Mix the dough

• Pour 350 g of water into a bowl.
• Add 125 g of bubbly active sourdough starter and whisk together until frothy.
• Add 525 g of bread flour and 10 g of salt.
• Mix until fully incorporated into a shaggy wad of dough.

Rest the dough

• Cover the bowl with a shower cap or cloth.
• Let the dough rest for 1 hour.

Stretch and fold

• Wet your hands, then stretch the dough up and fold it over itself.
• Do a first round of stretch and folds.
• Wait 30 minutes and repeat for a second round.
• Wait 30 minutes and repeat for a third round.
• Wait 30 minutes and do a fourth and final round.

Bulk ferment

• Transfer the dough to a large clean bowl.
• Cover and let it bulk ferment for the rest of the day.

Shape the loaf

• Lightly flour the countertop.
• Turn the dough out and let gravity help it release from the bowl.
• Shape it gently, creating tension on the surface.
• Flour a banneton generously and place the dough inside, seam side up.

Cold proof overnight

• Cover the banneton with a shower cap or cloth.
• Let the dough nap in the fridge overnight.

Bake

• The next day, bake the loaf in a preheated oven until deeply golden and hollow-sounding.