This is a simple recipe that takes some time (like most sourdoughs). An overnight stay in the fridge improves flavor, but isn't necessary.
- Starter Sponge: Add starter to the water and wisk together. Add flour, mix well, cover and let sit at room temperature (70 to 75F) until doubled in volume (6 hours or overnight).
- Dough: Wisk starter sponge into the water and add enough flour to make a thin batter. Wisk to aerate dough, forming some bubbles. Add the rest of the flour and mix well to incorporate.
- Cover the bowl and let rest for 20 minutes.
- Add salt and knead for 8 minutes. Cover and let rest 5 minutes.
- Stretch and fold the dough once by stretching dough into a rectangle and folding letter-style side to side and top to bottom.
- Place in oiled container (straight sided is best) and mark the point on the container where the dough is doubled.
- Let rise in 75 to 80 F area for 30 minutes. Stretch and fold the dough for the second time.
- Let rise in 75 to 80 F area for 1 more hour or until doubled in volume (3 1/2 to 4 hours).
- Remove dough and divide into 2 pieces weighing just shy of 1 lb each.
- Shape into batards or torpedo or boule (ball) shapes. Place loaves on a floured cloth folded to support the sides of each loaf and cover with oiled plastic or in proofing baskets or bowls.
- At this point, I let rise for 20 - 30 minutes and place in the fridge but you can let the loaves rise until 1 1/2 times their volume and bake.
- If refrigerated, remove the loaves and let warm in a warm place for about 45 minutes as the oven prehneats to 450°F.
- Add a cast iron skillet near the bottom of the oven to preheat as well.
- Add 1 cup of hot water to the skillet carefully to avoid breaking the oven door glass and score the loaves with a razor blade.
- Transfer the loaves to parchment paper and place in the oven using a flat baking sheet or a peel.
- Bake for 12 minutes and rotate loaves for even cooking. Remove steam pan as well.
- Bake for 10 more minutes until browned or 205 F internal temp Cool on rack.