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Molecular Profiles Point The Way To A Better Pint Of Beer

You don’t have to look too hard to find beer on the Colorado State University campus in Fort Collins. But not all of it is at keggers. In the microbiology building, it’s a legitimate study subject.

What started as a creative teaching tool has now blossomed into cutting-edge research that may change the brewing industry.

Visit CSU’s Proteomics and Metabolomics Core Facility on a typical day, and you’re likely to see scientists running samples of bodily fluids on state-of-the-art machines.

The usual suspects are serum, urine, and tissue extracts, says Jessica Prenni, the Core Facility’s director. Oh, and feces, too.

Prenni and her colleagues study a relatively new field of science called metabolomics that focuses on the many products of metabolism in a given organism. The tool of their trade is a mass spectrometer, a kind of molecular scale that weighs the tiny products, or metabolites. From the weight, the scientists can piece things together like an atomic jigsaw puzzle, and figure out what the metabolites are.


By comparing urine from healthy people to that of sick patients, for example, Prenni can identify molecules that could be used to diagnose diseases. But minute differences in urine aren’t all that exciting to students. And Prenni and her coworkers were big connoisseurs of another far tastier and more interesting liquid to most budding scientists.

Why not see if their machine could also pick up minute differences between beers?

A Beer Run, For Science

So the CSU team bought a bunch of bottles from three Fort Collins-based brewers and loaded up their half-a-million dollar machine.

Credit Jessica McDonald/KUNC
One of the mass spectrometers used in the analysis of barley and beer at CSU.

The instrument takes only a tiny sip: one microliter, or about three millionths the size of a 12 ounce can of beer. That drop of beer flows through a column that separates the molecules over time so that each metabolite can then be weighed one by one. Within 30 minutes, the half a million dollar machine spits out a set of 30,000 mass measurements that make up the beer’s metabolite profile.

Even in a town as famous for its craft beer as Fort Collins, this type of experiment had never been done before with such a powerful instrument.

“For us, it was like, what did you do, what type of analyzers? At that point I was very interested and intrigued,” says Peter Bouckaert, brewmaster at New Belgium Brewing Company.

He saw potential in Prenni’s technique to improve how beer is made.

Back to the Basics: Barley


“We sell only flavor. We sell 10 minutes of pleasure. And never has that been a consideration in the varietal selection,” says Bouckaert.

By varietal selection, he means barley, the grain that’s malted, fermented, and brewed to make a glass of beer. Right now, barley varieties can take over a decade to develop as growers tinker with plant genetics to increase yield and add disease resistance. The problem is there’s no way to tell if the barley will produce good beer until the very end.

“We finally start brewing with it and taste it,” says Bouckaert. “And then based on that taste, we’re like, trash this 11 to 12 years of work.”

Bouckaert thought the advanced instruments at CSU might be able to inject flavor considerations into the breeding process earlier, which would save time and money for the industry. Not surprisingly, beer giant Anheuser-Busch was interested, as well as the American Malt and Barley Association, the organization that approves only a few of the thousands of barley lines in development every year.

With funding from the association, and cooperation from the two breweries, the CSU lab is now looking at the metabolites of the beer at each step along the way: the raw barley grain, the malt, and the final brew.

“Ultimately, what would be ideal is if we could determine a set of metabolite or small molecule markers from the barley that were correlated with beer quality,” says Prenni.

If they’re able to do that, they’ll be able to predict which barley varieties grown in which locations will work best for brewing, and can reduce the number that are scrapped for bad flavor.

The Taste Test


Prenni has already found that certain metabolites from barley are related to the quality of the malt. It’s an important step that in itself may be able to improve barley breeding.

But even a great malt doesn’t always guarantee a great beer, and for Peter Bouckaert at New Belgium, taste is everything.

In the back of one room at the brewery, Bouckaert has tasting booths where specialists try their tongues on his beers as they pop out behind a door. It’s here that the taste panel experts, able to detect the smallest of inconsistencies and off flavors, will evaluate the beer that Prenni will also analyze on her machine.

The final question about any beer is always, is it a ‘go,’ if it’s good, or a ‘no-go,’ if it isn’t quite right.

For the researchers at Colorado State University, the real question is whether they can predict whether it’s a ‘go’ just by looking at a few key barley metabolites.

I am covering science stories at KUNC this summer as a AAAS Mass Media Fellow, a program that matches scientists with news outlets so that they can try their hand at translating science to regular folks. My normal day job is as a graduate student at Yale University, doing immunology research with Dr. David Schatz. Previously, I graduated from Haverford College, majoring in English and biology.
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