Temperature control in food is one of the most important aspects of food health and safety. Not only does it ensure that food stays fresh for longer, but it also stops products from spoiling and becoming potentially dangerous to consume.
Most people use fridges, freezers, microwaves and ovens to control the temperature of the food they consume at home, but when it comes to businesses in the food industry, more stringent measures need to be taken to ensure that specific temperature values aren’t exceeded. This is incredibly important from a staff and customer safety point of view, and in this article we’ll go into more detail about the importance of each aspect of food temperature control.
Temperature control is an element of food safety that refers to the control and monitoring of the temperatures at which food is cooked, served and stored. It keeps food products safe for consumption by offering guidelines that ensure harmful bacteria will not have had the conditions to develop and multiply, preventing things like food poisoning.
We all use temperature control when cooking at home, but it’s a particularly important part of health and safety in the food industry because it prevents food waste and keeps customers safe. All businesses that produce, serve or sell food products must adhere to food temperature control guidelines in order to remain compliant with health and safety legislation and protect the people that purchase their products.
The biggest reason that temperature control for food is so important is that it stops the growth of potentially harmful bacteria. When food products are stored in warm and sometimes moist conditions, bacteria and fungus can grow and multiply rapidly, contaminating the food and potentially causing harm to the person that consumes it.
Controlling temperatures for food safety is the only way to prevent the rapid growth of bacteria and ensure that the products you sell to customers are safe to eat. It also keeps food fresher for longer and means that you can reheat leftover food products and safely serve them again, which prevents unnecessary food waste.
Food temperature control is also important because it’s an aspect of health and safety that is covered by official UK legislation. The Food Safety (Temperature Control) Regulations (1995) make it an offence to keep any food products at temperatures where it is likely harmful bacteria will develop, and anyone found doing so will be in breach of the law.
There are several different areas of temperature control in food safety that need to be considered and are all important for slightly different reasons. We will go into the specifics of each of these in the sections below.
A large proportion of the food served to customers from food retailers is hot. Controlling the temperature of hot food is incredibly important because it’s high temperatures that can cause the fastest and most dangerous growth of bacteria in food.
When cooking food for the first time, it should be heated to at least 75°C for two minutes before serving. This is especially important if serving meat or cooked fish, which should be checked using a kitchen thermometer inserted at the core to ensure that the whole product has been thoroughly cooked.
Hot holding is another important part of temperature control with hot food, involving cooked food that is kept at a high temperature for long periods of time so that it can be continuously served, such as in a buffet environment. Food that is being hot held needs to be kept at a temperature of 63ºC or above to prevent any harmful bacteria from growing whilst it is on display.
If you are keeping cooked food hot for long periods of time, you should ensure that the temperature of this is regularly checked to ensure that it has not dropped below 63ºC. Food temperature records should be kept of these checks, and any product found to be below 63ºC must be consumed within 2 hours or thrown away.
Storing food in a freezer does not kill harmful bacteria, but it does suspend it in a state that means it cannot grow. Once food has been defrosted, bacteria may start to multiply again, so it’s important when freezing food to control these low temperatures and ensure that nothing begins to unthaw before it is supposed to.
In order to stop the growth of bacteria, food should be kept in a freezer at temperatures below -18°C. It’s generally recommended that any product kept in a freezer should be defrosted and consumed within six months, particularly leftovers that have already been cooked or any frozen meat and fish products.
Whilst a lot of food temperature control is to do with keeping products at high temperatures, it is also important to keep some food at chilled temperatures. Whilst bacteria cannot be killed by being frozen or chilled, their growth is massively slowed down, meaning that cold food products can be stored or displayed at low temperatures for several days.
Products such as raw or deli meat, prepared salads, sliced fruit, juices, milk, cheese and other dairy products need to be stored or displayed between 0ºC and 5ºC for up to three days before they become unsafe to eat. After this time, harmful bacteria may have slowly developed and present a health risk.
In a commercial kitchen environment, fridge temperatures may also be regularly checked to ensure that they have not exceeded the safe temperature range. Any fridges unable to maintain a safe temperature should be replaced, and any food products in these fridges must be thrown away or immediately cooked, depending on how long they have been outside of the controlled temperature zone.
A big part of food temperature control involves safely reheating food. This is often done if an excessive amount of a product has been made and needs to be reheated and served again the next day to prevent food waste.
The same guidance applies to reheating food as it does to heating it; the core temperature of any food product needs to be above at least 75°C, which should be measured with a thermometer. Temperatures above 75°C need to be maintained for at least two minutes, as this ensures that the product has been kept at a high enough temperature for long enough that all bacteria will have been killed.
Whilst not directly related to temperature control, you should also bear in mind that food should not be reheated more than once. This is because going from one temperature to another multiple times increases the likelihood that some harmful bacteria may grow and make the food unsafe.
An area of temperature control in food that many people overlook is the correct way to cool food products from one temperature to the other. You may think that you can just leave hot food out until it reaches room temperature and is ready to go in the fridge or freezer, but this is definitely not the case.
Guidelines suggest that all hot food should be cooled to below 8°C within 90 minutes, as this means that bacteria is very unlikely to have had time to develop and ensures that the food is still safe to consume. You shouldn’t put any warm food products in a fridge to try and cool them down quickly however, as this can create condensation which can actually cause products to go off faster because it remains at a different temperature. Rapid cooling can also raise the temperature of the fridge above recommended levels, which can then contaminate all the other products in there if bacteria start to grow.
The best way to quickly but safely cool food down is to try and split products up into smaller portions so they cool faster, or use ice and cold water if the kitchen environment is very warm.
The danger zone is a temperature range that refers to the point when harmful bacteria are most likely to develop in food products. The Food Standards Agency states that the danger zone is between 8°C and 60°C, so most of the guidelines around temperature control in food work to keep food at temperatures outside of this range.
Official guidance suggests that food needs to be cooled to 8°C before it is put in a refrigerator. It’s recommended that you try and cool food to this temperature as quickly as possible, as this gets it out of the danger zone and means it can be refrigerated and kept safe for longer without the chance of any harmful bacteria contaminating it.
Whether you’re cooking fresh food or reheating a dish, the minimum temperature that the core of this food should reach is 75°C. This means that the food is out of the danger zone and that the temperature is high enough that any potentially harmful bacteria will have been killed.
The importance of temperature control in the food industry is mainly related to the potential for harmful bacteria growth, but is also connected to keeping products fresh or safe for as long as possible so that they don’t have to be thrown away. Whilst regularly checking the temperature of products and storage areas or equipment may be time-consuming and feel unnecessary, it ensures that high standards are maintained by businesses across catering and food manufacturing businesses and helps everyone to feel that the food they purchase will be safe to eat.
If you would like more information on food safety and temperature control, we cover this topic in greater detail across many of our online Food and Hygiene courses.