What Is Mozzarella Cheese and What Is It Made From?

Buffalo milk mozzarella with pesto of dry tomatoes and cashew nut
Luca Nebuloni/Flickr

True mozzarella cheese is made from water buffalo milk. However, most of the mozzarella cheese you see in the supermarket is made from cow's milk. Mozzarella cheese is a sliceable curd cheese originating in Italy. Traditional mozzarella is made from the milk of water buffalo (not North American buffalo or bison as many mistakenly think) and its flavor is highly prized.

How is Water Buffalo Milk Different?

Water buffalo milk is very high in fat and casein and not easily digestible in its raw form.

It is not consumed as a beverage but is used for making mozzarella, burrata, ricotta di bufala, yogurt, and similar products. The milk of the Italian Mediterranean buffalo is three times more expensive than cow's milk and is costly to ship, so expect a correspondingly high price tag on imported buffalo mozzarella. You may see it labeled mozzarella di bufala. Since these animals are herded in only a few countries, primarily Italy and Bulgaria, most mozzarella is now made from cow's milk. The Italian Mediterranean buffalo breed is believed to have been introduced to Italy in Roman times or later Barbarian invasions of Italy.

In Italy, if you want cow's milk mozzarella, you ask for mozzarella fior di latte, which may be made with pasteurized or unpasteurized cow's milk. In the U.S., this would be the same as the common mozzarella seen in the cheese section of the supermarket. Mozzarella contains 40 to 45 percent fat.

Lower-fat versions are made with part skimmed milk.

Sheep's milk mozzarella can be found in some areas of Italy, including Sardinia, Abruzzo, and Lazio. Goat's milk mozzarella is made by some small producers.

How Mozzarella Is Made

Mozzarella 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. The milk is incubated with a whey starter containing thermophilic bacteria. Then rennet is added to form the curds. 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. 

It is easy to make homemade mozzarella cheese. You need only rennet, citric acid, milk, and water. You can find rennet and citric acid in specialty markets and health food stores that may cater to home cheesemakers, or online. In 30 minutes, you can have fresh mozzarella to enjoy and impress your family or guests.

Use and Storage

If you buy or make fresh mozzarella, you should keep it in liquid until you are ready to use it. Packaged mozzarella usually includes some liquid. Keep mozzarella refrigerated. Because of the high moisture content, it does not keep as long as harder cheeses. Low-moisture mozzarella will keep longer.

Mozzarella can be used in a variety of recipes, including salads, meats, poultry, seafood, and vegetables. You are probably familiar with shredded mozzarella used on pizza and baked Italian dishes.

 Caprese salad with fresh mozzarella, tomato, basil, olive oil, and capers is a delightful traditional use of mozzarella.