Making oncom is almost magical. It starts with a pile of soy pulp, which is wrapped in banana leaves and sprinkled with the spores of a fungus called Neurospora intermedia. The bundle is left to ferment in a warm, humid place for about a day and a half. As the mold digests the proteins and starch within the fibrous pulp, it also breaks down the cellulose, turning what remains into a dish beloved by many across western Indonesia.
“It’s pretty astonishing,” said chef-turned-bioengineer Vayu Hill-Maini.