Designed from scratch today, a modern, profit-minded brewery would do no brewing. Instead, it would be a distillery — a lean, sterile study in efficiency that churns out pure alcohol from a cheap source of carbohydrates.
Artificial flavors and colors would go into that blank alcoholic base, the precise formulation depending on the desired style of beer. Maybe a little more color for a brown ale, a little less for pilsner. Fruitier flavors for hefeweizen, a chocolatey tone for stout.
For the finishing flourish, the “beer” would be hissed full of foam, then packaged and shipped off to thirsty drinkers across the globe.
“I hate it,” says enzymologist Charlie Bamforth of this futuristic vision. “I hate it,” repeats the grand old man of beer-making, holder of the esteemed Anheuser-Busch Endowed Professorship of Malting and Brewing Sciences at the University of California, Davis. Still, one can’t deny the inefficiency of standard brewing methods. “Viewed dispassionately, this time-honored process lacks logic,” Bamforth wrote in a recent scholarly review that outlined how a sane, modern-minded person would craft beer today.
Of course, the historical and cultural roots of this millennia-old practice, and the passion of brewers and drinkers, run too deep for any such apocalyptic overhaul. But that doesn’t mean that the art remains static. There are unexplored corners of the ancient recipe of water, carb-laden grain, flavorful hops and yeast that spins sugar into beer — and brewers and scientists are starting to probe those nooks. (...)
“Fermenting a sweet, bitter soup into a beer is a very complex thing,” says biotechnologist Troels Prahl of White Labs in Copenhagen, a company that supplies yeast strains to brewers. The broad strokes of that process were illuminated years ago, partly by researchers at large, brewery-based labs. (Some fundamental scientific tools originated in breweries, too: Scientists at the Carlsberg brewery in Copenhagen developed the pH scale in 1909, and the statistical staple known as the student’s t-test was devised by a brewer at Guinness around the same time.)
At its heart, brewing is chemistry, enzymes and microorganisms, and beer science at breweries was once a positive bustle. When Bamforth joined the Bass brewery in beer-loving Britain as a research manager in the 1980s, he led a team of 30 ambitious scientists — fundamental chemists, molecular biologists and biochemists. Other breweries, including Guinness in Ireland and Foster’s in Australia, housed large research teams, too. “There were meetings all over the place, and people would be racing to be the first to present the science of malting and brewing,” Bamforth recalls.
Many of those robust programs are now gone, and most of the big questions about brewing have been answered. These days, people can easily access the tools and knowledge needed to make good beer.
But for all that early research, there are still large swaths of unmapped territory, says hops chemist Tom Shellhammer of Oregon State University in Corvallis, who delights in finding and filling these knowledge gaps. “It’s like, ‘Wow, this is an open spot on a plot of land that people have been walking around on for 5,000 years.’” (...)
... brewers’ understanding of yeast is still incomplete. Today, many keep to their own special yeast strain or two and consider them sacrosanct, key to churning out a consistent and delicious brew. Yet a prized strain may still be quite mysterious, with hazy origins (given by a friend, or even illicitly purloined at some point in the past) and poorly understood genetics and physiology. “It might make the beer they want to make, but it’s not always the best yeast,” Verstrepen says.
To bring some knowledge and order to the scene, Verstrepen, Prahl and collaborators scrutinized the genomes and behavior of 157 distinct strains of Saccharomyces cerevisiae, the yeast used in brewing and baking. “We’re cataloging what’s out there,” Verstrepen says. Most of these strains were brewing yeasts, but the samples included a handful of yeasts that make wine, spirits, bioethanol fuel and bread, as well as a few strains scientists use in labs for basic research.
The detailed genetic catalog, published in 2016 in Cell, describes the wild early days and eventual taming of many of the strains, as well as their beer-making abilities. It’s a guidebook for adventurous brewers, one that might ultimately point to superior yeast strains that can brew more efficiently, or imbue the beer with different flavors.
The DNA of flavor
With such data, and with cheap and thorough genome-sequencing tools in hand, scientists can start linking particular genetic attributes of yeast to flavors — because hops don’t tell the whole story. Explaining a taste in biochemical terms is tricky, says molecular cell biologist Johan Thevelein of KU Leuven. Flavor molecules can be influenced by many genes, and in many cases there’s no easy way to predict what kinds of flavors a yeast strain will make without actually fermenting with it.
That’s what led Thevelein and colleagues to conduct a giant experiment in which they created thousands of genetically different S. cerevisiae strains through breeding. Then they set up thousands of tiny fermentations for each offspring, each one enough to yield about two shot glasses’ worth of beer. The search was for yeast strains that produced lots of the rose- or honey-flavored chemical phenylethyl acetate, and then to pinpoint the responsible parts of the yeast genome. After combing through the results, the researchers found DNA sequences at two spots in the genome that could each cause a big uptick of rose flavor.
