(WIRED) — The Momofuku restaurants are famous for their hip, worldly take on Asian cuisine. What’s less well-known are their secret ingredients: mold and bacteria. The fermentation enabled by these microbes is vital to traditional foods from miso to pickles. But even though people have been making these things for thousands of years, says Dan Felder, head of R&D at Momofuku’s test kitchen, “we’re still totally mystified.” So in the Momofuku kitchen laboratory in New York’s East Village, chefs fill plastic boxes with popcorn, adzuki beans, and split peas to study how they decay.