Can anybody give me advice on how long unopened white wine (screw top) can be kept? Came across them in back of kitchen cupboard and I am not a wine drinker at all, they were presents. One is 2009 the other 2010, have to,d someone she can have them but don't want to give them if they are bad.i know some wine can be kept many years but these are not the dead expensive ones. Tried looking it up but conflicting views. Thanks.