Does crushed grain go bad?

[P_Bio]

I bought some grain from my LHBS about a month and a half ago and I didn't get a chance to brew it until today. My mash efficiency was about 10% lower than it usually is all else being equal. My pH was also 5.6 instead of the usual 5.2 or 5.4 which I hover around. Is it bad to crushed grain sit around? It was in a paper bag (not sealed from air) in my closet. Oh yeah, it's florida so inside temps are 78.

 

[JKaranka]

Yes. I always crush it on the day of brewing. I don't mind some black patent that's been sitting around for some colour, but I wouldn't leave a big bunch of ground pale malt sitting around.

 

[P_Bio]

Thanks, would that account for my low mash efficiency? 10%? If that's the case I'm gonna buy my own mill

 

[AlCophile]

ALL foodstuffs will deteriorate from: oxygen, being finely-ground, light, heat, time, extremes of pH, others.
I store my ingredients in a little fridge my wife had at work before retirement. It's a Sanyo, and I can turn the little bugger down beyond freezing. Works well.
I also purge my materials with CO2, if they have been ground or are near out-date. Good luck.

 

[Yooper]

Thanks, would that account for my low mash efficiency? 10%? If that's the case I'm gonna buy my own mill

No.

The grain shouldn't be stale in a month, but it is better fresher. Next time, to test it out, just take a taste of a few kernels. If it tastes ok, not stale or gummy, it's fine to use.