Pasteurization

Milk is a kind of culture soup for bacteria and other disease-causing organisms and has, in the past, been the vehicle for the spread of vile things like tuberculosis and listeria. Pasteurization is nothing more than heating the milk to a temperature high enough to kill dodgy microbes.

The most frequently used technique is that of heating the milk to 62°C/144°F and keeping it at that temperature for half an hour, then rapidly cooling it. This also extends the milk’s life before the fats split and it sours.