Whole Wheat Rosemary Pecan Sourdough Boule

Steps

1. Day 1, 8 a.m.: Feed your sourdough starter as you usually do, with equal weights of fresh food and water, and leave it at about 75°F (24°C). It should peak, doubled and bubbly, in 4 to 6 hours.
2. While the starter rises, toast the pecans in a dry skillet over medium heat for 4 to 5 minutes, stirring, until fragrant. Cool, then chop coarsely and set aside.
3. About 1 hour before the starter peaks, mix the whole wheat flour and the bread flour with 360 g of the water (all but 30 g) until no dry patches remain. Cover and rest for 1 hour (autolyse).
4. Add the peaked starter to the dough and squeeze it in with wet hands. Sprinkle on the salt, then add the remaining 30 g of water and two-thirds of the olive oil (20 g). Squeeze and fold for 3 to 4 minutes until the dough is smooth and absorbs the liquid. The dough is about 78% hydration and 2% salt, measured against the combined whole wheat flour and bread flour, not counting the starter.
5. Bulk rise, covered, at about 75°F (24°C) for 4 to 5 hours. After 30 minutes, do the first set of stretch-and-folds: spread the pecans and rosemary over the dough, then stretch each side up and fold it over to work them in.
6. Do 3 more sets of stretch-and-folds, 30 minutes apart, then leave the dough undisturbed. Bulk is done when the dough has risen by about half, feels airy and shows bubbles on the sides and top.
7. Turn the dough onto a lightly dampened counter, pre-shape it into a loose round and rest it for 20 minutes. Shape it into a tight boule and place it seam side up in a parchment-lined bowl.
8. Cover and cold proof in the fridge overnight, 12 to 14 hours.
9. Day 2: Put a Dutch oven with its lid in the oven and preheat to 475°F (245°C) for 45 to 60 minutes.
10. Turn the cold dough onto parchment, seam side down. Brush the top with the remaining one-third of the olive oil (10 g) and score it with a deep slash.
11. Lower the dough on its parchment into the hot Dutch oven, cover and bake for 20 minutes. Remove the lid, reduce to 450°F (230°C) and bake 25 to 30 minutes more, until the crust is deeply browned and the center reads 205°F (96°C).
12. Cool the loaf on a rack for at least 2 hours before cutting into 12 slices.