Dutch oven bread

Steps

1. Make the poolish. In a small bowl, stir together the room temperature water, the tiny pinch of yeast and the bread flour for the poolish. Cover and let it ferment at room temperature for at least 4 hours, ideally 24 hours.
2. In a medium bowl, mix the warm water (about 30 °C), the yeast and all of the ripe poolish.
3. Add the salt, bread flour and whole wheat flour. Stir with a sturdy spoon until you can no longer move it through the mixture.
4. Switch to a wet hand and squeeze and massage the dough until there are no dry spots left and everything is evenly combined. Cover and let it ferment at room temperature for 30 minutes.
5. Do a strength building fold. Pull a handful of dough from one side and fold it over to the other side. Repeat about 7 more times, turning the bowl a little after each fold. Then grab the ball with one hand by its side and bottom, lift it while rounding and turning it, and set it back down to tighten the top. Repeat several times.
6. Cover and let it ferment at room temperature for another 30 minutes. Repeat the fold and the rounding.
7. Cover and let it ferment at room temperature for 60 minutes, 2 hours in total. The dough should have doubled in size.
8. Flour your work surface and gently turn the dough out onto it. Pull a corner or side of the dough about 60% of the way across to the other side, then do the same with the next side. Keep going all the way around, 7 to 9 times in total, popping any big bubbles.
9. Flip the ball so the seam is down against the work surface. With your hands on either side, roll it on its seam while tucking it under itself, to seal it and create tension across the top.
10. Line a medium bowl, just bigger than the ball, with a thin kitchen towel and dust it with a mix of whole wheat and all-purpose flour. Place the ball in it seam side up, tucking the seam again to seal it well.
11. Fold the towel over the dough and let it proof at room temperature for 45 to 120 minutes, until doubled in size. The warmer your house, the shorter the proof. The cooler it is, the longer it takes. When properly proofed, the dough should indent when poked, then slowly spring back.
12. Preheat the oven to 250 °C with the Dutch oven inside for 30 minutes.
13. Dust the bottom of the Dutch oven generously with semolina flour or fine cornmeal, so the bread does not stick.
14. Carefully flip the loaf into the Dutch oven, seam side down, and score the top with a few cuts.
15. Cover and bake for 18 minutes.
16. Remove the lid, lower the oven to 240 °C and bake for another 20 to 25 minutes, until deeply browned.
17. Transfer the loaf to a wire rack and let it cool before slicing.