Does Cinnamic Aldehyde (Cinnamaldehyde) Affect Yeast Activity In A Dough? The answer is Yes, Cinnamic Aldehyde is a organic compound giving cinnamon its unique flavor, taste and aroma. It is the main component In flavorings and extracts. Using high amounts of these extracts or flavor compounds that contain Cinnamic Aldehyde will affects the yeast activity in yeast based doughs. In actual productions where Cinnamon extracts that contained Cinnamic Aldehyde where used at 2-3% in frozen bread applications yeast activity was impeded by 80% even with fresh yeast amount of 8% in these frozen raw dough applications.