Step 1

Stir together the flours, salt, and yeast in a large mixing bowl. Add the water, and mix until no bits of dry flour remain. The dough will be very sticky.

Step 2

Cover the bowl with plastic wrap, and let the dough rise at room temperature overnight until the dough has doubled in size, about 12-18 hours.

Step 3

Generously dust a work surface with flour. Tip the bowl slightly, and use a rubber spatula or your fingertips to gently remove the dough from the bowl onto your work surface without tearing it. Lightly flour your hands, and gently fold the dough into itself, shaping it into a ball.

Step 4

Generously dust a tea towel with flour, and gently place the dough onto the towel, seam side down. Loosely fold the towel over the dough, and place it into a small mixing bowl. Let the dough rise until it's almost doubled, about 1 to 2 hours.

Step 5

A half-hour before the dough has finished proofing, put a rack in the lower third of the oven. Set the Dutch oven on the rack, and preheat the oven to 475 degrees Fahrenheit.

Step 6

Using oven mitts, carefully remove the preheated Dutch oven, and remove the lid. Use the tea towel to gently invert the dough into the Dutch oven, seam side up. Be careful: The pot will be very hot. Cover the pot, and bake 30 minutes.

Step 7

Remove the lid from the Dutch oven, and continue baking the bread 15 to 20 minutes, until it's a dark golden brown. Carefully lift the bread out of the Dutch oven, and let it cool on a rack for at least 20 minutes before slicing.