One of regulatory requirements for the meat industry in Canada is to follow the cooling step of the process. There are certain requirements that must be met, e.g. slow cooling: product must cool from 49C to 4C within 20 hours. Now, when we validated our cooling rooms (refrigerators), we encountered a problem which spot should be considered a "warm" spot.
1. The spot that reaches 4C the last, or
2. The spot that has the longest cooling time (for example 19 hours from 49C to 4C).
Very often these spots match, but not all the time.
Have you encountered a problem like this? How did you solve it? Which spot is the official "warm" spot in your validation?