For bulk foods, like grains, you can use aluminized polyester film bags, and blow in pure nitrogen or drop in an oxygen-absorber packets while sealing the bag.

For bulk foods, like grains, you can use aluminized polyester film bags, and blow in pure nitrogen or drop in an oxygen-absorber packets while sealing the bag. Then you put the bags in a food-grade bucket and seal it. The bags can have resealable zip-locks on them. Yes, this uses plastic, but all of it is reusable when using certain bag-sealing methods.