The Back Art 3.1 does not oxidize very well (especially on the last 1/3 of the bottle). I noticed on my 4th and 5th drams after opening it that I was already loosing it's dynamic punch (although only very slightly). Still very good, all the way to less than 1/3 of a bottle up until 3-4 weeks ago (one year after opened). But now, on the last dram that can be squeezed out, it's lost most of what it once had.
The Black Art 3.1 needs to be consumed within in 6-10 months to fully enjoy this bottle, completely! Otherwise gas it once it's at 1/3 of a bottle (or sooner).