Make your leaven by mixing the sourdough starter, flour and water in a medium bowl until fully incorporated. Cover the bowl with plastic wrap and set in the refrigerator to sit for 12 hours overnight.

To test if your leaven is ready, make sure you visually see many bubbles at the surface. You can do a “float test” by dropping a small bit of the leaven in water. If the leaven floats, it is ready to work with.

To make the bread dough, first add the 2 1/4 cups of water to the starter mixture. Stir with a rubber spatula until the leaven seems to have fully dissolved into the water – it’s okay if a few clumps of leaven still remain in the bowl. Add the 700 grams of flour, and mix with the spatula until there is no more dry flour and you have a shaggy dough.

Turn the dough out onto a lightly floured work surface, and begin to knead the dough by hand, folding it over onto itself. At this point, you can add the salt to the dough and continue to fold until the dough starts to feel elastic, soft and incorporated. Let the dough sit for 30 minutes, making sure to cover it so it doesn’t form a skin. Continue to fold the dough every 30 minutes for 2 1/2 hours, and then let it rise, covered, for 1 hour.

Once the dough has fully risen, divide it in half to create two loaves. Shape them into spheres, and place them each in proofing baskets. Ceramic or wooden bowls will work as well. Cover and allow the dough to rest and proof for 3 to 4 hours, or in the fridge overnight.

Once the dough has proofed, preheat the oven to 500 degrees F.

Sprinkle the bottom of a dutch oven with cornmeal. Turn one loaf of dough out of the proofing basket or bowl into the dutch oven – if you used a proofing basket, make sure the ridges are facing up. Score the top of the loaf with a sharp knife or razor into your desired design. Put the lid on the dutch oven, and place into the oven to bake.

Bake the loaf at 500 degrees for 20 minutes, and then turn the heat down to 450 for 10 minutes. Remove the lid and bake for another 15-25 minutes.

Allow the loaf to fully cool to room temperature before cutting slices with a serrated knife.