I don't go through my coffee quickly but I buy a 3 lb bag at Costco so I divide it into 1 lb portions, vacuum seal them, and keep them in the freezer. I've never found it tasted stale while doing this.
This is helpful, thanks!
I just add it in a ZipLock bag and suck (literally) the air out of it. Seems to work well. I know there are some vacuum containers that suck the air out (have pumps and such) but don't know if its worth it.