The pH of milk is slightly acidic to near neutral, with a pH range of about 6.4 to 6.9. Fresh milk from a cow typically has a pH between 6.5 and 6.7, but as milk goes sour, it becomes more acidic and tastes sour due to the presence of lactic acid. The exact pH level of milk is less important than whether it is acid-forming or alkaline-forming. Milk is an acid-forming food, and its pH level is below neutral. The acidity of milk can vary slightly depending on factors such as the animals diet, milk processing methods, and the presence of other microorganisms. Other dairy products like butter, hard cheeses, cottage cheese, and ice cream are also acid-forming. Yogurt and buttermilk are alkaline-forming foods despite having low pH levels between 4.4 and 4.8. Raw milk may be alkaline-forming, but it may not be safe to drink untreated milk.