Step 1

UPDATE — July 10, 2020: This recipe has been updated to address issues some readers were having with it. Here is what we've changed: We now call for bread flour in place of all-purpose flour; a lower hydration amount (62 percent instead of 74 percent); proofing in a colander “banneton” to help the loaf keep its shape; proofing shaped dough in the refrigerator overnight; and baking in a hot Dutch oven for better spring. Thanks for your patience as we worked out these issues. For the best results, weigh your ingredients. Because step 2 of this recipe takes between 12 and 18 hours to complete, it’s best to start it early in the morning or in the evening. It’s important to move on to step 3 as soon as the dough is domed and bubbly. If ambient temperatures are above 80 degrees, use ice-cold water in the dough; if ambient temperatures are below 70 degrees, rising times will be closer to the end of the time ranges. This recipe requires a heavy-bottomed Dutch oven of at least 5 quarts in volume.

Step 2

FOR THE LEVAIN: Combine flour, water, and starter in small bowl and stir with wooden spoon until uniform. Cover with plastic wrap and let sit until doubled in volume, 3 to 5 hours. Use immediately or transfer to refrigerator and use within 7 days.

Step 3

FOR THE DOUGH: Whisk flour and salt together in medium bowl. In large bowl, combine water and 3 tablespoons (2 ounces; 57 grams) levain (discard remainder), and whisk until smooth. Add flour mixture to water mixture and stir using wooden spoon, scraping up dry flour from bottom of bowl until dough comes together, then knead by hand in bowl until shaggy ball forms and no dry flour remains. Cover bowl with plastic wrap and let sit at room temperature until subtly domed, lightly bubbly, and just doubled in volume, 12 to 18 hours.

Step 4

Transfer dough to lightly floured counter. Gently press dough into 8- to 10-inch disk, then fold edges toward middle to form round. Cover loosely with plastic and let rest for 15 minutes. Meanwhile, line colander or banneton with large linen or cotton dish towel and dust liberally with flour. Repeat pressing and folding of dough to form round, then place dough seam side down on counter and form into tight round. (To round, set dough on unfloured counter. Loosely cup your hands around dough and, without applying pressure to dough, move your hands in small circular motions. Tackiness of dough against counter and circular motion should work dough into smooth, even ball, but if dough sticks to your hands, lightly dust your fingers with flour.) Place dough seam side up on floured towel and loosely fold edges of towel over dough to enclose. Cover top of dough loosely with plastic wrap. Let sit at room temperature 1 hour, then refrigerate for 12 to 24 hours (whatever is most convenient).

Step 5

One hour before baking bread, adjust oven rack to middle position, set covered heavy-bottomed Dutch oven on rack, and heat oven to 475 degrees.

Step 6

Once oven has preheated for 1 hour, lay 12- by 12-inch sheet of parchment paper on counter and spray generously with vegetable oil spray. Uncover colander, and unfold edges of towel. Lay parchment sprayed side down over loaf, then invert colander onto counter. Remove colander and towel.

Step 7

Carefully remove Dutch oven from oven, place on stovetop, and set lid aside. Using razor blade or sharp knife, make one 7-inch-long, 1/2-inch-deep slit along top of dough. Pick up dough by lifting parchment edges and lower into Dutch oven. Carefully cover pot and transfer to oven. Bake for 20 minutes.

Step 8

Remove lid, reduce oven temperature to 425 degrees, and continue to bake until loaf is deep brown and registers 210 degrees, 15 to 25 minutes longer. Carefully remove bread from pot; transfer to wire rack and let cool completely before slicing, 2 to 3 hours. (Store uneaten bread cut side down on cutting board for up to 3 days.)