Mix 500 grams bread flour and 50 grams whole wheat or rye flour (if using) with 350 grams water until a shaggy mass forms.

Cover loosely and let the dough rest for 30 to 60 minutes at room temperature (autolyse).

Sprinkle 10 grams sea salt and 0.5 grams active dry yeast over the dough, add about 20 grams of water, then fold or mix on medium speed for 8 minutes.

Transfer the dough to a clean bowl, cover, and let rest undisturbed for 30 minutes to begin bulk fermentation.

Perform four sets of stretch and folds at 30 minute intervals over the next 2 to 2.5 hours, wetting your hand and folding each side of the dough into the center.

After the final fold, let the dough rest 1 to 1.5 hours until it increases in volume by about 50% and shows visible bubbles.

Lightly flour a work surface, pre-shape the dough into a round by folding edges toward the center, then rest for 20 to 30 minutes.

Flour a banneton, perform the final shape, place the dough seam side up into the banneton, and proof for 1 to 2 hours until it springs back slowly when poked.

About 45 minutes before baking, place the Dutch oven with its lid into a cold oven and preheat to 500°F (260°C).

When the oven reaches temperature, transfer the proofed dough onto parchment in the hot Dutch oven, score the top with a lame or knife, cover, and bake at 500°F for 20 minutes.

Remove the lid, reduce the oven temperature to 450°F (232°C), and bake for an additional 15 to 20 minutes until the crust is deep golden brown.

Remove the bread from the oven and cool completely on a wire rack for at least 1 hour before slicing.