1. 1. Combine Starter and Water: In a large mixing bowl, gently whisk together your active sourdough starter and the warm water until the starter is mostly dissolved. The mixture should look milky and slightly bubbly.

2. 2. Mix in Flours and Salt: Add the whole wheat flour, bread flour, and salt to the bowl. Use a wooden spoon or your hands to mix until all the flour is hydrated and a shaggy dough forms. Cover the bowl with a clean kitchen towel or plastic wrap and let it rest for 30 minutes.

3. 3. Perform Stretch and Folds: Drizzle the olive oil over the dough. Over the next 2-3 hours, perform a series of “stretch and folds” every 30 minutes. To do this, lightly wet your hands, grab a portion of the dough from the edge, stretch it upwards, and fold it over to the center. Rotate the bowl a quarter turn and repeat this process 3-4 times until you’ve gone all the way around. After the last stretch and fold, cover the bowl and let the dough bulk ferment at room temperature until it has visibly increased in size (about 50-75%) and looks bubbly (4-6 hours).

4. 4. Shape the Loaf: Lightly flour your work surface. Gently turn the dough out onto the floured surface. Carefully pat it into a rough rectangle. Fold the top third of the dough down to the center, then fold the bottom third up over the top. Gently roll the dough into a tight log, sealing the seam at the bottom.

5. 5. Second Rise (Proofing): Lightly grease a standard loaf pan (8.5 x 4.5 inches or similar) with olive oil. Carefully transfer the shaped dough seam-side down into the prepared loaf pan. Cover the pan loosely with plastic wrap or a clean kitchen towel. Let it proof at room temperature for 2-4 hours, or until it looks puffy and has risen noticeably. Alternatively, you can place it in the refrigerator overnight (8-12 hours) for a slower, colder proof.

6. 6. Bake the Bread: Preheat your oven to 400 F (200 C) with a rack in the middle position. Once preheated, place the loaf pan in the oven. Bake for 35-40 minutes, or until the crust is deep golden brown and the internal temperature reaches 200-210 F (93-99 C). If the top is browning too quickly, you can loosely tent it with aluminum foil.

7. 7. Cool Completely: Remove the bread from the oven and immediately transfer it from the loaf pan to a wire rack. Allow the bread to cool completely for at least 1-2 hours before slicing.