The show begins 15 minutes late.

Just as people are starting to squirm on their bar stools, Nick Kosevich charges into the room.

The spectacle tonight is a cocktail class. The stage is the back bar at Lawless Distilling Co., which is littered with spirits and glasses, cedar chips and marshmallows — all necessary ingredients for one of Kosevich’s semiregular classes at the Minneapolis distillery and cocktail lounge.

“Who’s back from the last class?” Kosevich bellows. A man and woman raise their hands, saying that they’ve made one of his cocktails almost every night since.

“That’s called research and development,” Kosevich quips.

Immediately, he and bartending sidekick Marco Zappia start turning out an impressive lineup of drinks. Kosevich and Zappia — one stout and bald, the other lanky and long-haired, both covered in tattoos — are a sight to behold. They zip back and forth behind the bar in a sort of spontaneous choreography. When Zappia aggressively shakes a cocktail, Kosevich grins and tells the class: “You don’t have to dance, but it helps.”

Kosevich and Zappia are part of the game-changing cocktail empire that is Bittercube — a bitters-making, cocktail consulting and creation company based in Milwaukee. And if this Tuesday night liquor-fuled theater looks like chaos, it’s by design. Kosevich’s classes feel like parties, his inventive drinks like joy rides.

But the atmosphere — like the cocktails — has been carefully calculated. And the over-the-top, fire-scorched, cotton-candy-laced drinks? They’ve been tweaked to the last drop: They’re not just delicious and potent, they’re fun to drink.

Bittercube, which has made Minneapolis its informal home, has developed custom cocktail menus and trained the bartending staffs at 25 bars and restaurants, including Twin Cities hot spots such as Lawless, Can Can Wonderland in St. Paul and the Hewing Hotel in Minneapolis.

Their classes sell out, and they’re in demand to bartend private events. Their bitters are used at hundreds of bars and sold in 36 states and four countries. Their footprint — and their influence — is growing. An apothecary to make their products is expected to debut in June, and they plan to open a Bittercube bar in the Twin Cities in 2018.

By combining radical ingredients, an unorthodox style and unexpected discipline, Bittercube is revolutionizing our cocktail culture.

“Bittercube has definitely elevated everybody’s game, whether it’s conceptual ideas, whether it’s making a martini the right way or it’s an ice program or a different way of learning to shake a cocktail,” said Jesse Held, bar director for Jester Concepts, which owns Monello and other Minneapolis restaurants. “Absolutely, they have changed the way people go about constructing a cocktail or constructing a menu.”

Drinking stories

On a recent weekday, Kosevich took a break during lunch to sip a drink, letting his fire-orange handlebar mustache steep in the frothy liquid. He rolled the sip around in his mouth, eyed the bartender and started firing questions.

Was there an egg in it? How much citrus? Rice syrup? Did he consider adding sparkling wine?

Five fixes later, the drink was ready to join Cafe Alma’s custom cocktail menu.

“It’s called Bolivia,” Kosevich said of the drink that uses Bolivian brandy as well as four of the South American country’s exports; rice (syrup), tangerines, silver and olives (silvered olives). “We’re taking the story of a region and we’re turning it into a cocktail.”

With Bittercube, there’s usually a story.

Take Starry Night, another creation on Alma’s list. Here’s how Kosevich tells it: He walked outside on a bitterly cold night and came to work the next day telling Zappia, Bittercube’s director of training, that he wanted a drink that tasted — and looked — like the clean, sharp winter air. The result? A vodka concoction tinged with charcoal and edible glitter.

“That’s my job now,” Zappia said. “The Nick Whisperer.”

It’s clear that creativity is key to Kosevich’s success.

At Lawless, the drinks menu Bittercube created includes “crocktails,” which are served in their own mini crockpots. At Can Can Wonderland, Kosevich & Co. created a drink that arrives with a sandbox of sugar, and another that looks so much like a potted plant that it concerned a health inspector — until he realized the “dirt” was made from Oreos.

But drinks are only part of the show.

Kosevich, a native of Faribault, Minn., who lives in Minneapolis, travels about half of the year. When he’s in town, he often can be found behind Twin Cities bars, clad in Crocs and a colorful apron, slinging drinks and one-liners, filling the room with his bellowing laugh.

Behind the extravagant beverages and larger-than-life personas at Bittercube are years of long hours, hard work and a meticulous approach to detail, Kosevich said. Rising from behind the bar to the head of an up-and-coming company has required not just showstopping confidence, but attention to the minutiae that many drink peddlers brush past.

“It’s undeniable that we’re trendsetters,” Kosevich said. “It’s undeniable that we’ve changed the way people drink in this culture and the way people make drinks in this culture.

“And there’s a systematic approach to that.”

