Fermentation in Space

The microbes (bacteria, algae and fungi) that coexist with plants influence everything from fruit colour and flavour to yield. How would microgravity affect this complex ecosystem? A new experiment on the International Space Station aims to answer that very question.

On Wednesday, the ISS crew unpacked the Grape Juice Fermentation in Microgravity Aboard ISS experiment from the Polar freezer. It launched into space on the NG-15 cargo mission on 20th February 2021.

A post shared by Freakshow✨Michael David Winery (@michaeldavidwinery)

There are two grape juice samples on the ISS, packed into 350ml IV bags. Researchers added a typical yeast to one of the bags, which will encourage fermentation. Over the next 15 days, the grape juice will be in the ambient ISS environment, and the crew will remove samples with syringes on days 3, 6, 9 and 12. They’ll put the syringes into the freezer, along with whatever’s left in the IV bags on day 15. 

Two matching bags remained on Earth and will be kept in an environmental control chamber that mimics the ISS ambient temperature. This control experiment will follow the same timetable as the one in space.

A post shared by Freakshow✨Michael David Winery (@michaeldavidwinery)

Before launch, the research team (led by Jeff Farthing of the Michael David Winery in California) analysed the microbial community in the grape juice. When the space-flown samples return to Earth, the team will analyse them and the ground control samples to look for genetic changes.

Humans have been cultivating vines for wine for millennia. We have developed an understanding that small variations in soil composition, water management, and climate (terroir) affect the characteristics (e.g. grape size, shape, colour, flavour and