Whether you work in a food establishment or want to expand your knowledge surrounding food safety and hygiene, it is highly important to learn about the food danger zone in food preparation procedures. Without following the correct precautions to ensure that food is cooked, reheated or stored at the correct temperatures, you could risk making yourself or others unwell with a foodborne illness.
Following the necessary precautions to ensure that food is cooked and stored properly is particularly important for businesses that serve food to their customers and ensure compliance with relevant health and safety legislation.
In this article, we explain exactly how you can keep your products out of the food danger zone, and detail the relevant information you require to ensure the safety of your customers when they dine at your establishment.
A window that the Food Standards Agency (FSA) defines the food danger zone as a window between 8°C and 60°C. The window is a danger zone for bacteria which provides the perfect climate for microorganisms to multiply and potentially cause food poisoning.
From a scientific perspective, this is because any bacteria living above the 60°C mark cannot function or survive, so cannot be of any harm to human health. Equally, any bacteria living below the 5°C mark can only function very slowly, meaning the rate at which they can multiply is much slower than their average rate at warmer temperatures.
You shouldn’t take risks when it comes to checking that your food is cooked to the correct temperature. Not taking the necessary measures to ensure food is cooked or reheated correctly means you may risk making yourself, or someone else, ill from a foodborne illness.
According to the Centre for Disease Control and Prevention (CDC), annually around 2.4 million cases of foodborne illness happen in the UK.
The most convenient way that you can measure the temperature of food when it has been reheated or cooked is by using a food thermometer, also referred to as a food probe.
Different from your standard thermometer, this is specifically designed to measure the internal temperature of food to ensure that it is cooked to the proper temperature throughout. This way, you can ensure that any harmful bacteria have been eliminated before consumption.
Different types of food thermometers are used for different purposes in the kitchen and when cooking. Here are some of the most common.
Digital Instant-Read (Thermistor)
Providing fast and accurate results within around 2-5 seconds, a thermistor can be used to measure the temperature of both thick and thin foods and displays the food’s temperature on a digital display. It cannot be used whilst food is cooking.
Thermocouples are particularly useful because they can read temperatures in as little as 2-5 seconds, so are very efficient if you’re looking to get a fast reading. They are often used in restaurants and commercial kitchens and can measure both thick and thin foods.
However, they are most efficiently used when food is nearly cooked and can be inaccurate during cooking, so are best not used for this purpose. They are also not able to measure food temperature during cooking.
Digital instant-Read (Bimetallic)
Also providing fast and accurate results in 10 seconds, a digital instant-read bimetallic thermometer is useful, but like many other thermometers, it is not able to be used to measure food temperature whilst food is being cooked. They can be used to measure both thin and thick food products.
Dial Oven-Safe (Bimetallic)
Slower than the other thermometers mentioned, the oven-safe bimetallic thermometer reads temperatures within 1-2 minutes. However, its advantage is that it can be used to measure the temperature of foods whilst they are cooking. Be cautious however to place the thermometer at least 2 inches into the food product for accuracy of the reading.
Bimetallic thermometers are most often used for products that are often cooked slowly for longer periods, for example with casseroles and roasts. You’re not advised to use this type of thermometer to measure the temperature of thin foods, and sometimes, because of their metallic nature, readings can be inaccurate due to metal being easily able to conduct heat.
Oven Probe With Cord
This thermometer is often used to measure most foods and has a specific use for measuring the temperature of food inside an oven or within a cooking pot whilst food is cooking. They can, however, also be used outside of an oven.
To correctly use a food thermometer and ensure that you’re accurately measuring the food’s temperature, you need to insert the thermometer into the thickest part of the food, making sure that the tip of the thermometer is not coming into contact with any fat, gristle or bone in the product.
The thermometer also needs to be inserted up until or past the point of the indentation or ‘dimple’ which marks the point at which the probe should be inserted into the food.
Checking the temperature of different food products can also vary. For example, when checking any foods with an irregular shape or that have multiple components (such as a casserole dish), check them in multiple areas. If you have a product that is thin, such as a burger, you can accurately adapt to its shape by inserting your food thermometer sideways to measure its temperature.
When using an instant-read food thermometer, it is best to monitor the internal temperature towards the end of the cooking process, but also again before your food is expected to have finished cooking.
Clean your food thermometer before and after each use. You can do this best with hot, soapy water, but make sure that you don’t submerge any digital components i.e., the head of the thermometer, in water or you’ll risk breaking it.
There are many ways in which you can ensure that your food is reheated to a safe temperature outside of the food danger zone:
Using a hob or stovetop to reheat food is one of the quickest and most convenient ways to do so. Typically, foods like soups, stews and sauces are best reheated on the hob.
