I bought some grain at my LHBS and milled it there last friday (10/4/13). I haven’t really stored it, but it’s has been in a paper bag that I’ve stretch-wrapped because it tore a little.
Will it still be viable for brewing this coming Saturday (10/12/13)??? Or should I just re-buy my grain bill?
Crushed malt is generally considered good for 2-6 months, depending mostly on humidity. Some of the bigger maltsters will go 6 months, but they monitor moisture levels.
As others have said, it will be fine. It will store longer and stay fresher if you put it in sealed bag and keep it in cool, dry place or even refrigerator.