We’ve had a pan of my mother-in-law’s famous southern cornbread sitting out on the counter for a couple of days covered in aluminum foil. When I pulled the foil back to cut a slice, I noticed that there were disgusting little holes in the foil as if bugs had eaten through it. I wish I had a picture to post here, but my wife threw it away before I had a chance to find out that it wasn’t as gross as we’d thought.
Conclusions:
I was pretty surprised to discover the cause of this phenomenon. I would have guessed roaches, metal-munching bacteria, manufacturing defect… but not that our cornbread had magically turned into a battery. Apparently, this is known as the “Lasagna Cell” effect, and it happens when you put a salty wet food (This ain’t your average cornbread. Think cheese log with cornmeal.) into a steel pan and cover it with foil. It becomes a recipe for electricity as much as it is for Coronary heart disease. Now anywhere the food touches the foil, it creates a short in the battery and corrodes a tiny bug-like hole.
Useful Search Results:
http://boards.straightdope.com/sdmb/showthread.php?threadid=143211