“I ACTUALLY HATE the taste of mushrooms,” says Josh Hahn, as he flicks on the lights in the clean room. Which is funny, because Hahn’s livelihood depends on fungi. Here, inside the lab at the biotechnology startup MycoTechnology, a few dozen Erlenmeyer flasks slowly gyrate on shake tables. They’re filled with a liquid the color and consistency of cloudy bone broth, a slurry of growth media and, yep, mushrooms. Or, to be more precise, mycelia: the thread-like strands that make up fungal colonies and produce mushrooms but that humans rarely see because they’re below ground.