Food Temperature Control: Cooking, Chilling, Freezing and Reheating

Effective temperature control is one of the most important ways to keep food safe. Correct cooking, reheating, hot holding, cooling, chilling and freezing can reduce bacterial growth and lower the risk of food poisoning.

What Is the Food Temperature Danger Zone?

Many harmful bacteria multiply rapidly in warm conditions. The food temperature danger zone is generally considered to be between 5°C and 63°C.

Good temperature control aims to keep food outside this range whenever possible and minimise the amount of time that potentially hazardous food remains within it.

Safe Cooking Temperatures

Food must be cooked thoroughly to destroy harmful bacteria. The centre of the food, often called its core, must reach a safe temperature for the required length of time.

Standard food safety guidance recommends cooking food to a core temperature of 70°C for two minutes or using an equivalent safe time and temperature combination.

Equivalent cooking combinations include:

• 60°C for 45 minutes
• 65°C for 10 minutes
• 70°C for 2 minutes
• 75°C for 30 seconds
• 80°C for 6 seconds

The correct combination will depend on the food, the cooking process and the business’s documented food safety procedures.

Checking the Core Temperature of Food

When checking food with a temperature probe:

• Place the probe into the centre or thickest part of the food
• Check more than one area when necessary
• Avoid touching bones, trays or cooking containers
• Clean and disinfect the probe before and after use
• Record the temperature where required

Temperature probes should be checked regularly to ensure they are accurate.

Reheating Food Safely

Reheating means heating previously cooked food again, not simply warming it. Reheated food must be steaming or piping hot throughout and reach the safe core temperature specified in the business’s food safety procedures.

Food businesses should:

• Reheat food thoroughly and evenly
• Stir liquids and sauces to remove cold spots
• Check the centre of the food with a clean temperature probe
• Serve reheated food immediately or transfer it to suitable hot-holding equipment
• Reheat food only once

Some bacteria can produce spores or heat-resistant toxins. This is why correct storage, cooling and handling remain just as important as cooking and reheating.

Hot-Holding Food Safely

Food that is being kept hot before service must normally be held at 63°C or above.

Hot-holding equipment should be preheated before food is placed inside it. It should be used to maintain the temperature of food rather than to cook or reheat it.

Hot food may be kept below 63°C for a single period of up to two hours. After this time, it must be:

• Reheated to a safe temperature and returned to hot holding
• Cooled quickly to 8°C or below
• Served immediately, where safe and permitted by the business’s procedures
• Disposed of safely

Safe Refrigeration Temperatures

Refrigeration slows the growth of harmful bacteria but does not normally kill them.

Food that requires temperature-controlled storage must generally be kept at 8°C or below in England, Wales and Northern Ireland. Setting refrigerators at 5°C or below provides a safety margin and helps ensure that the food itself remains within the legal limit.

Refrigerator and food temperatures should be checked regularly to confirm that chilled food is being stored safely.

Keeping Refrigerators Safe and Efficient

Refrigerators should be:

• Kept clean and in good condition
• Maintained at the correct temperature
• Checked regularly for damaged seals or other faults
• Organised to prevent cross-contamination
• Kept closed as much as possible
• Loaded in a way that allows cold air to circulate

Do not overload a refrigerator. Overcrowding can prevent cold air from circulating effectively and may cause some food to become too warm.

Storing Raw and Ready-to-Eat Food

Raw meat and poultry must be kept separate from cooked and ready-to-eat food.

Where raw and ready-to-eat foods are stored in the same refrigerator:

• Place ready-to-eat food above raw food
• Store raw meat and poultry on the lowest suitable shelf
• Keep raw food in covered, leak-proof containers
• Prevent juices from dripping onto other food
• Keep all food properly covered or wrapped

Separate refrigerators should be used for raw and ready-to-eat food wherever the business’s activities and risk assessment require them.

Covering and Labelling Refrigerated Food

Food should be stored in clean, suitable food-safe containers and covered to protect it from contamination.

