Hops generate both a beer’s taste and its aroma. And now researchers at Oregon State University have found that it’s possible to alter a beer’s aromatics using synthetic biology that doesn’t involve hops.
Here’s the deal…
Craft beer production in the US has grown exponentially over the last twenty years with hop-forward beer styles, such as India Pale Ales, leading that explosion.
Defined their pungent flavors and aromas these IPAs are typically made using large amounts of aromatic hops, with the essential oils in hops being the main contributor to aromas in beers.
But now Oregon State University brewing researchers and a team of bioengineers have shown that a genetically modified yeast strain can alter the fermentation process in such a way as to create beers with more pronounced hop aromas.
Many aromatic compounds are present in the hop’s essential oils, including thiols, which provide tropical aromas to beer. But thiol content can vary significantly among different hop varieties and harvests.
So Tom Shellhammer, a Nor’Wester Professor of Fermentation Science at Oregon State, enlisted the aid of Richard Molitor, a former Oregon State graduate student now working at Boston Beer, and along with a team of scientists at Berkeley Yeast set out to boost the concentrations of tropical flavored thiol molecules in beer using a genetically modified yeast strains rather than hops.
The Oregon State researchers brewed batches of beer using four versions of the genetically modified yeast strain and a conventional, unmodified version of the yeast.
“These findings could be extremely useful in creating new beer flavors and increasing the number of tools brewers have at their disposal for producing beers with strong and varied tropical flavors and aromas,” said Tom Shellhammer, an internationally recognized expert in hops chemistry.
When I was tasting these beers my eyes popped out of my head,” Shellhammer said. “This really represents a quantum shift, not just an incremental shift, in terms of the expression of these strong flavors.”
The findings which were recently published in the journal Fermentation, demonstrate how synthetic biology can help protect industries and consumers from the effects of climate change, said Jeremy Roop, a co-author of the paper and a bioengineer with Berkeley Yeast.
“The genetically modified yeast strains provide brewers an alternative means to produce tropical fruit flavor without relying on large amounts of hops,” Roop said. “This also translates to greater consistency in the brewing process.”
“The new strains are not meant as replacements for hops,” Shellhammer added, “instead they offer brewers a new tool for producing interesting and distinctive beers while also improving the sustainability of the entire brewing supply chain.”
(Image credits: OSU Today)