what is this white powder?

[bubbles4920]

i put a metal coated? wine stopper inside an empty red wine bottle for effect. we are moving house so did it to look homely! anyway, house sold now so removed stopper today and there was white powder at the bottom of the bottle and the stopper had white powder on it and it had made the metal start to disintegrate. what is the chemical process that has taken place here?

[bubbles4920]

Thanks everyone for your replies, especially to the Prof. you sound an amazing chap, i love intelligent men! xx

[theprof]

Thanks bubbles4920, but I do not deserve it as I did not give you the answers you were looking for as I did not have much to go on.

Anyway, Ithanks for the thanks!