The day before making the bread or early in the day, make the poolish (or biga) by placing 8 ounces of the flour, 7 ounces of room temperature water and the yeast in a large bowl and mixing it well with a wooden spoon. Cover the bowl with a kitchen towel and let it stand for 2 to 3 hours at room temperature or in the refrigerator overnight. The poolish should double in volume.
Add 1 pound of the flour and 12 ounces of room temperature water to the poolish and mix together well with your hands. It will be very sticky. Cover the bowl with the kitchen towel and let rest for 30 minutes.
Sprinkle the salt over the surface of the dough and then fold the dough onto itself several times until the salt is incorporated. Cover the bowl with the kitchen towel and let the dough rest for 1 hour.
Cover your hands with flour and sprinkle flour around the outside edge of the dough. Fold the dough onto itself 6 to 8 times. Cover the bowl with the kitchen towel and let rest for 1 hour.
Fold the dough onto itself 6 to 8 times, dust a board generously with flour and pour the dough out onto the board.
Divide the dough into two equal parts and turn and form each part into a ball, stretching the dough to form a smooth top. Sprinkle flour heavily in 2 separate bowls (there should be enough flour to keep the dough from sticking) and turn each ball of dough upside down into a bowl. Sprinkle the top of each ball with flour, cover each bowl with a kitchen towel and let it rise until doubled in size, about 45 to 60 minutes.
Preheat an oven to 500 degrees F and line 2 sheet pans with parchment paper.
Turn each ball of dough bottom-side up onto its own sheet pan and use a knife or razor blade to score a tic-tac-toe design on the top of each loaf.
Place the loaves in the oven, immediately lower the temperature to 450 degrees F and bake for 30 minutes. (Do not open the oven door!) The loaves are done when they are golden brown and make a hollow sound when tapped on the bottom. Cool the loaves on a baking rack.
This recipe has been updated and may differ from what was originally published or broadcast.