Frozen food isn't good if it has been exposed to frost, which causes freezer burn and a bad taste. To combat freezer burn, keep frost out of your freezer, which is performed for you in frost-free freezers; but even these freezers can develop problems that cause frost to build up. You can do several things to keep the frost out of your freezer and keep your food fresh.
Keep It Closed
Open the freezer only when you know what you want to get out. The longer the door is open, the more warm air will get inside. The warm air will make the freezer work harder to get the unit cool again, and frost will form. Make a list of items in the freezer, and cross them off as you use them. You can refer to this list before you open the door to decide what you want. For even more organisation, list what shelf the item is on so you can go right to it.
Remove Empty Space
Pack your freezer full of products. The fuller the freezer, the less air is available, which means a lower chance of frost. If you have space available, put in some sealed plastic containers, empty milk jugs with the lids on or some other objects to take up the extra space, which will fill in the holes and keep out the unneeded air pockets.
Add a frost-free mat to the freezer. These types of mats are meant to keep frost from building up in the freezer compartment, which helps with freezers that do not have a self-frosting feature, or with units that aren't frosting properly, by drawing moisture out of the air.
Seal Things Tight
Seal all products that are placed in the freezer so that moisture from the food doesn't get into the main area of the unit. Freezers are dry and will pull moisture from all possible places. If you aren't opening the door often, the freezer can draw the moisture out of the food if you do not seal it properly. The added moisture will increase the frost level in the unit and cause freezer burn in the food.