Feed the sourdough starter twice before making the dough so that 100 g of starter is active and bubbly.

Combine 100 g active sourdough starter with 325 ml warm water in a mixing bowl.

Add 450 g white flour and 50 g whole wheat flour to the starter mixture.

Mix until no dry flour streaks remain, then cover the bowl.

Rest the covered dough for 30 minutes.

Add 10 g salt and the remaining 25 ml warm water to the dough.

Dimple and mix the dough until the salt water is fully incorporated.

Cover the dough and rest it for 30 minutes.

Lift one edge of the dough and fold it over to the opposite side.

Rotate the bowl and repeat the stretch-and-fold three more times to complete the first set.

Cover the dough and rest it for 30 minutes.

Repeat the four-fold stretch-and-fold set, then cover the dough.

Rest the covered dough for 30 minutes.

Repeat the four-fold stretch-and-fold set for the third and final time.

Turn the dough onto a lightly floured work surface.

Shape the dough into a round by drawing the surface toward you to create tension.

Cover the shaped dough and rest it for 15 minutes.

Dust the proofing basket with approximately 6 g rice flour.

Fold the dough inward like an envelope to build surface tension.

Place the dough seam-side up in the floured proofing basket.

Dust the exposed dough edges with rice flour and cover the basket.

Refrigerate the dough for up to 8 hours or overnight.

Place a covered Dutch oven in the oven and preheat to 250°C (480°F).

Preheat the Dutch oven for 30 minutes.

Remove the dough from the refrigerator just before baking.

Score the dough surface with a bread lame.

Transfer the scored dough into the hot Dutch oven and cover it with the lid.

Reduce the oven temperature to 220°C (428°F) and bake the covered loaf for 25 minutes.

Remove the Dutch oven lid and bake the loaf for another 25 minutes.

Transfer the baked loaf to a cooling rack.

Cool the bread for at least 45 minutes before slicing.