The journalist H.L. Mencken once enlisted a mathematician to calculate the number of drinks that could be created using the ingredients available in an average well-stocked bar. The total was 17,864,392,788. Even if you're that guy who follows the trends of modern mixology, there's still plenty out there to surprise your palate. Culled from the thumbed-over pages of back-bar Rolodexes, here are 10 lesser-known but fantastic cocktails for the man who thinks he's drunk it all.

Gin, lemon juice, lime juice, sugar, cream, egg white, orange-flower water, soda water
Essential knowledge: A New Orleans classic. Don't order it unless the bar is dead (it takes ten minutes to make). And don't accept it unless the bartender has shaken it till he's out of breath—egg white plus cream plus eight straight minutes of elbow grease should give it the consistency of a cloud.

Gin, sweet vermouth, Green Chartreuse, orange bitters
Essential knowledge: A Negroni with green chartreuse. Rachel Maddow told Jimmy Fallon on Late Night that it was more manly than his drink of choice, the gin and tonic. She's right.

Genever gin, Maraschino liqueur, Cointreau, simple syrup and bitters
Essential knowledge: Unlike anything you've ever drunk before: an old-fashioned, but with gin—genever gin, to be specific, which tastes likes unaged whiskey (heavy on barley, imagine liquid bread). You'll hate it or love it.

Genever gin, quartered limes, Angostura bitters
Essential knowledge: Rumored to be one of Hemingway's hangover cures. We can't vouch for its restorative ability, but if you order and finish one, you're almost guaranteed to raise an eyebrow of the guy behind the counter.

Sweet vermouth, Campari, club soda
Essential knowledge: Light, refreshing, bittersweet. The perfect thing to drink when you're not supposed to be drinking.

Gin, sweet vermouth, maraschino liqueur, Bitter Truth old-fashioned aromatic bitters (or Angostura bitters)
Essential knowledge: The much-neglected evolutionary bridge between the Manhattan and the martini. A sunset of a cocktail.

Bourbon, Cointreau, Angostura bitters, Peychaud bitters, champagne
Essential knowledge: The most muscular champagne drink you'll ever put to your lips. Watch the barkeep turn the bitters bottles upside down—seven dashes of each. And expect that bourbon to be high-proof.

Rye whiskey, Green Chartreuse, lemon juice, maraschino liqueur
Essential knowledge: A variation on the potent and magical Last Word—the Prohibition-era concoction of lime, green chartreuse, gin, and maraschino liqueur. Whatever you do, don't let one follow the other.

Rye whiskey, sweet vermouth, Cognac, Angostura bitters, Peychaud's bitters and Bénédictine
Essential knowledge: Deserves its place among the other granddaddies, the Sazerac and the old-fashioned. Sip or you'll stumble.

Essential knowledge: An Italian amaro—dark and syrupy with notes of mint, eucalyptus, and shoe leather. Order one for yourself and one for the bartender. Swallow. Don't throw up. You've just made a new friend.