Ingredients

  • 12 ounces unbleached bread flour, plus flour for dusting
  • 3 ounces whole wheat flour
  • 3 ounces stone-ground rye flour
  • 1/2 teaspoon instant yeast
  • 2 3/4 teaspoons fine sea salt
  • 1/2 cup active natural starter (recipe follows)
  • Cornmeal for dusting

Method

  • Place flours, yeast and salt in a Cuisinart food processor fitted with a metal blade, and whirl to blend.
  • Using an instant-read thermometer, determine the temperature of the flour.
  • Measure 1 1/4 cups water, adjusting the temperature of the water so that when its temperature and that of the flour are added together, the total is 130.
  • Pour in the starter and, with the machine running, pour in the water through the feed tube and process 20 seconds.
  • If the dough seems dry and does not come together to form a ball, add 2 more tablespoons water.
  • Process the dough for another 25 seconds.
  • Test the temperature; it should be 75 to 80 degrees.
  • If it is lower, process it at 5-second intervals until it warms.
  • If it is higher, refrigerate for 5 to 10 minutes.
  • Place the dough in a bowl, cover with plastic wrap and set aside at room temperature for 3 hours.
  • Turn it onto a lightly floured board, shape it into a round loaf and place it, seam side up, in a well-floured round banneton or a cloth-lined basket.
  • Dust with flour, cover with plastic wrap and refrigerate 12 to 16 hours.
  • Remove the basket of dough from the refrigerator, and leave at room temperature 1 to 2 hours, until it is about 62 degrees and springs back very slowly when pressed.
  • One hour before baking, place a baking stone on a low oven rack and a pan for water on the oven floor.
  • Preheat oven to 475 degrees.
  • Turn the loaf out, seam side down, onto a bakers' peel heavily dusted with cornmeal.
  • Make four 1/2-inch-deep slashes in the top of the loaf, forming a large square.
  • Dust lightly with flour.
  • Pour a cup of hot water into the pan on the bottom of the oven.
  • Slide the loaf directly onto the stone.
  • Reduce heat to 450 degrees, and bake 2 minutes.
  • Add another cup of water to the pan, and bake 15 minutes.
  • Rotate the bread so it bakes evenly, and bake another 25 to 30 minutes, until the bread is a deep brown and the internal temperature has reached about 205 degrees.
  • (Reduce the oven temperature to 400 degrees during the last 20 minutes if the bread is browning too fast.)
  • Remove the bread from the oven, and cool completely on a rack before cutting.