Nicole Garneau, a geneticist and researcher at the Denver Museum of Nature and Science , is often seen with a swab in hand, usually swiping the inside of museum-goers mouths to study the genetics of taste. But one late afternoon in June, she was poking around City Park, hunting for something very different: yeast. Her goal? To make beer with what she found.
Garneau and Denver Beer Co.  co-founders Patrick Crawford and Charlie Berger are the geniuses behind Science on Tap , an annual event that explores the science behind beer. Yeast, an overlooked part of beer production, "makes a major contribution to the flavor profile of a beer,” Crawford says. Together, they wondered if it would be possible to isolate a strain of wild yeast from somewhere in Denver, and a bet ensued: If Garneau could successfully grow a strain of wild yeast that ferments beer, Crawford would spend a day as a museum curator. If the experiment failed, then Garneau would work as a master brewer for a day.
“Right then and there I gave them each a lab coat and gloves,” Garneau says, and the trio headed into City Park to search for wild yeast. They swabbed five locations: blue spruce needles, ponderosa pine bark, rose petals, the wolf sculpture, and two bugs. (Don’t worry, the bugs aren't a part of the recipe.)
Next, Garneau had to coax individual yeast strains from the samples and test to see if they would ferment a sterilized wort (a mixture of malted barley and hops). “The tricky business about wild yeasts is that they haven’t been domesticated to ferment efficiently,” she says. Five days later, tests revealed that all five samples were fermenting slowly, but the rose petal yeast was the best performer by a small margin.
This Monday, Science on Tap attendees will have the chance to sample the rose petal beer, plus three others brewed with traditional brewer’s yeasts. “Its been so fun for me to share how experimentation works,” Garneau says. “I want people to realize that there is science in everything and that science is really fun.” We'll drink to that.
The jury is still out on when Crawford will hold up his side of the bet and work as a museum curator for a day.
Science on Tap: Head to the Denver Beer Company at 6 p.m. on July 22 for a taste of Denver. Tickets  are $35 and include the beer tasting plus a pint of your choosing, and food from the Über Sausage, Basic Kneads Pizza, and Peteybird Ice Cream. Garneau will give a short lecture on yeast’s role in beer production and the science behind the City Park brew.
—Image courtesy of Shutterstock