The co-founder of a heralded craft brewery, Greg Koch of Stone Brewing, has said he will never sell out to "Big Beer." Now, with a lawsuit, he's attempting to prove it.

Stone Brewing is taking MillerCoors to court, alleging that the beer giant is trying to co-opt its name.

In its suit filed this week in federal court in San Diego, Stone Brewing, based in nearby Escondido, Calif., alleges trademark infringement that occurred when MillerCoors rebranded its Keystone Light beer.

MillerCoors denies Stone's allegations, which it labeled a "publicity stunt."

The beer giant's revamping of Keystone Light last April was done to emphasize the word "Stone," the lettering of which covers much of a side of a can, Stone says in its suit. "Keystone’s new can design overtly copies and infringes the Stone trademark." 

Packaging for 30-packs of Keystone cans have the word "Stone" displayed prominently, without "virtually any reference to 'Keystone' at all," says the suit, and "the packaging is designed to create a 'wall of Stone' when displayed in stores."

An escalating social media campaign on Facebook and Instagram — and ads on sites such as ESPN.com — refers to Keystone as Stone. "Such mass advertising broadcasts the infringing 'Stone' name beyond Keystone’s immediate social media audience to the general public at large," the suit says.

Stone is the ninth-largest craft brewer in the U.S., according to the Brewers Association. It’s the 17th largest brewery overall when you add in all U.S. brewers including Anheuser-Busch, MillerCoors and Pabst.

In 2017, Stone produced 12 million gallons of beer and recorded total revenue of $242 million, the company says.

The U.S. Patent and Trademark Office turned down MillerCoors' attempt to register "Stones" in 2007 and the company "instead abandoned its application, admitting that confusion with Stone beer was likely," the suit says.

This current campaign is an attempt, Stone Brewing says in the suit, "to capture the Stone mark and associated goodwill ... (and) to mislead consumers: about the source of MillerCoors’s 'Keystone,' the heritage of Stone’s beers, and whether Stone is just another member of MillerCoors’s craft brew holding company."

But MillerCoors considers Stone's suit "a clever publicity stunt" launched with a "multi-camera, tightly-scripted video" of Koch. "Since Keystone’s debut in 1989, prior to the founding of Stone Brewing in 1996, our consumers have commonly used ‘Stone’ to refer to the Keystone brand and we will let the facts speak for themselves in the legal process,” MillerCoors' spokesman Marty Maloney said.

In the video, Koch holds up a Keystone Light and notes that "Stone" and "Light" are "two words you would never use in association with our company."

MillerCoors' strategy is also part of a larger war being waged by Big Beer against independent, craft beer, Stone says in the suit.

In the $100 billion-plus U.S. beer market, sales of major brand beers have generally been flat, but craft beer sales have continued to rise, although at a slowing rate. In recent years, Anheuser-Busch InBev and MillerCoors have both acquired smaller breweries, too.

MillerCoors established a craft beer and import division in 2010, which includes former independent craft breweries including Hop Valley Brewing in Eugene, Ore., Saint Archer Brewing in San Diego and Terrapin Beer in Athens, Ga.

This is part of megabrewers' strategy "to wrestle back market share," Stone says in the suit. 



Stone has been expanding its reach. In 2016, it also opened a brewery in Berlin and a production brewery in Richmond, Va.

Follow USA TODAY reporter Mike Snider on Twitter: @MikeSnider.