Why hot food shouldn't be put in the fridge: reasons you didn't know
Since childhood, we have all known about one of the basic rules of using a refrigerator - you cannot put hot food in it. But have you ever wondered what the point of this prohibition is? If refrigerators are designed for cooling, why do we have to wait until the food reaches a normal temperature before putting it inside?
In fact, the ban is not just about the functionality of the appliance. What happens if you put hot food in the fridge, Science ABC explains.
Why hot food should not be put in the refrigerator
The operating instructions, which, of course, few people read, usually indicate that hot food in the refrigerator can affect the operation of the appliance in the long term. Storing hot food puts additional pressure on the refrigeration equipment, so it should be avoided.
However, there are other reasons besides the operation of the refrigerator, including the quality of the food. The presence of hot food raises the temperature inside the appliance - that is, all the food begins to heat up, and the refrigerator compressor must work harder to maintain the temperature inside at the desired level.
If you remember your high school physics class, the second law of thermodynamics states that heat moves from places with higher temperatures to places with lower temperatures.
Convection is a method of heat transfer that occurs in states that are free to move, such as liquids or gases. When a hot liquid or gas is heated, it becomes lighter and rises upward, while colder air comes in to replace it at the bottom.
When we put hot things in the refrigerator, the temperature difference causes condensation. The drops fall on the back of the refrigerator. Food that is in close proximity to this wall can freeze. In addition, condensation increases the humidity level, which is not recommended for food storage.
As a result of the combined process of convection and condensation after we put hot food in, the internal environment of the refrigerator becomes unfavorable for food preservation. In fact, the functionality is significantly reduced due to the increase in internal temperature and humidity.
The optimal time
According to CDC guidelines for food protection and safety, food can be stored out of the refrigerator for a maximum of two hours after cooking. After that time, bacterial growth can begin.
Two hours is enough time to cool a hot meal.
But what if you need to put a hot meal in the fridge right away and leave for an important meeting that will last until the evening? One way to protect the fridge from overheating in such an emergency is to divide the food into smaller portions. Leave space around the food so that cold air can "flow" around it, which will speed up the cooling process.
As OBOZREVATEL previously reported, neglecting the temperature settings in the refrigerator is dangerous for health: a temperature above 4 °C causes spoilage of milk, eggs, and meat. A temperature that is too low creates a freezing effect, which is also harmful to nutritional properties. Read the article to find out what temperature is optimal.
OBOZREVATEL also told you how to recognize nitrates in vegetables and fruits and neutralize them.