Combine the Flours and Water: In a spacious mixing bowl, blend the bread flour and whole wheat flour (or your preferred flour mix). Gradually add the lukewarm water and stir until a coarse dough starts to come together. Don’t worry if it looks a bit shaggy at first – you’re on the right track.

Incorporate the Sourdough Starter and Salt: Add your active, bubbly sourdough starter along with the salt to the dough. Mix thoroughly until all the ingredients are fully combined and the dough begins to form, which should take only a minute or two.

Knead the Dough: Transfer the dough onto a lightly floured surface and knead it for approximately 8 to 10 minutes. You’re looking for a smooth, elastic dough that’s slightly tacky but not overly sticky. If it's too sticky, sprinkle a little more flour, but don’t overdo it. The dough should feel soft but firm enough to hold its shape.

Let the Dough Rest: After kneading, transfer the dough to a lightly greased bowl and cover it with a damp kitchen towel. Allow it to rest and rise at room temperature for 4 to 6 hours, or until it has doubled in volume. During this time, the wild yeast in your sourdough starter will work its magic, creating air pockets and giving your bread that signature chewy texture.

Stretch and Fold: Every 30 minutes during the first 2 hours of the rise, perform a series of stretch and folds. To do this, wet your hands and gently stretch the dough from one side, then fold it back onto itself. Rotate the bowl and continue this motion all around the dough. This helps develop the gluten structure, resulting in a lovely crumb once baked.

Pre-shape the Dough: Once the dough has risen, carefully take it out of the bowl and place it onto a lightly floured surface. Gently fold the edges toward the center to form a rough round shape. Allow it to rest for about 15 minutes to let the gluten relax.

Final Shape: Now, shape the dough into a tight round ball by tucking the edges underneath. This creates tension on the surface of the dough, helping it maintain a nice round shape while it bakes.

Let it Proof: Place the shaped dough seam-side down into a well-floured proofing basket or bowl. Cover it with a damp cloth and let it rise for another 2-3 hours at room temperature, or overnight in the refrigerator if you prefer a slower fermentation (this enhances the flavor).

Test for Readiness: To check if the dough is ready, gently press your finger into the dough. If it springs back slowly and leaves a slight indentation, it’s ready to bake.

Heat the Dutch Oven: About 30 minutes before you're ready to bake, preheat your oven to 475°F (245°C). Place a Dutch oven (or another heavy baking pot with a lid) inside to heat up. This helps create a steamy environment that encourages a perfect crust.

Score the Dough: Once the oven is preheated, carefully turn your proofed dough out onto a piece of parchment paper. Using a sharp razor blade or bread lame, score the top of the dough with a few shallow slashes. This helps the dough to rise beautifully during baking.

Bake in the Dutch Oven: Carefully place the dough, still on the parchment paper, into the preheated Dutch oven. Place the lid on and bake for 25 minutes. This initial baking time traps steam and helps the bread develop its crispy crust.

Uncover and Finish Baking: After 25 minutes, take off the lid and bake for an additional 20 to 25 minutes, or until the bread turns golden brown and sounds hollow when tapped on the bottom. The crust should be richly browned and crisp.

Cool on a Rack: Once baked, remove the bread from the oven and let it cool on a wire rack for at least 1 hour before slicing. This allows the crumb to set and develop its full flavor.