Walnut Raisin Rye Boule

Steps

1. Day 1, morning: give your starter its usual feeding (equal weights of its regular feed and water) and leave it at about 75°F (24°C); it should double and peak, bubbly and domed, in 4 to 6 hours.
2. While the starter rises, toast the walnuts in a dry skillet over medium heat for 5 to 7 minutes until fragrant, cool, then chop coarsely.
3. When the starter peaks, stir the molasses into 360 g of the water (all but 20 g) in a large bowl, then whisk in the sourdough starter.
4. Add the rye flour and bread flour and mix with a wet hand or spatula until no dry patches remain. Cover and rest 30 minutes.
5. Sprinkle the salt and the remaining 20 g of water over the dough and squeeze it in until fully absorbed. The dough is about 79% hydration and 2% salt, counting the starter's share.
6. Fold in the walnuts, raisins and cinnamon until evenly spread through the dough.
7. Bulk rise covered at about 75°F (24°C) for 3 to 4 hours. In the first hour, do 2 gentle sets of stretch-and-folds 30 minutes apart with wet hands; rye dough is sticky and won't feel stretchy, so just lift and fold each side over. It's ready when it has grown about 50% and shows small bubbles on top.
8. Dust a banneton or towel-lined bowl with a little extra rye flour. Turn the dough onto a lightly wetted counter, shape it gently into a tight round boule with wet hands, and place it seam side up in the basket.
9. Cover and cold proof in the fridge overnight, 12 to 14 hours.
10. Day 2: place a lidded Dutch oven in the oven and preheat to 475°F (245°C) for 45 minutes.
11. Turn the cold dough onto parchment, score a shallow cross on top, and lower it into the hot Dutch oven. Cover and bake 20 minutes.
12. Remove the lid, lower the oven to 450°F (230°C) and bake 25 to 30 minutes more, until the crust is deep mahogany brown and the center reads 205 to 210°F (96 to 99°C).
13. Cool the loaf on a rack at least 4 hours before slicing so the rye crumb sets; cut into 12 slices.