The initial discovery was made with brute force. But a slick new genome-editing tool called CRISPR/Cas9 allowed the researchers to recreate those same flavor-linked DNA sequences and thus prove that the two regions truly were behind the sweet rose characteristic. The same tool could enable scientists to create rosier flavors in whatever yeast strain they chose.
Advances like CRISPR editing hold great potential, says Verstrepen. His research group does a lot of old-fashioned yeast breeding, but he’s also got genetically modified yeast sitting in his lab freezer. “With breeding, we can go to 50 percent more fruity,” he says. “But with genetic engineering, you can go tenfold or more.”
Buckets of something better
Sophisticated genome techniques also allow scientists to take a census of the microbial fermenters that nature has already provided, including ones that may have escaped brewers’ notice. Geneticist Maitreya Dunham of the University of Washington and colleagues wanted to see if a method they’d developed, called Hi-C sequencing, could help parse the still somewhat mysterious ecosystem of a barrel of beer. (Dunham has a financial stake in a biotech company based on the method, which allows one to distinguish the genetic material of closely related species.)
So the scientists left their gleaming genetics lab in the heart of Seattle and ventured south, to a dusty warehouse. An eclectic brewer named Cody Morris had been tinkering there with wild beers — brews that start in open buckets and get fermented by whatever microbes happen by. The basement had a dirt floor, Dunham recalls. “There was junk all over the place, cobwebs.” Morris had let nature take its course in buckets of sugary wort that were scattered around the space. One of Morris’s favorite buckets, a beer he sold as “Old Warehouse,” had just been topped off with fresh wort and was full of action, brimming with bubbles. The team took a sample and headed back to the lab.
Their analyses, which appeared online October 19 in the journal Yeast, identified four different yeast species, including one particularly exotic specimen: a hybrid brand new to scientists. One of its parents seems to be a species called Pichia membranifaciens, an under-studied yeast that may protect grapes from a fungal disease but also rots strawberries and other foods. The other parent is unknown. News of Dunham’s discovery spread, and experimental brewers have been requesting the yeast, which the researchers informally call Pichia apotheca, for “warehouse.”
by Laura Sanders, Knowable Magazine | Read more:
Artificial flavors and colors would go into that blank alcoholic base, the precise formulation depending on the desired style of beer. Maybe a little more color for a brown ale, a little less for pilsner. Fruitier flavors for hefeweizen, a chocolatey tone for stout.
For the finishing flourish, the “beer” would be hissed full of foam, then packaged and shipped off to thirsty drinkers across the globe.
“I hate it,” says enzymologist Charlie Bamforth of this futuristic vision. “I hate it,” repeats the grand old man of beer-making, holder of the esteemed Anheuser-Busch Endowed Professorship of Malting and Brewing Sciences at the University of California, Davis. Still, one can’t deny the inefficiency of standard brewing methods. “Viewed dispassionately, this time-honored process lacks logic,” Bamforth wrote in a recent scholarly review that outlined how a sane, modern-minded person would craft beer today.
Of course, the historical and cultural roots of this millennia-old practice, and the passion of brewers and drinkers, run too deep for any such apocalyptic overhaul. But that doesn’t mean that the art remains static. There are unexplored corners of the ancient recipe of water, carb-laden grain, flavorful hops and yeast that spins sugar into beer — and brewers and scientists are starting to probe those nooks. (...)“Fermenting a sweet, bitter soup into a beer is a very complex thing,” says biotechnologist Troels Prahl of White Labs in Copenhagen, a company that supplies yeast strains to brewers. The broad strokes of that process were illuminated years ago, partly by researchers at large, brewery-based labs. (Some fundamental scientific tools originated in breweries, too: Scientists at the Carlsberg brewery in Copenhagen developed the pH scale in 1909, and the statistical staple known as the student’s t-test was devised by a brewer at Guinness around the same time.)
At its heart, brewing is chemistry, enzymes and microorganisms, and beer science at breweries was once a positive bustle. When Bamforth joined the Bass brewery in beer-loving Britain as a research manager in the 1980s, he led a team of 30 ambitious scientists — fundamental chemists, molecular biologists and biochemists. Other breweries, including Guinness in Ireland and Foster’s in Australia, housed large research teams, too. “There were meetings all over the place, and people would be racing to be the first to present the science of malting and brewing,” Bamforth recalls.
Many of those robust programs are now gone, and most of the big questions about brewing have been answered. These days, people can easily access the tools and knowledge needed to make good beer.
