The Old-Fashioned isn't just a classic cocktail. Really, it's the classic cocktail. And two centuries after the sacred combination of spirit (usually bourbon or rye whiskey), bitters, sugar and water graced its first glass, it remains a memorable elixir.

"For us, it's the perfect cocktail," said Nick Kosevich of Bittercube and Eat Street Social. "It's the cocktail that started it all."

Kosevich doesn't just wear his Old-Fashioned love on his sleeve. Last year the veteran barman and bitters maker had an image of an Old-Fashioned tattooed on his right arm. While modern bartenders have taken the art of drink to complicated heights, he says he measures bartenders' merits by how they make the basic-by-comparison Old-Fashioned.

"It's the cocktail I'll order anytime I go to a new bar or sit in front of a new bartender," he said. "How you interpret the Old-Fashioned means a lot."

Its permutations — both glorious and abominable — are endless. By its minimalist blueprint, perhaps no other cocktail gives a better spotlight to the base spirit (whiskey or otherwise).

"I think people tend to overcomplicate it," said Adam Gorski, an Eat Street Social alum who was recently tapped to lead La Belle Vie's bar. "For me, it's: Showcase the spirit, add enough sugar to it to make it so it's palatable once it's diluted, so as little sugar as you can, and then bitters just to accentuate it."

The Old-Fashioned has been remixed and riffed on since before it was, well, old-fashioned. Once simply known as "the whiskey cocktail," the drink earned its throwback moniker after bartenders started gussying it up with liqueurs, well before the turn of the 19th century. One of the earliest renderings was the "improved whiskey cocktail," which added absinthe and cherry liqueur (in downtown Minneapolis, Saffron's superbly peppery Black Betty Old-Fashioned is perhaps a closer descendant of the improved whiskey cocktail).

From whiskey to gin the Old-Fashioned formula — 2 ounces spirit, a quarter-ounce simple syrup and a dash or two of bitters — noble in its simplicity, plays well with most liquor. Oaxaca Old-Fashioneds leverage tequila and mescal for a smoky sipper, while a rum Old-Fashioned makes a sweeter treat that sings with falernum (a clove-flavored syrup) or orgeat (almond-flavored syrup) instead of the standard simple syrup.

Though you won't find it in many cocktail bars, those wacky Wisconsinites are partial to a gooey brandy version with muddled cherry and orange and a splash of soda. "Some of my staff is from Wisconsin, and they'll have friends or family come in and wonder what we're doing," said Andrew Campbell of Bradstreet Craftshouse with a chuckle, noting the Old-Fashioned's fruit-muddled form was rampant in the 1990s.

While the citrus smashing might be best left in the Clinton era, pinching an orange peel over the drink to express its oils (sometimes through a flame) for aroma and a non-cloying hint of flavor has become de rigueur. A follow-up swipe of the glass rim is a nice touch, too.

With the spirit taking center stage, selecting the right bottle is important, and Campbell and Kosevich caution that price isn't always synonymous with quality. Bradstreet uses Bulleit bourbon in its classic Old-Fashioned. At Eat Street Social, Kosevich's bottled house version, dubbed Of the Older Fashioned, is seasoned with a trio of his Bittercube bitters and uses Old Weller Antique 107. Both that and Bulleit are midrange whiskeys that run about $25 a bottle. Still, it's hard to miss with a top-shelf whiskey.

"Using a high-quality product in any cocktail is important," Kosevich said. "But these are the types of drinks that we're going to pull down the Pappy [Van Winkle] for and make an Old-Fashioned with it, for sure."

With the venerated cocktail seemingly as popular as ever (Eat Street Social sells around 24,000 per year), the Old-Fashioned and all its idiosyncratic variations are ingrained in imbibing culture.

"It's an exciting thing that people are tasting in a new way — or an old way," Campbell said.

Michael Rietmulder writes about beer, spirits and night life.