I ended up with about a pound of CBW Sparkling Amber DME leftover. I figured it might be worth keeping around so I put it in a plastic bag and tried to get as much air out as a could. Since then I've left it in a box in at roughly room temperature (probably a little lower).
I'm considering adding some or all of it to an upcoming batch but hesitated when I saw that the Briess product information sheet mentioned that "Storing opened bags is not recommended." I'm hoping this may not apply to transferring it to a sealable bag since it seems that moisture and oxidation are the biggest factors for DME going bad, but for all I know I've potentially already over-exposed it.
It will have been stored about a month and would contribute about 5-10% of the sugars depending on the amount I use. Would this re-packaged DME be worth using in a separate batch? I'm thinking worst case scenario I could save it to use for a starter or something in the future.
Also, if it is not worth using, is there some other way I could have stored it to help it keep or is saving leftover malt basically just a lost cause?