How is Cheese Made?

by Stephanie Melchert, UNL Nutrition 453

Have you ever wondered how cheese is made? You probably know that cheese is made from milk. But the process of converting milk into cheese may be confusing.

Any mammal's milk can be used to make cheese, but in the United States it is 'ost common to use cow's milk. The next step is coagulation. Coagulation is "the process of clotting or precipitation of a protein in a liquid into a semisolid compound." In the case of cow's milk, the protein coagulated is casein. This can be coagulated either through the use of the enzyme, rennin, or by acid coagulation.

In enzyme coagulation the milk and enzyme are heated to about 95 degrees F in order to foster the growth of bacteria and the formation of curd. Once the curd has formed, the liquid portion (whey protein) is removed. The whey portion can be removed by cutting, heating, salting, knitting or pressing.

Once most of the whey is removed, you are left with a solid mass of cheese curd. This is usually bland and lacking in flavor. In order to add flavor, the cheese must go through an aging process. Bacteria and mold growth may help to develop those flavors as the cheese sits in different varieties of temperatures and humidity's depending on what type of cheese is being made. The aging process ranges from four weeks to as many as two years or more.

After the aging process is complete the cheese curd is formed into bricks and packaged for you to purchase and enjoy.

Reference: Understanding Food: Principles and preparation by Amy Brown 2nd ed. 2004.