How do I maintain the crunchy crust of home baked bread?
The reason the crust is going soft is a combination of factors:


Moisture from inside the bread transfers to the outside during cooling: This is most prevalent in breads with thinner developed crusts. Leave your bread to cool completely either in the cooling down oven (best) or on the side on a rack.
Humidity of bread storage: never put warm bread in a container (not even a bread box) and never ever put it in the fridge (unless saving for croutons or breadcrumbs)
Ambient room humidity: If your kitchen is really humid this will definitely have an effect. I typically store bread in the oven if it's currently really humid (which it typically is in Ireland).


There are a few steps you can take to ensure you get a crispy crust for longer:


Take extra time to develop the crust after the initial bake


Remove the bread from the dutch oven at the end of your bake and place directly on the oven rack with the oven door open as it cools down.
Don't place your bread into a container (even a bread box) until hours after finished.

Store bread properly


Keep open in dry conditions. If cut, place cut side face down on board or countertop. Can cover with a tea towel (after complete dryness) and then just leave alone.

Rejuvenate the crust (best tip I ever received)


This seems counterintuitive, but if you've got some soft crust bread you want crisped up, crank your oven up, then wet the bread where you want it crispy (running a wet hand over it is about enough water), and chuck it in the oven directly on the rack and bake for a few minutes until you're satisfied.
This method works wonders for stale bread as well, and you can keep the soft (cut) side softer by wrapping that bit in some foil. It won't make it like day one fresh bread but it'll certainly make it edible again and good enough for some nice oil &amp; vinegar or a nice slab of soft butter.



Update
+1 for oven cooling! http://blog.kingarthurflour.com/2015/09/15/keep-baking-crispy/