To make the Poolish: Stir together flour and yeast in a medium bowl. Stir in water until blended. This dough will be like thick cake batter. Cover with plastic wrap and let sit overnight or up to 24 hours at room temperature. The dough will become frothy and have lots of little bubbles.
To make the Dough: Dissolve yeast in lukewarm water in a large bowl. Stir in Poolish and mix until thoroughly blended. Add 3 cups of the bread flour and salt. Stir until combined. Dough will be soft and slightly sticky like biscuit dough. Add remaining 1/4 cup bread flour, if necessary. Cover bowl with plastic wrap and let rest for 20 minutes.
Turning Dough: Turn the dough onto a floured surface and knead for 2 minutes using a dough scraper if necessary to pick up and fold the dough over. Place in a large ungreased bowl. Cover and let rest 1 hour. With a slightly wet hand give the dough several turns by sliding the hand down the edge of the bowl, lifting and stretching the dough up and over the center. Give the bowl a quarter turn and repeat 7 times until you have gone around the bowl twice. Cover and let rest 1 hour. Repeat turning and resting once more for a total of 3 hours rising time.
Primary Shaping: Turn the dough out onto a lightly floured surface. With floured hands gently press to deflate dough. Divide in half or thirds. If dough is too sticky, dust surface lightly with bread flour and use a dough scraper to pick up and fold over dough several times as for kneading. Return to Primary Shaping. Working with each portion separately, on a lightly floured surface with floured hands shape into a rough rectangle (6 x 9-inches) with a short edge toward you. Fold the far edge of the dough toward the center about 2 inches, gently stretching the bottom of the dough over the edge and pressing the edge to dough under it. Repeat folding and pressing until a roll is formed. Cover and let rest for 20 minutes.
Final Shaping: Working with the seam side up, flatten the dough to a rough rectangle (6 x 9-inches) with a long edge toward you. Now fold the far edge toward the center about 1 inch, pressing into the dough under the edge. Repeat folding and pressing several times working toward you, until almost to near-edge. Fold up near-edge and pinch to seal. Turn the loaf over and gently roll back and forth under two hands to about 14 inches long. (Never use a rolling pin.) Place seam side up on a towel or parchment paper generously dusted with bread flour or rice flour. Cover and let rise 1-1/2 to 2 hours or until double. Repeat with remaining dough.
For best baking results, place a baking stone, pizza stone or unglazed ceramic tile on bottom shelf of oven. Preheat oven to 475°F for 20 minutes to allow stone to get to temperature. Depending on the size of your baking stone, bake 1, 2 or 3 loaves at a time, placing seam side down on parchment paper. Score each loaf with 2 to 4 slashes using a sharp knife or blade. Slide the dough with parchment onto bread peel or rimless baking sheet. Carefully slide onto heated baking stone, immediately spritzing the oven with water around the dough 7 to 10 times. Bake for 20 to 30 minutes spritzing every 5 minutes 3 more times. Bake to an internal temperature of 200°F. Remove from oven and parchment; cool on wire rack. Bake remaining bread.