Private Reserve works for this as well - but really, the most important thing when it comes to whisky is how you store it. The less air that's in the bottle, th

Private Reserve works for this as well - but really, the most important thing when it comes to whisky is how you store it. The less air that's in the bottle, the longer it will last - also keeping it out of light. If your bottle is down to 1/3rd or 1/4th remaining it will change sooner than a full bottle. Changing isn't spoiling though - it's somewhat the same as the wine oxidation issue, but it has a different chemical reaction to the oxidation. It's still OK to drink, and some whiskys actually improve this way.