Mix everything together in a large bowl by hand until all the flour is wet. Cover and let rest for 30 minutes.
Do a series of stretches and folds in the bowl. Pull an edge up and over onto the center of the dough. Rotate the bowl ¹/6 of a turn and repeat until you go all the way around. Use wet hands to prevent sticking.
Repeat every 30 minutes for 2 hours, for a total of 4 sets of folds.
The dough should have developed enough gluten to be stretched thin. If not, give it another set of folds after 30 minutes.
Once you start to see signs of fermentation, such as bubbles, and the dough starting to get a little poofy, place the dough in the fridge for 8–16 hours. Keep it covered tightly with a lid or shower cap.
Remove the dough from the fridge. If it hasn’t risen much, leave it out at room temperature until it has increased 30–50 percent in volume.
Dust the top of the dough, and scrape it out onto a lightly floured work surface. Shape it lightly into a loose round. Cover with a bowl, damp towel or oiled plastic film, and let relax for 1 hour. When ready to shape, it should be inflated a bit but more relaxed.
When the dough is ready, shape it into a ball and proof it in a well-floured proofing basket, or in a large bowl lined with a well-floured thin towel.
Using rice flour helps prevent it from sticking to the basket, or you can be generous with white flour.
Cover the dough with another towel and let rise in a warm place for 1–3 hours.
Preheat oven, with a dutch oven inside, to 500° (about 1 hour).
When the dough is properly proofed, it should feel gassy and light and jiggle like a bowl of Jello. If you poke it with a finger, the dough should slowly spring back and almost fill in the depression.
With the dough still in the basket, dust the top with flour to dry out any moist parts — this will become the bottom of the loaf and will keep it from sticking to the pot.
Carefully invert the dough into the hot pot, cut a square on the surface with a razor blade or sharp knife, and cover with the hot lid. Place into the oven.
Immediately turn down the oven to 450°, and bake covered for 30 minutes.
Remove the lid, and bake another 10 minutes. Check that the bottom isn’t getting too dark.
Remove the dough from the pot, place it on a cool baking sheet and bake another 10–20 minutes until it’s very dark in some areas. The loaf should feel light and sound hollow when the bottom is tapped. The crust should feel a bit hard (it will feel more thin and crisp as it cools), and the color should be a dark brown.
Remove the bread, and place on a wire rack until it is completely cool, about 2 hours.