In a large mixing bowl, combine the active sourdough starter and warm water. Stir gently with a spatula or your hand until the starter is mostly dissolved into the water.

Add the flour and salt to the bowl. Mix with your hand or a sturdy spatula until no dry flour remains and a shaggy dough forms. Do not knead. Just ensure everything is incorporated.

Cover the bowl with a lid or plastic wrap and let it rest at room temperature for 30 minutes (autolyse/first rest).

After 30 minutes, perform your first set of 'stretch and folds'. With wet hands, gently grab a portion of the dough from the edge, stretch it upwards, and fold it over to the center. Rotate the bowl and repeat this 3-4 times until you've gone all the way around.

Cover the bowl and let it rest for another 30-45 minutes. Repeat the 'stretch and fold' process 2-3 more times, with 30-45 minute intervals between each set. You'll notice the dough becoming smoother and more elastic with each set.

After the last set of stretch and folds, cover the bowl and let the dough continue its bulk fermentation at room temperature (around 70-75°F / 21-24°C) for 8-12 hours, or until it has visibly increased in size by 50-75% and shows good signs of activity (some bubbles, domed top). The exact time will depend on your starter's strength and room temperature.

Lightly flour your work surface. Gently tip the dough out onto the floured surface. Using a dough scraper, gently shape the dough into a rustic round or oval. This isn't about perfection; just gather it into a cohesive shape. The 'unloaf' aspect means less stress on perfect shaping.

Prepare your banneton or a bowl lined with a floured cloth (rice flour works best to prevent sticking). Carefully transfer the dough, seam-side up, into the prepared banneton/bowl.

Cover the banneton/bowl with plastic wrap or a shower cap and refrigerate for 2-12 hours (cold proof). This slows down fermentation, develops flavor, and makes the dough easier to handle.

Approximately 45 minutes before you're ready to bake, place your Dutch oven with its lid into your oven. Preheat the oven to 450°F (232°C).

Once the oven and Dutch oven are fully preheated, carefully remove the hot Dutch oven. Gently invert the cold dough from the banneton onto a piece of parchment paper. If desired, lightly score the top of the dough with a sharp knife or razor blade (lame).

Using the parchment paper as a sling, carefully lower the dough into the hot Dutch oven. Place the lid back on.

Bake with the lid on for 30 minutes.

After 30 minutes, remove the lid from the Dutch oven and continue baking for another 15-20 minutes, or until the crust is a deep golden brown and the internal temperature reaches 200-210°F (93-99°C).

Carefully remove the bread from the Dutch oven and transfer it to a wire rack to cool completely for at least 1-2 hours before slicing. This is crucial for the crumb to set properly.