My food in the freezer looks like it has been snowing in there. Can anyone tell my why?

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This is freezer frost. What happens, essentially, is that on a warm or humid day when you open the freezer a lot -- or more commonly when you accidentally leave it ajar (when the edge of a package gets stuck in the seal as you close it, for example) -- condensation builds up as warm, humid air hits the cold, dry air inside. It collects on the inside surfaces. This condensation then quickly re-freezes from the cold of the freezer itself or the frozen food under it, and it forms this "snow".

Unless you have a frost-free freezer that automatically prevents this, you should defrost a freezer a couple times a year (as the ice builds up) by emptying it and turning it off for a day. Once it's clean and dry, put the food back in. Obviously, try to do it when there's not much perishable food to deal with.

A self-defrosting freezer uses special "evaporation coils" to aggressively pull the moisture out of the air, keeping this buildup from occurring.

First answer by Jayrusalem. Last edit by Jayrusalem. Contributor trust: 653 [recommend contributor]. Question popularity: 28 [recommend question]