How does milk become into cheese?

Milk undergoes a process of transformation to turn into cheese through the action of specific enzymes and bacteria. Cheesemaking involves several key steps:

1. Acidification: The first step is to acidify the milk, which is done by introducing a starter culture of lactic acid bacteria (LAB). These bacteria convert lactose, the natural sugar in milk, into lactic acid. As lactic acid accumulates, the pH of the milk decreases, causing the milk proteins, especially casein, to destabilize and form a gel.

2. Coagulation: Once the milk reaches the desired acidity level, it is coagulated by adding rennet, which is an enzyme complex traditionally derived from the stomachs of young mammals like calves or lambs. Rennet contains specific enzymes, such as chymosin, that act on the casein proteins in milk, causing them to coagulate and form a semi-solid gel-like substance called a curd.

3. Cutting the Curd: The curd is then cut into small pieces to facilitate the expulsion of whey, the liquid part of the milk that remains after coagulation. Cutting the curd also helps in controlling the final texture and moisture content of the cheese.

4. Heating and Cooking: After cutting, the curd is heated gently to further firm it and expel more whey. This step also helps in controlling the cheese's final texture and consistency.

5. Draining and Pressing: The whey is drained from the curd, leaving the solid curds behind. Depending on the desired type of cheese, the curds may be placed in molds and pressed to expel additional whey and shape the cheese.

6. Salting: The cheese may be salted either by dry-salting the curd directly or by immersing it in a salt brine solution. Salting helps in preserving the cheese, enhancing its flavor, and controlling its moisture content.

7. Ripening and Aging: Finally, the salted cheese is left to ripen and age for a certain period. During this time, the cheese undergoes further biochemical changes and develops its characteristic texture, flavor, and aroma. The ripening environment, temperature, and humidity play significant roles in determining the final characteristics of the cheese.

It's worth noting that different types of cheese may involve variations in the cheesemaking process, such as using different starter cultures, varying rennet usage, aging times, and additional steps like washing, rubbing, or smoking the cheese.