Chocolate owes its irresistible taste to microbes at work
Like wine and cheese, chocolate reflects its terroir — the soil, climate, and rainfall where it is grown. But much of chocolate’s unique flavor comes from microbes that ferment cocoa beans after harvest. These wild yeasts and bacteria shape whether a bar tastes floral, fruity, or more one-dimensional. From humble cocoa beans to rich chocolate, microbes work behind the scenes to unlock the flavors we love David Gopaulchan, a plant geneticist at the University of Nottingham, and colleagues studied cocoa fermentation on Colombian farms. By cataloging microbial communities and monitoring fermentation changes, they discovered how yeasts such as Saccharomyces cerevisiae kickstart the process by breaking down sugars into alcohol, raising bean temperature. This heat is crucial to kill the beans and prevent germination. Within 48 hours, bacteria like acetic acid– and lactic acid–producers transform alcohol into acids, further breaking down the pulp and releasing flavor precursors. Additional ...