Makes 2 large or 3 smaller round loaves:
1 1/4 teaspoons active dry yeast or 1/2 small cake (9 grams) fresh yeast
1/4 cup warm water
2 1/2 cups water, room temperature
1 cup (250 grams) biga
scant 2 cups (250 grams) whole-wheat flour, preferably stone ground
3/4 cups (500 grams) ubleached all-purpose flour
1 tablespoon (15 grams) salt
Stir the yeast into 1/4 cup warm water in a large mixing bowl; let stand until creamy, anout 10 minutes. Add 2 1/2 cups water and the starter; squeeze the starter between your fingers to break it up and stir vigorously. Mix the flours and salt and stir 2 cups at a time into the yeast mixture; beat with a wooden spoon for 4 to 5 minutes. Flour your work surface generously, flour a dough scraper, and have a mound of flour neraby your hands. Turn the dough out onto the floured surface and, with the help of the dough scraper and extra flour, turn and knead the dough until it gradually loses its stickiness, although it will remain wet.
First rise. Place the dough in a lightly oiled large bowl, cover tightly with plastic wrap and let rise until tripled and full of air bubbles, about 3 hours. Do not punch down.
Shaping and Second Rise. Turn the dough out onto a well-floured surface and shape into 2 big flat rounds or 3 smaller ones, pulling tight on the surface of the dough with cupped hands to make a taut loaf. Place the loaves, rough side up, on well-floured baking sheets, peels, or parchments paper set on baking sheet. Cover with a towel and let rise until there are lots of air bubbles under the skin, about 1 hour.
Baking. Thirty minutes before baking, heat the oven with baking stones in it to 450°F. Dimple the tops of the loaves all over with your fingertips or knuckles, and let rest for 10 to 15 minutes. Just before baking, sprinkle the stones or griddle with cornmeal. Gently invert the loaves onto the stones. The bread will look deflated when you initially put it in, but it will puff up like a big pillow in no time. Bake for 45 to 55 minutes. Cool on racks.
Source: Carol Field, “The Italian Baker” (HarperCollins Publishers).