I have several questions regarding aged Bourbon. I have been a fan of wines for a few years now, so most of my questions here are from the perspective of a wine drinker who's new to whisky.
When searching this site, I found several comments that bourbon will not change at all with age once it's in the bottle. Why is this? In regards to wine, my teacher always said that the aroma components and tannins (both of which are also present in whisky from the oak) undergo chemical reactions and form completely new aroma molecules, which add complexity. This happens even in port wines, which have enough alcohol (at least 18%) to prevent oxidation. Does the much higher level of alcohol in whisky prevent these reactions? Why?
I am a bit skeptical of this idea, since I've evaluated 2 or 3 Bourbons that had been bottle aged 30-40 years, and all of them were FAR more complex and had more intense aromas than new bottlings of the same whisky. All of these Bourbons were in fancy bottles or decanters. Perhaps the manufacturer just saved back the very best barrels to put in his fancy bottles? Or maybe this is just a case of "they don't make it like they used to". ? I have also had a few bottle aged bourbons that really did not seem any better than modern stuff.
So... when a bottle is labeled "10 years old" or "aged 30 years", etc., they are referring to aging in the barrel, right?