E-Mail 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. Even with this testing in place, spoiled beans can evade human noses and ruin batches of chocolate, so a more objective assessment is needed for quality control. In previous studies, researchers used molecular techniques to identify the compounds that contribute to undesirable smoky flavors, but a similar method has not clarified other volatile scent compounds. So, Martin Steinhaus and colleagues wanted to determine the principal compounds that cause musty and moldy odors in tainted cocoa beans.