Miso Made in Space Tastes Nuttier, Researchers Find
by Cell Press
Miso is a traditional Japanese condiment made by fermenting cooked soybeans and salt. In a study published in iScience, researchers successfully made miso on the International Space Station (ISS). They found that the miso smelled and tasted similar to miso fermented on Earth—just with a slightly nuttier, more roasted flavor.
The team hopes this research will help broaden the culinary options available to astronauts, improving the quality of life for long-term space travelers.
Understanding Microgravity and Fermentation
"There are some features of the space environment in low Earth orbit—in particular microgravity and increased radiation—that could have impacts on how microbes grow and metabolize and thus how fermentation works," says co-lead author Joshua D. Evans of Technical University of Denmark. "We wanted to explore the effects of these conditions."
Motivated by curiosity surrounding the food options available to astronauts and how microbial communities evolve in space, the researchers sought to determine whether food fermentation was possible in space and what differences might arise in flavor and microbial composition compared to Earth-fermented foods.
Experimental Design
The researchers sent a small container of "miso-to-be" to the ISS in March 2020, where it stayed for 30 days to ferment before returning to Earth as miso. Two other miso batches were fermented on Earth: one in Cambridge, MA, and the other in Copenhagen, Denmark. Environmental sensing boxes kept tabs on the fermentation environment, monitoring temperature, humidity, pressure, and radiation.
Analyzing the Results
Once the ISS miso was back on Earth, the team analyzed its microbial communities, flavor compounds, and sensory properties. They found that the ISS miso fermented successfully, but that there were notable differences in the bacterial communities present in the misos.
"Fermentation [on the ISS] illustrates how a living system at the microbial scale can thrive through the diversity of its microbial community, emphasizing the potential for life to exist in space," says co-lead author Maggie Coblentz of the Massachusetts Institute of Technology.
Flavor Comparison
The researchers compared the flavor and scent of the ISS miso with that of the Earth misos, finding that the samples contained the same aroma compounds and similar amino acid profiles. Taste tests were carried out, and researchers reported that all samples tasted good, with similar salty umami flavor profiles recognized as miso. However, the ISS miso exhibited a more roasted, nutty flavor than the Earth fermentations.
The Larger Implications
"By integrating microbiology, flavor chemistry, sensory science, and broader social and cultural considerations, our study opens up new directions to explore how life changes when it travels to new environments like space," Evans states. He indicates that this research could enhance astronaut well-being and performance on future long-term space missions.
Furthermore, Coblentz believes the impact of this research could extend beyond a single jar of space-made miso. "We've used something as fundamental as food as a starting point to spark conversations about social structures in space and the value of domestic roles within scientific and engineering fields," she explains.
"The way we design systems in space sends a powerful message about who belongs there, who is invited, and how those people will experience space," concludes Coblentz.
More Information
Food Fermentation in Space: Opportunities and Challenges, iScience (2025). DOI: 10.1016/j.isci.2025.112189. Full Text
Journal Information
Provided by Cell Press