A slower method for reheating food, but can be desirable for particular foods if you’re wanting to make sure the texture is maintained, e.g., for pies, casseroles etc.
Using a microwave is an even more convenient method for reheating food. However, it can reheat food products unevenly, so you must reheat your food in regular intervals so that the food can be removed and stirred to ensure it heats properly all the way through.
There are other methods you can use to reheat your food, however, we do not advise them purely because they can keep food in the food danger zone for too long a period, risking microorganisms being able to multiply rapidly within this danger zone for bacteria.
These methods include:
As a rule of thumb: All food products should be reheated to a minimum temperature of 165°F or 79°C. Upon checking with a thermometer, the food product should reach this temperature for a minimum of 15 seconds when checking in different locations. If you are reheating food after refrigeration, the food should be reheated within 2 hours after removing it from the refrigerator.
Remember: Always check the temperature of your food before consumption. You want to make sure that your food is cooked to the correct or desired temperature before consuming it to ensure that it is out of the food danger zone for bacteria.
Knowing how to ensure food is kept out of the danger zone for bacteria when cooking and preparing meals is crucial for our health.
Keeping food out of the danger zone is a straightforward process with minimal variation. Whether you’re cooking and preparing food in a professional kitchen or in the kitchen at home, knowing the correct temperatures at which to store and consume food products and how you can keep food within these safe boundaries is very important.
Here are some of the key things to remember.
Reheating food to a minimum temperature of 75°C ensures that the danger zone for bacteria is avoided and harmful foodborne microorganisms cannot make us ill. The recommended temperature for reheating food, as mentioned above in the section for ‘how to reheat food safely’, is 165°F or 79°C.
Storing food that has cooled at a maximum temperature of 5°C means that the conditions in which harmful bacteria can multiply are avoided. Refrigerator temperatures are usually between the range of 35°F/1.7°C and 38°F/3.3°C, but ideally, you want your refrigerator set between 37°F/3°C and 40°F or 5°C.
If you’re planning on keeping food hot for a period of time, you’ll want to keep it at a temperature of 60°C or hotter. This is because the bacteria that contribute to food poisoning multiply at an extremely rapid rate at temperatures between 5°C and 60°C, so keeping your food above the 60°C mark means that you are keeping it out of the food danger zone.
There are several recommended internal temperatures that food has to be cooked at to ensure that any foodborne bacteria have been eliminated. This varies depending on the food type.
You may find that people cook certain foods to higher temperatures due to texture or taste preferences but, as a rule of thumb, ensuring that your food products are cooked to the following minimum temperatures ensures that food is kept out of the food danger zone and harmful bacteria is destroyed.
Eggs and ground meat:
Recommended temperature of 71°C / 160°F
Fish, Beef, Pork, Lamb and Veal:
Recommended temperature of 62°C / 145°F
Poultry, Game, Foul and Casserole Dishes:
Recommended temperature of 74°C / 165°F
Food that has been removed from the refrigerator should not be left out for longer than 2 hours. This would allow for the temperature of the product to acclimate to room temperature and be in the perfect range for harmful bacteria to multiply, which can contribute to food poisoning.
If the temperature of food is above 90°F/32°C, then food should not be left out for longer than 1 hour. Allowing your food to cool is fine, but remember to refrigerate it no longer than 1 hour after it has been cooked to stop harmful bacteria from having the opportunity to multiply.
If you intend to keep food hot - then do so to a minimum temperature of 167°F or 75°C.
The danger zone is a temperature window between 8°C and 60°C. The number of bacteria present in a food product can double in as little as 20 minutes when within this window, making the likelihood of having food poisoning much greater.
For meat, the danger zone lies between 46.4°F/8°C and 145.4°F/63°C. The most common bacteria that contribute to food poisoning is a bacteria called Clostridium Perfringens (C. Perfringens), which is most often found on poultry and raw meat. Thus, food must be heated to the necessary temperature out of the food danger zone.
Everyone cooks and or reheats food on a daily basis, making it all the more important to ensure that you are heating your foods to the appropriate temperatures to keep your food out of the danger zone for bacteria and reduce the likelihood of becoming ill with food poisoning. Learning how to keep food out of the danger zone may seem like a lot of effort if it is something you have never given a second thought to, but this can make a huge difference to your health and wellbeing in the long run.
If you’d like to learn more about health and safety in the kitchen, we cover this topic in greater detail during our ‘Level 2 Food Safety & Hygiene for Catering’ course, which is RoSPA assured.