Sourdough Boule

Combine flour and water in a large bowl. Mix by hand until no dry flour remains — this takes about 2 minutes of rough mixing. The dough will be shaggy and rough, almost reluctant. Cover and rest at room temperature for 30–60 minutes. During this rest, the flour's enzymes begin breaking down proteins and starch, and gluten bonds form without any mechanical effort. When you return to the dough, it will have visibly smoothed and relaxed.

Add the active starter and scatter the salt over the dough surface. Dimple the salt in with your fingers, then perform a series of 4 stretch-and-folds: wet your hand, reach under one side of the dough, stretch it up until you feel resistance, then fold it over the top. Rotate the bowl 90° and repeat all the way around. Do this for 4 rounds total, spaced 30 minutes apart. After the last fold, let the dough bulk ferment undisturbed at 75–78°F (24–26°C) for a total of 4–5 hours from when starter was added, until it has grown by 50–75% and is visibly bubbly throughout.

Turn the dough onto a lightly floured surface. Fold the edges in toward the center, then flip it seam-side down. Using both hands cupped around the dough, drag it toward you across the bench with gentle downward pressure — the friction tightens the surface. Repeat this motion 4–5 times, rotating slightly each pass, until the boule has a taut, smooth top with no tears. Transfer seam-side up into a well-floured banneton (rice flour is ideal) or a flour-dusted bowl lined with a floured tea towel. The boule should hold a round shape and not sag sideways.

Refrigerate the shaped boule, covered, for 10–16 hours (overnight is ideal). The cold retard slows fermentation while allowing the sour flavor to develop and the dough to firm up for cleaner scoring. The dough does not need to look dramatically different after retarding — a slight increase in size is normal. Bake directly from the refrigerator without warming to room temperature; the cold dough will score more cleanly.

Place a Dutch oven in the oven and preheat to 500°F (260°C) for at least 45 minutes. When oven-hot, remove the boule from the refrigerator. Cut a large square of parchment to act as a sling. Flip the cold boule seam-side down onto the parchment. Using a lame or sharp bread knife held at a 30–45° angle, score a single confident arc across the top — the ear — with one continuous stroke. Depth should be about ½ inch (1.2 cm). Additional decorative scores can be added perpendicular, but the main ear is the pressure valve.

Lower the boule on its parchment into the preheated Dutch oven. Cover with the lid and bake at 500°F for 20 minutes (the steam from the dough creates the oven-spring environment). Remove the lid, drop the temperature to 460°F (238°C), and bake a further 20–25 minutes uncovered until the crust is a deep mahogany-brown. Remove from the Dutch oven and cool on a wire rack for at least 1 hour before cutting — the crumb is still setting up inside.