Pain au levain with whole-wheat flour

I have avoided to make this bread because the author mentions that will not raise as much as the other ones. Nevertheless, I have decided to give it a try. And I was not disappointed at all. It raised nicely and the taste and the flavor were amazing.

Ingredients:

Preferment (total 279g):

• 145g organic bread flour 
• 10g rye flower
• 93g water
• 31g stiff sourdough

Final dough (total 1729g for one big bread):

• 605g bread flour
• 40g rye flour
• 200g whole wheat flour
• 587g water
• 18g salt
• the above preferment (279g)

Directions:

1. Make the preferment 12 hours before. Let it sit at 21ºC.
2. Mix all ingredients except salt and sourdough for 1-2 minutes.
3. Autolyse for 20 minutes.
4. Add salt and sourdough and mix 10 min, desired dough temperature 24ºC.
5. Bulk fermentation 2h30" with stretching and folding twice after 45 minutes.
6. Shape it in a boule.
7. Final fermentation in floured banneton 2h30" at 24ºC.
8. Bake for 45" at 240ºC with steam in the first 15".

This recipe was adapted from Bread: A Baker's Book of Techniques and Recipes - Jeffrey Hamelman, page 160-161.