I use about 80-100 lbs, of base malts/ year. I don’t have room to store it inside my house, but I could store a 50 lb. bag of uncrushed base malt in one of the large 60 lb. pet food containers in my garage. That would expose the grain to a potential temp swing of -20 F to 107 F. How would that affect the grain?
I think farmers and shippers store their grain under those conditions before it comes to us.
Comments please and thanks in advance for your advice.
The biggest problem I think would be humidity. My garage is super humid. When it warms up outside, I have condensation on the cold slab. I kept a car in there all winter (on blocks) and pretty much everything rusted up on the rotors and undercarriage.
In the summer, it’s like an oven.
Plus, mice.
I see recommendations of dry and cool-moderate temperatures. BYO says 50-70°F and Briess says <90°F.
Maybe you buy a bag in the spring and a bag in the fall, and try to avoid storing through the winter and summer. The extremes you mentioned sound like they have the potential to degrade malt quality over a period of time.
This is just some information I found, and my interpretations of the information. Nothing concrete here.
I have stored grain in hot warhouse conditions for months, sealed, with no problems with friability of flavor. Some malts stored sealed through 2 Alabama summers and still in great condition.
My home brew store (WeakKnee in Pottsgrove, PA) vacuum seals the grain for me in a large oxygen-blocking bag. I store it in a closet in my basement that seems to be pretty much a constant 60F (winter) - 70F (summer). I let one bag “out of the closet” after 7 months and it smelled fresh as when Brendon crushed it. The resulting beer (Irish Red Ale) was excellent. I agree with many of the previous posts that moisture is what will be harmful to long-term storage. You absolutely do not want mold formation due to excess moisture.