Heat Treatment: Raw, Thermized, or Pasteurized Milk
Cheese may be prepared from raw, thermized or pasteurized milk. Whereas fresh cheeses are mostly prepared from pasteurized milk, sometimes even at relatively high temperatures, ripened cheeses may be prepared from raw or thermized milk as well. Although traditional extra-hard-cooked cheeses are microbiologically safe due to the long ripening period (more than 6 months) at ambient temperature, soft cheeses prepared from raw milk, due to their short ripening period, cannot rely on this self-sanitizing process and must therefore be strictly monitored regarding the microbiological quality of milk supplies, notably for the presence of pathogens.
Homogenization of Cheesemilk
Homogenization of cheesemilk is a common practice for certain types of fresh cheese, notably those produced by lactic coagulation, and for some blue cheeses, where a high degree of lypolysis should be obtained within a shorter time of ripening.
The texture of the cheese becomes finer, smoother, and more stable. The color of the cheese becomes whiter, similar to goat or ewe cheese, and this characteristic is sometimes appreciated. This treatment offers also the advantage of reducing the losses of fat into the whey, probably incorporating caseins into the membranes of the fat globules.
Less common is the use of milk homogenization when making ripened cheese. Homogenization favors lipolysis and this is not always seen as an advantage, but in the case of blue cheese. In addition the milk treatment at high pressure may decrease the tension of the gels while certainly may contribute to increase the cheese yield due to higher water retention in the curd.
Either milk or cream may submitted to homogenization, and their volume may be either total or partial (if only one part of the cheese milk is treated).