Hi. Does anyone have a resource or point of reference for what happens to barrel aged spirits after they are opened? I know that nothing BAD is actually going to happen to it, but I also know that there will be an evaporation of esters and alcohol alike. Most of the time, this doesn't matter much, but that bottle of Yamazaki 35, Maccallan M, or Hennessy Richard may not sell very quickly, and it damn well better taste like it was meant to when the consumer pays that kind of money. What is the time limit on this? If the bottle has been sitting on the shelf for three years because the owner is a rabid collector of status symbols, how much has the whiskey or brandy changed?
Barcadi did some research on degradation leading into Tales in 2015. Honestly, what we do to care for wine is what we should do for spirits. Keep away from direct sunlight and try to avoid temperature fluctuations.
"By exposing various glass-bottle-stored alcohols to UV radiation intended to simulate the effects of sunlight, the researchers found that over a period of 10-day exposure, bourbon lost 10 percent of its color and scotch lost 40 percent."
Now, obviously bottles can go through oxidation based on how the bottle is stored after opening. Corks, natural and synthetic, can let in oxygen that can affect a bottle.
There's an interesting article about oxidation that can be read here: Bottle maturation (OBE)