Miso Fermented in Space Offers Unique Flavor Insights

Researchers recently performed an important proof-of-concept experiment on the International Space Station (ISS). They were able to ferment miso, a traditional Japanese common seasoning, and learn how the conditions of space can greatly change a food’s taste. The experiment, conducted in March 2020, combined cooked soybeans, salt, and fermented rice known as kōji, which was frozen before launch and allowed to ferment for 30 days in microgravity.

Once back on Earth, the space miso was subjected to careful scrutiny along with two ground-based counterparts produced in Cambridge and Copenhagen. The flavor profiles were judged by 14 tasters made up of chefs and food scientists. They all agreed unanimously that the space miso had decidedly nuttier and more roasted notes compared to its earthly brothers.

The unusual flavor profile of this space miso is all due to its unique microbial community. Most intriguingly, one bacterial species was found only in the ISS batch. Flavor was impacted by the fermentation process in space, which is reflected in this finding. Yet, surprisingly, it introduced new layers of complication to microbial interactions.

Researchers observed that the fungus used to ferment the kōji displayed more genetic mutations in the ISS miso than in the Earth samples. This change could be linked to the higher radiation exposure that astronauts undergo in space. The study highlights how the space environment can impact food fermentation processes and emphasizes that fermentation is feasible for foods orbiting Earth.

Indeed, as MIT’s Space Exploration Initiative researcher Maggie Coblentz recently noted, this research holds great promise.

“Fermentation is a really exciting way to open that up, so to invite a diverse community of microbes that will interact with one another and also preserve food while growing and enhancing flavor.”

This experiment is a big deal, though, because it’s the first food known to have been purposefully fermented in space. It highlights the amazing opportunities to develop innovative, flavorful products in microgravity. While remarkable in and of itself, this leap forward emphasizes the importance of sustainable food production on long-duration space missions.