Fullsteam will release "Rachel's Wild Yeast Belgian Pale Ale," made with yeast from Duke Gardens, at its four-year anniversary party on Saturday, Aug. 30. Visitors to the Durham brewery at 726 Rigsbee Ave. will be able to buy the beer beginning at 1 p.m.

While Duke has found many ways to connect with the broader Durham community, one Durham business is brewing a stronger relationship with Duke – literally.

Durham-based brewery Fullsteam will soon release beers made with local yeast strains from plants at Sarah P. Duke Gardens. The wild yeast, swabbed from a lavender plant in the Asiatic Arboretum, is one of the key ingredients in the brewery’s attempt to craft a beer with local flavor.

The yeast, which ferment sugars in the beer, not only create alcohol, but also offer unique flavors like cracked pepper and orange zest.

"We at Fullsteam pride ourselves on using local ingredients to make distinctly Southern beer,” said Sean Lilly Wilson, Fullsteam’s owner and “Chief Executive Optimist” who also holds a master’s in public policy and business administration from Duke. “But this time around, we wanted to challenge ourselves and get as local as possible, harvesting from our own backyard. We wanted something not only distinctly Southern, but distinctly Durham.

The process of cultivating the yeast began in May, when Fullsteam’s “yeast wrangler,” Rachel Simpson, set out into Durham to find the right strain that could be used to brew a beer. Her search led to the plethora of options at Duke Gardens, where she used cotton swabs to extract yeast from 14 different plants found in the Blomquist Garden of Native Plants, Historic Gardens and Asiatic Arboretum.

Simpson said the trick was to look for plants that had been flowering and weren’t still green and not yet blossomed. If she swabbed a plant that wasn’t mature, she’d extract a yeast strain called Brettanomyces, which wouldn’t be useable because it would create off-flavors in a beer.

Rachel Simpson, Fullsteam Brewery's "yeast wrangler," looks at yeast cultures through a microscope in her lab at the brewery. Simpson developed a yeast from Duke Gardens to use in Fullsteam beers. Photo by Bryan Roth.

“It’s best when things are pollenating because bees are out spreading different kinds of yeasts to different flowers, which makes for an eclectic swabbing experience,” Simpson said. “It’s not always the kind of plant you’re swabbing, but it’s the bugs that leave things behind, too.”

Some of the yeast from Duke Gardens that didn’t make the cut included samples from black gum and banana magnolia trees, a Guelder rose bush and the Southern Indica azalea. Once she was able to grow yeast from those plants, she noticed off-flavors that reminded her of finger nail polish remover and acetone.

However, along with yeast from lavender, Simpson was also able to find useable yeast from Chinese lilac in the Asiatic Arboretum.

To best utilize the different pepper and orange flavor created by the Duke Gardens’ yeast, Fullsteam is partnering with Saxapahaw’s Haw River Farmhouse Ales to brew a cucumber mint saison. Brewers are also crafting a Belgian pale ale and a sour beer. Wilson and Simpson both noted, however, that customers to their Durham taproom will soon be able to sip on a beer utilizing the uniquely Durham – and Duke – yeast.

“This area is so sweet and salty to me, I’d expect beer made with our yeast to taste rustic and fresh,” Simpson joked. “My favorite part has been creating something that’s such a valuable part of the brewing process from right here.”