Before beginning, make sure your starter is ready to go. Place a small amount of starter into a cup of cold water. If the starter floats, you know the starter is ready to be used for bread!
In a large bowl, add water and starter. Whisk until starter is dissolved into the water.
Add in both flours and mix with until completely combined.
Cover and let rest 30 minutes.
Next, sprinkle salt over the top of the dough. Mix in salt with hands until completely combined. You want to be thorough with this step so that you don’t end up with pockets of salt in your bread. Let rest, covered, 1 hour.
Next begin the series of folds. Fold dough over itself, on all four sides. *see video
Cover and let rest 1 hour.
After 1 hour, fold dough over itself again, on all four sides. *see video
Cover and let rest 1 hour.
After the 1 hour, fold dough over itself again, on all four sides. *see video
Cover and let the dough rest for another 1-3 hours depending on how warm/cold your house is. You are looking for the dough to be about doubled in size, and to appear jiggly and fluffy when you gently shake the bowl of dough.
Once the dough is done rising, carefully transfer dough to a floured surface.
Roughly shape dough into a round shape by using cupped hands. *see video
Lightly flour the top of the dough and cover with a kitchen towel. Let rest 30 minutes.
Uncover dough. Add a touch a more flour to the top of the dough and flip dough over onto that floured side. *see video
Shape dough by folding the side of the dough closest to you up, and then each side of the dough in towards each other. Next, fold the farthest side of the dough in towards yourself. Then, using the side closest to you, flip the dough all the way over so that what was once the bottom of the dough is now the top. *see video
Using cupped hands, shape the dough into a tight uniform ball. *see video
Transfer the loaf to a floured (I used semolina here, but flour also works!) bread basket by flipping it over so the smooth, shaped side of the loaf is face down in the basket. Pinch and pull on all sides of the loaf to “sow” the top. *see video
Cover with a kitchen towel and refrigerate until the next morning.
The next morning, with the cast iron you will be using inside the oven, preheat your oven to 500ºF.
Once preheated, remove the loaf from the fridge and cast iron from the oven. Flip dough out onto the hot cast iron. Score loaf as desired. *see video
Cover with cast iron lid and place back into the oven. Bake for 25-30 minutes.
Carefully remove lid from cast iron and return bread to the oven to finish browning and cooking. This next baking step will take about 10-15 minutes depending on how brown you like it.
Remove bread from oven and carefully transfer to a wire rack to cool.
Cool completely before slicing into the bread. Enjoy!