Mr Pounder wrote

For being a good boy, pulling my guts out and making a 10/10 job of
painting the interior of my house the wife has given me a bottle of Bells
Whiskey. Seems she has had it in a drawer for maybe three years.
It looked a bit pale. The top was on tightly but there was no click sound
when I opened it.

It tasted awful so I have poured it down the drain.
Does Whiskey deteriorate?

Nope. In fact the best of its 20-80+ years old.

Bells isnt much of a whiskey when brand new.