Why did the foil deteriorate?

Question

I had left-over spagetti in the fridge which I covered with a store brand foil. When I took the foil off to prepare it for eating about 3 days later it had deteriorated to a point of at which holes could be seen in the foil and the deteriorated foil bits had stuck to the spagetti. I wound up throwing the leftovers out.

Answer 1

Moisture from the spagetti wound up destroying the foil by rusting it almost on a molelecular level. Just make sure when you cover food up, it's cooled down.

Answer 2

the acidic tomato sauce dissolved the foil