Your Fridge Might Be Too Cold. Here’s How to Find Out

A refrigerator that is too cold or too hot will have difficulty keeping your food fresh. Produce is particularly sensitive to erratic temperatures, but almost anything you put inside benefits from setting your cooler to a magic number,

Not one to waste, I looked to see how cold my fridge was since it didn’t have a built-in thermometer. The ultimate goal was to make sure it was set to that Goldilocks zone: the recommended temperature to keep most items as cool as possible without freezing.

Here’s how it went and what I learned after testing almost every temperature setting on my refrigerator.

What temperature should your refrigerator be at?

Scientific consensus sets the ideal refrigerator temperature at 40 degrees Fahrenheit (4 degrees Celsius) or lower – cold enough to control bacteria, but not so cold that delicate foods will freeze.

Your freezer should be set to 0 degrees Fahrenheit (minus 18 degrees Celsius) or lower. It might seem like anything below 32 degrees Fahrenheit (0 degrees Celsius) would do the trick, but the coldest target exists for good reason: It keeps food solidly frozen even when you open the door, add fresh items, or come out of a brief power outage. As an added bonus, lower temperatures also speed up freezing, which means smaller ice crystals and better preservation.

I carried out tests using real conditions

When testing the refrigerator’s temperature settings, I didn’t unload all of my food, although I moved the more sensitive items (fresh produce, eggs, and a few glass jars) into temporary coolers for colder testing. Likewise, I couldn’t keep items out of the refrigerator or in warmer temperatures for more than two hours.

All of this forced me to keep my tests short. Every time I opened the door, checked the temperature, or changed a setting, I affected the test. These inconsistencies, while distressing to my scientific mind, resulted in results that more closely correspond to the real-world conditions in which you might open a jam-packed refrigerator several times per hour.

Refrigerator thermometers make these tests possible

As with any test, I needed a way to measure and track temperatures over time. For this test, I used three different types of temperature sensors: ThermoPro refrigerator thermometers, Hatusoku digital thermometer with external sensor and the recently announced Ikea Timmerflotte intelligent temperature and humidity sensor.

ThermoPro is the most suitable option for most people as it can be hung on shelves or transformed into a useful stand. The built-in light also helps you see the LCD screen in low light conditions, like my freezer, which has no interior light.

Hatusoku’s long temperature probe makes it a great option for a thermometer that you can stick to the outside of the refrigerator for at-a-glance checks. However, the probe is extremely sensitive and almost always reacts when I open the door.

Because it is very sensitive, the min/max setting is not as useful. Consider waiting a few minutes after a cooling cycle before checking the temperature. You also have to deal with an extra wire when placing the probe.

Timmerflotte built up my testing arsenal after pitching the idea to a company representative. They were just as curious as I was to see how the sensor worked in the refrigerator. Still, a developer at the company said the sensors could manage my fridge’s internal temperature, but the metal could interfere with its connection to the Dirigera smart hub. (Luckily, I had no connection issues during my test.)

Because it is a smart temperature sensor, Timmerflotte provided me with real-time temperature readings without me needing to open the refrigerator. Ikea sent enough sensors so I could track the temperature on the front and back of the fridge, which was incredibly helpful in finding the perfect setting. The Ikea Home Smart app did not track temperature over time. I couldn’t spot trends beyond my manual checks.

However, I should note that Timmerflotte’s minimum temperature was around 14 degrees F (minus 10 degrees C), so it was unable to keep up with my freezer temperature. It also shut down after about 12 hours because freezing temperatures and alkaline batteries don’t get along.

How I Tested My Refrigerator Temperature: Limitations and Caveats

My refrigerator uses a simple dial thermostat to control both the refrigerator and freezer. The dial lists the numbers 1 through 9, with 9 being the coolest setting. Starting with 1, I measured the temperature for at least 20 minutes (often longer at cooler settings) to allow it to stabilize after each compressor cycle.

Here’s the problem: my results are unique to my house and my refrigerator.

• Although GE still makes my refrigerator (model GTR15BBMRWW), it is an older model with a likely manufacturing date of April 2001. The owner’s manual even recommends setting the temperature control dial to 5 and adjusting from there.
• I have a lot of food in my refrigerator from Thanksgiving preparations. With such a large heat load, it takes considerable time for the temperature to stabilize once adjustments are made. A high food load also blocks airflow during cooling, leading to cold and hot spots.
• The average temperature in my kitchen during these November tests was around 64 degrees Fahrenheit, which affects how long the refrigerator runs.
• Frequently opening the door during testing certainly affected the results.
• I generally use a slightly cooler setting in the summer to keep food in the safe zone, and GE’s advice takes this into account. Even then, I only put items that can be safely frozen in the back of the refrigerator, just in case.

Finally, my measurements were more consistent and reliable in the refrigerator than in the freezer, which fortunately stayed below 14 degrees Fahrenheit (minus 10 degrees Celsius) throughout the test. (I attribute this mainly to forgetting to photograph the refrigerator thermometer readings for levels 2, 3, and 4.) However, the freezer thermometer was not consistently at 0 degrees Fahrenheit (minus 18 degrees Celsius) or below until I reached level 4.

My Test Results and Takeaways

In the end, level 5 (actually slightly lower) was the only one that kept all my food within the target range. The front, back and freezer all met the aforementioned food safety guidelines. Other settings froze the rear elements or kept the front elements too hot.

You can see why I canceled the test after level 8, which put the entire refrigerator at or below freezing. This level also caused the compressor to run continuously for almost an hour before shutting off.

So I couldn’t risk spending at least that much time trying to reach level 9, which I suppose could turn my entire refrigerator into a freezer — even if the refrigerator compartment doesn’t quite reach 0 degrees Fahrenheit. (I don’t have enough cooler space to hold a refrigerator’s food.)

For my refrigerator, level 5 is right in the middle, which is probably what the manufacturer intended when selecting the different settings. From a user perspective, I found this impressive. My biggest takeaway from the results is that setting the refrigerator to a colder temperature isn’t necessarily better, which is sometimes my instinct when I perceive food is spoiling too quickly.

Should you test the temperature of your own refrigerator?

If your food constantly spoils or freezes without explanation, it may be because your settings are not properly calibrated. You may not even know which setting is intended to achieve the refrigerator’s target temperature of 40 degrees Fahrenheit (4 degrees Celsius) or lower. If so, it would be a good idea to perform a similar test on your own refrigerator.

I recommend getting a refrigerator thermometer set like I did. I consider them essential for simple refrigerators like mine, which use a dial thermostat that does not display the actual temperature.

While many refrigerators have a digital thermostat that shows your target temperature, the flexibility of a standalone refrigerator thermometer can help you learn more about your refrigerator. For example, you can move the thermometer to find cold spots or track temperatures during a power outage.