Okay, as I sit here with a strange tea-like flavor in my mouth I think I can reliably report that BBotE is not meant to be stored for 6+ months.
All five samples that had made it this long were sampled this evening (Papua New Guinea, Sumatra, Ethiopian, Panama, and Yemen). Why these five you might ask? To be honest, they were the ones that were left after a party back in December 2009 where most of my 375ml samplers were completely consumed by the happy crowd or purloined before I could hide these ones.
I had previously sampled them at the three month mark and discovered that the flavor had not particularly shifted in any for the worse, although the Yemen was showing acidic hints. The Panama, however, had aged remarkably well and gained an interesting cinnamon & caramel flavor as it aged.
At the six month mark, they were all undrinkable though with slight variations. The Panama and Papua New Guinea had a strange acidic green apple flavor that came as a surprise. The rest were tannic. Tongue to battery terminal, tannic. They all are now probably eating their way through my pipes as a team since they went down drain. I remain amazed by the fact that none of them had moldered in the slightest.
So, I stand by my declaration that you should store your BBotE cold and consume it within three months. I am beginning a new longevity test considering that the previous samples were made with my old pre-January labor intensive and arthritis tempting hand-wringing and pressing process. While the old hands on approach gave me a good appreciation of how things should look and feel, it also tended to let a lot of grounds through as filters failed. Those stray grounds, in turn, would continue to leach acid into the BBotE.
More science…