Mix the dough

• Pour the water into a bowl and add the active starter, mixing to dissolve.
• Add the bread flour and whole wheat flour and mix until no dry spots remain.
• Cover and set aside.

Add bassinage and salt

• Add the extra water and the salt.
• Mix to incorporate.

Slap and folds

• Slap the dough on the counter and fold it over itself repeatedly.
• Continue until the dough comes together, is smooth and no longer sticky.

Coil folds

• Cover the dough and complete a round of coil folds.
• Repeat every 30 minutes for 4 rounds total.

Bulk ferment

• Cover and let sit at room temperature until the dough pulls away from the container, has at least doubled in size and is filled with bubbles.

Divide and rest

• Turn the dough out and divide it into 2 pieces.
• Shape into balls, cover and let rest.

Shape and cold proof

• Flip the dough over and fold the bottom to the top, then the sides in, crossing over.
• Pull the dough down to the bottom, tucking the corners, then roll it against the counter to tighten.
• Place seam side up in floured bannetons or lined bowls, dust with flour and cover.
• Refrigerate overnight.

Preheat the baking vessel

• Preheat the baking vessel at 500 °F (260 °C).

Bake

• Score the cold dough with one strong line down the side.
• Place in the hot baking vessel and bake with the lid on at 500 °F (260 °C).
• Drop the heat to 450 °F (230 °C) and bake with no lid.

Cool

• Let the loaves cool before slicing.