These petit pain are perfectly fermented and beautifully scored, with a pillowy soft interior that's just begging for a slick of butter. It’s the same recipe as the baguette, but with a different shaping technique. (For baking, accurate metric measurements produce the best results, so we recommend using a digital scale for this recipe.)
Starter: Also called pre-ferment, levain, or poolish (which contains commercial yeast, as in this starter), this is the leavening or rising component of the bread. Turn on a digital scale and weigh your empty container. Deduct the weight of the container by pressing the "tare" function, which resets the scale to zero. Add water to the container, then the pinch of yeast. Tare to zero again and add the correct amount of flour to the water and yeast. Use a chopstick to stir the starter until the dry and wet ingredients are just mixed. Cover the container with plastic wrap and let rest at room temperature, away from direct sunlight, for 10-16 hours, but optimally 12 hours.
Dough: Place container with starter onto the scale and tare to zero; then add water around the edges of the container and use a rubber spatula loosen the starter. Empty contents into a bowl and use a sturdier wooden spoon to mix, so there are fewer lumps. Stir in pinch of yeast. Then add white flour, rye flour, and salt. Using a wooden spoon, and starting in the middle of the bowl, slowly stir to the edges until most of the flour has been mixed in and hydrated. Dough will look shaggy, with some flour still visible in the bowl.
Roll and Tuck: A technique to develop gluten in the dough so it becomes firmer and easier to work with. This is done one time, followed by a resting period. Using a plastic bowl scraper, push the dough and residual flour out of the bowl onto a clean work surface. If there are any dry bits, pile them on the center of the dough so they get absorbed. Use the scraper to stretch the dough into a rectangle (dough will still be slightly shaggy); then, starting at one end, roll and tuck the dough like a tube, about 3-4 times around. Flip the dough so it’s seam-side up; then flatten again to a rectangle so that the seam runs from left to right. Repeat rolling and tucking, always returning to a seam-up position, and continuing to pile any loose bits of dough onto the center to be absorbed. (When the dough feels firm enough and is no longer sticky, set the scraper aside and use only your hands.) Continue rolling and tucking the dough until the dough feels stronger and begins to resist any further rolling, about 10 times. All of the flour will get absorbed into the dough during this process. Shape the dough into a ball and place into a bowl coated with nonstick spray. Cover with plastic wrap and let rest at room temperature, 45 minutes.
Stretch and Fold: This technique strengthens the dough by folding it over onto itself. This process is done twice, with a resting period after each stretch and fold. Combine 1 part fine semolina with 5 parts unbleached white flour to make dusting flour, and lightly dust the work surface and your hands. Release the dough from the bowl (being gentle to avoid tearing!) and place on the work surface. Flip back and forth (like pizza dough), and gently shape it into a rough rectangle. Fold the dough in thirds, like a letter. Pat it down slightly, then do the same fold in the other direction. Place the dough back in the bowl, cover with plastic wrap and let rest at room temperature, 45 minutes. For the second and final stretch and fold, repeat the steps for the first stretch and fold. Cover with plastic wrap and let rest at room temperature, 20 minutes.
Shaping/Fermentation(proofing): Shaping/Fermentation (Proofing): Shape the dough to prepare it for baking, then ferment (proof) it in the refrigerator to expand the dough and develop flavor. Using a bench scraper, divide the dough into 12 equal pieces; it’s a good idea to weigh the dough for uniform size, 45 grams each. (The goal here is to make as few cuts as possible, as it's best not to have rolls made up of many individual pieces of dough.) Preshape by using the palm of your hand to gently roll each piece into a ball, with an inward or outward circular motion. Once you have 12 dough balls, make the final shape by lightly dusting the work surface with dusting flour. Slightly press each ball into a 3-inch disc. Fold the top edge to meet the bottom edge. Press against the seam and roll 3 times, like a tube. Then roll the tube to about 3-4½ -inches long. Use a bit more pressure on the ends to taper them. Line a rimmed baking sheet with a cloth towel and dust generously with dusting flour. Arrange the rolls seam-side up on the towel-lined pan, in 3 rows of 4 rolls each. Fold the towel to create support ridges along the length of the rolls on both sides of each row. Lightly cover with another towel, let rest 5 minutes at room temperature, then place in refrigerator to ferment, 12–16 hours.
Preheating Oven/Baking: Heat the cast-iron skillet while the oven is preheating. By filling the skillet with ice just prior to baking, you will create an optimal environment to steam the bread, resulting in a crispy crust and tender interior. Place cast-iron skillet on the lowest rack of a cold oven and place baking stone on rack above. Preheat oven to 460 F (preferably convection) for 1 hour. Remove rolls from refrigerator and place on a baking peel, leaving a little space between each roll to expand during baking. Using a lame or razor blade, score the top of each roll horizontally from end to end. This will create a controlled place for the gas to escape, thus preventing blow-outs. Place rolls directly on the preheated baking stone in the oven. Carefully fill skillet with about 1½ cups of ice cubes. Close oven door and lower temperature to 440 F. Bake until tops are lightly browned, 12–13 minutes.
Cooling, Serving, and Storing: Remove rolls from the oven and cool completely, about an hour. Rolls are best eaten the day they're baked, but can be stored in a paper bag for up to 24 hours.