I had two bottles of prewar Scotch from my dad who had diabetes and had quit drinking. One was a ceramic jug of Red Hackle and the other was a bottle of Haig and Haig Pinch.
I opened the Red Hackle last year and the cork crumbled but the whiskey was intact, and I filtered it and put it in a bitter bottle. Tasted good. After I decanted it and waited 6 months it tasted really good.
This Christmas, I will open the Pinch!
bitter bottle = better bottle