Storing large quantities of flour
I want to bake my own rye bread (proper rye breads being rare in England was the main reason why I took up bread baking). Unfortunately supermarkets in my area only supply stoneground rye flours, and I need medium or even finely ground. I found this great little mill who take online orders http://www.shipton-mill.com/flour-direct-shop/rye-flours  and - yeppee!! - they grind to a medium grade, AND they have dark rye! There's little else I could wish for.
However, their 1 kg bags are priced at £1.30 with £5 delivery which makes it rather costly. The only size up is a 25-kilo sack, that's only £21.50 with free delivery! Question is, that amount is going to last me a good year if not two, so how do I store all that at home? I do have a corner in the kitchen where I could stick the sack, but how do I keep it dry, aired and free from flour bugs?
Of course dry climate isn't something England is famous for, and it does get quite humid in the house. I've also had lots of problems with fungi killing my houseplants, so that's another issue to consider.