Ensure Food Safety through Fast Cooling Processes
Improper fast cooling is the leading cause of food safety outbreaks in restaurants, hotels, hospitals and schools.
Harmful pathogens grow in the so-called ‘Danger Zone’ between 63°C (140°F) and 5°C (40°F) and flourish in particular in the ‘Super Danger Zone’ between 49°C (120°F) and 20°C (70°F).
Protein-rich foods pose a significant risk, and are responsible for the majority of outbreaks of foodborne illness. Food service operators should pay special attention to foods containing meat, dairy or eggs. The golden rule is to bring cooked food as quickly as possible down to a safe temperature, and to store it in a way that does not allow heat to linger or transfer where large volumes are involved.
The Food and Drug Administration (FDA) requires food to be cooled from 57.2°C to 21.1°C (135°F to 70°F) within two hours and from 57.2°C to 5°C (135°F to 41°F) within a total of six hours.
In Europe, the food needs to be brought down from 63°C to 5°C in less than 2h.
This is the accepted standard across the food service industry.
The most common mistakes, in both domestic and commercial kitchens, are leaving cooked food at room temperature for too long, and transferring hot food directly to a refrigeration unit.
Remember that contaminated food may show no visible signs of bacterial growth, and often emits no odor that would indicated danger.
Another common misconception is that cooking food destroys pathogens.
On the contrary, many foods (even rice) form heat-resistant spores that multiply at an astonishing rate within the Danger Zone.
Especially when cooling large pots of sauce, stew or casserole, it is important to break down the volume of the food into smaller portions to accelerate cooling. Large meat joints, whole poultry or big batches of soup/stew can take a day or more to cool to 4°C (40°F).
As a result, food service operators should:
- Break down large volumes into shallow trays, which have a larger surface area and therefore cool quicker. These trays should be uncovered at first, but covered once transferred to a cooler
- Cut down large meat or poultry cuts into smaller slices to draw heat away from the core
- Place containers in a cold water or ice bath to draw out heat
- Use containers that conduct heat efficiently, most notably aluminum or stainless steel
- Use a blast chiller to bring the temperature down quickly at first
- Stir food with a sterile utensil or cooling wand during cooling to distribute heat evenly
- Place containers in the cooler with plenty of room to let air circulate. Do not, for example, overload the fridge or stack pans on top of each other.
Safe food cooling is an integral part of the HACCP process. It is an area where nothing should be left to guesswork or the senses. Use an automated tracking system with clear labelling to schedule and manage cooling times and temperature, not only to monitor food in a live environment, but also to produce clear evidence in the event of a safety outbreak.
Recording cooling processes is mandatory to show due diligence