Containers should be labelled where necessary with information such as:

• The name of the food
• The preparation or opening date
• The use-by or discard date
• Allergen information
• Defrosting information

Storing Food from Open Cans

Once a metal can has been opened, any unused food should normally be transferred to a suitable food-safe container, covered, labelled and refrigerated where required.

This helps protect the food from contamination and prevents possible changes to its taste or quality.

Using FIFO Stock Rotation

Stock should be rotated using the first in, first out system, commonly known as FIFO. This means that older stock is used before newer stock.

Food handlers should:

• Place newer deliveries behind existing stock
• Check use-by and best-before dates
• Label prepared and opened food clearly
• Remove food that is no longer safe
• Follow the manufacturer’s storage instructions

Food must not be used or supplied after its use-by date.

Safe Freezer Temperatures

Freezing is an effective way to prevent bacteria from multiplying. Food should generally be stored at -18°C or below.

Freezing does not usually kill harmful bacteria. Instead, it causes them to become inactive. Bacteria may begin multiplying again when the food defrosts.

Freezers should be:

• Maintained at the correct temperature
• Checked and recorded regularly
• Kept clean and in good condition
• Defrosted when necessary
• Kept closed as much as possible
• Used in accordance with the manufacturer’s instructions

Defrosting Food Safely

Frozen food must be defrosted safely to prevent harmful bacteria from multiplying.

Food should normally be defrosted:

• In a refrigerator
• In a designated defrosting unit
• Using a microwave when it will be cooked immediately
• In accordance with the manufacturer’s instructions

Raw food should be placed in a suitable container while defrosting to prevent liquid from contaminating other food or surfaces.

Food must be completely defrosted before cooking unless the manufacturer’s instructions state that it can be cooked safely from frozen.

Cooling Cooked Food Safely

Cooked food that will not be served immediately must be cooled as quickly as possible before being refrigerated.

Slow cooling allows food to remain within the temperature danger zone, giving harmful bacteria an opportunity to multiply.

Food businesses should have documented procedures to ensure that cooked food passes through the danger zone quickly and is refrigerated without unnecessary delay.

How to Cool Food Quickly

Safe cooling methods may include:

• Dividing food into smaller portions
• Placing food in clean, shallow containers
• Using a blast chiller
• Placing a container in an ice-water bath
• Using cooling racks to improve air circulation
• Separating large joints or batches into smaller amounts
• Stirring suitable liquids using clean equipment

A common food safety target is to cool suitable food to below 8°C within 90 minutes. The correct cooling limit should be established within the business’s food safety management system.

Putting Hot Food in a Refrigerator

Large quantities of very hot food should not be placed directly into a refrigerator if doing so could raise the temperature of other chilled food.

Instead, divide the food into smaller portions and use an appropriate rapid-cooling method. Once sufficiently cooled, place it in the refrigerator without unnecessary delay.

Food must remain protected from contamination throughout the cooling process.

Monitoring and Recording Food Temperatures

Businesses should check temperatures at appropriate stages, including:

• When chilled or frozen food is delivered
• During refrigerated and frozen storage
• After cooking
• During hot holding
• After reheating
• During cooling
• During transport or display

Temperature records should be completed where required by the food safety management system. Any unsafe reading must be investigated and appropriate corrective action taken.

Maintaining Temperature-Control Equipment

Cooking, hot-holding, refrigeration and freezing equipment should be:

• Kept clean
• Maintained in good working order
• Serviced in accordance with the manufacturer’s guidance
• Checked for faults and damaged seals
• Suitable for the quantity and type of food being stored

Staff should report equipment faults and unusual temperature readings immediately.

Why Food Temperature Control Matters

Effective food temperature control helps prevent harmful bacteria from growing and is a fundamental part of food safety.

By cooking and reheating food thoroughly, maintaining safe hot and cold storage temperatures, cooling food quickly and monitoring equipment, food businesses can reduce the risk of food poisoning and protect their customers.