Photo by Dr. Anne Madden

Some stories almost write themselves. This is one of those stories.

We all know Raleigh’s craft beer scene is hopping, from breweries popping up overnight to canned beer to podcasts talking about beer to beer festivals. Last Friday night I thought I’d found the coolest local beer story ever.

Natural Selections was all about the science of beer, and NC State’s team oozed scientific innovation. Its two beers on tap at the tasting were more than a little unusual: sour bee beer and sour wasp beer. Seriously. 

In addition to my surprise at the beer’s uniqueness, I was equally surprised to meet Dr. Anne Madden serving it — we had connected on Twitter just the day before, and her pinned tweet showing a hairy dinosaur covered in a new fungus she had named wasn’t easy to forget.

Psyched to write a breaking news story about this new wild yeast discovery from the very insects we all love to hate, I started researching, quickly turning up Matt Shipman’s story from September 2015. A science writer and research communications lead at NC State, he’d covered the story a year before I thought it was breaking news, explaining it better than I ever could. It’s partially republished here with his permission.

“When John Sheppard was asked to brew beer from wild yeast, he was skeptical. Humans, after all, have been brewing beer for millennia. If there were yeasts out there that could make a good pint, they would surely have been found years ago. But, it turns out, Sheppard proved himself wrong.

Sheppard is a bioprocessing professor at NC State University, where he splits his time between a small office and an industrial-looking research laboratory tucked away in the basement of an academic building. And what Sheppard studies is beer. Particularly, Sheppard’s research is focused on the art and science of turning water, hops, malt and yeast into ales and lagers. He’s both a brewer and a scientist.

In spring 2014, the North Carolina Science Festival overlapped with the World Beer Festival in Raleigh, and representatives of the festival approached Sheppard about developing an exhibit on the science of brewing. They suggested Sheppard work with NC State biologist Rob Dunn to find wild yeasts and use them to make beers that could be sampled by patrons at the World Beer Festival. It could be, they said, a tasty and accessible way to get people interested in the microbial biology of the natural world.

Still, Sheppard’s initial skepticism was well-founded.

Yeasts are a type of fungus — single-celled organisms that, individually, are invisible to the naked eye. And there are hundreds of different species, many of which include numerous different strains. But of all those species, only two are typically used in making beer.

The reason more yeasts haven’t been used in brewing is because a beer-making yeast needs to be able to do two things: it has to both “eat” maltose (the sugar in malt) and produce ethanol efficiently. Most yeasts can’t do either, much less both.

But Sheppard was willing to give it a shot, and so he reached out to Dunn. The biologist, in turn, reached out to the people in his research group to see if they had any ideas. One of those researchers was Anne Madden.

Madden is a postdoctoral microbiologist affiliated with both Dunn’s lab at NC State and Noah Fierer’s lab at the University of Colorado. In her official capacity as a postdoc, she studies the microorganisms of the “built environment” – particularly, how insects and other arthropods introduce microorganisms to homes, workplaces and other buildings. She is, in other words, an expert on the microscopic organisms that live on insects.

Before joining the Dunn lab, Madden did extensive work on the microbial communities found on paper wasps. Because of that background, she knew that wasps are home to communities of yeasts, some of which are associated with winemaking. Maybe one of those yeasts would work for brewing, she thought.

Taking samples from wasps, Madden ultimately isolated a wild species of yeast that had never been used for commercial brewing and shared it with Sheppard.

Sheppard cultured the sample, growing the yeast until he had enough to try brewing with it. And the results were not what he expected.

image“That first batch produced a really sour beer,” Sheppard says. “But when we served it at the World Beer Festival, people loved it.” And, since people loved it, the researchers did it again.

Last summer, Madden provided Sheppard with a second wild yeast sample – this time found on a species of bee, which turned out to be particularly apt.

“The beer we brewed with the second yeast included flavor compounds that tasted like honey – very sweet and aromatic,” Sheppard says. “People liked it, and couldn’t believe there was no honey in the beer.

“So, I kept experimenting with different ale recipes, with promising results.”

And what Sheppard found was, well, kind of amazing. By making small adjustments to the brewing process, the wild yeasts produced very different flavor compounds, called esters. Some of the ales tasted like sour beers, some like honey, some like apple cider. And these characteristics could be extremely useful for brewers.

“For example, sour beers are increasingly popular, but they’re tricky for brewers – because traditionally, producing sour beers requires brewers to work with bacteria as well as yeasts,” Madden says. “And that process means it can take six months, or even years, to produce a sour beer. But our yeast strains can produce sour beers within five days, and they don’t rely on bacteria – eliminating the risk of contaminating other beers in a brewery.”

Once they realized the potential of these wild yeasts, the researchers began collecting data on how these yeasts grow and precisely which esters they produce.

They also worked with NC State to file an invention disclosure to protect their intellectual property, and secured financial support from the Chancellor’s Innovation Fund, which provides grants to faculty to help researchers move innovative concepts from the laboratory to the marketplace.

They got the funding, and Sheppard is now working to develop a yeast management strategy to ensure that brewers using the same recipe will consistently produce beers with the same flavor profile.”

