do wonders for your indigestion.