Why did my foil discolor after baking?

[Anonymous]

I've never had this happen before. Baked an item, left it on the stovetop to cool for an hour with a piece of foil on top, before putting in fridge. The item was in a pyrex dish, not a metal pan. The item didn't have anything acidic in it--it was egg based with a few veggies. When I removed the foil it was all darkened/discolored. I am concerned, I have never seen this happen before in all my years of cooking. Is the food still safe to eat?

[Anonymous]

DONT EAT IT!!

[Anonymous]

PP is funny! Actually you're fine.

The darkening may be caused by moisture from a food being covered. It is the result of a buildup of aluminum oxide, a totally harmless substance.

Occasionally, foil comes in contact with a different metal or a highly salted or acidic food and, as a result, pinholes develop in the foil. This reaction does not affect the safety of the food.

[Anonymous]

Happens to me all the time, no worries.

[Anonymous]

That dark tin foil is great for making tin foil hats. Make one, wear and count yourself lucky to have no greater problems.

[Anonymous]

Anonymous wrote:That dark tin foil is great for making tin foil hats. Make one, wear and count yourself lucky to have no greater problems.

LoL!