Traditional Mozzarella cheese is made from milk of water buffalos herded in very few countries such as Italy and Bulgaria. As a result, most of the Mozzarella cheeses available now are made from cow's milk.
This cheese is not aged like most cheeses and is actually best when eaten within hours of its making. The process of making mozzarella is called pasta filata, which means the curds are heated in water or whey until they form strings (hence the term "string cheese") and become elastic in texture. The curds are stretched, kneaded until smooth, and then formed into round balls to make fresh mozzarella cheese.