Sourdough bouillon

Ingredients:

• 5 cups of premium flour + extra for working with the dough
• 1.5 cups + 3 tablespoons water (25°C)
• 0.5 cups of bread sourdough
• 2 teaspoons coarse salt

Preparation:

1. In a large bowl, mix the flour with 1.5 cups of water until a lumpy, loose dough forms. Cover the bowl with a lid or plate and let it sit until the flour absorbs the water, 30-45 minutes.
2. Add the starter, salt, and the remaining 3 tablespoons of water to the dough. Pinch and twist with your hands until you have a sticky dough (it will be runny at first, but keep mixing).
3. Knead the dough in the bowl, sliding your hand under it, pulling it up and folding it, while rotating the bowl a quarter turn. Slap the dough back down on the bowl and repeat. Continue kneading until it is smooth and pulls away from the sides of the bowl, 5-7 minutes.
4. Cover and let rest in a warm place for 30 minutes.
5. Unfold the dough. Carefully insert a damp hand under the dough, pull it upward as far as possible without tearing it, then fold the dough over. Rotate the bowl a quarter turn and repeat three times, rotating the bowl a quarter turn each time.
6. Do another round of turning, then cover the bowl again and return to a warm place for 30 minutes.
7. Continue turning the dough twice every 30 minutes until it's doubled in size and is covered with large bubbles, another 2.5 to 3.5 hours, covering the bowl after each turn. After the final turn, cover the bowl and let the dough rest for another 30 minutes.
8. Turn the dough out onto a generously floured work surface. Slide a bench scraper or large spatula underneath and fold the dough in half. Dust the dough with flour and gently roll it in a circular motion into a tight ball. Let rest, uncovered, for 20 minutes (the dough will flatten slightly).
9. Line a medium bowl with a clean, lint-free towel and dust it generously with flour. Lightly dust the top of the dough with flour, then slide a bench scraper or large spatula underneath and flip it over. Working carefully to avoid deflecting the dough, pull each of the four sides of the dough up and into the center, folding the last side over to cover the entire surface of the dough. Roll the dough so the seams are facing down. Slide a bench scraper or large spatula underneath and carefully transfer it, seam-side up, to the towel-lined bowl. Loosely fold the edges of the towel over the dough.
10. Let the dough rest in the refrigerator for at least 8 hours and up to 18 hours.
11. About 30 minutes before baking, place a 25-27 cm diameter Dutch oven with a lid on the middle rack of the oven and place a stone or large cast iron skillet on the bottom rack to absorb the heat; preheat the oven to 230°C.
12. Carefully remove the cauldron from the oven and remove the lid. Remove the dough from the refrigerator, uncover it, and place a large piece of parchment paper on top. Invert the dough onto the parchment. Carefully lower the dough (on the parchment) into the hot cauldron. Using kitchen scissors or a knife, make several 0.5-1 cm deep slits in the surface of the dough.
13. Transfer the cauldron to the oven and cover. Bake until the bread is puffed and pale in color, about 20 minutes. Remove the lid and bake until the crust is brown and crisp and a thermometer inserted into the center of the bread reads 205°F (98°C), 25-35 minutes.
14. Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely, about 2 hours.