For the Starter:
1 cup plus 3 tablespoons (200 grams) fine- or medium-grind cornmeal
½ cup plus 3½ tablespoons (100 grams) all-purpose flour
Pinch instant yeast
1 cup plus 1½ tablespoons (260 grams) water, at about 60°
For the Dough:
2½ cups plus 3 tablespoons (380 grams) white flour, plus more for dusting
¾ cup (120 grams) fine- or medium-grind cornmeal
2½ tablespoons (30 grams) granulated sugar
2½ teaspoons (15 grams) fine sea salt
¼ teaspoon (1 gram) instant yeast
½ cup plus 2 tablespoons (150 grams) water, at about 60°
¼ cup (60 grams) bourbon
1¾ tablespoons (25 grams) unsalted butter, softened
1. Make the starter: In a tall 2-quart glass container, combine the cornmeal and flour. Stir the yeast into the water and pour over the flour mixture. Mix with your fingers until completely incorporated, cover with a tight lid and let sit at room temperature for 10 to 14 hours.
2. Make the dough: In a large bowl, stir together the flour, cornmeal, sugar, salt and yeast. Pour some water around the edges of the starter, releasing it from the sides, and pour into a separate, large bowl. Add the remaining water and bourbon, and gently stir with a wooden spoon, breaking apart the starter. Add the flour mixture and continue to stir with a wooden spoon until combined. Switch to a plastic bowl scraper and continue to mix until fully incorporated and sticky to the touch, adding more flour if needed. Using the bowl scraper, turn the dough onto a floured work surface.
3. Roll and tuck the dough: Form the dough into a 1½-inch-thick rectangle with the short end facing you. Slide your fingers under the top 3 inches of the dough and make one small roll toward you. Push down the edge of the roll into the dough, tucking to seal it with the side of your hand. Repeat 3 to 4 times until the dough is fully rolled, then rotate the dough 90 degrees and flip to seam-side up. Press gently with the palm of your hand to create a 4-by-10-inch rectangle. Repeat the rolling-and-tucking process as before. Make a total of 7 to 8 rolls and tucks, then transfer the dough, seam-side down, to a large, clean bowl. Cover with a kitchen towel and let rest 30 minutes.
4. Do the first stretch and fold: Lightly dust the work surface and your hands with flour. Using a plastic bowl scraper, release the dough from the bowl onto the work surface, seam-side down. Gently lift and stretch the dough into a 10-by-12-inch rectangle and fold the dough in thirds from top to bottom, beginning with the long side and then again left to right, creating 9 layers. Tuck the sides under toward the center and return the dough to the bowl, seam-side down. Cover and let rest 30 minutes.
5. Do the second stretch and fold: Repeat the steps for the first stretch and fold, then return the dough to the bowl, cover and let rest for 30 minutes.
6. Incorporate the butter: Place the dough onto a lightly floured work surface and gently stretch into a 10-by-12-inch rectangle. Spread the butter over the dough with your fingers and, starting at a long end, roll up tightly. Turn the dough seam-side up, gently pressing to seal, and fold the dough into thirds. Do a total of 4 or 5 roll-and-tuck sequences to incorporate the butter and return the dough to the bowl. Cover with the towel and let rest for 30 minutes.
7. Do the fourth stretch and fold: Repeat the steps for the first stretch and fold, and return the dough to the bowl. Cover and let rest 20 minutes.
8. Transfer the dough, seam-side down, to a lightly floured, parchment-lined baking sheet and cover with a kitchen towel. Chill in the refrigerator for 16 to 22 hours.
9. Place a large Dutch oven on the top rack in the oven and place its lid on the bottom rack, then preheat the oven to 480°.
10. Gently flip the chilled loaf onto a lightly floured rimless baking sheet. Using a sharp knife, make 3 cuts on the diagonal across the loaf, then make 3 more cuts in the opposite direction, creating diamonds.
11. Carefully remove the hot Dutch oven and set it on a stovetop or a heatproof surface. Transfer the dough to the preheated Dutch oven and return, uncovered, to the oven. Lower the temperature to 440° and bake, rotating the Dutch oven halfway through baking, until the bread is deep brown, 35 to 45 minutes. Cover with the lid and continue to bake until the crumb is set, another 10 to 20 minutes. Transfer the loaf to a cooling rack and let cool completely before slicing, at least 4 hours.