Poilane was and is correct. A sourdough miche of whole wheat is great bread. It is better without yeast or white flour. Yeast speeds rising, so there is less flavor. White flour also diminishes flavor. I use fresh, stoneground hard red wheat with 10% spelt, 2% rye, and 2% chick pea flour. My starter (old dough) is about 20 % of final dough weight. Salt is 2.2 % added mid- way through stretch and folds. The dough is fairly firm, so I do not bother with a banneton. Fermentation time varies with temperature, yesterday, the kitchen was ~70F, and it was about 16 hours from mixing the dough to taking it out of a 450F oven. The loaf was 1.6 kg, Crumb is about the right density for a sandwich bread. The dough was mixed in a 6 l plastic tub with a tight fitting lid. Stretch / folds and final loaf formation were done on the counter. Final rise was done on a piece of parchment paper sitting on the peel. Bake it big, cut it into quarters, it freezes well.
And no, I do not bother sifting out the bran from half the flour. If I was serving the bread with delicate Ille de France menus – Never mind, I do not cook bland stuff any more.
Why does everyone put white flour and yeast in their recipes for Poilane style bread?
I'm no expert on Miche, but I looked at the Polaine masterclass online and followed the recipe with yeast and some sourdough and it was a same day bake with some home milled wholemeal and some plain flour. It was BORING.
So, since then, I've been refining my miche and it's sooo much better with an overnight retard and more rye. The wholemeal really makes the texture brilliant and I'm doing her lower hyrdration and one long knead, then shape a bit later, then longer proof and then popped in fridge. I am interested in the lower protein flours in this which stand up well because of the lower hydration. Much darker bake than usual for me and also very thick crust. Very springy too. Fun to try something quite different to what I normally do and it's tasty.