I really do not think it effects the baccy Mike. I have noticed that when I moved a while back, some I had been into recently had been sucked down, I am assuming this was from the heat when moving. But I know this also happens over long term storage, due to the tobacco giving off......I can't remember what it is called, gasses or fermenting gases. Something like that. I'm sure if you leave them for a while they will suck back in.