Wanted to say that I love this website and the willingness of y'all to share your ideas and information.  To that end, I buy hard-to-find flour like durum spelt and light rye in bulk (Heartland Mills) and vacuum-seal it in 5 lb. bags using a Food Saver.  Storing these vacuum-sealed bags in a cool part of the house, away from light should keep them fresh for a very long time.