A Food Safety Expert Explains Why (and How) You Should Defrost Your Freezer [CNET]

An overly frozen freezer can taint the food inside and burn the motor out on your large appliance.

Be honest — can you currently account for everything in your freezer? Or is it packed to the degree that you’re afraid to take anything out for fear of what you might find lurking in the dark corners? Worse yet, are you even able to get anything out? If your freezer looks like the makings of a snow cone factory…well, it’s not supposed to.

“My parents tend to plan as if the apocalypse is happening tomorrow,” says Trevor Craig, food safety expert at Microbac Laboratories. “Their freezer is stocked with things they will never eat, and you all but need an ice chipper to get to anything.”

While the build-up of frost in the freezer can be partially attributed to overfilling, “freezers actually maintain temperature better when they’re full,” Craig says. Good news for fellow apocalypse planners, but your freezer can get frosty for several reasons, which overfilling may exacerbate. “Usually frost forms because of moisture in the air that is trapped in the freezer condenses and freezes,” Craig says. An overfull freezer can prevent the freezer from sealing properly, which allows humidity to creep in.

While some frost buildup is inevitable, you can help stave it off by being mindful about the number of times you open and close the freezer door and making sure to first cool any items that are destined for the freezer. Hot foods put in the freezer will also create excess evaporation. Older freezers are also more prone to frost than newer ones.

Read more: Can You Guess Which Zones in Your Fridge Are the Coldest (and Warmest)?

Freezer efficiency and food safety

Making sure your refrigerator is running efficiently isn’t only good for your electricity bill, but it has implications for your health as well. “Heavily frosted freezers can burn out or fail to keep your food frozen,” Craig says. “If the food gets too warm, it’s not going to survive its full shelf life, and it might even be a health hazard if it doesn’t stay cold enough.”

Frost can also lead to unwanted and unexpected replacement costs, which is way more problematic than a slightly elevated electricity bill. According to Craig: “If heavy frost builds up, your freezer could even break, and then there is little option but to throw all the thawed food out,” he says, not to mention you have to potentially buy a new appliance.

How to defrost your freezer

Fortunately, defrosting your freezer is a relatively simple process, once you get past the trauma of having to confront what’s lurking in there. A little planning is the only requirement, especially if you do have a permanently well-stocked freezer.

Step 1: Remove all items from the freezer

“Ideally, you should defrost your freezer when it is almost empty before you restock it,” Craig says, adding that you can tightly store your frozen items in a cooler during the process if needed. “If you defrost frequently enough, it shouldn’t take too long and you can keep everything frozen or cold until placing it back in.”

Step 2: Set your freezer to defrost or turn it down all the way

Newer freezers often have a setting for defrosting, otherwise, you’re just turning the dial down to its off or lowest setting. (Note: Do not unplug the entire appliance, as we’re still trying to keep the items in the refrigerator cold during this process.)

Step 3: Let it sit until all the frost melts away

“Once you have everything out of the freezer and have it shut off or set to defrost it should only take a few hours if the frost isn’t bad, or about a day if it’s particularly bad,” Craig says. “You can keep the door open during this process to speed it along if that’s what the manufacturer recommends.

Step 4: Wipe it down

After it’s fully thawed, clean out any pooling water and wipe down all surfaces before starting up again.

The refrigerator cavity shouldn’t be threatened by the freezer defrost process, but you can put out some towels on the ledge of the fridge door, or on the floor, if you’re concerned about water leakage. If you do see leakage, it could be a sign that the seals on the freezer or fridge are damaged.

Step 5: Turn the dial back up to your preferred temp

Once the freezer is dry and cranked back up, you’re free to restock it with items for safekeeping. 

Freezer maintenance and upkeep

Once you’ve ripped off the band-aid and defrosted your freezer, you can save yourself time (and perhaps money) in the future by staying on top of the process. 

“You should defrost about once a year, or if you see the frost growing to thicker than about one-quarter of an inch,” Craig says. “It will make your freezer run better, keeping your food temperature and electric bill down.”

Defrosting your freezer isn’t only about facing your demons in the form of long-forgotten items that may have gotten freezer burned beyond repair or outlived their shelf life by a cringe amount of time. “Typically for me, there are a few popsicles or frozen Girl Scout cookies that I forgot about,” Craig says, “so I have a nice little snack while cleaning up.”

To defrost a chest freezer, you’ll want to take a slightly different approach. Here’s how to defrost a freestanding chef freezer in minutes.