SAN FRANCISCO SOURDOUGH BREAD

Steps:

• Do ahead
• To make the starter, combine all of the ingredients in a mixing bowl. If using a mixer, use the paddle attachment and mix on the lowest speed for 1 minute, then increase to medium speed for about 30 seconds. If mixing by hand, stir for about 2 minutes, until well blended. The starter should feel doughlike and tacky or slightly sticky; if not, stir in additional flour or water as needed.
• Transfer the starter to a lightly floured work surface and knead for about 30 seconds. Place it in a clean, lightly oiled bowl, cover the bowl loosely, and leave at room temperature for 6 to 8 hours, until the starter increases to about 1 1/2 times its original size. If you plan to use the starter the same day, allow 1 more hour of fermentation so that it nearly doubles in size. Otherwise, put the starter in the refrigerator for up to 3 days.
• To make the dough, cut the starter into 10 to 12 pieces and put them in a mixing bowl. Pour in the water and mix with the paddle attachment on the lowest speed or with a large spoon for about 1 minute to soften the starter.
• Add the flour and salt, as well as the yeast (unless you're making the "purist" version). Switch to the dough hook and mix on the lowest speed, or continue mixing by hand, for 2 minutes, to form a coarse ball of dough that's very tacky and slightly warm. Let the dough rest for 5 minutes.
• Mix on medium-low speed or by hand for 4 minutes more, adding flour or water as needed to make a soft, supple, slightly sticky ball of dough.
• Transfer the dough to a lightly floured work surface and knead by hand for 1 minute, then form it into a ball. Let the dough sit uncovered for 10 minutes, then do a stretch and fold, either on the work surface or in the bowl, reaching under the front end of the dough, stretching it out, then folding it back onto the top of the dough. Do this from the back end and then from each side, then flip the dough over and tuck it into a ball. Cover the dough and let it rest for 10 minutes. Do another stretch and fold, then immediately form the dough into a ball, place it in a clean, lightly oiled bowl large enough to contain the dough when it doubles in size, and cover the bowl.
• If using the mixed method with instant yeast, refrigerate the dough immediately. If making the "purist" version, without instant yeast, let the dough sit at room temperature for 1 1/2 to 2 hours before refrigerating; it won't rise very much, but it should show signs of growth and continue to rise in the refrigerator. Either version will be ready to use the next day and for up to 3 days. (If you plan to bake the dough in batches over different days, you can portion the dough and place it into two or more oiled bowls at this stage.)
• On baking day
• For the "purist" version, remove the dough from the refrigerator about 4 hours before you plan to bake; after 2 hours, shape it (see instructions for lean bread, page 48), then let it proof for 2 hours before baking. For the mixed method, remove the dough from the refrigerator 2 hours prior to baking and shape it right away. Remove only the portion you wish to bake: 19 ounces (539 g) for a 1-pound (454 g) loaf; 28 ounces (794 g) for a 1 1/2-pound (680 g) loaf, and so on. You can also bake the entire amount of dough as a large, 3-pound (1.36 kg) miche (round country loaf) or as a large torpedo loaf. See chapter 1, page 20, for instructions.
• Proof for 2 hours as a freestanding loaf, in floured proofing baskets, or on proofing cloths. The dough should increase in size to 1 1/2 times its original size and be springy yet hold an indentation when pressed with a finger. It may spread as it rises, but it will grow taller as it bakes.
• If using a baking stone, about 45 minutes before baking preheat the oven to 500°F (260°C) and prepare the oven for hearth baking (see page 30). Otherwise, just preheat the oven to 500°F (260°C) about 20 minutes before baking.
• Just before baking, score the dough with whatever style of design you prefer (see page 29). Transfer the dough to the oven, pour 1 cup of hot water into the steam pan, then lower the oven temperature to 450°F (232°C), or to 425°F (218°C) if baking a large miche.
• Bake for 12 minutes, then rotate the pan and continue baking for 15 to 35 minutes, or longer, depending on the size of the loaf; a large miche could take up to 75 minutes to bake. When fully baked, the crust should have a rich, caramelized color, the loaf should sound hollow when thumped on the bottom, and the internal temperature should be about 200°F (90°C) in the center. Cool on a wire rack for at least 1 hour before slicing or serving.
• Variations
• For country-style pain au levain, you can substitute whole wheat flour or other whole grain flours for an equal amount of bread flour (by weight), in which case you'll need to increase the water by about 1/2 tablespoon (0.25 oz / 7 g) for every 3 1/2 tablespoons (1 oz / 28.5 g) of whole grain flour you use. A typical pain au levain would substitute 2 to 3 ounces (56.5 to 85 g) of whole grain flour for an equal amount of bread flour, but there really is no limit.
• One of the best variations of this bread has crumbled blue cheese (or chunks of any good melting cheese) and toasted nuts or seeds (walnuts are highly recommended). Add nuts to the dough during the last minute of mixing, using about 25 percent nuts to total flour. Since the total flour in this recipe is about 34 ounces (964 g), counting the flour in the starter, about 8.5 ounces (241 g) of nuts would be just right. With the cheese, you can add anywhere between 25 to 45 percent of the weight of the flour; so that would be 8.5 to 15.3 ounces (241 to 434 g). Fold the cheese in by hand at the end of the mixing or roll it into the dough during shaping (see the crusty cheese bread recipe on page 121).