In for a penny...

One of those "life-hacks" which appear now and then on the Net involves rescuing the remains of a bottle of wine which has gone "off" by using a penny.  Make sure it's nice and clean and drop it into the wine and stir for about a minute.  Remove the penny and, according to the website, lo and behold, your wine is drinkable again. The logic is that the reason the wine goes off is due to oxydisation, and the copper in the coin neutralises this.  Speaking for myself, I find it difficult to understand why anybody would ever have any left-over wine!