Sour Taste perception

Sourness is caused by the taste of acids, such as vinegar in alcoholic beverages. Sour foods include citrus, specifically lemons, limes, and to a lesser degree oranges. Sour is evolutionarily significant as it is a sign for a food that may have gone rancid due to bacteria.[17] Many foods, however, are slightly acidic, and help stimulate the taste buds and enhance flavor.