How long freshly potentially hazardous foods can be safely held at temperatures in the danger zone (between 5 and 60 degrees Celcius)
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When it comes to keeping food safe, food storage is a major issue.
Food which is not correctly stored can spoil or become contaminated, which can then lead to making people sick.
Food storage refers to food which is kept it the fridge, freezer, pantry or in some instances a warming receptacle. There are very specific rules regarding the temperatures that food must be stored at, cooked to and reheated to and if not followed, the risk of becoming ill as a result of contamination increases.
General Food Storage
Ensuring that food is properly stored goes a long way towards maintaining a high level of food safety and keeping yourself and others safe. One of the first things to check regarding food which has been stored in the ‘use-by’ or ‘best-before’ dates printed on the packaging.
These dates will give you the most accurate indication of a food’s shelf life, however, when a packet or can is opened, the expiry date almost always changes.
Food should be stored in clean, dry, sanitary containers that are airtight if possible. This will help keep food for longer and reduce the risk of contamination. Food should also be stored off the floor when possible in order to help prevent against pests and other contamination.
Always remember that it is better to be cautious when it comes to food safety and ‘if in doubt, throw it out.’
Refrigerating and Freezing Food
To reduce the risk of bacterial contamination, many foods must be stored in the refrigerator and thus kept below 5 degrees Celsius. These foods are often classified as ‘high-risk foods’ and include – meat, poultry, dairy, seafood, eggs, smallgoods and cooked rice and pasta. This also refers to ready-to-eat foods that have high-risk foods as ingredients and include – casseroles, quiche, pasta salad, pizza, sandwiches and many cakes.
By keeping these high-risk foods under 5 degrees Celsius it stops them from entering the ‘danger-zone’ – temperatures between 5 degrees Celsius and 60 degrees Celsius. The danger-zone is the temperature zone which provides bacteria with the perfect environment to rapidly grow and multiply to numbers that cause food poisoning.
By freezing food its longevity is increased because the water content of the food freezes – this prevents bacteria from multiplying and food spoiling. Food should be kept frozen at -18 degrees Celsius; when thawing, it should be stored in a refrigerator that reaches no more than 5 degrees Celsius until it is ready to be prepared.
Fridges and freezers should be equipped with thermometers so that you can easily check and record the temperatures inside to ensure they are working properly and keeping food out of the danger-zone. Use a weekly checklist to ensure that temperature checks are being done twice a day — click here to download a free Fridge Freezer Temperature Checklist.
It's important to remember that freezing food does not eliminate bacteria and when the food thaws, bacteria will begin growing and multiplying again. It is also important to avoid refreezing food which has already been frozen and thawed as food which is frozen for the second time is more likely to have a higher bacteria count.
When refrigerating and freezing food it is important to keep raw and cooked foods separate as well as storing cooked food above raw food to reduce the risk of cross-contamination.
Cooking and Reheating Food
When it comes to cooking and reheating food, temperatures are just as important as storing food. Even if food has been properly frozen or refrigerated there will still likely be some bacteria present so heating food to a safe temperature will lower the risk of food poisoning.
High-risk food must be heated to at least 75 degrees Celsius in order to reduce the number of bacteria to a safe level of consumption. Once the food has been heated to this temperature it should not be allowed to drop under 60 degrees Celsius until it is served. This goes for both cooking and reheating food and the best way to monitor the temperature is to purchase a food thermometer.
After the food has been cooked to this temperature it should be eaten or refrigerated within two hours. Food which has been kept in the Temperature Danger Zone (between 5 – 60 degrees Celsius) for between two and four hours cannot be put back in the refrigerator and must be consumed. Any food which remains in the Temperature Danger Zone for four or more hours must be discarded.
Hot food which is to be refrigerated or frozen should first be put in separate shallow containers to allow it to cool faster, rather than being left in one container. Also, food that is heated in a microwave should be periodically stirred while heating as microwaves rarely evenly cook food.
To safely prepare food, you should follow these tips:
- keep raw foods and ready-to-eat foods separate to avoid cross-contamination
- use separate, clean utensils and cutting boards for raw foods and ready-to-eat foods, or wash and sanitise utensils and cutting boards between uses
- thoroughly clean, sanitise and dry cutting boards, knives, pans, plates, containers and other utensils after using them
- thoroughly rinse all fruit and vegetables in clean water to remove soil, bacteria, insects and chemicals
- make sure food is thoroughly cooked and the centre of the cooked food has reached 75 °C
- avoid leaving recently cooked food out to cool for more than 1 hour; as soon as food has cooled, place it in the refrigerator
- know about and avoid the temperature danger zone - Bacteria grow quickly in high-risk foods that are kept at temperatures between 5 °C and 60 °C.
- thaw frozen food on the bottom shelf of the refrigerator to keep it out of the temperature danger zone
- take extra care when preparing foods that contain raw eggs – such as egg nog, homemade mayonnaise and aioli – because bacteria on the egg shells can contaminate the food
- be trained in safe food handling and preparation.
