After pasteurization, milk should be rapidly cooled down to 4.5°C. A temperature
rise to over 5°C results in an alarm and if it cannot be stopped, the process should
be stopped at a temperature above 6°C (Dijkers et al., 1995). Although GMPs include
the necessary maintenance of the equipment, leaks in the barrier between milk and
cooling fluid may eventually occur. To control the hazard of recontamination of
pasteurized milk, a slight over-pressure on the side of milk is exerted (van Schothorst
and Kleiss, 1994).