Combine all dry ingredients in large mixing bowl. Mix thoroughly.
Add 1 1/2 cups water and stir with rubber spatula. Add remaining water (and more) as needed until you have a thoroughly mixed, wet, sticky mass of dough. (The dough will be wet and will not form a ball.).
Cover bowl with plastic wrap and let sit at room temperature, out of direct sunlight, for 12 to 18 hours.
After 12 to 18 hours have passed, your dough should be dotted with bubbles and more than doubled in size. (It may also have a strong alcohol smell to it, but don’t mind that, it will burn off in the baking.) Dust wooden cutting board with bread flour and, using your plastic dough scrapers, scrape dough loose from sides of bowl and turn out onto board in one piece. Dough will be loose and sticky, but do not add more flour. Dust top lightly with flour and cover with clean cotton or linen tea towel (terry cloth will stick and leave lint on dough). Let dough rise for another 1 to 2 hours.
About 30 minutes before second rise is complete, place your cast-iron pot (without lid) on rack positioned in lower third of oven (not at the very bottom). Heat oven to 475°F.
Once oven has reached 475°, remove pot using heavy-duty potholders (be very careful at this stage – the pot and oven are extremely hot). Sprinkle about 1 teaspoon coarse cornmeal evenly over bottom of pot.
Uncover dough and, using two plastic dough scrapers, shape dough into a ball by folding it over onto itself a few times. With scrapers, lift dough carefully and let it fall into preheated pot by slowly separating the scrapers. Dust top of dough with rolled oats. Cover pot and bake for 30 minutes.
After 30 minutes, remove cover from pot and continue baking for additional 15 minutes, or until loaf is browned, but not burned.
Remove pot from oven. With sturdy wooden or metal spatula, pry loaf from pot and transfer to cooling rack. Do not slice bread for minimum of 1 hour – this cooling time completes the process and shouldn’t be overlooked!