I finally got around to making Hamelman's "Pain au Levain with Whole Wheat Flour." For comparison, I also baked his Pain au Levain. The former was cold retarded overnight. The latter was not. However, I did retard the firm sourdough starter used for both breads overnight, and I believe this resulted in a tangier pain au levain than my previous bakes.
On to some photos:
Pain au Levain boules
Pain au Levain crumb
Pain au Levain crust
If I were nit picky, I'd say this dough was slightly over-fermented, and I think the loaves were slightly over-proofed. However, it had a thin, crisp crackly crust that I wish I could reproduce at will, and the flavor was delicious, with more of a tang than usual, as mentioned.
Pain au Levain with Whole Wheat Flour
Pain au Levain with Whole Wheat Flour crumb
This bread had a more complex flavor that the "regular" pain au levain when tasted 2 hours out of the oven. There was a slight WW grassiness, which I do not enjoy, and a lingering sourdough flavor, which I do enjoy. This type of bread usually tastes better to me on the day after it was baked, and I trust this bread will follow the pattern.
It's hard for me to say which of the three version of pain au levain in "Bread" is my favorite. Experience suggests it's whichever one I'm eating at the moment. I really, really like all three.