Mix all ingredients except salt and starter and let the dough autolyze for one to two hours. Add sourdough starter and salt and incorporate it thoroughly into the dough.

Perform 3-4 sets of stretch and fold, spaced out with 30 minutes.

Let the dough rest for about 5 hours at a temperature of 78ºF/25ºC if possible.

Lightly flour your working surface and dump out the dough. Flatten the dough gently with your hands. Form each piece of dough to a boule. There's a link to an excellent video showing how to form a boule in the recipe notes*.

Let the loaves rise until they pass the finger poke test. The time required depends a lot on ambient temperature so don't look at the clock.

Preheat your oven to 480ºF / 250ºC with two oven plates. One to bake the bread on and one just below. If you have a baking stone or dutch oven, use them instead.

Score the loaves in your preferred pattern and place them in the oven. Pour some water on the plate below and bake each loaf in 35-45 minutes.

Let the breads cool on wire racks.