Caramelized Onion Bread

Why this recipe works Flavor-packed caramelized onions are one of our favorite ingredients. So we dreamed of incorporating them into a crusty, chewy, artisan-style loaf with a sweet-and savory profile. For concentrated onion flavor, we loaded 3 cups of onions into the recipe; along with brown sugar, thyme, and garlic, they cooked down to a deep golden brown. Finely chopped onions worked best—larger pieces left us with soggy pockets of uncooked dough surrounding the onions after baking. However, we found it difficult to mix such a large volume into the dough at the end of kneading; the slippery onions just slid off of the developed dough. To solve this problem, we mixed half of the onions with the wet ingredients at the beginning of mixing, where they incorporated easily and broke down during kneading to lend more flavor to the crumb. We reserved the remaining half to mix in at the end of kneading, which was just the right amount to incorporate evenly and provide textural contrast. Yellow onions are our favorite variety here; they offer a good balance of flavor and a firm but yielding texture. You can use white or red onions, but they vary in flavor. Vidalia onions have a high water content and make the dough too wet. You can substitute a round banneton, or proofing basket, for the towel-lined colander.

MAKES: 1 loaf

COOKING TIME: 17 minutes

RESTING TIME: 6 hours 20 minutes

RISING TIME: 3¼ to 4¼ hours

BAKING TIME: 45 minutes

TOTAL TIME: 11½ to 12½ hours, plus 3 hours cooling time

KEY EQUIPMENT: 12-inch nonstick skillet, water-filled spray bottle, large linen towel, 5-quart colander, baking stone, 2 (9-inch) disposable aluminum pie plates, 2 quarts lava rocks, pizza peel, lame, instant-read thermometer

INGREDIENTS:

FOR THE SPONGE

• ⅔ cup (3⅔ ounces) bread flour
• ½ cup (4 ounces) water, room temperature
• ⅛ teaspoon instant or rapid-rise yeast

FOR THE DOUGH

• 2 tablespoons extra-virgin olive oil
• 3 cups finely chopped onions
• 2 garlic cloves, minced
• 2 teaspoons minced fresh thyme or ½ teaspoon dried
• 2 teaspoons packed brown sugar
• Salt and pepper
• 2⅓ cups (12¾ ounces) bread flour
• 1¼ teaspoons instant or rapid-rise yeast
• ¾ cup plus 2 tablespoons (7 ounces) water, room temperature

INSTRUCTIONS:

1. Stir all the ingredients in a 4-cup liquid measuring cup with a wooden spoon until well combined. Cover it tightly with plastic wrap and let it sit at room temperature until the sponge has risen and begins to collapse, which takes about 6 hours (the sponge can sit at room temperature for up to 24 hours).
2. Heat oil in a 12-inch nonstick skillet over medium heat until shimmering. Stir in onions, garlic, thyme, sugar, ½ teaspoon salt, and ¼ teaspoon pepper. Cover and cook, stirring occasionally, until the onions are softened and have released their juice, which takes 3 to 5 minutes. Remove the lid and continue to cook, stirring often, until the juice evaporates and the onions are deep golden brown, which takes 10 to 15 minutes. Transfer the onion mixture to a bowl and let it cool completely before using.
3. Whisk flour and yeast together in the bowl of a stand mixer. Stir water and half of the onion mixture into the sponge with a wooden spoon until well combined. Using the dough hook on low speed, slowly add the sponge mixture to the flour mixture and mix until a cohesive dough starts to form and no dry flour remains, which takes about 2 minutes. Scrape down the bowl as needed. Cover the bowl tightly with plastic and let the dough rest for 20 minutes.
4. Add 1½ teaspoons of salt to the dough and knead on medium-low speed until the dough is smooth and elastic and clears the sides of the bowl, which takes about 5 minutes. Reduce the speed to low, slowly add the remaining onion mixture, 1 tablespoon at a time, and mix until mostly incorporated, which takes about 1 minute. Transfer the dough to a lightly greased large bowl or container, cover it tightly with plastic, and let it rise for 30 minutes.
5. Using a greased bowl scraper or your fingertips, fold the dough over itself by gently lifting and folding the edge of the dough toward the middle. Turn the bowl 45 degrees and fold the dough again; repeat turning the bowl and folding the dough 6 more times (for a total of 8 folds). Cover it tightly with plastic and let it rise for 30 minutes. Repeat the folding and rising process. Fold the dough again, then cover the bowl tightly with plastic and let the dough rise until nearly doubled in size, which takes 45 minutes to 1¼ hours.
6. Mist the underside of a large linen or cotton tea towel with water. Line a 5-quart colander with the towel and dust it evenly with flour. Transfer the dough to a lightly floured counter (the side of the dough that was against the bowl should now be against the counter). Press and stretch the dough into a 10-inch round, deflating any gas pockets larger than 1 inch.
7. Working around the circumference of the dough, fold the edges toward the center until a ball forms. Flip the dough ball seam side down and, using your cupped hands, drag in small circles on the counter until the dough feels taut and round, and all the seams are secured on the underside of the loaf.
8. Place the loaf seam side up in the prepared colander and pinch any remaining seams closed. Loosely fold the edges of the towel over the loaf to enclose it, then place the colander in a large plastic garbage bag. Tie or fold under the open end of the bag to fully enclose it. Let it rise until the loaf increases in size by about half and the dough springs back minimally when poked gently with your knuckle, which takes 1 to 1½ hours (remove the loaf from the bag to test).
9. One hour before baking, adjust the oven racks to the lower-middle and lowest positions. Place a baking stone on the upper rack, place 2 disposable aluminum pie plates filled with 1 quart of lava rocks each on the lower rack, and heat the oven to 425 degrees Fahrenheit. Bring 1 cup of water to a boil.
10. Remove the colander from the bag, unfold the edges of the towel, and dust the top of the loaf with flour. If any seams have reopened, pinch them closed before dusting with flour. Lay a 16 by 12-inch sheet of parchment paper on top of the loaf. Using one hand to support the parchment and loaf, invert the loaf onto the parchment and place it on the counter. Gently remove the colander and towel. Transfer the parchment with the loaf to a pizza peel.
11. Carefully pour ½ cup of boiling water into one disposable pie plate of preheated rocks and close the oven door for 1 minute to create steam. Meanwhile, holding a lame (scoring tool) concave side up at a 30-degree angle to the loaf, make two 7-inch-long, ½-inch-deep slashes with a swift, fluid motion along the top of the loaf to form a cross.
12. Working quickly, slide the parchment with the loaf onto the baking stone and pour the remaining ½ cup of boiling water into the second disposable pie plate of preheated rocks. Bake until the crust is dark brown and the loaf registers 205 to 210 degrees Fahrenheit, which takes 45 to 50 minutes, rotating the loaf halfway through baking. Transfer the loaf to a wire rack, discard the parchment, and let it cool completely, about 3 hours, before serving.