I have a lot of mazuri here, I keep it in air tight dog food type containers (at least I think there air tight), the containers I use are not all that large and probably hold 5lbs of the small pellet mazuri.

I have quite a bit of large pellets also that have been here for some time, I keep this in large zip lock freezer bags.

I dont freeze any of it and I havent had or noticed any problems yet and I have been doing it this way now for a few years.

Now the mazuri gel I think would be a differant story, this I would image would need to be fridged or froze if not used after prepared. I'm not positive though as im yet to actually try it out.