Memorising endless recipes is less important. Danny Fierstone, ex- barman of Detroit (where I've been receiving cocktail instruction), speaks of a guy who knew 400 recipes. "The only problem," adds Danny, "was that he couldn't make any of them well."
At Detroit, taste is king. When a barman finishes a complicated cocktail, he dips a straw in and tastes the drink himself. Even if he's never made that drink before, and even if he doesn't actually like it, he will know whether it's good. If it isn't, he will correct it.
They can do that because they understand the basic principles. There may be thousands of cocktails in the world, but most are based on a small number of ideas. Master those ideas and you can make anything.
My experience of hanging out with professionals certainly bears that out. Of course, it's easy for them: they've got the experience. Boneheads trying to get a crash course (like yours truly) will find the abstract principles baffling. My cocktail guru Dick Bradsell, head barman at Detroit, tried to simplify using diagrams, showing how the principal flavours of a drink are brought together by ancillary flavourings, and when he draws his diagrams (usually on a napkin) you think you've seen the light. But try to duplicate the results yourself and - well, it doesn't look so easy. Dick and his team did a lot of demonstrating for me. I looked, listened, tried to make notes - but there was too much to take in.
For the record, however, here's an approximate version of cocktail basics. First are the aromatics: a base spirit "adjusted" with vermouth or bitters. The most important of this class are the Martini, the Old-Fashioned (Bourbon, sugar and orange peel), and the Manhattan (Scotch, sweet vermouth, bitters). These all need "gentle, loving, respectful treatment, no shaking, no messing around."
Next comes the sour. In the States, it's a whisky sour; in Brazil it's a Caipirinha; in Mexico, a Margarita. All combine sweetness and sourness, typically in proportions of 6:2:1.
Then comes punch. All punches are essentially "a sour made long" (i.e. with ice in a tall glass). Based on the Planter's Punch, they follow exactly the same principle: four parts weak, three parts strong, two parts sour, one part sweet, regardless of which spirits are used, and which mixers.
Sixth is the Daiquiri. This is just rum, lime and sugar, with the variations coming from different types of rum and the addition of fruit blended in. Daiquiris can be shaken or blended.
The crucial point is balance. "You have to make the different flavours into a whole flavour on the palate," as Dick puts it.
Many of the newer cocktails are just gimmicks, and a popular one is to provide a novel shortcut to inebriation. This is the raison d'etre of shots and shooters; short drinks served in shot glasses for quick inhalation. Detroit sells one called The Three Wise Men, consisting of Jim Beam, Jack Daniels and Johnny Walker Red in the same glass. "What's the point of that?" I asked Dick. "It's a code," he replied. "With these drinks, the code means: 'I want to get drunk.'"
Layered drinks are another gimmick. Detroit sells a few of them, including the B-52 (Kahlua, Bailey's and Grand Marnier) and the Vulcan Mind Probe (Bailey's, creme de menthe, overproof rum). Perhaps the code here is: "since you don't serve Mars Bars, I'll have one of these."
If these concoctions make you think about reaching for the sickbag, you're on the right track. Dick reckons there are 30 good cocktails in the world. Many of the remainder are disgusting, and others are just pointless.
Detroit sells around 40 cocktails, and each bartender there should know how to mix one without thinking about it. If they need a reminder, they can use what he calls the "Idiot Book" - each cocktail described in method and measurements.
The Idiot Book and I seemed to be set for a beautiful friendship.