I admit, I’m behind the times. While my friends are attending increasingly popular beer festivals and visiting the growing number of micro-breweries around the world, I can’t tell the difference between a lager and a stout. This means that not only am I the worst person to send to the bar, I’ve also never given much thought to what it takes to brew a great beer.
Unlike me, John Sheppard is a beer expert. As a bioprocessing professor at North Carolina State University, Sheppard spends much of his time in his lab (which could easily be confused for a miniature brewery) studying how to best grow and control yeast—the fungi that convert sugar into alcohol. His current project, brewing with wild yeast, has brought him outside that controlled environment into a world he didn’t expect.
Typically, the yeasts used to brew beer are specifically selected from a small group of previously tested strains to protect the beer’s characteristics. In fact, Sheppard’s research usually centers on controlling yeast metabolism to achieve consistent performance of the essential ingredient. Sheppard says, “wild yeasts have always been considered a contaminant in brewing and you want to keep them out, because they create off-flavors.”
In 2014, the North Carolina Science Festival coincided with the World Beer Festival in Raleigh, North Carolina. That overlap prompted Jonathan Frederick, director of the science festival, to ask Sheppard about creating a special exhibit on the science of beer—specifically, on fermenting beer with wild, unknown yeasts. Frederick suggested that Sheppard reach out to Robert Dunn, a biological sciences professor at North Carolina State University, and the rest is history.
Just kidding, the rest included a lot of hard work and time spent finding wild and useful yeasts to develop new brews. Work in Dunn’s lab focuses on the ecology of small species, some of which carry yeast in and on their bodies, so they decided to try some pests. Along with post-doctoral researcher, Anne Madden, the team isolated a yeast carried by wasps and found that it was suitable to ferment and brew.
Full Story by Lindsay Smith. Courtesy “The Plate” National Geographic 》》》》