Chalky freeze-dried ice cream and individually packaged mashed potatoes may soon be things of the past for astronauts, as those aboard the International Space Station (ISS) have demonstrated that it is possible to prepare fermented delicacies, such as the Japanese soybean paste known as miso, in space.
This development holds significance not only for the taste preferences of those on the ISS but also for the feasibility of more extensive space missions. One major challenge these missions face, particularly future ventures to Mars, is sustaining astronaut nutrition over long durations. The ability to ferment ingredients could enhance nutrition and provide astronauts with comfort and enjoyment through more flavorful meals.
This culinary achievement began in March 2020 when a team of international food scientists sent a mix of soybeans, rice kōji, and salt to the ISS. Astronauts then conducted an experiment to determine if the mixture would successfully ferment into the familiar miso paste.
Details of why miso was chosen were outlined in the journal iScience, where researchers cited the growing interest in the diversity and uniqueness of miso microbial communities. Additionally, miso’s firm texture minimized the risk of leaks and its fermentation timeline matched the 30-day window available for the experiment. The paste was also selected for its robust flavor and high nutritional value.
After fermenting for 30 days, the miso was returned to Earth for analysis of its chemical and microbial properties, as well as its taste and safety.
Concerns existed regarding the experiment’s success due to environmental differences on the ISS, such as microgravity and higher radiation levels, both of which could have disrupted the fermentation process. Despite these concerns, the fermentation was successful. The space-made miso differed in microbe ratios when compared to Earth samples, yet it was still confirmed to be authentic miso.
Joshua D. Evans, a senior researcher and group leader at the Technical University of Denmark’s Novo Nordisk Foundation Center for Biosustainability, expressed interest in exploring how microgravity and increased radiation levels might affect microbial growth and metabolism, and consequently fermentation.
Regarding the taste, scientists noted that the ISS miso had distinct sensory differences, particularly stronger "roasted" and "nutty" aromas, affecting its flavor profile.
This experiment marks the latest advancement in space food since John Glenn’s historic consumption of a tube of applesauce in 1962. More recently, the ISS has even managed to grow and consume fresh produce like lettuce, and NASA has been actively encouraging new food technology innovations through competitions.
Although missions to Mars and beyond are still in the planning stages, learning how to sustain astronauts without overloading spacecraft with snacks is a critical challenge. The success of making fermented, nutty miso in space provides a valuable step forward in addressing this issue.