Safe food storage and display
To safely store and display food, you should follow these tips:
- keep raw foods and ready-to-eat foods separate, to avoid cross-contamination
- store food in clean, food-grade storage containers
- don’t store food in opened cans
- make sure food storage containers have not been used to store things other than food, and wash and sanitise them before use
- don’t reuse containers that are only meant to be used once
- if a reusable container is in poor condition, throw it out
- cover food with tight-fitting lids, foil or plastic film, to protect the food from dust, insects and cross-contamination
- wash and rinse any garnishes used on food
- store food in areas specially designed for food storage, such as refrigerators, coolrooms, pantries and food storerooms
- never store food on the floor or on pallets, or in areas containing chemicals, cleaning equipment, clothing or personal belongings
- remove and avoid using foods that are past their use-by dates, spoilt, or are in damaged containers or packaging
- know about and avoid the temperature danger zone - Bacteria grow quickly in high-risk foods that are kept at temperatures between 5 °C and 60 °C.
- be trained in safe food handling and preparation.
Cross-contamination
Raw food must be kept separate from cooked and ready-to-eat food. Raw food may contain bacteria, which causes food poisoning.
Cross-contamination happens when cooked or ready-to-eat food contacts raw food. Raw food should always be stored below ready-to-eat or cooked food in refrigerators and display cabinets. This way, juices from the raw food cannot drip onto cooked food.
Cross-contamination can also happen if you use dirty knives, chopping boards or other equipment. If possible, don’t use the same equipment when preparing raw food, and cooked and ready-to-eat food. Thoroughly clean and sanitise equipment after each use.
Bacteria can be transferred to food from your hands. Thoroughly wash and dry your hands before handling food, and between handling raw food and cooked or ready-to-eat food. Also use clean, sanitised utensils (tongs, spoons, spatulas) to handle cooked or ready-to-eat food.
Gloves
Disposable gloves can help prevent cross-contamination. The same precautions should be taken when handling raw food, and cooked or ready-to-eat foods. Wash and dry your hands thoroughly before putting on gloves, and always use fresh gloves.
Change your gloves:
- at least once every hour
- if they become contaminated
- if they tear
- when switching between handling raw and ready-to-eat foods
- when changing tasks
- after taking the rubbish out
- after sweeping, mopping and cleaning.
Temperature danger zone
The temperature danger zone is between 5 °C and 60 °C. Bacteria grow quickly in high-risk foods that are kept in this temperature range.
Cold food storage
You need to keep cold foods at 5 °C or colder, and keep frozen foods frozen solid during storage at –15 °C or colder. Cool rooms, refrigerators and freezers must have proper thermometers, and temperatures should be checked regularly.
Hot food preparation and display
Hot food must be kept at 60 °C or hotter. Bains-marie and other hot food holders are designed to keep food at this temperature.
Do not use bains-marie and similar equipment to heat food. If this equipment is used for heating food, the food will spend too long in the temperature danger zone.
Before placing food in the bain-marie, make sure the food is thoroughly cooked. Ensure that the centre of the cooked food has reached 75 °C. Most bacteria are killed when food is cooked properly.
Some tips for safely using bains-marie include:
- preheat bains-marie before use and operate them on the highest temperature setting
- make sure the temperature of the food does not fall below 60 °C
- use a clean thermometer to check the temperature of the food
- do not overfill bain-marie trays, because the temperature of the food could fall below 60 °C.
Cooling food
Food that has been cooked should not be left out to cool for more than 1 hour. As soon as food has cooled, place it in the refrigerator or freezer.
Note that large portions of food cool faster if divided into smaller portions.
Thawing frozen food
Be sure to keep frozen food frozen solid while it is in the freezer.
Thaw food thoroughly before cooking. Bacteria can grow in frozen food while it is thawing, so keep frozen food out of the temperature danger zone. To do this, thaw frozen food on the bottom shelf of the refrigerator (so the juices do not drip onto other foods) and keep it in the fridge until it is ready to be cooked.
If using a microwave oven to thaw food, cook it immediately after defrosting.
If you have to cook food that is still frozen, make sure that the food is cooked right through, and that its core temperature reaches 75 °C.
Do not refreeze food that has been frozen and thawed already. Freezing does not kill bacteria, and live bacteria are still in food when it is thawed again.
Food serving and labelling
Store food in clean, food-grade storage containers that are strong enough for the food they contain. If containers are reusable, wash and sanitise them before using them. Do not reuse containers that are only meant to be used once.
Food labels or tags can carry bacteria. For cooked and ready-to-eat food, use tags or labels on the trays or containers, and not on the food itself. Be sure not to pierce cooked or ready-to-eat food with tags or labels.
When serving food, make sure that all cutlery and crockery is clean and undamaged.