Post #694376 by djmont on Mon, Sep 23, 2013 2:06 PM

All spirits start to lose flavor (and alcohol content) once they're open, due to oxidation. The longer its open, the more it oxidizes.

At what point is it noticeable? People say 6 month, a year...It just depends.

I've never noticed any significant degradation of spirit in an open bottle. But I try not to have too many open at one time to avoid this.