- ¾ teaspoon active dry yeast
- 1 cup warm (10° to 110°F) water
- 1 cup bread flour
- 1 cup fine or medium stone-ground whole wheat flour
- 1¼ teaspoons active dry yeast
- 2 tablespoons warm (105° to 110°F) water
- 1¾ cups plus 2 tablespoons cold water
- 4 cups bread flour
- 4 cups stone-ground whole wheat flour
- 1 tablespoon plus 2 teaspoons salt
- Prepare the starter: In a large bowl, dissolve the yeast in the warm water and set aside to rest for 15 minutes. Stir in the bread flour and whole wheat flour until the mixture becomes batter-like in consistency. Cover the bowl with plastic wrap and set aside at room temperature for 6 to 8 hours. The starter will double in size and develop a thick layer of bubbles on its surface as it ferments.
- Prepare the bread: In a large bowl, dissolve the yeast in the warm water. Set aside to rest for 15 minutes.
- Add the starter, cold water, and both types of flour. Slowly mix the dough with a wooden spoon for 3 minutes so that it becomes easier to handle. Add the salt and knead the dough with your hands until smooth, about 9 minutes. Place the dough in a clean, lightly greased bowl, cover with plastic, and set aside to rise at room temperature until it doubles in size, 1½ to 2 hours. Do not punch down.
- Remove the dough from the bowl and divide into 4 equal pieces. Shape each portion into a long or round loaf, cover loosely with plastic wrap, and set aside to rise at room temperature, until doubled in size, 1½ to 2 hours.
- Place clay tiles on 2 racks of the oven and preheat it to 425°. Allow the tiles to get hot.
- Place 2 loaves on each of 2 baking sheets. Place the sheets on top of the hot tiles. Bake until the loaves are dark brown, 20 to 30 minutes.