Two compounds can cause musty, moldy scents in cocoa Chocolate is a beloved treat, but sometimes the cocoa beans that go into bars and other sweets have unpleasant flavors or scents, making the final products taste bad. Surprisingly, only a few compounds associated with these stinky odors are known. Now, researchers reporting in ACS' Journal of Agricultural and Food Chemistry have identified the two compounds that cause musty, moldy scents in cocoa -- work that can help chocolatiers ensure the quality of their products. Cocoa beans, when fermented correctly, have a pleasant smell with sweet and floral notes. But they can have an off-putting scent when fermentation goes wrong, or when storage conditions aren't quite right and microorganisms grow on them. If these beans make their way into the manufacturing process, the final chocolate can smell unpleasant, leading to consumer complaints and recalls. So, sensory professionals smell fermented cocoa beans before they are roasted, detecting any unwanted musty, moldy, smoky or mushroom-like odors.