Freezers were introduced to people during the 1940s. They certainly changed the way food was stored, prepared, and cooked. However, freezers back then (and some nowadays as well) had a downside. That is the fact that frost and ice would build up on the top and inside of the appliance.
Freezer frost happens when there is too much moisture in the freezer environment, causing ice to build up on the walls. Moisture enters through a worn door gasket when you leave the door open for too long, or from steam from overheated foods. While many freezers self-defrost, ice can still accumulate and should be cleaned on a regular basis. That will help you eliminate bad odours and sort the mysterious items that have been forgotten in the freezer for way too long.

How often does a freezer need to be defrosted and cleaned?

Cleaning a self-defrosting freezer can be done once a year. If your freezer is a manual defrosting one, you should clean it more often (the best way to determine when is to notice the amount of ice buildup).

Keep in mind that it is best to always consult the manufacturer’s instructions before defrosting a freezer. If you don’t have it handy, practically all manuals are available online. Some manufacturers advise using hot water to speed up the defrosting process, while others advise against it because refrigerant pressure might build up in the evaporator, making restarting the freezer difficult.

How to defrost a freezer

Remove and store all frozen goods accurately – Grab an ice box and place everything from the freezer inside. Make sure you insulate them well since you want to avoid the food defrosting as much as you can. Now is the best time to sort out your frozen goods. If you label them you will know when some of them are about to expire. Get rid of anything that is too old or will not be used.
Unplug the appliance once the freezer is empty if it is a stand-alone freezer.
Simply open the door of the empty freezer if the freezer is part of a refrigerator. To keep the temperature stable, try to limit the number of times you open the refrigerator door during the defrosting process.
Follow the manufacturer’s instructions and place bowls of hot water to speed up the defrosting process or simply let the air do its job. Place towels and other absorbent cloths at the bottom of your appliance. You will avoid puddles.
Once the ice has loosened up a bit, you can use a wooden spoon or a plastic scraper to remove larger ice chunks.
Once the frost is completely gone, clean the walls following the steps below. Then plug the freezer in, close the door, and wait for 15-30 minutes (enough time for it to start the frosting process again). You can place your food back then.

Extra tip: If your food has frost on the packaging, let it melt and wipe it away. Make sure all packages are dry before placing them back since that will prevent moisture from quickly accumulating again, causing more icy buildup.

Cleaning a freezer once it is defrosted

Mix a cleaning solution. We suggest you avoid commercial products. A quart of water with a tablespoon of baking soda would be sufficient. Mix them in a bucket or a large pot (depending on the size of your freezer).
Once the freezer is completely defrosted, grab a microfiber cloth, dip it in the cleaning solution and wipe down the interior surface of the appliance. Do not forget to clean the seal and rubber gasket around the door. Now is the time to check for any damage (it may cause your freezer to malfunction). Rinse the cleaning cloth as moisture and food particles are transferred. Once you are done, grab a clean dry cloth and wipe the interior of the freezer.
Use the same cleaning solution to clean the exterior of the freezer.
If food has spoiled, bad odours will remain in your freezer. To get rid of them you can apply a paste of baking soda and a bit of water or a solution of water and vinegar. If the smell persists, place an open container of activated charcoal in the freezer and close the door for several days. If the odour lingers, replace the charcoal with a fresh one.

Regular maintenance such as defrosting and cleaning should be sufficient in keeping your freezer in good condition. However, there are some steps you can take in order to prevent the ice from building up. See below:

Place the freezer in a cool, dry, and well-ventilated area.
If the freezer has exposed coils, keep it at least two inches away from the wall.
Do not put hot or warm items into the freezer. First, chill them in the refrigerator.
Keep the storage temperature at or below 0°F.