The keg of Unique I am currently working out of is dated 2008. Not ancient by any means but it has spent some time in my basement which can get damp. I usually store them upstairs before opening. Since this is my last keg I need to place an order soon and will be getting at least three 8-pounders. Yesterday I looked at a Harbor Freight email that advertised vacuum storage bags and it got me thinking. Would there be any possible benefit to sealing a keg or two (if they fit) in a vacuum bag? From what I recall the keg is not sealed under the cap but I don't know if environmental changes (humidity) can really permeate into an unopened keg over a few years. Recently I have had some smoky loads which I was told could be moisture in the powder. I think it was mostly loaded ammo that I had at a class where we got rained on and it was exposed.