History was made last week on South Manitou Island, as a team of nine hardy souls from Mammoth Distilling harvested — by hand— the first crop of Rosen rye to leave the island in over 70 years. The Central Lake-based craft spirits company is leading a charge to revive a prize-winning Rosen rye linked to the Prohibition-era whiskey trade.

The Manitou Island Transit vessel BEAR transported the crew and the harvest back to the mainland, where Mammoth Distilling Founder and CEO Chad Munger says the rye is now at “MSU for cleaning, head selection and evaluation.”

The reintroduction of Rosen rye to the Hutzler Farm on South Manitou, where it was originally planted 100 years ago, will allow Mammoth Distilling to revive a varietal of rye celebrated by legal whiskey makers and moonshiners for its distinctive, superior flavor.

Munger says the quality of this first harvest was as hoped in terms of yield and vigor of seed. In terms of flavor and character? “We have to wait until we distill. Right now we are replanting all the seed we grow to get our crop size up to production levels.” Munger tells the Leelanau Ticker that hand harvesting is exhausting and can even be a bit dangerous. “We had production staff, hospitality staff, marketing staff as well a one of our favorite staff mothers and a friendly local farmer all pitch in on this harvest.”

Whiskey aficionados take note: Expect two years to taste the first Rosen rye Mammoth whiskey.

Here is more from writer Craig Manning, on how Mammoth is sowing prohibition-style whiskey with heirloom seeds, from a story that originally ran in our sister publication Northern Express:

Mammoth Distilling's key to the past is a specific type of whiskey grain: Rosen rye, a celebrated varietal of rye that was extremely popular among Prohibition-era moonshiners — especially in the eastern United States. As Munger tells the story, Ari Sussman, Mammoth’s head distiller, has been “spending a lot of late nights combing the internet for all kinds of knowledge in the spirits area,” looking for new ways to lend unique character to Mammoth’s Michigan-made products. One of those  trips down the rabbit hole brought Sussman to the fascinating history of Rosen rye. 

“He stumbled across some information in the archives at Michigan State University (MSU) of a grain that was brought from eastern Europe to Michigan Agricultural College [former name of Michigan State University] in the very early 1900s by guy named Joseph Rosen,” Munger says.

“[Rosen] came, took a job at Michigan Agricultural College, and brought with him just a pocketful of seeds that would become, eventually, Rosen rye. His dad had sent the seeds with him because it was known where he came from as a very characterful and very highly productive variety of rye.” 

When Rosen showed the seeds to a fellow professor at the college, the professor was intrigued. Together, the two propagated the seeds, planted them in a greenhouse, grew Rosen rye in college greenhouses, and got it certified as a pure strain of rye by the Michigan Crop Improvement Association. 

“Sure enough, [the crop] was unusual,” Munger says. “It was unusually productive and had lots of character. So MSU introduced it to farmers all over the state, and by the mid-1910s, there were almost three million acres Rosen rye growing in the state of Michigan, which made it at that time the largest rye-producing state in the country.”

But Rosen rye’s dominance didn’t last. While the grain was productive and rich in character, it also cross-pollinated so easily that growing pure strains of Rosen rye proved difficult for Michigan farms. That hybridization, Munger explains, “just destroyed the character of the Rosen and took away what made it unique.”

But Rosen rye’s had one Safe Haven: South Manitou Island. There, a single farm was able to keep growing Rosen rye without any of the problems that everyone else was experiencing.

The conditions on South Manitou made it perfect for Rosen rye: There was nothing on the island for the crop to cross-pollinate with, which meant it stayed pure and retained its character instead of hybridizing over time. Thanks to westerly winds, the island was also far enough from the nearest significant landmass that a breeze wouldn’t carry a stray spore far enough to contaminate the South Manitou crop.

For years the island’s Hutzler farm served as a seed farm for Rosen rye seeds. Farmers who planted fresh Rosen rye seeds from South Manitou Island — rather than using seeds from the crops they themselves had grown — could continue producing rich Rosen rye crops without any of the cross-pollination worries that had caused the strain to fall out of favor. 

For more than a decade, Hutzler farm would take its Rosen rye to a seed show in Chicago. Repeatedly, the farm claimed the annual title for best rye in the United States. And because of that acclaim, when Prohibition struck, whiskey bootleggers in Pennsylvania, Maryland, and all up and down the East Coast continued to rely largely on Rosen rye to craft their spirits.

In the nearly century-long period that has elapsed since those days, pure Rosen rye died out, and became impossible to find, and large commercial distillers that had always used it, such as Seagram’s, opted for alternatives. At this point, it’s been so long that there might not be anyone left alive who can definitively describe what kind of character or flavor profile Rosen rye imparts on whiskey made from it. 

“The last company that made rye whiskey in the United States using identified Rosen rye as the type of rye that was in the mash was Michter’s, and I believe that was 80 years ago,” Munger says. “So, probably very few living people have ever actually tasted [Rosen rye whiskey].” 

Mammoth is ready to change that. Two years ago, the company planted Rosen rye on the historic Hutzler and Beck farms on South Manitou Island. It’s a complicated project, one that Munger says is only possible because multiple pieces fell into place just right. First, the USDA agreed to hand over a small handful of Rosen rye seeds — 56 in total — to help the project get started. Second, MSU agreed to partner with Mammoth on the project, thanks in part to the historic roots that Rosen rye has at the college. Finally, the National Park Service (which owns and manages South Manitou Island as part of the Sleeping Bear Dunes National Lakeshore) agreed to issue a permit that allows Mammoth and MSU to cultivate 14 acres of South Manitou farmland for Rosen rye. 

Even with all those pieces in place, though, the project hasn’t been easy. While the National Park Service has kept the farm buildings and land on South Manitou maintained over the years, Munger says the soil hadn’t been tilled in decades, which meant it needed a lot of work to pave the way for a successful crop. One problem? Extremely dense vegetation all over the island, including a “six-inch-thick carpet of poison ivy” to which several Mammoth team members fell victim. 

Despite the hurdles, though, work is now well underway. MSU has been cultivating Rosen rye in greenhouses and supplied Mammoth with enough seeds to plant and harvest South Manitou’s farmland.

“And then every year, we'll pull the crop out,” Munger said. “It comes out in late July or early August. You clean it and dry it, and then we'll disperse [the seeds] to a small handful of growing partners here in Antrim and Grand Traverse County — people we trust as excellent farmers — and they will actually grow the crops we use to make the rye that we're actually going to distill. And that'll be the cycle.”

Ultimately, Munger says the goal is for South Manitou Island to function as a seed nursery for Rosen rye, always supplying fresh, pure seeds that can then be cultivated into usable rye crop on the mainland. That strategy should stave off cross-pollination and hybridization concerns, just as it did when Hutzler Farm was winning “best rye in the United States” titles a century ago. It will also mean that Mammoth has enough Rosen rye to make whiskey that has true Michigan-made terroir, with all the forgotten character that distillers fell in love with in the 1910s and 1920s.