In a large bowl, whisk together the flour, salt, sugar, and yeast. Add the water and mix until the water is absorbed and the dough comes together in a sticky ball., Cover the bowl and set aside in a warm spot to rise for 1 to 1 1/ 2 hours, until the dough has doubled in bulk., Place a rack in the lower third of the oven and preheat it to 425°F. Use the butter to generously grease two 1-quart oven-safe bowls or a 3-quart casserole dish (for one large loaf)., Use two forks to deflate the dough by releasing it from the side of the bowl and pulling it toward the center. Rotate the bowl as you deflate, turning the mass into a rough ball. To make a single large loaf, pick up the mixing bowl, turn it over, and plop the dough into the larger casserole dish., To make two small loaves, use your forks to separate the dough down the center, dividing it into two equal pieces. Use the forks to lift each half of the dough into the prepared bowls. If the dough is wet and hard to handle, try lightly greasing your hands and transfer each half to a bowl by hand., Don't cover the dough. Let it rise on the countertop in a warm spot for 10 to 20 minutes, until the top of the dough just crests the rims of the small bowls, or is almost doubled in the larger casserole dish., Bake the bread at 425°F for 15 minutes. Then reduce the heat to 375°F and bake for 17 to 20 minutes more for smaller loaves, or 25 to 30 minutes more for a single large loaf. (Baking the dough initially at a higher temperature will give your bread an immediate lift, called "oven spring.") When the bread is golden brown all over, remove from the oven and turn the bread out onto a cooling rack., Store, well wrapped, at room temperature for several days; freeze for longer storage.