My bottle is Batch 18 @ 54.8 % Now open for 12 1/2 months now and has gone completely flat. I was thinking of throwing away but I'll keep and blend in a different fresher malt to try to save. As I stated before this bottle was never good so I believe there must be a quality issue at the distillery as so many rave about this bottle but unfortunately I would never buy another whole bottle. The 15 year old I just finished a 15 and it was delicious.