Logo

Case Study: Black Frost and the Pursuit of “Rum Oil”

Led by a brewmaster with a family legacy, a hunger for knowledge, and a passion for mixed-culture fermentation, Minnesota’s Black Frost Distilling is producing fragrant, old-fashioned rums using half-wild yeast and open-topped wooden fermentors.

Subscriber
Case Study: Black Frost and the Pursuit of “Rum Oil”

When Black Frost Distilling opened in late 2022, cofounder Jace Marti envisioned a distillery that put the flavors of “northern terroir” on display. However, during downtime in the initial stages of the coronavirus pandemic, he began exploring the science of rum—not exactly a big thing in Minnesota.

So, Marti looked to the Caribbean—in particular, to chemist Rafael Arroyo’s research in the early 1930s and ’40s in Puerto Rico. That study led Black Frost to concoct two different rums, both steeped heavily in science and made distinctive by using the distillery’s wooden, open-top fermentors.

Marti is a brewer, and his family still runs August Schell’s Brewery in New Ulm—the second-oldest family-owned brewery in the United States, after Pennsylvania’s Yuengling. Schell’s began using local barley in its helles lager about a decade ago, and that’s when Marti began to wonder about using local crops in the production of spirits.

Marti revels in fermentation and spearheaded the mixed-culture program at the brewery’s Starkeller taproom. Growing up in New Ulm allowed him to befriend local farmers—including Nate Gieseke, a sixth-generation farmer whose background neatly parallels Marti’s status as a sixth-generation brewer. Given their interests, cofounding a distillery just made sense—and Gieseke could grow whatever they needed.

“Looking back, it sounds weird, but it was COVID times,” Marti says, “and we had to find something to do.”

As Marti dove into Arroyo’s research, he began planning how he wanted to produce heavy, high-ester rums.

This article requires a subscription

Subscribe today to continue reading and unlock unlimited access to our premium brewing content.

What you get with your subscription

3,000+ exclusive articles
700+ tested recipes
Digital magazine issues
100+ brewing video courses
Expert brewing guides
Cancel anytime
Already a subscriber?

Plans start at $4.99/month • 30-day guarantee

Trusted by thousands of craft beer enthusiasts and brewers worldwide