14 DAY TRIAL // In cultures that do not consume milk or dairy products, cheese can be one of the most disgusting food items.
Such is the case of China or other nations in southeastern Asia, even if they have their own variant of vegetal cheese, the tofu.
But for animal-based cultures, milk and dairy products are the base of their alimentation, and cheese is extremely priced in the western diet. "All cheese types-there are now more than 1,400--initially arose due to the unique constraints forced by geography and the human effort to preserve the valuable commodity that is milk," said food scientist Paul Kindstedt, of the University of Vermont.
Cheese appeared as a method of preserving the nutritional value in milk for longer periods of time. "The cheese was deliberately built to last, so to speak. But in order to make the cheese long-lived, large and durable, it had to be low in moisture content. The cardinal rule of cheese: the higher the moisture content, the shorter the shelf life."
In a culture that practices the transhumance, it was practically impossible for each herder/shepherd to deliver daily the milk of their herds, so the milk production was kept as cheese in the mountains until the end of the summer. "Whether you're talking about milk from a cow, goat, sheep, water buffalo, camel, yak or any other mammal thats milk is used for cheese-making, all milk contains five basic components," Kindstedt said. And these are: water, lactose ("milk sugar", which gives milk intolerance to populations which are not accustomed to it), fat, protein and minerals.
The milk proteins are of two types: casein and whey. Cheese is basically made of fat and casein, and whey is contained in the liquid left after the milk curdles. Casein has a strong affinity for calcium phosphate (the main mineral of bones and teeth), which binds casein molecules in larger spheres (micelles). The micelles' surface is hydrophilic (water-loving), which gives milk its white color, due to the suspended casein.
To get cheese, water must be expelled from milk, casein must be demineralized, and salt added. As these processes vary, each cheese type has its own water percentage, acidity and salt content, determining its resulting aroma, texture and flavor. "So you've got to get these three parameters right, or the newly-made cheese, which starts out very curdy, very uninspiring, very bland, will never ripen into what it's intended to be," Kindstedt said.
To initiate milk coagulation, rennet (enzymes of the stomach linings of milk-producing mammals) is added to the milk. The rennet cuts off the casein water-loving surface, coagulating the micelles into the curd. In dry types of chees, moisture must drop down to 37 % from 87 %.
The curd is chopped into smaller particles, and the smaller the particle, the more water is expelled. In dry cheese, these may be pea-sized.
After that, the curd is heated and stirred, to lose more liquid. "For some cheeses like Parmigiano Reggiano, they're cooked to very high temperatures with considerable stirring for long periods of time. At the other extreme, some cheeses like brie, traditional brie, receive essentially no heating, no stirring, no cooking." Kindstedt said.
Draining and knitting extort more whey from the curd, while the curd particles bind into a larger mass.
The cheese is also pressed and squeezed to get its final form.
Salt is added by sprinkling or rubbing it on the cheese or by submerging the cheese in a brine; salt further pulls out the water.