1. Make the preferment: Put the yeast in the water and stir. Mix the flour and salt together in a bowl and pour in the yeasted water. Mix until the flour is hydrated, adding a little more water if necessary. Cover the bowl with plastic wrap and leave the pre-ferment out at room temperature overnight.
2. Make the dough: To make the final dough, combine all of the ingredients except the pre-ferment in a mixing bowl. Chop the pre-ferment up into small pieces and mix in. Turn onto a floured surface and knead for 10 mins, until smooth and thoroughly combined. Dough should be tacky but not sticky, so knead in flour accordingly.
3. Place the dough in a greased bowl and ferment for 2 1/2 hours, folding the dough at 1 hr, and 1:45. (To fold dough, take the dough out of the bowl, spread it out a little on a clean surface and fold it in thirds like a letter. Rotate it 90 degrees and fold it up again. Return the dough to the bowl and cover again.)
4. At the end of the fermentation, divide the dough into three pieces and preshape each into a ball. Cover with a clean towel and let each rest for 5 to 10 minutes before shaping into an 8-9 inch loaf with tapered ends. Once shaped, place on a well floured peel and cover the loaves with a clean towel. Set aside for a final rise, approximately 1 1/4 to 1 1/2 hours.
5. Halfway though the final rise, begin preheating the oven and baking stone to 450 degrees. Place a cast iron pot on the bottom rack and fill with boiling water 10 mins before you start baking the bread.
6. Slash the tops of the loaves with a razor blade, about 1/3 of the way through. Bake for 25-30 mins, rotating the loaves 180 degrees after 12 mins so that they'll bake evenly. Crust should be a deep golden brown, and loaves should sound hollow when you knock on the bottom. I baked two loaves at a time.
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