Mix all the whole wheat flour with 80 g water and let it autolyze for 3-6 hours. Before it is time to mix the dough, add the remaining water to the wheat flour and let it autolyze for one hour.

Mix wheat dough, whole wheat dough, salt, and starter.

Let the dough ferment at 73ºF / 23ºC, until it has expanded about 1/3 of it's size. Make on o

Dump out the dough on a floured working surface and form to a batard. Place the loaf in a floured banneton.

I placed the banneton in the fridge and let it proof for 8-12 hours. You can also let it proof in room temperature. Check it regularly, at least every half hour, and perform a finger poke test.

Preheat the oven to 480ºF / 250ºC. Turn out the dough gently on a piece of parchment paper. Score it as desired and load it into the oven, preferably on a baking stone and add steam. Open the oven lid and let out the steam after 15-20 minutes. Bake for an additional 15 to 20 minutes.