Rich Shih, the ferment and koji authority behind the OurCookQuest blog, is a mechanical engineer by day and a ferment overlord by night. Between jars of lacto-ferments sits his incubator (an Igloo cooler rigged with an aquarium heater and a bubbler), which currently houses bricks of nixtamalized corn koji in progress.

But for one of his initial trials five years ago, he decided to experiment with popcorn kernels. It’s the most “perfect medium,” writes Shih, his engineering mind-set perfectly at home in the kitchen. He goes on to explain how airy popcorn maximizes surface area for the koji to eat, providing tons of accessible starch while maintaining a great deal of separation. After being incubated for 48 hours in his basement, just north of Boston, the popcorn emerged coated in a white, downy fuzz. It was popcorn koji.

The use and abuse of koji in culinary applications isn’t new, but it has grown increasingly popular over the past five years. The magic ingredient has been lauded for its ability to make food taste like its most perfect version, inject “sweet and salty deliciousness” into anything and even reduce social anxiety and neuroticism.

But what is koji, and how does it work? Koji is most commonly rice inoculated with Aspergillus oryzae, an ancient Japanese mold responsible for the complex, fermented flavors in products like miso, soy sauce and even sake (“koji-kin” refers to the mold itself). As koji’s hyphae consume the substrate, they produce enzymes. For umami purposes, we are most interested in the protease enzymes that convert proteins into amino acids.

We all love the elusive fifth taste “umami,” and koji not only makes free glutamates (also known as amino acids) readily available but also makes them faster. Last year, fellow koji authority and coauthor Jeremy Umansky opened Larder, a Jewish-style deli in Cleveland that serves koji-cured, well, everything, after discovering that growing koji-kin directly on the surface of a coppa (or beets, for vegan charcuterie) cuts the dry time by 50 percent and reveals a variety of previously uncharted flora, fauna and flavor.

So, if koji promises to improve flavor and texture — and in half the time — why not kojify everything? “I mean, of course it tastes good,” explains Shih. “As human beings, we’re biologically wired to crave and seek umami, which is an indicator of protein. But when you bump the umami in everything, it’s not food; it’s crack.” He makes a comparison with fast food. “Take Doritos, for example,” he says. “They add monosodium glutamate to trick our senses into thinking that we’re being nourished with protein, but it’s not.” However, unlike fast food, koji-manipulated foods can be marketed as “natural.”

This doesn’t discourage Shih. While there are some people who are leveraging koji to create umami bombs, he is encouraged by the community that koji affords (he has created the hashtag #kojibuildscommunity for social media users to track and share projects) and the critical thinking and creativity it inspires in the kitchen.