One-hundred-fifty-four years of Minnesota history are rooted in a bluffside estate overlooking the Cottonwood River in New Ulm. In a sense, it’s a pastoral time capsule and an emblem of the American dream — the inspirational birthplace of a German immigrant’s success, which has survived six generations of triumph and tragedy.

But last Saturday people just wanted to party there.

“The fun meter’s in the red,” declared Jesse Kirkeeide of Plymouth, pointing to a novelty pin on his jacket reiterating that good-time statement. His “Party Time” glasses and flamingo hat hammered home the point.

Roughly 4,500 foolhardy, layered-up beer drinkers were convened outside the August Schell brewery amid subzero temperatures for the 28th annual Bock Fest. “What else would you be doing when it’s negative-5 degrees outside in Minnesota?” cracked Schell’s assistant brewmaster Jace Marti in the brewery’s rustic lodge-like break room.

Outside, the Carhartt- and hunting-orange-clad masses were jamming out to polka, wolfing down brats and hoisting brews with an admirably ridiculous “What cold?” attitude. It’s a classic Minnesota scene. And Schell’s is a — if not the — classic Minnesota beermaker, one that also controls the iconic Grain Belt brand. The little red-brick brewery has withstood the Dakota War of 1862, Prohibition and the Bud/Miller/Coors market takeover that shuttered many small breweries in the 1970s. Now Schell’s is doing its part to stay fresh and relevant amid Minnesota’s craft-beer renaissance and an influx of startup brewers.

“We’re making a real concerted effort to get that word out: Take another look. We’re innovative,” said Schell’s President Ted Marti, Jace’s father, by phone. “We’ve been innovative for 154 years. Sometimes it’s easy to forget somebody that’s been here a long time.”

Old yes, stodgy no

In the contemporary craft beer world, where big-tasting brews with cheeky names are king, Marti admits the perception of German beer can be “old and stodgy” — an image he said Schell’s has worked to change over the years. Just last month the country’s second oldest family-owned brewery got a bit of a makeover, launching its “German craft” campaign and announcing a partnership with 89.3 the Current for a limited version of Schell’s Zommerfest (available this spring in hipster-approved tallboys).

But don’t confuse a collaboration with a taste-making indie radio station, plus a few retro-chic bus shelter ads, for Dylan going electric. The Martis know their Deutschland lineage is their pumpernickel bread and butter.

“There are so many craft breweries out there today, and you’ve got to find a way to stand out,” Jace Marti said. “What makes us unique is our history and our heritage. We’re going to focus on lagers and German-style ales. That’s what we’ve hung our hat on.”

Inside Schell’s time-tested brewhouse, he and brewmaster Dave Berg aim to blend the old and new schools. Commemorating the 30th anniversary of Schell’s Pils — a three-time medalist at the Great American Beer Festival that Jace calls the brewery’s “first foray into craft beer” — Schell’s released a special-edition sampler pack Thursday, featuring the original 1984 pilsner recipe, its current version, plus two experimental riffs on the Minnesota staple. The mash-minded duo also is introducing a hopped-up Arminius lager, named after a Germanic warrior better known as Hermann the German, whose statue looms over New Ulm.

Last year’s Noble Star Collection dug up suds history while playing into the current sour-beer trend — popular among IBU-fatigued beer geeks. Focusing on the relatively defunct Berliner weisse style, the series has produced a pair of knockout brews, including the tart and effervescent Star of the North, which Draft Magazine dubbed one of the top 25 beers of 2013. Around the end of the month they’ll start bottling a Märzen weiss, which they teased at Winterfest (look for a cherry-aged version this fall).

“It took a long time to convince my dad to do it,” said Jace, the eldest of three sons, with a satisfied grin.

The beers’ pucker is derived from a wild yeast strain that can contaminate other batches, making it a somewhat risky endeavor. The funky yeast is added during a secondary fermentation in refurbished 1930s cypress tanks, which barely fit into the brewery’s high-ceilinged cellar.

“It’s like, ‘This is the biggest hot tub I’ve ever seen!’ ” said Berg, dwarfed by the towering 140-barrel tanks.

Officially a craft brewery now

While Schell’s bills itself as Minnesota’s original craft brewer, the Brewers Association, a national craft-beer group, hasn’t always agreed. In December 2012, it included Schell’s on a list of “non-craft brewers” that it later pulled after some controversy. The brewery, born in 1860, was pegged as not “traditional,” because some of its American lagers contain corn, in accordance with how they were made out of necessity more than a century ago.

“It’s frustrating because the story doesn’t die,” Jace Marti said, chuckling. “People look to the Brewers Association as a resource. When they make this black list of breweries you should not buy from for whatever reason, it hurts our business. So I end up spending a lot of time educating people and telling them the whole story.”

But on Monday the undying story took a favorable spin for the Martis. The Brewers Association announced a revised “craft brewer” definition acknowledging that the use of adjuncts (like corn) is “quite literally traditional, as brewers have long brewed with what has been available to them.”

“Obviously, we’re happy they made the change,” said Ted Marti, a former board member for the association’s predecessor. “We’ve never doubted the fact that we are a craft brewer — and certainly a traditional brewer.”

Regardless of labels, Minnesota’s most senior brewery isn’t ready to croak anytime soon. The Martis are juggling several expansion and renovation projects that will push production capacity from 130,000 to 160,000 barrels per year. “There’s obviously lots of interest in everything new, new, new, but the old classics never go away,” Ted said.

And, hey, they still throw a good party.