Add 1 1/2 cups water to a large mixing bowl. Sprinkle 1/2 teaspoon active yeast over the top and allow to sit for 5-10 minutes. Add the 3 cups unbleached all purpose flour and 1 3/4 teaspoons salt and stir everything together. Mix until a shaggy mixture forms.
Tightly cover bowl with plastic wrap and allow to rise for 12 - 18 hours.
When you're ready to bake the bread, preheat your oven to 450 degrees F. When the oven has reached 450 degrees, place a covered cast iron dutch oven in the oven and heat the pot, empty, for 30 minutes. While the dutch oven is heating, pour dough onto a heavily floured surface and shape into a ball. Lightly cover with plastic wrap and allow to set undisturbed while the pot is heating.
Remove hot pot from the oven and drop in the dough. Cover with the hot lid and return to the oven to bake, covered, for 30 minutes. After 30 minutes remove the lid and bake an additional 15 minutes.
Remove bread from the dutch oven and place on a cooling rack to cool.
My house is pretty cold so I heated up the oven to 200 degrees F and then turned it off and cracked the door to make it slightly warm. I stored the covered dough in there overnight.