Tartine Sourdough Batard

Build the leaven (8-12 hours, overnight). Mix the starter, flour and water in a jar. Cover loosely and leave at room temperature. It's ready when it's bubbly, domed and floats in water.

Autolyse (30 minutes). Mix the flours with the 186 g of water until no dry flour remains. Cover and rest.

Add the leaven (30 minutes). Dimple in 50 g of leaven and squeeze it through the dough until combined. Cover and rest. Add the salt (5 minutes). Sprinkle the salt over the dough, add the 25g of water, and pinch and fold until fully absorbed.

Bulk fermentation (3-4 hours at about 78°F). Every 30 minutes for the first 2 hours, do a set of stretch and folds: grab one edge, stretch it up, and fold it over the center, rotating the bowl four times. Then leave the dough undisturbed until it's up about 20-30%, jiggly, and has bubbles along the edges.

Pre-shape and bench rest (25 minutes). Turn the dough onto an unfloured surface. Gently round it into a loose ball with a bench scraper. Rest it uncovered.

Final shape (5 minutes). Flip the dough over, fold the edges toward the center to build tension, and flip it seam-side down. Drag it toward you to tighten the surface. Place it seam-side up in a floured banneton or towel-lined bowl.

Final proof (3-4 hours at room temperature, or 8-12 hours in the fridge). The fridge option gives more flavor and an easier score. The dough is ready when a floured finger leaves a dent that springs back slowly.

Preheat (45-60 minutes, during the final proof). Put a Dutch oven with its lid in the oven at 500°F.

Score and bake covered (20 minutes). Turn the dough onto parchment, score the top with a razor, and lower it into the hot pot. Cover and bake at 475°F.

Bake uncovered (20-25 minutes). Remove the lid, lower the oven to 450°F, and bake until the crust is deep mahogany.

Cool (1 hour minimum). Cool the loaf on a rack before slicing so the crumb can set.