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This side dish of spicy, bubbly, funky pickled vegetables is such a staple in Korea that no meal is considered complete without it—and recently, kimchi has found its way into burgers, pasta, grilled cheese, and even tacos. In this episode, we trace the behind-the-scenes story of the “kimchi diplomacy” that turned Korea’s favorite fermented cabbage into an international food trend. And then, because we’re Gastropod, we take part in our very own cutting-edge science experiment to understand one of kimchi science’s most mysterious questions: Where do the microbes that transform the sugars in cabbage into such tangy, savory flavors actually come from? Is it our hands? The soil? Or could the secret to all that deliciousness actually lie in the stomachs of beetles and bugs? Listen in this episode for kimchi secrets, kimchi explosions, and a little bit of kimchi K-pop, too.

“Koreans traditionally have kimchi at all three meals: breakfast, lunch, and dinner,” the food ethnographer Kevin Kim told us. Some scholars say the true origin of kimchi lies in China and Chinese fermented vegetables, while others point out that the chili pepper that gives most kimchi its distinctive spiciness is a New World ingredient. But kimchi is so quintessentially Korean that, according to the historian Michael Pettid, as early as 2,000 years ago, Chinese records remarked on the special fondness that people living on the Korean peninsula had for fermented vegetables.

More recently, Kim said, Korean politicians have invested heavily in supporting kimchi producers, kimchi science, and kimchi marketing campaigns as a “soft power” strategy to promote the country and its culture overseas. Their efforts have paid off. As Lauryn Chun, the creator of Mother-in-Law’s Kimchi and the author of The Kimchi Cookbook, can attest, today kimchi is found on grocery-store shelves across America, where it’s beloved for its salty, spicy, garlicky crunch, as well as its probiotic potential. Some credit the kimchi taco, which the chef Roy Choi first served from his Los Angeles–based Kogi food truck in 2008, with inspiring kimchi’s cult status among foodies, but kimchi has since gone mainstream: In the past decade, the condiment has begun popping up on chain-restaurant menus from TGI Friday’s to California Pizza Kitchen.

Surprisingly, it turns out that all that deliciousness is dependent on a set of microbes—specifically lactic-acid bacteria—that is extremely hard to find on cabbages or in the field. “One thing that I find really fascinating about kimchi compared to other fermented foods is that, unlike cheese or salami or yogurt, where you use starter cultures—these microbes that you buy—kimchi is not inoculated,” says the Tufts University researcher Benjamin Wolfe, who also serves as Gastropod’s in-house microbiologist. This made him wonder: If these bacteria don’t really like to hang out on cabbage leaves, and we don’t intentionally add them to our ferments, where do the microbes that turn cabbage into kimchi come from?

To investigate, we teamed up on an experiment of our own, making multiple large jars of kimchi in an attempt to discover whether the microbes in the final ferment differ depending on the farm where the cabbage was grown. Listen now to find out the results of the experiment—and hear stories of insect-smushing, kimchi block parties, and the kimchi that was specially designed for space!


This post appears courtesy of Gastropod.

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