Researchers are investigating how microgravity affects beer brewing, not just for the prospect of one day drinking beer in space, but also to ensure human survival beyond Earth.
Nearly every civilization throughout history has used fermentation to make everything from alcohol to bread, pickles, and yogurt. As humanity’s technological knowledge has expanded, we’ve applied the same chemical principles to a variety of uses, including medicines and biofuels. Fermentation may not be the first necessity that comes to mind when planning a moon base or long-term settlement on Mars, but the fermentation process is essential to the success of any long-term mission.
To explore how these concepts might work outside of Earth, a team from the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) first conducted experiments to brew beer in microgravity, the results of which are published in the journal Nature. Beverageshas shown that microgravity can not only speed up the fermentation process but also potentially produce a higher quality product.
“As we continue to explore space, fermentation in microgravity will undoubtedly be a future endeavor, and the outcomes will be very difficult to predict,” said study co-author Andrew McIntosh, associate professor of food science at the University of Florida/IFAS. News from the University August 14th.
But sending a brewer’s starter kit to the International Space Station is still in the planning stages. Instead, a team from the University of Florida, led by undergraduate researcher Pedro Fernández-Mendoza, built a tiny microgravity simulator on Earth. After gathering locally grown barley and turning it into wort (the sugary liquid from grains that’s essential for beer and whiskey), Mendoza and his colleagues separated it into six samples. Then they added yeast, which is used in lagers. Saccharomyces pasteurolianusIn one experiment, the researchers injected yeast into each tube, leaving three tubes as controls. The remaining three were placed in a clinostat, a device that can simulate microgravity conditions by constantly rotating its contents around a horizontal axis. Over the course of three days, the researchers periodically assessed the density, yeast count, and yeast viability of the fermenting baby beers.
After three days, the researchers were able to confirm one of their original hypotheses: that microgravity would not have a negative effect on fermentation. Moreover, the fermentation process actually accelerated in the clinostat samples compared to the control group. But there was another unexpected result: microgravity yeast could produce a higher quality product than simply fermenting it on Earth. Although more investigation is needed, the researchers think this may have to do with a specific gene in the yeast that controls the levels of esters, the fermentation by-products that determine whether the beer tastes good or bad.
[Related: The science and history of the evolution of lager.]
Typically, the ratio of the amount of high-alcohol groups to lager esters ranges from 3 to 4:1, with higher ratios resulting in drier, less aromatic beers. The team recorded a ratio of 4.6:1 for the microgravity beers compared to 1.4:1 for the control samples, suggesting that the latter “was less aromatic by this standard.” Meanwhile, two esters in particular, isoamyl acetate and 2-phenethyl acetate, showed “significant differences” between microgravity and the control. High concentrations of these esters give beer a fruity, banana-like flavor that is often considered objectionable by many drinkers. Ester concentrations were “reduced by several fold” in the microgravity brews compared to the standard examples.
“While these compounds may be desirable in some breweries, their presence above detection limits is typically considered a defect,” the team wrote. Taking this into account, the microgravity results provided a final product that was “considered to be of higher quality” due to the reduction in esters.
As for brewing beer in space, the researchers now believe that microgravity could potentially help make the beer taste better, potentially offering “advantages that can’t be realized on Earth,” but McIntosh and his team can’t prove any potential benefits just yet, because they haven’t tested their brew.
“Unfortunately, when you make beer for science, you use pretty boring recipes,” he says. Popular Science They always write, “We have several local collaborators who make very high quality beers and we rely on them for quality when we feel it is necessary…”
