Sour milk refers to one of Mongolia's dairy products. Sour milk is made from raw milk or cooked milk. To make this product, the milk is kept at about sixty-four degrees Fahrenheit in jars and allowed to ferment for about two (2) days. The milk appears to form chucks. When making sour milk from cooked milk, the milk is boiled first and needs to sit a while longer until it gets slightly sour.