The best big brewery in America has a staff of 12, distributes only in its home state and produces 11,000 barrels a year—less than Boston Beer Co. of Sam Adams fame churns out in a couple of days.

The AC Golden crew consists of six brewers, led by a head brewer who used to work in wine and has a candy invention to his credit. The brains behind it all is a marketing wiz with a Kentucky drawl and little patience for critics who don’t think his guys are craft brewers.

AC Golden co-founder and president Glenn “Knip” Knippenberg was honored—and humored—after winning large brewing company and large brewing company brewer of the year honors at the 2014 Great American Beer Festival in September. As a tiny craft-beer incubator within MillerCoors, AC Golden competes with the big boys, even though its brands are never mentioned in earnings reports.

The truth is AC Golden, while small, can do what it does only because it is part of MillerCoors. The parent company, which reported $1.3 billion in net income in 2013, provides access to ingredients, technology and capital that small start-up breweries can only dream of.

“We don’t have to be an overnight success,” Knippenberg said in his office tucked inside the Coors plant on the banks of Clear Creek in Golden, Colo. “We have failures. We have winners. They give us the time to do this right.”

Pete Coors, the great-grandson of brewing entrepreneur Adolph Coors, came up with the idea of an incubator brewery after seeing untold millions lost on failed new brands.

To launch the venture, Coors recruited Knippenberg, an industry veteran who started work at Pabst Brewing out of college and joined Coors as it expanded eastward. In 2007, AC Golden launched on the premise of patiently building a brand with a dedicated sales force in a small territory with the goal of growing it to a point where MillerCoors would take it over.

Knippenberg struck upon the idea of a flagship brand that would tap into the “buy local” movement—an accessible but out-of-the-box amber lager brewed exclusively with Colorado ingredients he could market as “Colorado’s homegrown beer.”

Finding barley was not a problem, as the Coors name is all over barley fields in Colorado. Hops were another matter. To say Colorado lagged behind the Yakima Valley is an understatement. The state’s hop crop was virtually non-existent beyond a couple of hobby farmers. So Knippenberg approached farmers and promised to wildly overpay for any hops they managed to grow, a subsidy for the steep labor and capital costs to start.

The recipe for Colorado Native Amber Lager was born on a scribbled-upon napkin at a Golden bar. Brewer Steve Fletcher says the target was a hoppier amber, something citrusy and “happy.”

In an era of hop-forward ales, Colorado Native Amber Lager is a hit, with sales up 18 percent in 2014, Knippenberg says. This success was welcome, but it also created a conundrum. Under a prearranged deal, AC Golden was to turn over Colorado Native to Tenth and Blake, MillerCoors’ craft beer and import division of MillerCoors, once production hit 10,000 barrels.

As that came within reach, Knippenberg convinced Tenth and Blake president Tom Cardella to keep the brand with AC Golden for at least three more years to grow the brand and the Colorado hop crop. Knippenberg promised to increase sales 2.5 times by introducing new beers under the Colorado Native label. A crisp, hoppy India pale lager rolled out in the fall, and an easy-drinking golden lager—a 2014 GABF silver medalist—is coming this spring.

Nothing about the AC Golden brewhouse screams “corporate.” The 30-barrel system was built in the 1970s as a pilot system. The half-million visitors a year who take the Coors tour never see AC Golden’s copper kettles, its windowless maze of passages and stairwells, or the century-old copper and brass desk one of the Coors brothers once tried to commandeer as a wet bar.

Knippenberg likes to say AC Golden is not independently owned, but it is independently operated. No one from South Africa or Milwaukee is hosing down the floor, building hop trellises or hunting down peaches to pitch into a barrel of sour beer. Along with the six brewers, the staff includes Knippenberg, an operations manager and a sales crew of four.

Head brewer Jeff Nickel graduated from Iowa State University with a degree in biology and a minor in food science. After graduation he worked in the candy business for the Willy Wonka Candy Co. and the company behind Trolli Gummi Bears. Nickel can even claim to have invented a candy: Brite Crawlers, neon-colored sour gummies that resemble earthworms.

Nickel left the world of sweets to enroll at the University of California, Davis, where he earned a master’s degree in enology, the study of wine and winemaking. He worked at a couple of wineries before drifting into beer, moving to Colorado to open Big Horn Brewing, or C.B. and Potts. Nickel went to work for Coors in 2000 as a quality-control chemist, left to join Oskar Blues for a few years and then returned to AC Golden in 2010.

“I’ve got the best job in the world,” Nickel says. “I work with great people, get to brew beer and create new styles on a small scale, yet have all the resources of a large brewery to help.”

Yet to some, AC Golden’s beer is “crafty,” not “craft.” In 2012, the Brewers Association trade group issued a statement accusing multinational brewing companies of “deliberately attempting to blur the lines” between their brands and small, independent craft brewers in the BA.

The statement stung AC Golden, where brewers often share ingredients and lager know-how with other small breweries. AC Golden also has won raves from beer geeks for barrel-aged sours, imperial stouts and other specialty beers in its small-batch Hidden Barrel Collection, which probably never will be snatched up by MillerCoors but gives AC Golden added credibility.

Consider Kriek, a 5.5% ABV sour with flavors of cherry pie, toffee and cranberry. AC Golden brewers traveled to western Colorado to hand-pick sweet and sour cherries that survived a hail storm, then pitted them by hand at the brewery. The cherries were pitched into oak barrels with a sour base beer, bacteria and wild yeast.

“We’re absolutely craft,” says brewer Jason Meherg, who has worked at Abita Brewing in Louisiana and Avery Brewing in Colorado. “Some other guys may not give us the credit because we are part of a larger brewery. We know we make craft beer.”

Knippenberg calls the BA statement “unfortunate. I don’t belittle any brewer, large or small.”

Julia Herz, the BA’s craft beer program director, says the goal was “absolutely not” to belittle anyone, but to call for truth in labeling and marketing.

“Small brewers stand on the shoulders of large brewers that came before them,” Herz says. “And large brewers stand on the shoulders of the brewers that came before Prohibition.”

If all goes as planned, Colorado Native will grow to where it will be enjoyed outside its home state. The small brewery winning big recognition just needs to get a little bigger first.