Bringing cooked food down through the danger zone quickly, from 60 degrees C to 21 degrees C within 2 hours and to 5 degrees C within a further 4 hours.
Cool from 60 degrees C to 21 degrees C within 2 hours, then from 21 degrees C to 5 degrees C within a further 4 hours.
The hotter part of the range lets bacteria grow fastest, so getting food below 21 degrees C quickly is the most important part of safe cooling.
Divide food into smaller or shallower portions, use shallow trays, stir, use ice baths or an ice paddle, or use a blast chiller and a cool area.
It is not recommended. A large mass can cool too slowly in the centre and warm other food in the fridge. Portion it down first to cool quickly.
If it has not passed the checkpoints in time, it may need to be reheated rapidly to 60 degrees C and cooled again correctly, or discarded if that is not possible.