The operation of a refrigerator is similar to that of air conditioning. When the appliance’s interior exceeds the temperature assigned in the thermostat (from 4ºC to 8ºC, depending on the zone), the compressor that cools the interior starts up.
Again, when the set temperature is reached, the compressor stops. But what happens when the refrigerator door is accidentally left open for a long time? Does the temperature rise so high that it spoils the products inside? The refrigerator is one of the great allies to guarantee safe food.
For its function to be perfectly fulfilled, the interior must maintain a temperature of 5 ºC or lower. At this temperature, microorganisms multiply very slowly.
The everyday gesture of opening the refrigerator door to take a product from inside already modifies the appliance’s internal temperature. By doing so, the cold air from the inside escapes to the outside, and, in turn, the warm air entering the inside increases its temperature.
left refrigerator door open: What to Expect
Can you leave a refrigerator door open? No. In general, refrigerated foods are safe, as long as the lack of cold has not exceeded a few hours.
It should be taken into account that, in cases where the power goes out, if the refrigerator door is kept closed for about 4 hours, it is possible that all the food can be used without any problem.
The risk increases if the door has been open all night or for about 11-12 hours. In this case, some foods may not “survive” the lack of cold. You can check the temperature by looking at the displays that mark the temperature or put a thermometer to ensure that the interior is at 5 ºC.
Leaving the refrigerator door open for more than four hours will have negative repercussions, especially for perishable products, that is, those that need refrigeration to be kept in optimal conditions.
Other foods, however, can survive longer at room temperature. In the Food Safety and Inspection Service (FSIS), the United States Department of Agriculture advises to discard the following products if they have been kept for more than two hours above 4.5 ºC:
- Meat, poultry, fish, and seafood.
- Cheeses. • Milk or yogurt.
- Fresh fruits.
- The opened mayonnaise or the tartar sauce must be thrown away if they have been more than eight hours at about 5 ºC.
- Pasta or cooked rice.
- Cakes filled with cream.
- Fresh mushrooms.
- Cooked vegetables.
What to Do if you left your fridge doors open
Not only opening the refrigerator too frequently or leaving it open for a long time makes you lose the cold, puts food preservation at risk, and increases energy consumption.
It is advisable to think about what you want to take before opening it, and not hesitate to open it, looking to see what you need.
It is also important not to introduce hot food because this gesture increases the rest of the products’ temperature and makes the appliance consume more energy.
Another fundamental factor, as reported by the Public Health Agency of Catalonia (ASPCAT), is to respect the load capacity of the appliance, without overloading it, so as not to increase the temperature of the food and lose safety.
It is advisable to leave spaces between containers to allow the cold to reach the stored products quickly. The order is also essential to optimize the function of the cold and improve the preservation of food. It should be borne in mind that the temperature inside the refrigerator is not homogeneous in all parts.
Fruit and vegetables will be placed in the drawers, where they are protected from direct cold. On the lower shelf, which is the coldest area (2-4 ºC), place the meat, fish, and shellfish in a container with a wire rack so that the juices fall.
On the upper shelves, the less cold part, you can store yogurts, cheeses and cured meats, cooked, and packaged foods. Drinks, jams, sauces, or chocolate should be stored at the door.
What if the open door is from the freezer
Leaving the freezer door improperly closed or open also carries a risk of deterioration of the stored products. The degree of risk varies depending on aspects such as the volume of food stored, the time it has been open, and the freezer’s capacity.
A thermometer can be used to check the temperature inside the various parts of the freezer. Knowing the highest temperature is one of the main factors in determining whether frozen food is safe.
If you do not know how long the products have been in the thawing process, it is safest to throw them away. If the food still contains ice crystals, it can be frozen again.
But those that have reached temperatures above 4ºC for more than two hours should be discarded. In most cases, if food has started to defrost several hours ago, it will need to be thrown away, although some are more resistant to defrosting, such as red meat and poultry.
If consumed immediately, raw meat exposed to more than 5 ºC for up to six hours can be used. To avoid any risk, the inside of the piece must reach 75ºC during cooking
. Precooked food and shellfish, on the other hand, cannot be refrozen and must be discarded if they have reached temperatures above 5ºC for more than three hours.