In a large bowl, combine the sourdough starter and warm water. Mix well.
Add flour and mix until a rough dough forms. Let it rest for 30–60 minutes.
Add salt and gently mix it into the dough.
Perform stretch-and-fold movements every 30 minutes for about 2 hours.
Cover the dough and let it rise at room temperature for 4–6 hours, or until it becomes light and bubbly.
Transfer the dough onto a lightly floured surface and gently shape it into a round loaf.
Place the dough in a floured proofing basket. Cover and refrigerate overnight for slow fermentation.
Preheat the oven to 230°C (450°F) with a Dutch oven inside.
Carefully place the dough into the hot Dutch oven, score the top, and cover with the lid.
Bake covered for 20 minutes, then remove the lid and bake for another 20–25 minutes until golden brown.
Allow the sourdough bread to cool completely before slicing and serving.