Pucker Up: Sour Beers are Here to Stay

August 7, 2019

Tart and fruity. Funky and acidic. Light, but citrusy. The beer scene isn’t the same as it used to be, and one thing’s for certain – the trend towards sour isn’t going anywhere, anytime soon. For a little lesson in the science of sour, we spoke with three of Southern Minnesota’s brightest brew masters who are bringing the trend to breweries near you.

Schell’s Starkeller – New Ulm, MN

2215 N Garden St, New Ulm, MN

With rich history dating back to the late 1800s, Schell’s is considered something of a legend in southern Minnesota. Carrying on the family tradition is Jace Marti, a sixth-generation Schell, who got his start at the brewery in high school and has since worked his way up to assistant brewmaster.

Marti’s initial interest in sours came from years of home brewing. In 2011, he left for brewing school in Berlin, Germany, and after six months of schooling and two internships spanning an additional three months, he was back in New Ulm and ready to bring the taste of northern Germany’s Berliner Weisse-style sour to his homeland.

The introduction of this style of beer presented an opportunity to reuse 10 Cypress wood lagering tanks, purchased in 1936 by the brewery and eventually discarded for steel tanks. These old wooden tanks provided the perfect solution, as this new line of beer – dubbed the Noble Star Collection – needed a vessel that could breathe, something their steel counterpart was just not capable of.

The restored tanks surround the walls of the latest addition to the Schell’s brewery, the Starkeller, a completely separate taproom in New Ulm dedicated to Marti’s sours.

To start, these beers use a method called “mixed culture fermentation,” a technique that differs greatly from a “clean” brewing process. For one, it takes much longer – while a standard lager can take two to three weeks to come to fruition, a mixed culture brew can take up to three years from start to release date.

The wort – the liquid product of the malted grains – is pasteurized, brewed, and then cooled to bring back to the Starkeller. The brewers then pitch a culture of yeast and bacteria and let it ferment for about a week. At this point, the mixture tastes almost sickeningly sweet, due to the lack of hops used in the process.

Once the mixture is moved to the old wooden tanks, the brewers add another yeast called brettanomyces. Over the next year, the brew will begin to develop more of an interesting, spicy and fruity bouquet. Then, it’s hand bottled, pitched with more sugar and yeast, and left to rest for two months.

It’s a tedious process, but from a portfolio offering standpoint, the Noble Star Collection offers a very different taste – and one that is nearly impossible to replicate. Framboise Du Nord was the first of Marti’s Berliner Weisse sours that Schell’s recreated. Though it has subtle differences, it is still very close to the original.

“This is all a part of the mixed culture fermentation,” says Marti. “You are letting wild yeast make the culture for you – it does what it wants, and you get what you get. There are ways to create consistency through blending and we are always working on improving that.”

Montgomery Brewing – Montgomery, MN

306 2nd St. NW, Montgomery, MN

The historical Montgomery Brewing building opened its doors in the late 1800s, and in 2000 was purchased with the intent to renovate the building for residential apartments. Charles Dorsey, son-in-law of the building’s owner, took this opportunity to bring his homebrewing inside of the facility – and back to the city of Montgomery in northern Le Sueur County.

Now founder and owner of Montgomery Brewing, Dorsey officially opened the doors of Montgomery Brewing – a cozy 1,500 sq ft of space inside the old bottling house – in December 2015. Nearly three years later and the microbrewery has expanded its offerings to include sour beers – starting with the launch of the Raspberry Sour in April 2019, to the Peach Sour, which is now on tap.

Dorsey uses a different method, known as “kettle souring,” to bring his sour brews to fruition. Rather than a wooden barrel (and a few years, mind you,) the mixture is soured in a steel tank using a special bacteria called “lactobacillus.”

This bacteria is a probiotic that converts sugars to lactic acid, and can take anywhere from 12-30 hours to lower the pH to the level of sour that is desired. Once the anticipated level of tartness is achieved, the normal brewing process is resumed. Boil; add hops; cool wort; pitch yeast and let ferment. Unlike mixed culture fermentation, a traditional kettle sour can be turned around and enjoyed in a matter of three to four days.

This method has allowed Dorsey to create a beer for the non-drinkers that visit his taproom and satisfy the palate of the ever-changing market for interesting new kettle sours.

Dorsey is confident the trend isn’t going to sour anytime soon.

“Five years ago, the craze was more hops, more International Bitter Units (IBUs) – who can push the bitterness boundaries,” he says. “Back then they said IPAs won’t last. Today, it’s who can make the best beer that doesn’t really look or taste like traditional beer. Juicy, hazy, IPAs. Hops so fruity in character that you think fruit was added. Triple fruited kettle sours. I love that people are just looking to expand their idea of beer and that’s what makes this job fun.”

And though sours are relatively new to this small-batch brewery, they have been an immediate success. Currently, Montgomery Brewing is testing one recipe and learning what flavors different fruits provide and how different pH levels affect the sourness.

Ultimately, their overarching goal — sour or not — is to produce beers they are excited to share with their customers. If they don’t like it, you won’t find it on tap.

Forager Brewing – Rochester, MN

1005 6th Street NW, Rochester, MN

A casual dining venue and brewery in Rochester, Forager Brewing – which opened in September 2015 – offers it all.

Co-owner and Head Brewer Austin Jevne was brewing beer at home and picking wild Minnesota fruits for sours years before its inception.

Forager has been making sours since the beginning, and its sour program still sources local berries. Guests can oftentimes find Jevne foraging (hence the name) in the woods in search of the brightest and ripest wild berries to use in his brews.

Jevne and his crew use three different methods of producing sours: mixed culture fermentation, kettle souring (used for its Saisons and sour red ales,) and the third – spontaneous fermentation — which is brewed according to a traditional Belgian process called “lambic.”

The process and ingredients of spontaneous fermentation are very different than those used in “clean” beer production. The beer is pumped into a shallow vat and left to cool outside overnight, allowing the micro flora present in the natural environment to inoculate the wort.

No yeast or bacteria is added — only the naturally occurring yeast and bacteria in the environment ferments the mixture. It is then transferred to oak barrels where it ferments very slowly, taking anywhere from one to five years to reach the desired pH level.

Jevne says their first 100% spontaneous ales will start being released this fall.

“I think that people willing to try a very specialized local product will love our spontaneous ales when we release them,” he says. All the fruits in their spontaneous ales are sourced in Minnesota or Wisconsin.

On tap now is their popular “Gummies Make Us Likable,” a Berliner Weisse- style beer made with passion fruit, mango and pink guava, and a tiki-inspired kettle sour called “Tiki Killers,” a pink brew dosed with pink dragon fruit, mango and passion fruit.

If not for its unique brewing processes, come for the tasty, award-winning beer that gets them recognized all over the world. Stay for the delicious food pairings and fun-loving crowd!


By Meghan Rook


SouthernMinn Scene | editor@southernminnscene.com |
115 5th Street West Northfield, MN 55057