Lab fermentation with defined microbes standardizes cacao flavor

A team of researchers from the University of Nottingham has demonstrated that the fermentation of cacao beans can be reproduced in the lab with a defined mix of bacteria and fungi, effectively standardizing a process long regarded as spontaneous and inherently variable. In controlled lab fermentations using beans from Colombian farms, the scientists produced chocolate with the same fine-flavor characteristics as traditionally fermented beans, suggesting a new era in how high-quality chocolate might be crafted, tracked, and scaled.

Fermentation is the pivotal early stage after harvest, shaping aroma, flavor complexity and bitterness in the final chocolate. On farms, harvested beans are piled in stacks or boxes and left to ferment under the influence of ambient microbes from the surrounding environment. This natural, microbe-driven process can yield a broad spectrum of flavors, but it is also unpredictable, with outcomes that vary from harvest to harvest and from farm to farm. The researchers set out to answer whether this variability could be understood, controlled and reproduced in a laboratory setting by defining the microbial community involved in fermentation.