But for all that early research, there are still large swaths of unmapped territory, says hops chemist Tom Shellhammer of Oregon State University in Corvallis, who delights in finding and filling these knowledge gaps. “It’s like, ‘Wow, this is an open spot on a plot of land that people have been walking around on for 5,000 years.’” (...)
... brewers’ understanding of yeast is still incomplete. Today, many keep to their own special yeast strain or two and consider them sacrosanct, key to churning out a consistent and delicious brew. Yet a prized strain may still be quite mysterious, with hazy origins (given by a friend, or even illicitly purloined at some point in the past) and poorly understood genetics and physiology. “It might make the beer they want to make, but it’s not always the best yeast,” Verstrepen says.
To bring some knowledge and order to the scene, Verstrepen, Prahl and collaborators scrutinized the genomes and behavior of 157 distinct strains of Saccharomyces cerevisiae, the yeast used in brewing and baking. “We’re cataloging what’s out there,” Verstrepen says. Most of these strains were brewing yeasts, but the samples included a handful of yeasts that make wine, spirits, bioethanol fuel and bread, as well as a few strains scientists use in labs for basic research.
The detailed genetic catalog, published in 2016 in Cell, describes the wild early days and eventual taming of many of the strains, as well as their beer-making abilities. It’s a guidebook for adventurous brewers, one that might ultimately point to superior yeast strains that can brew more efficiently, or imbue the beer with different flavors.
The DNA of flavor
With such data, and with cheap and thorough genome-sequencing tools in hand, scientists can start linking particular genetic attributes of yeast to flavors — because hops don’t tell the whole story. Explaining a taste in biochemical terms is tricky, says molecular cell biologist Johan Thevelein of KU Leuven. Flavor molecules can be influenced by many genes, and in many cases there’s no easy way to predict what kinds of flavors a yeast strain will make without actually fermenting with it.
That’s what led Thevelein and colleagues to conduct a giant experiment in which they created thousands of genetically different S. cerevisiae strains through breeding. Then they set up thousands of tiny fermentations for each offspring, each one enough to yield about two shot glasses’ worth of beer. The search was for yeast strains that produced lots of the rose- or honey-flavored chemical phenylethyl acetate, and then to pinpoint the responsible parts of the yeast genome. After combing through the results, the researchers found DNA sequences at two spots in the genome that could each cause a big uptick of rose flavor.
The initial discovery was made with brute force. But a slick new genome-editing tool called CRISPR/Cas9 allowed the researchers to recreate those same flavor-linked DNA sequences and thus prove that the two regions truly were behind the sweet rose characteristic. The same tool could enable scientists to create rosier flavors in whatever yeast strain they chose.
Advances like CRISPR editing hold great potential, says Verstrepen. His research group does a lot of old-fashioned yeast breeding, but he’s also got genetically modified yeast sitting in his lab freezer. “With breeding, we can go to 50 percent more fruity,” he says. “But with genetic engineering, you can go tenfold or more.”
Buckets of something better
Sophisticated genome techniques also allow scientists to take a census of the microbial fermenters that nature has already provided, including ones that may have escaped brewers’ notice. Geneticist Maitreya Dunham of the University of Washington and colleagues wanted to see if a method they’d developed, called Hi-C sequencing, could help parse the still somewhat mysterious ecosystem of a barrel of beer. (Dunham has a financial stake in a biotech company based on the method, which allows one to distinguish the genetic material of closely related species.)
So the scientists left their gleaming genetics lab in the heart of Seattle and ventured south, to a dusty warehouse. An eclectic brewer named Cody Morris had been tinkering there with wild beers — brews that start in open buckets and get fermented by whatever microbes happen by. The basement had a dirt floor, Dunham recalls. “There was junk all over the place, cobwebs.” Morris had let nature take its course in buckets of sugary wort that were scattered around the space. One of Morris’s favorite buckets, a beer he sold as “Old Warehouse,” had just been topped off with fresh wort and was full of action, brimming with bubbles. The team took a sample and headed back to the lab.
Their analyses, which appeared online October 19 in the journal Yeast, identified four different yeast species, including one particularly exotic specimen: a hybrid brand new to scientists. One of its parents seems to be a species called Pichia membranifaciens, an under-studied yeast that may protect grapes from a fungal disease but also rots strawberries and other foods. The other parent is unknown. News of Dunham’s discovery spread, and experimental brewers have been requesting the yeast, which the researchers informally call Pichia apotheca, for “warehouse.”
by Laura Sanders, Knowable Magazine | Read more:
Image: Oregon State University
[ed. I don't know... beer seems to taste pretty good already.]
[ed. I don't know... beer seems to taste pretty good already.]
