While cows are often associated with cheese, they do not directly “make” cheese. Cows produce milk, which serves as the fundamental raw material for cheesemaking. The actual transformation of milk into cheese is a complex process carried out by humans, involving specific scientific principles and techniques.
Milk as the Starting Point
Cows produce milk, which is composed of approximately 87% water and 13% milk solids. These solids include fats, proteins (primarily casein and whey), lactose, minerals, and vitamins. Milk’s rich nutritional profile makes it an excellent foundation for dairy products, including cheese.
The Cheesemaking Process
The journey from liquid milk to solid cheese begins with milk preparation, often involving pasteurization. The next stage, acidification, is initiated by adding beneficial starter cultures that convert lactose into lactic acid. This acidification lowers the milk’s pH, controlling undesirable microorganisms.
Following acidification, a coagulant, typically rennet, is introduced. Rennet, enzymes, causes the milk proteins, particularly casein, to coagulate and form a gel-like curd. This process separates the milk into solid curds and liquid whey.
Once a firm curd has formed, it is cut into smaller pieces. The size of these cuts influences the final cheese’s moisture content and texture; smaller curds generally lead to harder, drier cheeses. The curds are then gently stirred and heated, which helps them expel more whey and further develop their texture.
After draining the whey, the curds are salted, which enhances flavor, controls bacterial growth, and aids in moisture removal. Finally, the cheese is shaped and aged in controlled environments, a process known as ripening. During aging, bacteria and enzymes continue to break down proteins and fats, contributing to the cheese’s unique flavor, aroma, and texture.
Why Cow’s Milk is Used
Cow’s milk is the most common type of milk used for cheesemaking due to its specific composition. Its protein content is suited for forming stable curds. Casein, which makes up about 80% of milk’s protein, readily coagulates when rennet or acid is added, trapping fat and other milk solids. This efficient curd formation leads to a good yield of cheese.
The fat content in cow’s milk also plays a role, contributing to the flavor, richness, and texture of the final cheese. While other animal milks, such as goat, sheep, or buffalo milk, are also used in cheesemaking, cow’s milk offers a balance of components that consistently produce a variety of cheese styles. The ease of coagulation and the resulting curd structure make cow’s milk versatile for cheesemakers.