I'm calling this "Mixed Flour" because I used a lot of different flours. I wanted to see if I could get the characteristics I wanted in the crumb by adjusting just the flours. It seemed to have worked, so here's what I used:

Again (It's a family/personal favorite :-)), I was following Susan's Simple Sourdough formula. Only hers doesn't call for so many flours!

50g Firm Starter (mine is 50% hydration composed of 10% rye and 90% AP)

205g Water

100g AP Flour (I used Wheat Montana)

100g Bread Flour (KA Bread Flour)

25g Durum Flour (also King Arthur)

25g Hard Red Whole Wheat (home-milled wheat berries)

50g Hard White Whole Wheat (home-milled wheat berries)

6g Salt (I used Hawaiian Sea Salt)

Method: Mix all by hand, rest 30 min. S+F three times at hour intervals. Let rise until double. Pre-shape, rest 15 min, shape. Into brotform and retard overnight. Out of fridge 2 hours, score and bake @450 covered for 20 min., uncovered for 20 more and 5 min in shut-off oven w/ door open.

Whew- that's quite the mishmash of flour, I know, but it tasted really good. I used the whole wheat because I want to start transitioning everything over to 100% whole wheat, but have to do it gradually. I also have tons of wheat berries that I need to use instead of buying more flour from the store! Not to mention the extra nutrition.

The reason I used the Durum is because I like the buttery flavor it lends to the bread and it seems to balance out the whole wheat flavor when added with freshly ground whole wheat. I've tried this in a couple of other things and it seems to neutralize that "earthy" flavor or any "bitter" tones from the hard red I suppose. 

And as for the 50/50 of AP and Bread flour- I like a mix of the really chewy/shiny crumb (from the BF) and a bit of "fluffyness" from the AP. The crumb: creamy/ buttery/ wheaty.