Acidified milk or acidulated milk is the food produced by adding one or more food-grade acids to milk, cream, or buttermilk, with or without the addition of microorganisms. [1] [2] In the United States, acids used to manufacture acidified milk include acetic acid (commonly found in vinegar), adipic acid, citric acid (commonly found in lemon juice), fumaric acid, glucono-delta-lactone, hydrochloric acid, lactic acid (commonly found in fermented milk), malic acid, phosphoric acid, succinic acid, and tartaric acid. [1] Acidified milk lacks certain nutritional benefits that fermented milk has. [2]