31-07-2025
Miso produced in 1st fermentation attempt in space tasted 'nuttier'
Miso that has been returned to Earth after being fermented in space (Provided by Maggie Coblentz)
In one small step for astronaut foods and one giant leap for Japanese cuisine, miso became the first successful fermentation in space, although it had a stronger flavor than paste produced on Earth.
A scientific paper was published this past spring trumpeting the success aboard the International Space Station.
The U.S. and European researchers who conducted the study chose miso, instead of cheese or wine, as the food item to be fermented.
An interview with leading authors of the article showed their enthusiasm for the selection of the traditional Japanese condiment.
'I think 'surreal' is the word.' 'Yeah, it was crazy.'
Maggie Coblentz, a research affiliate of space food with the Massachusetts Institute of Technology Media Lab, and Joshua Evans, a senior researcher of fermented foods with the Technical University of Denmark's Center for Biosustainability, sounded excited as they were interviewed.
A group of scientists including Coblentz and Evans prepared a mixture of steamed soybeans, rice koji (boiled rice fermented with the Aspergillus oryzae fungus) and salt, and put several hundred grams of the paste in a transparent, semihermetic container.
They sent the mixture aboard a rocket to the International Space Station in March 2020.
The space facility is under 'microgravity,' equivalent to one-10,000th to one-one-millionth of the gravity on Earth.
The paste was kept for about 30 days in a special box that can sense changes in temperature, humidity, off-gassing and other conditions.
The container was returned safely to Earth, even though the power supply was disrupted a few times.
The scientists said they had to overcome many hurdles during the experiment.
They received a succession of inquiries from the ISS operator, including on the possible toxicity of the fermentation and on potential impact on other equipment aboard the ISS.
They grappled with mountains of documents to clear the rigorous safety standards one by one.
That was a single-shot test, wherein the experimental equipment couldn't have been repaired even if had succumbed to abnormalities in space.
The researchers were told, ahead of the rocket lift-off, that a strange smell was coming from their equipment. They explained that was just the miso, giving off a beautiful aroma.
CLOSE SHAVE OF 3 DAYS
The rocket was launched around the time COVID-19 was raging across the globe.
Evans said that, had the lift-off been scheduled for three days later, the experiment could have been rendered impossible by the pandemic-imposed lockdowns.
Analysis of samples taken from the container of the miso raw materials showed they contained microbes of the same species that are found in miso fermented on Earth.
The scientists concluded, on the basis of the taste, aromas and ingredients, that miso was present.
Following peer-reviews and other procedures, their article was published in iScience, a U.S. science journal, in April to describe what they label as the first food fermentation experiment in space.
Western media outlets covered the topic of the 'space miso' one after another.
That is considered the first time that food was fermented aboard the ISS, even though a test culture of yeast cells, wine maturing, and other processes had taken place earlier in space.
The researchers said the space miso contained more glutamic acid, an umami ingredient, than miso made from the same raw materials during the same period on Earth, and had a stronger 'nutty' and 'roasted' aroma.
But lactic acid bacteria and yeasts, both of which are considered essential for Japanese miso production, were not found in the space miso.
A chef who has lived in Japan used the space miso residue from the experiment to prepare miso soup, which members of the research team relished.
'Bringing it to space was really exciting for us to expand the creativity and the challenge of how to cook and prepare miso,' Evans said. 'It offered me the chance to view Earth as if I were seeing it from space by proxy.'
FOOD DIVERSITY INSTEAD OF BIAS
Coblentz stressed food diversity as she explained why she and her colleagues chose miso for the first fermentation project in space.
Western food items account for the bulk of the space food offered aboard the ISS.
'Much of the research on fermented foods has tended to be predominantly in English,' Evans said. 'There can sometimes be a bias toward Western products such as bread, cheese and wine. Why not use that platform to showcase a greater diversity of products and traditions?'
Since it is said that humans have a reduced sense of taste in outer space, nutritional efficacy is the major consideration in space food.
'Something like miso is really powerful because it's so concentrated in umami, protein, and flavor, and it is very versatile culinarily,' Evans said. 'It struck us as the ideal choice.'
There are expectations the latest experiment will mark a step toward food diversification, which would make long-term stays in space closer to life on Earth in the future.
In addition, the experiment will also be helpful for research on fermentation processes under microgravity.
The experiment used rice koji spores, an essential ingredient for miso production, that were manufactured by Bio'c Co., a seed koji maker based in Toyohashi, Aichi Prefecture.
Bio'c officials said they learned of the fact only upon reading the article.
'I find it a great honor that our product was used there,' said Bio'c President Yuichiro Murai. 'Miso is popular in Western countries, where, as I have been told, many people eat it without knowing that it has its origins in Japan. I hope we will take this opportunity to advertise the charms of miso.'
SAKE BREWER IN WAITING
Dassai Inc., a sake brewer based in Iwakuni, Yamaguchi Prefecture, is hoping to follow on the heels of the miso fermentation by making Japanese rice wine in space.
The company has plans to send a set of raw materials and equipment, aboard a domestically produced H3 rocket, to the ISS's Japanese experiment module Kibo by the end of this fiscal year.
The raw materials will be placed in a special device for fermentation into 'moromi' sake mash, which will be returned to Earth in refrigerated storage, where it will be used to make a commercial product, Dassai officials said.
A 100-milliliter bottle of sake from the project was put on sale, through a preorder, to the tune of about 100 million yen ($670,000). The preorder slot has already been sold, company officials added.
Dassai CEO Kazuhiro Sakurai said he felt heartened by the space miso experiment, as he has ambitions to brew sake on the moon in the future.
'The fermentation process in space marks a very big step,' Sakurai said. 'Humans will need pleasures and delights when they expand their sphere of living to outer space in the future. I hope that sake has a role to play there.'
Takeo Koizumi, director of the nonprofit Fermentation Culture Promotion Agency, sounded skeptical about the authenticity of the space miso.
'It remains open to question whether that could be called a miso of the sort that Japanese usually have in mind,' he said, pointing out that yeasts and other microbes were not found in the space miso.
But Koizumi sounded more upbeat as he added: 'The very fact the space miso became the talk of the town across the world is a positive note for the future of Japan's fermentation culture.'
