For some reason scientists sent ‘miso sauce’ on a rocket to space and back. Then they tasted it

While screening “The Martian,” we were rooting for Matt Damon to sprout some potatoes as he struggled for sustenance. That moment alone carried the heavy weight of a civilization’s expectations from space travel. It has been exactly 10 years since the film was released, and here we stand today, witnessing a true scientific feat — space miso.

Usually, astronauts are left to feast on freeze-dried food. Not only is it heavily devoid of taste, but it also lacks most of the microbes typically found on Earth. This hampers the gut, with astronauts regularly pleading for salty and spicy food. Research finds that they usually undereat despite having full supplies. This is largely owing to the food’s taste (or lack thereof). Astronauts have also reported a reduced sense of taste and smell, which has led to some confusion about the actual reason.

Well, things might be changing. In a paper titled ‘Food fermentation in space: Opportunities and challenges,’ published in April 2025, in the iScience journal, a team of scientists explained a food experiment they had conducted in space along with what it revealed about the “space frontier.” Joshua Evans, along with his colleagues, set out to determine if space can support fermentation and/or influence taste or properties. Leading the research group called Sustainable Food Innovation at the Danish Technical University, he assembled a team of scientists for this endeavor. 

In March 2025, they cooked soybeans, salt, and fermented rice (koji) to create about 1 kilogram of paste. This was split into three equal portions among the scientists — one for Copenhagen, one for Cambridge, and one for Florida, from where it would be sent to the International Space Station (ISS). The container intended for space contained high koji and low salt. The idea was to survey the fermentation process by putting these items in Earth’s orbit. The questions were endless since nothing of the sort had been tried before. The ISS had once received some wine and kimchi, but although they are fermented products, no real fermentation process had been carried out in space.

Before this day, that is. “We didn’t know what to expect — fermentation had never been done before in space,” Evans, the co-lead author of the study, told CNN. After 30 days had passed, the space miso was sent back, after which the fermented batches were frozen again and tested for microbial communities, flavor profile, and sensory elements. They found that not only had the space miso fermented beautifully, but it wasn’t too different from its earthly counterparts. This marks it as “recognizable and safe,” while providing hope for astronauts’ menus in the near future.

The space miso displayed a more pronounced roasted, nutty flavor, possibly due to the effects of microgravity and higher radiation levels. These conditions speed up the fermentation process. In addition, the high temperature aboard the ISS also gave this batch a darker color than its counterparts, as per Space.com. The space miso also differed due to its travel under unusual circumstances, with sensors closely monitoring temperature, relative humidity, pressure, and radiation. All 14 tasters who had the privilege of tasting and comparing the three miso containers agree that space miso's taste stands out as its biggest defining factor.