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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.

Louis Livingston-Garcia Jan 22, 2024 - 8 min read

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

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.

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Louis Livingston-Garcia has worked as lead storyteller for Crafted for All, a consulting firm and professional development platform that fosters inclusive, equitable, and just spaces and experiences in the craft-beverage sector. He also helms the Tulip and Schooner beer and spirit newsletter for Heavy Table, which creates culinary stories for Minnesota and beyond.