Researchers in North Carolina mashed up a wasp, found a weird yeast, and turned it into award-winning booze. They say it tastes amazing. Would you try it?
A few years ago, the North Carolina Science Festival and the World Beer Festival intersected in time and space in Raleigh, North Carolina, home of NC State University. NC State happens to employ a brewing researcher by the name of John Sheppard, who teaches students the science of beer-making in what has to be one of the campus’s most popular classes.
Wouldn’t it be neat, one of the Science Festival organizers asked Sheppard, if you made a new kind of beer for display at the festival? Maybe you could get together with ecologist and microbe researcher Rob Dunn and make beer from a new yeast?
Another brewer might have said it was impossible. Almost every commercial beer is brewed from just a handful of related yeast, predominantly Saccharomyces cerevisiae (ale yeast) and Saccharomyces pastorianus (lager yeast). Sure, some brewers leave their vats open to catch whatever might waft in, but in general, most beer is made with grain, hops, water, and isolated strains of ale-ish or lager-ish yeast.
But Sheppard said yes, and Dunn tapped a post-doctoral researcher in his lab named Anne Madden. Madden had spent much of her collegiate education working to understand microbes in unusual environments like nursery schools, human armpits, and insects, and she knew that wild yeasts lived inside paper wasps. Like a bear in a cave, the yeast hides out in the wasp’s gut over winter. “Then the wasps wake up in the springtime and they go after sugar sources, like tree sap or nectar or rotting fruit,” Madden says. And the yeast hitches a ride—clever.
Madden had a simple directive: find a yeast that could eat maltose, poop out ethanol, and not kill people. She took a single wasp, ground it up, mixed it with some liquids, spread it on plates covered in warm microbe food, found the growths that glistened like yeast, selected those that seemed best for beer production, decoded their DNA, and checked them against a database for toxicity. (Yes, some can kill you. Do not try this at home.) She gave the winners to Sheppard.
“When I did the first fermentation and I tasted it myself, I thought, ‘Oh my God, I can't serve this at the beer festival!’” Shepard recalls. The beer was sour and tasted awful. He adjusted some of the parameters and tried again: better, still sour. That sour taste comes from lactic acid. “I thought initially the beer was contaminated with some kind of bacteria that was making these acids,” Sheppard says. That’s because brewers who want lactic acid in their beer have to add bacteria. They were surprised to learn that the sour taste came from the yeast. “I was not aware that yeast could make a lactic acid,” Sheppard says.
But how would it go over at the beer festival? “Most of them liked it, which was a surprise to me because I wasn't a big sour beer fan at the time.” Sheppard says most sour beers, “have these mixed cultures of microbes in them,” which means, “you get some good characteristics, but you also get some…very strange tastes and aromas,” like vinegar, body odor, and horse blanket. But Sheppard and Madden’s sour beer had none of those.
Their yeast, multiple strains of Lachancea thermotolerans, are not a traditional brewing variety. They naturally make lactic acid from brewer's wort, producing a rapid sour beer without the need for bacteria, and unlike conventional sour beer, it has none of the typical funky taste or smell. Rather it is floral, fruity, and its glycerol content makes it feel delightfully soft.
Seeing a potential business opportunity, Sheppard and Madden found a way to refine the yeast and the duo began licensing it to breweries. Madden is quick to point out that they didn’t need any more wasps: “Very few insects were harmed.” Apparently even the assholes of the air have advocates. They named their company Lachancea (pronounced la-chance-ee-ah) after their hard-working little microbe.
Since 2016 these yeast strains have been used by several commercial US breweries, producing a total of over 18,000 gallons of specialty beers. One of the key selling points for their yeast is the incredible speed at which beer can be produced. Normally, a sour beer can take an average of six months to make, but Lachancea thermotolerans, can churn out delicious brew in 12 days, with fewer resources. “We were able to do this, from the idea of making a beer to our first commercial product, in 10 months,” Madden says. To Madden, this proves that when it comes to microbes, “We have to ignore our assumptions.”
After the success of their wasp yeast, Madden and Sheppard expanded their search and found another related strain in bumblebees. Despite outing myself as a sour beer novice, the people at Ecusta Brewing Company were kind enough to send me a sample of their bumblebeer. Specifically, what arrived at my door was a well-packaged little can of Pink Beds wild ale. Madden was worried it would be past peak but if anything it might have ruined me on other sour beers forever.
I was a goner as soon as I saw the pink foam but I worked to not let myself be biased by its pretty appearance. And then I took a taste. Wow. It was sour but refreshing, like the way lemonade is refreshing on a hot day. I tasted flowers, honey, citrusy tartness, and was that rhubarb? It was crisp, not at all bitter and yes, soft. By the bottom of my glass I was sorry I had given my spouse a taste.
Now I am desperate for more. Sadly, the breweries currently producing these beers are all in North Carolina. But Sheppard is hoping to expand. Lachancea has begun to collaborate with a brewery that distributes to a few other states, and if they get more of these large partners, he foresees nationwide access. Maybe I can try and beg a few cases from our local specialty store.
These yeasts are great for other fermented drinks too. The first commercial cider made with their yeasts was produced in Japan in 2019, and Lachancea’s partners released their first bug-based commercial sakes in Japan last February. “It was a treat to be in Tokyo and to have this sake tasting event,” Madden says.
She says the wasp sakes are “Millennial pink” in color with high acidity and a sweet taste almost like white wine. Madden says people’s eyes lit up, and they squealed with delight. “I love that because so often scientists don't get to experience that same joy. Like I squeal with delight when I isolate microbes and grow them, but to see them create delight in an audience is truly magical.”
Intriguingly, the research suggests that the aromatic character of this yeast might be why the bugs are attracted to it in the first place. It appears that wasps and bees are great partners in the search for new, natural flavors. While their competitors hack an organism's DNA to create a GM yeast with the flavor profile of interest, Madden and Sheppard say they have chosen to "hack nature's pipeline."
All this from a mashed up wasp in North Carolina. “For all of our lives we've had paper wasps that have been building nests as pests on our window sills,” Madden says, “And all along they'd had this microbe inside of them,” Madden says. “So what other secrets lay waiting?”