Step 1: In a large mixing bowl, combine 150g of your active sourdough starter with 300g of warm filtered water. Stir until well mixed.
Step 2: Add 450g of the flour mixture and 12g of salt. Mix until a shaggy dough forms.
Step 3: Turn the dough out onto a lightly floured surface and knead for about 8-10 minutes until smooth and elastic.
Step 4: Place the kneaded dough back into the bowl, cover with a damp towel, and let it rise for about 1 hour until doubled in size.
Step 5: Gently deflate the dough, shape it into a loaf, and let it rise for another 30-45 minutes on a baking sheet.
Step 6: Preheat the oven to 450°F (232°C) while the dough rises.
Step 7: Bake for 30 minutes in a Dutch oven, then remove the lid and bake for an additional 15-20 minutes until golden brown.
Step 8: Let the bread cool on a wire rack before slicing.