I suppose this is true with liquor but I would swear shine changes in a jar after some years...course it could be the peach breaking down
Wine of course can get stellar or go bad in glass...is it the cork contact?
this is curious
Yes, it’s the cork, allowing a small amount of air circulation over time. Note: whisky bottles a century ago were corked, too!
Going bad is usually a function of lack of cork contact...bottles stored upright allow the cork to dry, which cork then shrinks and allows bacteria to enter and contaminate the bottle.
But it's true, wines do change in the bottle over time even when the cork remains wet and tight. This is because wine isn't distilled; there are live microorganisms continuing to live and metabolize substances in the wine over the course of years, albeit in tiny amounts.
Because liquors are distilled, there's no microbial action. Changes in flavor over time in distilled beverages are due to strictly physical and chemical actions, not microbial ones. Whiskey changes in the barrel due to interaction with the wood. It soaks up vanilla-like flavors from good white oak. In a charred cask, the charcoal lining the container gradually soaks up trace fusel oils that ruin flavor and smoothness. Glass can't do any of those things.