The first rule of business — any business — is this: Do what you do well.

And what Chicago does well is drink.

Oh, there are other things to be sure (architecture! comedy! baseball!), but in this city, booze is as much a business as it is a way of life. Perhaps that passion stems from Chicago’s history. It was, after all, a bootlegger’s playground during Prohibition.

After bellying up to some of the city’s best bars, I can say the tradition lives on. The craft cocktail movement, which reimagines classic drinks using modern techniques and house-made ingredients, is alive and well here.

As an eager imbiber, I was ready to explore, yes, but my quest to sip at some of Chicago’s more contemporary cocktail bars also turned out to be quite a history lesson. Places that once operated as speak-easies and bathtub gin houses during Prohibition now offer unique opportunities for liquid lessons.

“When I say to people, ‘Chicago has its roots in beer and booze,’ they don’t even realize they’re learning,” Elizabeth Garibay, public programs manager at the Chicago History Museum, told me. “In Chicago, it’s so easy to make the connections between history and drinking. It’s just part of our culture.”

The museum runs monthly trolley tours highlighting the city’s history, a past that’s inextricably linked with alcohol and its consumption. During Prohibition, Al Capone, Bugs Moran, John Torrio and Hymie Weiss did their part to make sure that Chicago — and the rest of the country, for that matter — remained well-watered.

There’s still a dedication to that notion. Local bartenders use old-fashioned building blocks — house-made drinking vinegars called shrub, reconstituted dried fruit, bitters, preserves, local cider and tinctures, among them — to push the envelope and to put Midwestern winter on the run. There’s not a sliver of stone fruit in sight, but it’s that very absence that drives creativity behind the bar.

As a native Angeleno, I was admittedly a bit skeptical about the city’s genuine niceness on my visit here last month. Why are these bartenders so friendly? And why is everyone smiling when there’s not so much as a palm tree or Technicolor sunset in sight? It could be because Chicago was having the mildest winter in years. Or maybe it was the booze talking.

If it was the latter, here’s what it said: “Stop by the Sable and the Aviary. Don’t forget the Twin Anchors, the Pump Room and the Bedford. You’d be foolish to miss the Violet Hour or the Whistler.”

So what could I do but listen? It didn’t help my liver that I was staying at Hotel Palomar in River North, home to Sable, one of Chicago’s better cocktail bars. The program is headed by Mike Ryan, a die-hard cocktailian with a culinary background. He believes in gently nudging customers to experiment with new flavors, challenging the palate without a hint of snobbery.

“If you’re limiting yourself so that you can only drink one thing, you’re limiting your own possibilities,” Ryan says. “We’re here to help you break yourself free of some of those shackles.”

That shackle-busting is reflected in Ryan’s “Cocktails for Thinking” menu, which features such libations as the Stockyards, made with a cinnamon-driven reposado tequila, Madeira, maraschino liqueur and Peychaud’s bitters — basically booze on top of booze. But like alchemy, it all comes together to make a well-balanced, subtly smoky cocktail. The drinks at Sable showcase his ability to layer flavors, perhaps because of his years as a chef in fine dining establishments.

I also found that culinary influence at the Aviary, a cutting-edge cocktail bar developed by Grant Achatz and Nick Kokonas. Chefs are culled from Achatz’s three-Michelin star Chicago restaurant,Alinea, to prepare liquid tasting menus. The results are mind-bending.

The Aviary flips the traditional tasting menu on its head. Here, cocktails take center stage: They’re served with nibbles that complement the drinks’ flavor profiles. During the seven-course degustation, sips were sent out in architecturally inspired glassware. Ginger-spiked apple brandy cider arrived in a metal-lined glass canteen. Shortly after, a rocks glass encased by a plastic pillow was placed on my table, then cut open, sending forth a cloud of lavender-scented vapors. Then came a warm Rooibos tea cocktail (the Rooibos tea leaf hails from Africa) delivered in a coffee siphon. Using that device’s vacuum pressure, the drink’s gin and maraschino components were infused with flavors from lavender, citrus, cinnamon and the tea leaves.

With all this highfalutin’ boozing, I was hard-pressed to imagine a day when drinking wasn’t legal here. But that doesn’t mean it wasn’t going on: During Prohibition, Chicago and a few other Great Lakes cities were distribution hubs for alcohol coming from Canada and U.S. moonshiners. Speak-easies and brothels flourished in the Levee District, near the South Side of Chicago. Some of them — the speak-easies, I mean — are still around. The history museum’s historic bootleggers tours visit four Prohibition-era watering holes still in operation.

Some, like the Green Door Tavern, the Kerryman and Marge’s Still, were known for their bathtub gin (which may or may not have been made in a bathtub). The Twin Anchors, a bar now known for its strict no-dancing policy, once operated as a speak-easy but disguised itself as a soda fountain. If you’re tall, as I am, getting through the cubby-sized trap door that the Anchors’ owners used to make a quick exit during raids is no small feat.

It’s said the Anchors became the second home to Frank Sinatra, who was not shy about his love of drink or Chicago. He was also a regular at the Pump Room, which recently got a face-lift, courtesy of hotelier Ian Schrager. Sinatra’s private table remains, as does the swinging vibe. The room is gently illuminated by hand-painted Italian light fixtures that resemble planets floating in the night sky. On Saturday nights, the Pump Room hosts a supper club where the hip crowd tosses back well-crafted drinks, including the Old English Gentleman, made with Dewar’s White Label, tobacco syrup, fresh lemon sour, sweet vermouth and egg.

The Bedford in Wicker Park is another made-over joint. The converted Art Deco bank vault is home to some of the city’s best cocktails and comforting vegetarian food. It also hosts an industry night on Mondays, when travelers can mingle with the city’s restaurant staff. Chefs and bartenders are drawn by classic drinks and the presence of Fernet Branca on tap. This Italian liqueur, which is made with several herbs and spices, has a cult-like following, thanks to what’s said to be its digestion-promoting properties and unique taste, which reminds me of bitter black licorice and Listerine warmed over a campfire.

Also popular among local industry insiders is Jeppson’s Malört, a distinctively Chicagoan distillate made from wormwood, used in absinthe. Bartenders around town challenge themselves to make something potable with the firewater, which has the bite of citrus pith and the burn of bootlegged moonshine. Each time I revealed my out-of-town origins, bartenders tried to push the stuff on me. I’m now an unofficial Chicagoan.

One of the best iterations is the Wicker Park Sour at the Violet Hour, a hipster bar just off the Damen stop on the blue line. Here, Malört is combined with grapefruit, honey syrup, egg white and angostura bitters. A less toxic tipple on the menu — and one of my favorites of the trip — was the bourbon-based Woolworth Flip, whose frothy sarsaparilla notes come off as an adult root-beer float.

The Whistler is a quick cab ride from the Violet Hour, a low-key watering hole that also operates an indie record label, doubling as a venue for local musicians. The menu is small and the drinks are gimmick-free. The vibe at the Whistler is decidedly homey, like Echo Park minus the I-know-better-than-you attitude.

After trying the Elk’s Own, a wintry mix of Old Heaven Bonded Bourbon, ruby port, Cynar, lemon, egg white and a walnut liqueur rinse, I can see why it has garnered so much attention. But here it’s about hospitality, approachability and that quintessential Midwestern charm.

“It’s always popular to be doing something honest,” says Robert Brenner, a co-owner of the Whistler. “We are a city that’s not content with mediocrity.”

travel@latimes.com