In a large mixing bowl, whisk together the flour, salt, water, and starter. Stir with a wooden spoon or nonstick spatula until you can't see any dry flour; the dough will be sticky and somewhat lumpy. Cover the bowl tightly with plastic and let rest at room temperature for 12 to 24 hours. During this time, the dough will rise and bubbles will form on the surface and you might see long strands of glutinous dough clinging to the side of the bowl as it rises.
Recipe: No.10 No-Knead Sourdough Bread
900 grams (7½ cups) all-purpose or bread flour
14 grams salt (2 teaspoons fine sea salt or 1 tablespoon kosher salt)
630 grams (2⅔ cups) water
120 grams (¾ cup) starter, fed or unfed
The Field Method for Cast Iron Care
Transfer the bowl to the refrigerator and let sit until you're ready to bake, 1 to 5 days. During this time, the dough is undergoing cold fermentation, which both strengthens the network of gluten (making the dough easier to shape and transfer later) and develops its flavor (to taste more like a sourdough bread).
When you're ready to bake, remove the dough and place it on a well-floured surface. Stretch and fold one side of the dough over the middle, then repeat with the opposite side (like you're folding a letter). Rotate the dough one-quarter turn and repeat. Sprinkle the dough and your hands with flour, then fold the sides under to form the dough into a ball (the top of the ball will be stretched and tight, with the seam underneath). Generously flour a clean kitchen towel and drape it over the dough ball. Let the dough rise at room temperature for 2 to 4 hours.
About 1 hour before you're ready to bake, preheat the oven to 450°F and position a rack in the lower third of the oven (usually the second rung from the bottom) and place a No.10 Dutch Oven (with its lid) on the rack. If you have a baking stone or steel, place it on the lowest oven rack.
Place a square of parchment paper next to the dough and transfer the dough on top. Cut the parchment into a circle around the dough, leaving about 3 inches of space on all sides. Using a bread lame, razor blade or very sharp knife, score the top of the dough with ½-inch-deep slashes; you can either make a criss-cross or square pattern.
Place the preheated Dutch oven next to the dough, grab two sides of the parchment paper with kitchen towels or potholders (to protect your hands!), and gently drop the dough into the Dutch oven. If the dough looks off center, give the pot a wiggle.
Cover the Dutch oven and transfer to the oven. Bake for 35 minutes, then remove the lid and continue baking until the crust is deeply browned and an instant-read thermometer inserted into the center of the loaf reads 200°F to 210°F, 35 to 40 minutes longer.
Remove the loaf from the Dutch oven and transfer to a wire rack. Let the bread cool for at least 30 minutes, and ideally a couple of hours or longer, before serving.