Since Shipman did all the work for me on the beer, I decided to focus my story on Madden, fascinated about how she worked through the yeast idea. I emailed some questions and offered to interview her over the phone if she would “rather talk than type.”

Quick to point out that she was only one member of the larger team, Madden emailed me her answers within the hour. They were so descriptive that I’m simply posting them here in a Q&A format.1

How did you get interested in wasps in the first place?
After returning to academia from industry I joined the lab of Dr. Philip Starks at Tufts University for my Ph.D. His lab did all sorts of work on the behaviors and physiology of wasps. He tended to ask questions about why an invasive wasp from Europe was doing so well in the U.S., and how these wasps knew which nest was their home. These questions help us understand big questions in how animals relate to their environment.

I am a microbiologist though, so I tend to look at the world with that size-bias — what’s going on microscopically here? I was surprised to learn about how little we knew about the microorganisms of wasps. These are insect species that people have been studying for many, many years. They live in the eaves of all of our houses, yet they are as mysterious as an exotic jungle. By looking at the microorganisms — bacteria, fungi, yeast — inside their bodies and nests, we found a new fungal species to science. We also found bacteria that had antimicrobial activity. The more we looked, the more we found in these insects that most people consider pests.

Where is the yeast from exactly? External or internal, or nests?
This is a great question. Other researchers have found that yeast can be found in the intestines of wasps, so we know at least some of the yeast we are interested in are there. When we, in the Dunn lab, culture the yeasts, we don’t mind if it is on the inside or the outside. It’s likely that most are inside, but we can’t say for certain that all of the yeast are on the inside.

Why are “Arthropods natural reservoirs for yeasts”?
We are looking into that right now! The mystery throughout our history has been where yeasts are in the environment. They are globally distributed, but hard to predict. In the summer we know they are associated with sugary environments like tree sap, flower nectar, or rotting fruit. In vineyards it appears that wasps, and many related insects, are keeping the yeast safe while the insects hibernate in logs. When the temperature is warmer and those readily available sugar sources are back, the yeasts are likely to get a ride to them from the insects.

Yeasts are not mobile, so it’s likely these insects are key to helping transport them throughout the world. Not all insects behave the same way and this means some insects are likely to have closer relationships with some yeasts than others. We’re using this ecology information to help guide our own search for useful yeasts.

Who is the principal for the Chancellor’s Innovation Fund grant?
Drs. John Sheppard and Rob Dunn are the co-authors on the grant. I’m the third member of the original team. It has been a fantastic example of how different science groups can work together. I can’t say enough about how fun it has been to be a part of this team.

How does this get “handed off” to the private sector?
The yeasts that have gotten a lot of attention are now patent-pending technology. This means they can now be licensed from North Carolina State University by interested groups who want to make sour beer in record time and without the customary lactic acid bacteria, or off-flavors of other wild yeasts.

Ok to have a little fun with your hair award?
Of course! Anyone who knows me is pretty amused that I got an award for something as superficial as my hair.2 Hopefully my science — and those of my colleagues — will speak to the hard work we actually do. I hope the hair award displays that as scientists we are pretty good at laughing at ourselves.

It also shows the next generation of women scientists and engineers that a scientist can look like whatever you want it to look like: disheveled flannel and taped glasses, or stilettos and bleach blonde. It’s not about what you do or don’t look like. A scientist doesn’t have to look like Einstein, or an androgynous person in a lab coat. A scientist looks like everyone.

What’s next for you?
I am now a postdoctoral researcher in the lab of Rob Dunn at NCSU; before I was splitting my time between here and Colorado. For the near future I am continuing to work with the Dunn lab on some more projects investigating the crazy world of wild microorganisms and how we can apply this knowledge to make new products and services.

These projects include understanding what microbes help make the best sourdough (a citizen science project where the public can help!), and why certain microorganisms might make polyester athletic clothes stink so much.

I’m also working with the Sheppard brewing lab to look at more yeasts that can make new flavors in ciders and beers. I love the challenge of finding out what wild microorganisms can naturally do when wrangled into the lab. They can often find solutions to seemingly insurmountable problems. In that way they are far more magical than the unicorns and mermaids we always dreamed of finding when we were young. Vaguely related to that, I’ll be giving a TEDx talk in Charlotte in the fall about the search for new food and beverage flavors from these wild microorganisms.

The Chancellor’s Innovation Fund was established in 2010 to support short-term commercially focused research projects based on NC State intellectual property. The grant program is available to NC State inventors and is managed by the Office of Technology Transfer. The FY17 awards were recently announced and include projects on engineering better crops, speeding up antibiotic research, light-activated anti-infective coatings, and more.

I’m sure the 2017 awards will brew up some cool stuff, but honestly it will be hard to top bee, and wasp, beer. Cheers.

  1. Told you this story wrote itself.
  2. The Luxuriant Flowing Hair Club for Scientists (LFHCfS) selected Madden as its 2015 Woman of The Year. Her reaction? “As my hair is a natural dark red brown, it is a testament to modern science, and particularly chemistry, that it is now this bright, blond color. Yay applied science!”
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