How Cheese Is Made
Thousands of different varieties of cheese are produced around the world from the milk of cows, goats, sheep, water buffalo, yaks, camels — even reindeer and horses. Depending upon the country, this ancient food can hold significant cultural, nutritive, and economic value. Yet making cheese all comes down to a few basic steps:
Bring the milk up to temperature and add the starter culture.
Warming the milk to between 77 and 100 degrees Fahrenheit simulates the animal’s body temperature, which activates the starter culture. The starter culture acidifies the milk, increasing the population of beneficial bacteria.
The starter culture works by fermenting the lactose (natural sugar) in the milk and converting it to lactic acid. When the pH is low enough, the milk will be able to coagulate.
Add a coagulant, such as rennet.
Rennet is an enzyme that occurs naturally in the stomach lining of young cud-chewing mammals (known as ruminants). Instead of traditional rennet, many cheesemakers now use non-animal rennet. Fluid milk can also be coagulated through acidification alone, which is how some soft, fresh cheeses are made.
Check with your cheesemonger about rennet types if you have a dietary preference.
Form and mold the curd, and drain the whey.
After coagulating (Step 2), the milk sets and is then cut, stirred, and often heated to form the right-size curds. The curds are then scooped up or cut, and transferred into perforated forms that will determine the final shape of the cheese.
Whey is the liquid (mostly water and protein) that remains after cheese production. Some cheeses, such as ricotta, are traditionally made from whey.
How the curd is handled is all-important to the cheese it will become. In general, the smaller the curd is cut, the more whey it expels. And if the curd is stacked (as in the cheddaring process), the pressure of the weight expels more whey. Cooking the curd, too, releases more whey. To make a cheese that’s soft and gooey, the curd needs to be left uncut and handled gently — usually hand-ladeled into forms. The opposite is true for harder cheeses, which need to have the moisture expelled from them.
Salt the cheese.
Salt plays several key roles in cheese production: It slows down enzymatic activity, enhances flavor, keeps unwanted organisms away from the cheese, inhibits bacteria growth, and helps form the rind.
Age the cheese.
During the aging process, the rind develops (with the exception of fresh cheeses). Aging needs to occur in a controlled environment, within a specific temperature and humidity range appropriate to that style of cheese.