Kombucha in Space

Header image: The Expose-R2 facility outside the International Space Station. Image credit: Roscosmos.

Kombucha is a fermented tea beverage, made by fermenting sweetened tea with the help of a symbiotic culture of bacteria and yeast (SCOBY). The SCOBY, often referred to as a “kombucha mother” or “kombucha mushroom,” is a rubbery disc-like mass that floats on the surface of the tea.

Kombucha is known for its slightly effervescent, tangy flavour profile. It is also often consumed for its potential health benefits, as it contains probiotics, organic acids, and antioxidants. Believed to have originated in China over 2,000 years ago, Kombucha has spread across the world – and off it. Bolted to the outside of the International Space Station (ISS) are the same bacteria and yeasts used in making Kombucha.

Tests on Earth have shown that these multicellular biofilms are tough and will most probably survive an unprotected trip through space. But there is only one way to tell for sure, and so the Kombucha-making organisms and other biological specimens are now circling Earth, exposed to space.

The BIOlogy and Mars EXperiment (BIOMEX) is one of the three ESA experiments on the Expose-R2 astrobiology payload, which was installed outside the ISS in August 2014

ESA’s Expose experiments explore the limits of terrestrial life, whether the organisms can survive in space and how the full blast of solar radiation affects accompanying chemicals. For the Expose-R2 project, 46 species of bacteria, fungi and arthropods spent 18 months inside containers bolted to the outside of the ISS.

The vacuum of space is sucking out the water, oxygen and other gases in the samples. Their temperature can drop to –12°C as the Station passes through Earth’s shadow,