Kimchi, the traditional fermented Korean staple, is hugely popular all around the world. But vegans and vegetarians avoid the age-old dish because most recipes call for some kind of seafood to give a little extra umami boost.
Now people avoiding fish can celebrate: Researchers compared kimchi made with fish sauce to kimchi made with miso paste and found the two support remarkably similar microbes, reports Andrew Masterson for Cosmos Magazine.
Sequencing gene samples from the beginning, middle and end of fermentation gave a team led by Brown University's Michelle Zabat, an undergraduate majoring in Health and Human Biology, a good picture of changing bacterial communities over time. The research appears in the journal Food Microbiology.
At first, the researchers found that vegan kimchi was very different on a microbial level from the non-vegan version. Miso, a paste of fermented soybeans, brings its own unique load of bacteria to the brew. But by the end of the fermentation process, both batches featured communities that starred bacteria in two genera: lactobacillus and leuconostoc.
The bacteria unique to miso's savory, salty paste quickly disappeared from the fermenting cabbage, supervising researcher Peter Belenky, a microbiologist and associate professor at Brown says in a press release. “The fact that those bacteria were lost almost immediately during the fermentation was surprising,” Belenky says. “We thought they'd carry over to the kimchi, but they didn't." The salt in the miso may have supported salt-loving bacteria, he suspects. Once in the kimchi, those microbes were overwhelmed by others.
The project was originally a "side venture" in Belenky's lab, Brown University research assistant William Sano told Cate Ryan for the university paper. The lab typically tackles questions about how antimicrobial agents can affect communities of bacteria — so as to better understand antibiotic resistance and other ways bacterial communities affect human health. But Zabat's interest in food science inspired the team to investigate the differences between vegan and non-vegan kimchi.
Commercial kimchi producers, in fact, already have a history of swapping fish products for miso to make vegan-friendly products. The switch works because miso delivers a wallop of glutamic acid — the chemical responsible for the savory, umami flavor, wrote J. Kenji López-Alt for Serious Eats back in 2012.
Vegan kimchi recipes may veer from traditional practices, but the long history of kimchi includes a fair amount of variation. There are about 200 types of kimchi in Korea alone, noted scientists from the Korea Food Research Institute in a 2015 article for the Journal of Ethnic Foods.
The importance of kimchi as a cultural staple may be difficult to overstate, explain Davia Nelson and Nikki Silva, "The Kitchen Sisters," of NPR. "Kimchi is like air in Korea," Hyunjoo Albrecht, a San Francisco-based chef who grew up on the border of North and South Korea, tells NPR.
Now, with at least one version of vegan kimchi getting a microbe-based blessing, even more people around the world are free to enjoy the delicacy.