Bakery Style Sourdough Bread - cooking recipe

Ingredients

1/2 cup sourdough starter (proofed)
3/8 - 1/2 cup bottled water
1 cup unbleached flour (with high protein content, I use bread-making flour)
1 1/2 cups bottled water
4 3/4 cups unbleached bread flour
2 1/2 teaspoons table salt

Preparation

You will need a 1-quart bowl, a 2-quart or large bowl, a baking stone, a baking peel or rimless cookie sheet, spray bottle for water, and a rubber spatula or wooden spoon.
First make the sponge:
Combine starter, 1/2 cup bottled water.
Stir in 1 cup flour until combined, mixture should resemble thick pancake batter.
Cover container with plastic wrap and let rise at room temperature until doubled in bulk, 2 to 3 hours.
Make the Dough:
Use a mixer with dough hook (I used my bread machine on dough cycle).
Pour 1 1/2 cups water in large bowl.
Add 'sponge' to water.
With mixer running on low, add flour, 1/2 cup at a time.
Once all flour (4- 4 3/4 cups) has been added, continue kneading until forms a ball, about 1 minute longer. Cover bowl with plastic wrap and let dough rest 20 minutes.
Using fingers, create a pocket in rested dough; add salt to pocket. Knead dough until forms a firm ball. about 6 minutes. (If using mixer, knead at low speed, until dough is soft, smooth and moist, should not be sticky, about 5 minutes. Transfer dough to clean work surface and knead by hand until dough forms firm ball, about 1 additional minute).
Lightly spray bowl with non-stick cooking spray; place dough in container and lightly spray surface of dough. Set in draft-free area (room temperature) and let stand until doubles in bulk 3 to 5 hours.
Once doubled in bulk, remove the dough to clean work surface.
Stretch the dough (to redistribute and refresh yeast) as far as possible without tearing, then fold into thirds like a letter.
Divide the dough in half using chef's knife.
Form each half into rough ball, cover loosley with plasic wrap or damp kitchen towel, and let rise for 15 minutes.
Using your hands to push the dough against the unfloured work surface, form a taught ball without ripping the surface.
Pinch bottom seam and set each round, seam side down, on separate sheets of parchment paper on dinner plates.
Spray rounds lightly with non-stick cooking oil and cover loosley, but completely, with plastic wrap.
Refrigerate for 8- 12 hours.
Remove the rounds from refrigerator and gently slide (with parchment paper) on to room-temperature surface where they can rise undisturbed for several hours.
Loosen plastic wrap to allow rounds to rise; let rise until double in bulk and dough barely springs back when poked with your knuckle, 3-4 hours.
Place baking stone on lower-middle position.
Preheat oven to 500\u00b0F.
Carefully slide rounds on parchment to baking peel or rimless cookie sheet.
Using sharp knife slash rounds diagonally.
Spray loaves with water and slide carefully on to baking stone.
Immediately reduce the temperature to 450\u00b0.
During the first 5 minutes spray the loaves 2 additional times.
Bake until golden brown, about 30 minutes.
Transfer loaves to wire rack and cool to room temperature.