Another common secondary aroma would be the yogurt or sour cream aroma that comes from malolactic fermentation.
Secondary Aromas: Secondary aromas come from the fermentation process (the yeast). A great example of this is the “sourdough” smell that you can find in Brut Champagne that is sometimes described as “bready” or “yeasty.” Yeast aromas can also smell like old beer or cheese rind. Another common secondary aroma would be the yogurt or sour cream aroma that comes from malolactic fermentation. All-and-all, some of these aromas are quite bizarre.