The lowly wasp. We swat it, curse it, kill it and shoo it away from our eaves. But where we see pain and swelling, John Sheppard sees beer.
An N.C. State professor of bioprocessing science, Sheppard and fellow scientists Rob Dunn and Anne Madden have brewed six styles of beer using the yeasts of wasps and other arthopods such as bees and spiders.
"A wasp's nest at the microbial level is an unexplored jungle," says Madden, a microbiologist. It was luck. And then John came in. He's the magic behind the brewing."
Yeast is responsible for half of a beer's flavor; malt, hops and water conspire to influence the other half. Yeast converts sugar into alcohol and carbon dioxide, but it also imparts other aromas and flavors. The brewer's challenge is to control a yeast's metabolism to minimize bad flavors (sulphur = bad) and amplify good ones (fruity = good).
Sheppard speaks of his yeasts as if they are pets. Since yeasts comes from the wild, it must be "domesticated," he says, and tested under different conditions. "You have to train it. You get to know what it likes."
Sheppard became interested in brewing as a counterpoint to the scientific research of the 1970s. Back then, scientists began vigorously researching genetically modified organisms, but altering the DNA of yeast, a life form, is strictly verboten. "I wasn't interested in GM, because naturally occurring yeast could be exploited," he says. "That's what drew me to brewing."
Living microorganisms, yeast are technically classified as fungi and responsible for fermentation. There are hundreds of types of yeast, and they live nearly everywhere: in our food, in the air, on our skin. The type of wasps used to harvest the yeast, and the brewing process are proprietary. But it's doubtful Anheuser-Busch will send its brewers into yards with Mason jars and butterfly nets in search of wasps.
That's because to maintain consistency in their beers, large commercial brewers use only a few traditional yeasts; it's the same reason McDonald's doesn't tinker with its special sauce. "For quality control in industrial beer, they weren't interested in experimenting; they standardized the brewing process," Sheppard says.
But that conservative approach makes for very predictable beers, opening a market for brewers like Sheppard willing to take a risk. The N.C. State beers adhere to traditional German brewing purity laws—using only yeast, malt, hops and water. These newly discovered yeasts yield new flavors, without adulterating the beer with extracts such as blueberry, basil, sweet potato.
"We didn't expect that it would make beer so well," Sheppard says. "It's surprising."
Sheppard and N.C. State have applied for a patent on the use of the yeast. Eventually, they could license its yeast to local brewers, who could further amplify their locally sourced ingredients. (Imagine: The Stinging Lager: Now made with malt from Lee County, hops from the North Carolina mountains and yeast from Raleigh wasps.)
Sheppard's lab fridge is full of his beer, but few people have tasted it. Until recently, N.C. State didn't allow the sale of alcoholic beverages on campus, but administrators recently agreed to apply for a permit allowing Sheppard to sell limited amounts of his beer at university events. Later this year, he expects the beer to be sold commercially, although in small batches.
Fortunately on this late spring morning Sheppard has several bottles in the fridge, and we celebrate beer-thirty with a few ounces of his latest creations. He pops an orange cap from a brown bottle of an English IPA. It's highly hopped and fruity but fear not, it's refreshing, delicious and not the least bit treacly. A session beer, it contains only 5 percent ABV, making it an apt breakfast drink.
Next, Sheppard unveils a green-capped sour. It's lighter, with a honey nose and bracing tartness. With a ph of 3.7—that's acidic for those of us who didn't take chemistry—it's in the range of Lambic-style beers.
Because once harvested the yeast continues to grow on its own, the brewery doesn't endanger the local arthropod population. "To get bumblebee beer, two bumblebees died," Madden says. "You killed more bugs on the sidewalk to the bar." •
This article appeared in print with the headline "This beer does not sting."