I don't remember where, but in the last few months there has been some discussion about aging blacks, with some people reporting wonderful experiences finding tea tins they had forgotten about for years that tasted better than ever. Although freshness is usually prized in FF dj's, blacks -- even first flush dj's -- are not as much a subject of concern as are greens. Keep out light and air as much as possible and it should be drinkable for up to 2 years. After all, even light oolongs, when aged, may be sold for a premium price.
You're on the cutting edge here! Take notes, and post your results back here in 5 years.