Re: Open bottle for how long?
There exists varying opinions on this. If you do a little research, you will see that there is at least one thread discussing this topic.
I have had bottles open for more than 7 years, some of which had a finger or less at the bottom for over a year. The big deal is the amount of air exposure. Corks will go bad and allow air to move to and from the bottle. There are a few ways of minimizing this. I know folks that get the equivalent of shrink wrap and others that use electrical tape around the cork.