· 1 cup (227g) ripe (fed) sourdough starter· 1 3/4 cups (397g) lukewarm water· 5 cups (602g) King Arthur Unbleached Bread Flour· 1 tablespoon (18g) salt· 2 teaspoons diastatic malt powder optional for a more golden color and stronger rise
Step 1Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. , Combine all the ingredients in a large mixing bowl, or a large (6-quart) food-safe plastic bucket., Mix and stir everything together to make a sticky, rough dough. If you have a stand mixer, beat at medium speed with the paddle attachment for 30 to 60 seconds. If you don't have a mixer, just stir with a big spoon or dough whisk until everything is combined., Leave the dough in the bucket or 6-quart bowl, cover it with the bucket’s lid or a piece of plastic wrap, and let it rise for 1 hour., Gently pick up the dough and fold it over on itself several times, cover it again, and let it rise for another hour., Repeat the rising-folding process one more time (for a total of 3 hours), folding it again after the last hour. Then, place the bucket or bowl in the refrigerator, and let the dough rest for at least 8 hours (or up to 48 hours)., When you're ready to make bread, turn the dough out onto a well-floured work surface, and shape it into a rough ball. Leave the dough seam-side up, cover it, and let it rest on a floured surface for 15 minutes., Next, shape the dough to fit the vessel in which you’ll bake it: a 13” log for a 13" pain de mie pan or long covered baker, such as our glazed long covered baker; or a large boule (round) for a round baker or Dutch oven, such as our bread baking crock. Place the shaped dough into the lightly greased or semolina-dusted base of the baker and cover it with the lid., Let the loaf warm to room temperature and rise; this should take about 2 1/2 to 3 hours. It won't appear to rise upwards that much, but will relax and expand., With a rack positioned in the middle, start preheating the oven to 500°F one hour before you’re ready to bake., Just before baking, dust the loaf with a fine coat of flour and use a lame or a sharp knife to make one or several 1/2” deep slashes through its top surface. If you're baking a long loaf, one arched slash down the loaf lengthwise is nice, or if baking a round, a crosshatch or crisscross pattern works well., Cover the baker with its lid and place it in the oven. (If you're using a pain de mie pan, leave the lid off.) Reduce the oven temperature to 450°F and bake the bread for 45 minutes., Remove the cover of the baker and bake the bread for 10 to 15 minutes longer, until the bread is deep golden brown and crusty, and a digital thermometer inserted into the center of the loaf reads at least 210°F., Remove the bread from the oven and transfer it to a rack to cool completely., Store leftover bread in a plastic bag at room temperature for several days; freeze for longer storage.