That vulgarian James Bond popularized shaken martinis, but is that really the best way to prepare them? And how does stirring change the cocktail? What exactly makes a martini a martini, anyway? All these questions and more have been racing through our heads as the sun creeps over the yardarm on National Martini Day, a sacred made-up holiday that gives us unnecessary encouragement to booze it up. For guidance, we turn to PDT's head bartender Jeff Bell.

Strictly speaking, a martini is made with gin (gulp), not vodka, not chocolate, not olive juice. A martini is gin and vermouth, garnished with an olive or a lemon twist. We know from Wikipedia that H. L. Mencken called the martini "the only American invention as perfect as the sonnet," while E. B. White called it "the elixir of quietude". Here's what Bell has to say about the great shaken vs. stirred debate:

The shaken martini is so common that it's considered the norm by many, but it is not the optimal way to mix the elegant cocktail. It should be stirred to retain the rich texture of the gin and vermouth and will remain clear, not opaque. Shaking a martini over-dilutes and aerates the cocktail, leaving it with ice chips floating on top and a cloudy color—not very elegant.

Asked about his preferred choice of martini ingredients, Bell says, "Tonight I'll have a 3:1 Gin Martini. 3 parts London Dry Gin and 1 part Dry Vermouth with a lemon twist." But PDT, an excellent "hidden" bar in the East Village, also serves a martini variation with Tanqueray Gin, Bianco Vermouth, Orange Bitters and an Orange Twist.

Bell is what you'd call a purist when it comes to martinis. "You will never see me drink a dirty vodka martini," he declares. "Vodka doesn't have a huge flavor so adding a giant like olive juice in there just makes for a very salty, olive flavored drink, which is very far off from what a martini actually is."

So there you have it. Is your cocktail glass in the freezer yet? Get it in the freezer STAT and have an intern start peeling some lemon twists! It's five o'clock somewhere... actually, it's five o'clock here.