Experts Reveal the Ideal Freezer Temperature for Optimal Freshness

In my garage, I keep a small freezer stocked with extra ice cream and leftovers. Food from this freezer always seems harder and more solid than those from my kitchen freezer. This got me wondering: Is my kitchen freezer too warm? Curious about the optimal freezer temperature and how to ensure food safety, I did some research to find out more.

The U.S. Food and Drug Administration advises that the ideal temperature setting for freezers is at or below 0°F (-18°C). If your freezer model includes a built-in thermometer, adjusting and monitoring the temperature is straightforward.

To verify that your freezer maintains the set temperature, consider using a budget-friendly appliance thermometer.

An effective method to test your freezer’s functionality without a thermometer is by freezing a cup of water. “Place an eight-ounce cup of water in the freezer and check if it’s solid after an hour,” suggests Kumar Mallikarjunan, a Professor and Director of Graduate Studies in Food Science and Nutrition at the University of Minnesota, and a member of the Institute of Food Technologists’ refrigerated and frozen foods division. “If it hasn’t frozen, your freezer might not be cold enough.” In this case, it’s wise to have a professional inspect it.

For freezers that display settings as numbers (like one through five) rather than temperatures, Mallikarjunan recommends always setting it to the highest number for maximum coldness.

The Importance of Setting Your Freezer at 0°F or Lower

Maintaining your freezer at 0°F or colder ensures that the food inside remains safe to consume.

“While freezing at 0°F doesn’t kill bacteria, it does stop them from multiplying,” explains Tracy Fink, Director of Scientific Programs and Science and Policy Initiatives at the Institute of Food Technologists. “This temperature is effective at inactivating various microbes, including molds, yeasts, and fungi in your food.”

Microbiologist Jason Tetro, who hosts the Super Awesome Science Show and authored The Germ Code and The Germ Files, adds that as long as food does not warm up beyond 39.2°F (4°C), there is no risk of microbial growth.

Additionally, keeping your freezer at this low temperature helps prevent freezer burn, which occurs during freeze/thaw cycles that cause large ice crystals to form on the food, compromising its taste and texture, according to Fink.

Tetro notes that inadequate freezing can lead to larger ice crystals, which negatively affect the quality of products like meats and ice cream.

Is There Such a Thing as Too Cold for Freezers?

It’s generally safe to set your freezer temperature even lower than 0°F; there’s no harm in erring on the colder side.

“While most guidelines provide a temperature range, technically, no freezer temperature is too low,” states Tetro. “However, most household freezers are designed to go no lower than -10°F (-23°C).”

Setting the freezer below 0°F may just mean more waiting for your ice cream to soften, but it won’t compromise safety or food quality, although it might increase your energy costs, according to Fink.

Effective Food Storage in Your Freezer Affects Temperature Control

The U.S. Department of Energy recommends keeping your freezer full yet not overcrowded to maintain the temperature. If you don’t have much to store, consider placing bags of ice to help keep the cold air circulating effectively around the food.

Opening the freezer door often can cause temperature fluctuations, impacting the food stored near the door. It’s advisable to store items sensitive to temperature changes, such as ice cream, away from the door.

“Storing meat and seafood in lower drawers or at the back of the freezer helps protect them from temperature variations,” Mallikarjunan recommends.

Fink emphasizes the importance of keeping ice cream at consistently low temperatures to prevent melting and refreezing, which can degrade its quality.

Tips to Prevent Freezer Burn

Discovering freezer burn on your ice cream or frozen chicken can be a letdown, even though it’s still safe to eat. The flavor, however, might be less appealing.

“Freezer burn occurs when food is exposed to dry air,” explains Mallikarjunan. To avoid this, ensure your food is well-wrapped in plastic or foil, or stored in airtight containers.

Tetro advises reducing the air content in any sealed package like a freezer bag. “Also, make sure the seal on packages such as ice cream containers is tight to minimize air entry,” he adds.