Milk is often pasteurised before humans drink it. It is made into dairy products like cream, butter, yoghurt, ice cream, or cheese. Pasteurised cows' milk will turn sour if it is not kept in a refrigerator. Milk should be stored between 1° and 4° Celsius. If milk is treated with very high temperatures, it will last longer before spoiling. This means it does not have to be put in the refrigerator until it is opened.