In a big bowl, stir together the active sourdough starter and water until cloudy.

Add the flours and mix until no dry flour remains. Cover and rest for 30 minutes.

Sprinkle in salt (and caraway if using) and mix by hand until evenly worked in. Cover again.

Let the dough rise for 3 to 5 hours at room temperature. For the first 2 hours, every 30 to 45 minutes, perform a stretch and fold.

After the bulk rise, sprinkle a little flour on the counter and shape the dough into a round loaf.

Place the shaped loaf seam side up in a floured bowl and cover to let rise for 1 to 2 hours at room temp, or overnight in the fridge.

Preheat the oven to 475°F (245°C) with a Dutch oven inside if available.

Transfer the dough onto parchment paper, score the top with a sharp knife, and place it in the hot Dutch oven.

Bake covered for 20 minutes, then uncover and bake for an additional 20 to 25 minutes until deep brown.

Let the bread cool for at least 1 hour before slicing to allow the crumb to set.