Step 1

(night before mixing, 9:00 p.m.)In a small container, mix the Levain ingredients and keep it at a warm temperature overnight.

Step 2

(the next day, 7:30 a.m.)Preheat your oven to 350°F (175°C). Spread the 160g walnuts out evenly on a sheet pan and bake for 10 to 15 minutes until they start to take on a little color and become very fragrant. Set aside until bulk fermentation.

Step 3

(8:00 a.m)In a medium mixing bowl, add the 600g medium-protein bread flour, 120g whole wheat flour, and 520g water and mix until no dry bits remain. Cover the bowl and let rest for 1 hour.

Step 4

(9:00 a.m.)To the mixing bowl holding your dough, add the levain and a splash of water. Mix thoroughly and strengthen the dough for about 5 minutes. Let the dough rest for 10 minutes in the mixing bowl. Add the salt, another splash of water, and mix until incorporated. Strengthen the dough further if necessary until it’s elastic and smooth. Then, slowly add the walnut oil over the course of the next few minutes while stretching and folding until the oil is absorbed and the dough is smooth and shiny. Transfer the dough to a bulk fermentation container and cover.

Step 5

(9:30 a.m. to 12:30 p.m.)Before you give your dough its first set of stretch and folds, spread about 1/4 of the mix-ins over the top of the dough. Add the rest of the mix-ins in the same way through the remaining folds for the first set. Perform two more sets of gentle stretch and folds during this 3-hour period, then let the dough rest the remainder of bulk fermentation.

Step 6

(12:30 p.m.)Lightly flour your work surface and scrape out your dough. Using your bench knife, divide the dough in half. Lightly shape each half into a round shape. Let the dough rest for 30 minutes, uncovered.

Step 7

(1:15 p.m.)Shape the dough into a round (boule) or oval (batard) and place in proofing baskets. Cover the baskets with a reusable plastic bag.

Step 8

(1:30 p.m. to 9:00 a.m. the next day)Cover proofing baskets with reusable plastic and seal shut. Then, place both baskets into the refrigerator and proof overnight.

Step 9

(The next day, bake at 9:00 a.m.)Preheat your oven with a baking surface or combo cooker/Dutch oven inside to 450°F (230°C).