If your freezer smells, chances are food has spoiled, mildew is present or there are spills that have gone bad. To get rid of the odour, a thorough cleaning, including sanitising, is in order. Before cleaning your freezer, take out all the food and dispose of the ones that have spoiled or are not stored properly. Move the foods you are going to save to another freezer or a cooler with ice, as cleaning a smelly freezer will take a couple hours, at a minimum.
Unplug the freezer and remove all the shelves, racks, ice cube trays and anything else in your freezer. Wash these separately in your sink using hot water and dish detergent.
Sanitise the shelves and items from the freezer using bleach water made with 1 tbsp of non-scented chlorine bleach per gallon of water. Rinse and dry all the items with a clean dish towel or air dry them.
Wipe down the inside of your freezer with a wet rag. Get up as much of the crumbs, debris and caked-on messes as possible. Lay a wet rag on top of stuck-on spills to loosen them.
Clean the inside of the freezer using hot water mixed with baking soda using 2 tbsp of baking soda for every 1 qt. of warm water. This helps remove any smells.
Sanitise and get rid of smells in the freezer by wringing a rag out in water that has been mixed with 1 tbsp of chlorine bleach per 1 gallon of water. Wipe down the inside thoroughly.
Keep the door open for at least 15 minutes. If the freezer still smells, proceed to the next step.
Place a dish of baking soda, coffee grounds or activated charcoal available in fish store in the freezer and close the door for about 10 days. You can also try lightly packing the door with damp newspapers, replacing them every couple of days. The newspapers absorb the odours.
Try other methods to get rid of the smell. For example, leave the door open for three or four days. Wipe down the inside of the freezer with a mixture made with one part white vinegar and one part water to get rid of mildew smells. Soak a couple cotton swabs with vanilla, close the door and check back in 24 hours.
Put the shelves, trays and everything else back into your freezer once the smell is gone. Keep a tray of baking soda to absorb future odours.