Mastered sourdough? Nerd out over macroscopic mold

Koji is a mold that survives by growing on its food source, secreting enzymes that perform special tasks such as breaking down starches into simple sugars. Koji does the hard work, kickstarting fermentation, while Jeremy Umansky and Rich Shih reap the rewards of creating complex boosts of flavor. Their book is “Koji Alchemy.”