Are non frost-free freezers really better for meat storage?
I've been told that the now-common frost-free freezers can promote freezer burn in meats (and seafood) because the air circulates throughout the freezer, which can remove moisture from the meat.
By contrast, non frost-free freezer don't create such a problem because, well, there is no air circulation because they are not self-defrosting ...
Is this true? Any experiences?
Frost-free freezers are by definition dehumidifiers, so if you have one it's important to get a good air-tight seal on anything you store lest it dry out. But properly sealed meats keep fine.
I think the improvements in freezer technology pale in comparison to the ways we now have to keep foods airtight. I remember my parents' freezer full of meat wrapped in brown butchers' paper for months on end. Needless to say, often the meat had freezer burn. Today it is very easy to keep meat very fresh in airtight freezer bags. The trick of course is to use a straw to suck out the excess air and your meat will stay great in the freezer for a long time.
Frost free freezers don't dehydrate meat via air circulation, they dehydrate meats (and other foods) due to the freeze/thaw cycle that allows them to be frost free.
When the frost free cycle runs, it partially thaws your food. The edges of the food will thaw and then refreeze, causing the ice crystallization to pull water from the edges of the food. After enough cycles of this, it will turn your food into leather.
Regular freezers don't have this problem since once the food is frozen, it stays frozen--the water never recrystalizes.
If you don't vacuum pack your food before storing it, it will keep longer in a regular freezer. However, if you vacuum pack your meats (and other freezables) they will suffer only minor damage even in a frost free freezer because there are no air voids for the water to accumulate and crystallize and draw the water from the food.