N.B.: All of the flour in this recipe is 100% whole wheat. Something locally milled and designed for bread baking is best; King Arthur organic WW will work in a pinch.
To make the starter
3 tablespoons whole rye or wheat flour
Enough water to make what looks like a “thick pancake batter.”
Stir to mix and let it sit out, loosely covered, for 24 hours. Then take 60 grams (1/4 cup) of the starter, discarding the rest, and mix it with 60 grams of water (1/4 cup) and 60 grams (3/8 cup) of flour. Repeat this process every 12 hours for 3 to 5 days. By the time it’s obviously alive—slightly bubbly and smelling distinctly acidic—you’ll have succeeded in creating a levain. You can continue with the new starter or store in the refrigerator until you’re ready to bake.
To prepare the starter for baking
When you’re ready to bake, start 24 hours ahead if you’re using a refrigerated starter. You’ll need to wake it up and get it ready to leaven a loaf.
a) Mix 60 grams flour (3/8 cup), 60 grams warm water (about a quarter cup), 30 grams starter (about 1/8 cup) in a small bowl. Let sit at room temperature (70 degrees F) for 12 to 14 hours.
b) Then, take 10 grams (about a tablespoon) of that starter (you can discard the rest), which will have begun to get lively, and mix it with 60 grams flour (about a half cup) and 60 grams water (about a quarter cup).
Let it sit for 12 to 14 more hours. Now you’ll have just enough lively starter for a loaf—a little more than a half cup—plus a bit left over to begin the next batch of starter.
Now, get that next batch going: Scoop out about 10 grams (1/8 cup) of the starter, and add 20 grams of flour (1 1/3 tablespoons) and 20 grams of water (1 1/3 tablespoons). Mix it, and let sit for 3 hours at room temperature, then store in the fridge, covered tightly. Keep it alive by baking every week; or feed it once a week by scooping out 10 grams (1/8 cup) of starter (discarding the rest), and mixing with 20 grams of flour (1 1/3 tablespoons) and 20 grams of water (1 1/3 tablespoons), as above.
To make the bread
580 grams (4 cups) whole wheat flour
506 grams (2¼ cups) water, at room temperature
12 grams (2½ teaspoons) salt
120 grams (½ cup) Starter
Step 1: This is known as the autolyse step. Mix the starter and water together in a large bowl or plastic bread-making tub. Add the flour, and mix well. Let sit 20 to 40 minutes.
Step 2: Mix the dough by folding it like a letter, 2/3 of the way across, from all four sides. Then fold it all the way over and invert; you should have a nice loose dough with good tension all the way across the top.
Step 3: Let it rest, covered, for 3 hours, periodically folding as above (3 to 4 times).
Step 4: Shape the dough into a round by gently folding it over on itself, leaving a smooth, round top and a seamed bottom. This is known as a boule. Let it rest, covered, 20 minutes.
Step 5: Very gently place the boule, seam side up, into a floured proofing basket for 1.5 to 2 hours. If you do not have a proofing basket, you can take a linen (or fine mesh cotton, but linen is best) cloth, rub plenty of flour into it and place it in a small mixing bowl. Make sure there is ample flour covering all surfaces that the dough will touch, and also be sure that the bowl is deep enough to really shore up the sides of the boule. (I used a bowl-shaped metal colander as my proofing bowl, lined with a well-floured cloth.) About an hour into the proof, preheat the oven to 500 degrees and put the empty Dutch oven, with cover, into the oven, so that it will become blazing hot.
Step 6: Very carefully, drop the boule into the hot Dutch oven, seam side down.
Step 6: Make a few incisions along the top membrane about ¼ inch into the dough’s surface, to help with the loaf expansion.
Step 7: Bake approximately 30 minutes , then remove the lid of the Dutch oven and bake until the boule is a deep brown—10 to 15 minutes more. (You can insert an instant-read thermometer into the loaf—when done, it will be within a few degrees of 212 degrees F).
Step 8: Let cool on a metal rack—at least one hour; 4-6 hours is optimal to let the loaf develop flavor.
Tom Philpott, Mother Jones