Cold ideal: what temperature should the freezer and refrigerator be?

To ensure that food does not lose its quality during storage, it is important to understand what temperature should be in the refrigerator. It is believed that the “gold standard” is +4°C in the main chamber and -18°C in the freezer. But different groups of products (meat and processed foods, dairy products, vegetables, fresh herbs, etc.) require specific temperature conditions. Let's find out how cold it should be in summer and winter in the freezer compartment, door compartments and on the refrigerator shelves.

Average and normal temperature

The question of temperatures is not as simple as it seems. The fact is that the operation of a refrigeration unit is influenced by many factors. The two most important are:

• Temperature outside the refrigerator. It depends on the time of year and the climatic characteristics of the region in which the refrigerator is operated. The higher the outside temperature, the more heat enters the chamber each time the door is opened.
• Refrigerator load level. If the amount of supplies is too large or small, the load on the compressor increases and it becomes more difficult to maintain the optimal temperature.

If the refrigerator is empty, place a few bottles of water on the shelves.This will make the compressor work easier, since water accumulates cold well.

Manufacturers' approaches to determining the optimal temperature also vary. Thus, a large manufacturer of refrigeration equipment BOSCH indicates in the instruction manual that the normal temperature in the main compartment is +4°C, in the freezer - -18°C. Other manufacturers may use different calculation methods and provide different figures.

The numbers given represent the average temperature. This can be achieved with optimal loading, and the door should not be opened for a long time. During this time, the temperature in all sections of the refrigeration chamber will equalize. But as soon as you open the door, a flow of warm air from the room will go inside the device, making the air in the part of the chamber closest to the room warmer.

Normal temperature is the value at which food stored in the refrigerator will not spoil for the longest possible time. Experts call normal temperatures ranging from +2°C to +4°С.

Storage area depending on temperature

Warm air entering the refrigerator when the door is open changes the temperature in different zones differently. If you measure the temperature in the vegetable container and on the top shelf, the readings will be different. But this is not a sign that the refrigerator is not working properly. The uneven temperature distribution allows you to select several storage zones in the refrigerator, each of which has its own unique microclimate.

By distributing food in the refrigerator taking into account the characteristics of storage areas, you can achieve the following results:

• The shelf life of each product will increase.
• Thanks to the optimal storage conditions, the taste will remain unchanged longer.
• Proper storage will preserve vitamins and other valuable nutrients.

But to achieve such results, you need to understand how the microclimate of each zone differs and what products it is most suitable for storing.

Freezer

The freezer, or freezer, is an area with a minimum temperature. If the refrigerator is two-compartment, the freezer is located behind a separate door and is better isolated from the refrigerator compartment. In single-compartment refrigerators, it is possible to get to the food in the freezer only if you open the common door. This reduces the refrigerator's efficiency and overloads the compressor.

Most manufacturers set the control equipment so that the freezer can be between -12°C and -24°C. In this case, the step from one control point to another is usually 6°C.

In this case, the modes have the following purpose:

• The operating standard at an average compressor load is a temperature mode of -18°C. At the same time, the products are frozen quite well.
• The -12°C temperature mode saves energy, but is less effective at preserving food. It can be turned on if the freezer load is small and the food freezes in the medium mode.
• The maximum load (-24°C) is appropriate if you need to quickly freeze loaded products. This mode is turned on for a short time and after 2-3 hours the refrigeration unit is returned to standard mode.

Modern refrigerators equipped with an electronic control unit usually have a “Quick Freeze” program. When it is turned on, the control unit itself will cool the freezer to -30°C, and then after 120 minutes will return the compressor to normal mode.Quick freezing ensures maximum preservation of vitamins in berries, vegetables, and herbs.

Freshness zone

This compartment in the refrigerator compartment is intended for cheeses, herbs, boiled fish, cakes, etc. The closed compartment creates a unique microclimate, which is characterized by high humidity levels at a temperature of about +3°C.

The freshness zone is marked differently in refrigerators from different manufacturers. The most common designations are Opti Fresh Zone, BioFresh Zone, Cool Select Zone.

The zero zone should not be confused with the freshness zone. This compartment (not all models have it) is designed for storing chilled meat, poultry, seafood, and fish. The temperature in it does not rise above +2°C and does not fall below 0°C.

If your refrigerator does not have a zero zone compartment, the conditions closest to it are observed on the top shelf of the refrigerator. Here the food is exposed to the cold coming from the freezer (provided that the freezer is installed in the upper part of the refrigeration unit).

Middle shelves

The temperature on the middle shelves depends greatly on how often the refrigerator door is opened. The temperature range typical for this storage area is from +3°C to +5°C. This mode is optimal for storing soup in a pan, ready-made cereals and other main courses, eggs, salads, groceries, dairy products, sparkling water and other soft drinks.

Do not place prepared foods in the refrigerator before they have cooled to room temperature. Hot food greatly increases the temperature in the chamber, which creates a huge load on the compressor.

Containers for vegetables and fruits

Vegetable containers are usually located as far away from the freezer as possible.For storing root vegetables (potatoes, beets, carrots) and fruits (apples, pears), the optimal temperature is in the range from +3°C to +6°C. It is undesirable for the temperature in containers to drop to 0°C or lower, as this will lead to freezing of the food.

Particular care must be taken to maintain the cleanliness of vegetable containers and the freshness area. High humidity and relatively high temperature are the most favorable environment for the development of mold fungi.

Exotic fruits (bananas, pineapples, passion fruit) are best not stored in the refrigerator. Because these fruits grew in hot climates, exposure to low temperatures causes the delicate tropical fruit to quickly deteriorate.

Shelves on the door

This storage area is the warmest. When you open the door, the shelves are outside the refrigerator compartment, so the temperature here is 1-2 degrees above average. You should store a container with butter, eggs, sauces (ketchup, mayonnaise, mustard), soft drinks, medicines (suppositories, eye drops, injection solutions) on these shelves.

Food storage table

To make the information presented easier to perceive, we have prepared a table showing the optimal temperatures for storing food in a household refrigerator.

Spoiled products that can be processed (for example, sour milk) must be processed as soon as possible. Otherwise, they will become a breeding ground for the development of bacteria and mold. These microorganisms can not only spread to unspoiled food, but also become a source of unpleasant odors, which will be very difficult to get rid of.

We also provide a table with optimal temperatures for retail installations operated in retail outlets:

Useful tips

A refrigerator, like any other household appliance, requires knowledge of the rules for its operation and maintenance. Read the instructions carefully before using the refrigeration unit for the first time.This will help not only understand how to properly defrost the freezer, but also select the optimal temperature conditions.

Defrost your refrigerator promptly. Ice that has grown on the walls of the freezer chamber interferes with the heat exchange between the air in the chamber and the freon in the tubes. Defrosting allows you to extend the life of the compressor and significantly reduces energy costs.

Stock up on bags and plastic bags for storing food. They will not allow food to absorb foreign odors. In addition, if any product begins to deteriorate, bacteria and molds will not be able to spread throughout the chamber space.

If you need to take a temperature measurement, take a working thermometer, place it on a dry plate and place it in the center of the container or shelf where you plan to take the temperature. You can check the thermometer readings 10 minutes after the door was last opened.

Following our recommendations will allow you to extend the life of your refrigerator and preserve the taste and freshness of purchased products. This result is worth the effort, isn't it?