Matt McGinn remembers when he first heard about nitro coffee.

It was like regular cold press, but on tap. And because of the gas, it cascaded from the tap like a Guinness. In 2014, only a few cafes — Cuvee Coffee in Austin, Texas, and Stumptown Coffee Roasters in Portland, Ore. — were serving it, alongside traditional drip coffee.

McGinn was instantly obsessed.

"Oh my god," he thought. "This is going to explode."

He wanted a piece of the action. So McGinn, then an operations manager for Dunn Brothers Coffee, bought a coffee shop in St. Paul and promptly installed beer draft lines, making Quixotic Coffee the first in the state to serve nitro coffee on draft.

Three years later, his prediction has come true.

Once a niche product enjoyed mostly by coffee snobs, nitro cold brew has surged onto the specialty coffee scene, capturing a wide fan base with its smooth flavor, cool-sounding name and quick-pour access. Local cafes and bars have rushed to capitalize on the latest coffee fad.

McGinn's hobby has since become its own company — Blackeye Roasting Co., which is moving into a new 30,000-square-foot cold brew facility as it anticipates selling 6 million cans next year.

"From the start, it felt like we were on the tip of the sphere," McGinn said. "We knew it would be a wild ride."

Now, the big boys are jumping on board. Last summer, Starbucks launched its own version of the trendy drink. In July, the mega chain announced it's pushing the product out to more than 1,500 of its stores by the end of the year.

What's so attractive to coffee drinkers? Well, for starters, the temperature. Nitro is an offshoot of cold brew, a segment of specialty coffee that has seen major growth the past few years. Unlike hot coffees, the cold versions tend to be less bitter and acidic, characteristics that appeal to the mainstream drinker.

Nitro also keeps more of the "body" that coffee nerds rave about. And getting one is as quick as pouring a beer or grabbing a can — a notable difference from the several minutes it can take for baristas to prepare a pourover or espresso drink — for about $4 a glass.

"It's so easy," said Noah Namowicz of Cafe Imports. "If you buy coffee at the grocery store, there is still another step to be completed — you've got to brew it as well. With these cans, you're getting a product that's finished. It's like wine."

The look hasn't hurt either. Because of the infused nitrogen, the beverage rolls in the glass and changes colors as it settles. Instagram has made it legendary.

Big Watt makes a kegged nitro coffee that it serves in its Five Watt Coffee shop in Minneapolis, but it only offers its regular cold press, sans nitrogen, in cans. Lee Carter, one of the company's founders, said that's because he believes nitro doesn't taste the same in a can.

"Putting nitro in a can, I don't think it's a good idea," he said.

Still, when Big Watt sells its cold press coffee in cans to gas stations and convenience stores, they're often asked the same question.

"They want to know 'Is it nitro?' " Carter said. "It's a buzzword, for sure.

"The category is growing so fast. It's people making that push, just trying to get a product out there as fast as they can," he said. "And people buy it because it's cool, it's nitro."

Despite its popularity, not everyone is rushing to join the game.

Greg Martin, owner of the trendy Minneapolis chain Urban Bean Coffee, hasn't taken the plunge into nitro.

"To be honest, it's not even something that people ask for," he said.

It's also substantially more expensive than regular cold brew, Martin said. Five gallons of the non-nitrogenized liquid costs him about $50, he said, while the same amount of nitro cold brew is closer to $100. At most coffee shops, though, the cost of both hover near $4 a glass.

"And you can't charge double the price" of the servings, he said.

There are also plenty of complaints in the coffee community that nitro, like any other cold brew, mutes the beans' complexity and creates a "blank slate" for people who really only want to taste milk and sugar.

"There are some very vocal opponents of it," Namowicz said. "Some people hate [all] cold brew [including nitro] because it strips away some of the things they love about coffee."

With Starbucks making a major commitment to the draft beverage, though, nitro's presence and allure will likely continue to grow.

That's a future McGinn dreams of — when his Blackeye can is sitting next to a Starbucks nitro can on grocery store shelves.

"They're investing millions of dollars into training people what nitro is," he said. "And my packaging is better and my product is better. I think people will gravitate toward it.

"I'm never taking Starbucks' market share, but if I can get even a piece of it, we're going to be worth a ton of money."