By Andrew Janjigian

     Sponge:

     ½ cup all-purpose flour

     (preferably King Arthur)

     1/8 teaspoon instant yeast

     ¼ cup room temperature water

Combine flour and yeast in medium bowl. Add water; stir until uniform and no dry flour remains. Cover tightly with plastic wrap and allow to rest at room temperature for 8 to 12 hours. If not using immediately, sponge can be refrigerated for up to 36 hours.

     Dough:

     1¾ cups all purpose flour  (preferably King Arthur)

     2⁄3 cup whole wheat flour

     ½ teaspoon instant yeast

     11/8 cup room temperature water

     Sponge

     1 teaspoon sea salt

In a large bowl, combine flours and yeast. Add water and sponge (recipe above); stir until uniform and no dry flour remains. Cover bowl tightly with plastic wrap and let rest 15 minutes.

Sprinkle salt over dough, stir to combine. Holding bowl with one hand, slip the fingers of other hand between the dough and the bowl to a depth of about 2 inches. Clasp the dough between thumb and fingers, and lift a flap of it up and over the center of the dough. Turn the bowl slightly and repeat, until you have worked your way around the bowl, a total of 6 to 8 folds. Cover bowl tightly and let rest 30 minutes. Repeat stretching, folding, and resting three more times.

To shape, repeat stretching and folding one last time, then invert dough onto a well-floured countertop. Cover loosely with plastic wrap, and let rest 15 minutes. Drape a cotton or linen towel over a large bowl, and dust liberally with flour. Dust top of dough lightly with flour, pat gently into a 6-inch circle, and fold edges into center of dough 4 to 6 times to form a ball. Place ball, seam side up, on center of towel, fold corners of towel loosely over dough, and cover loosely with plastic wrap. Let rise 1 to 1½ hours, or until doubled in size.

At least 30 minutes before baking, place BreadPot or enameled cast-iron Dutch oven on lower middle rack and heat oven to 450°. When hot, carefully remove pot from oven. Slide hand beneath towel and turn dough into center of pot (if using Dutch oven, shake pot from side to side to center it, if necessary). Cover with lid and transfer to oven. Bake, covered, for 30 minutes. Remove lid, and bake 15 to 30 minutes longer, or until loaf is golden brown. Transfer to wire rack and cool for at least 2 hours before serving.