trouble with brown sugar hardening. I keep mine in a Tupperware canister (no, I am not a Tupperware dealer) and this keeps the sugar at the same moisture level as when I take it out of the bag. If I have an extra bag I put that in the freezer until I need it. I live alone so one bag can last a long time. I have never had any get hard stored in this container. I am sure any other air tight container would work well. I just happen to have a set of Tupperware canisters.