Natural mozzarella cheese is produced from buffalosí or cowsí milk and the most prominent fat present is milkfat. Mozzarella cheese originated from Italy but the United States has become its principal producer. This cheese had remained an ethnic product with a limited market until around World War II, when Italian cuisine in general and pizza pie in particular, began its meteoric rise in popularity that continues to the present. Mozzarella cheese constitutes one of the most expensive ingredients of a pizza pie. It is normally used as a topping and its major function is to cling on to all the other ingredients as it melts.