In a large bowl, combine the flours and water. Stir until no dry bits remain. Cover and let rest for 30 minutes (autolyse).

Add starter and salt

Mix in the sourdough starter and salt until fully incorporated. Dough will feel stickier and heavier than all-white flour dough—this is normal.

Cover and let the dough rise at room temperature for 4–6 hours, performing stretch-and-folds every 30–60 minutes for the first 2–3 hours. Whole grain dough ferments slower and is heavier, so patience is key.

Lightly flour your surface and gently shape the dough into a round or oval loaf. Avoid overworking; whole grain dough is more delicate.

Place the shaped dough in a floured banneton or bowl. Cover and let rise 2–3 hours at room temperature, or overnight in the fridge for a more developed flavor.

Preheat your oven to 450°F (230°C) with a Dutch oven inside if using.

Carefully transfer the dough to the preheated Dutch oven. Score the top with a sharp knife or razor. Bake covered for 20–25 minutes, then uncover and bake another 15–20 minutes until deeply browned.

Remove from the oven and let cool completely on a wire rack before slicing. Whole grain bread needs extra time to finish setting—resist the urge to cut too early.