Born of desperation

There wasn’t, however, a systematic approach to starting Bittercube.

In 2005, Kosevich had decided to give up the restaurant life and go back to school at the University of Minnesota.

To study English.

“I had fallen out of love with the restaurant business,” said Kosevich, who briefly studied theater at the U after high school. “I never really looked at it as my career — it was the means to an end.”

That changed at Town Talk Diner. That’s where Kosevich met Aaron Johnson and Tim Niver, who were then co-owners of the Minneapolis drinking destination. Kosevich said the two taught him bartender bravado and how to craft cocktails.

“It was a wild time,” Kosevich said. “It felt like we were getting away with something every night.”

It was there that Kosevich met Ira Koplowitz, who became his business partner and co-founder of Bittercube.

Koplowitz, a bartender at Chicago’s groundbreaking Violet Hour, was visiting the Twin Cities to check out the cocktail scene when he stumbled across Town Talk. The duo struck up an instant friendship, and Kosevich soon visited Koplowitz in Chicago, where they checked out the local watering holes.

“From the day we met, he was the first person I listened to,” Kosevich said. “You get [set] in your ways, and I thought I was hot.” After Chicago, “I left with my tail between my legs. I thought, ‘I don’t know anything.’ ”

In 2009, Kosevich and Koplowitz left their bartending jobs to open their own cocktail bar in Milwaukee. It didn’t last. Not wanting to slink back to their old jobs, they dreamed up Bittercube.

To fund their fledgling company, they picked up bartending shifts around Milwaukee, pumping most of their meager earnings into Bittercube. After their shifts, they would head to a bar, grab a Miller High Life and split a cheeseburger.

“I’m not so much of a hamburger sharer,” Kosevich said. “Times were tough.”

Kosevich admits that Bittercube was “built on desperation. Sheer desperation has been the driving force of everything. Until that moment, I didn’t really understand work ethic, what it meant to give something your all.”

A year later, they landed their first client. Now Bittercube is a fixture in the Midwest cocktail scene and has garnered national attention.

“Not just locally, but people in New York, in Chicago, in San Francisco, they know Bittercube,” Held said. “They’ve put a bigger spotlight on our cocktail community here.”

Why is Bittercube so special?

While the drinks Bittercube creates may seem wacky, Kosevich takes a very disciplined approach to cocktailing. That means no freestyle pouring. Instead, bartenders are put through rigorous training. Kosevich sometimes recommends hiring newbies, who haven’t formed what he sees as bad drink-making habits.

“We use jiggers and measuring cups for absolutely everything,” said Bonnie Fredrickson, a bartender at Alma who was trained by Bittercube. “Consistency is a huge thing. It’s why we use the tools that we do and the pours that we do, even coming down to the way we hold the bottles to ensure things come out at the same rate and air is added at the same rate.”

In fact, Bittercube is in the process of designing a new, more accurate jigger.

Kosevich does encourage the bartenders he trains to think outside the box, but only after they’ve mastered the basics.

“People think that creativity comes from within — dreams and mad genius,” Zappia said. “But it’s never that. Creativity is a community, and a culture.”

When it comes to dreaming up new libations, Kosevich usually comes up with an idea first, then constructs a cocktail around it. At nostalgia-inspired Can Can Wonderland, malts arrive with breakfast cereal on the rim of the glass. Tomato soup is repurposed as a base for the Wonder Mary. A drink called Happy Birthday includes cream cheese frosting, sprinkles and a popper that explodes after the bartender sings.

Bittercube’s mission is more than just devising elaborate drinks — it’s making customers want those drinks. That means creating a cocktail culture that’s more fun than fussy.

“None of it matters if you don’t have butts in the seats,” Kosevich said. “So we’re trying to simplify this very complex thing so we can broaden our audience. And if we keep away the pretension and keep drinks coming out faster than 15 minutes, we have the opportunity to do that.”

After the show

Back at Lawless Distillery, Kosevich and Zappia have shaken, sipped and one-lined the class through a handful of artistic cocktails. Now it’s the students’ turn.

Kosevich places a miniature cast-iron pan filled with cedar chips in front of each of them. Pan by pan, he sets the chips ablaze and the room is suddenly filled with tiny campfires. Class members gasp and giggle as they roast marshmallows to dunk in their last drink of the night — a hot toddy.

“It’s very much theater,” Kosevich said of his classes. “It’s a two-person play. But so is bartending. You have to hold court.”

As Kosevich’s two hours in the spotlight draw to an end, the class members put on their coats and shuffle off, trailing “thank-yous” behind them.

“Thanks, everyone,” Kosevich shoots back. “Hope to see you soon.”

Kosevich has hours of work ahead of him, a pile of scheduling to be done.

He and Zappia head for the door, switch off the lights.

“Curtain drop,” says Zappia.