Put all ingredients in a large bowl and stir with a wooden spoon or mix by hand until a dough is formed. It will be soft and shaggy looking.
Cover the bowl tightly with plastic wrap and let it stand at room temperature for 12 to 18 hours.
Flour a piece of parchment paper and your hands. Scrape the dough from the bowl to the floured parchment paper.
With lightly floured hands, fold the dough over on itself about 4 times to form a taut, round or oval loaf.
Position the dough in the center of the floured parchment paper, seam-side down.
Sprinkle it with flour and put a lightweight kitchen towel over the loaf.
Let it rise for another 2 hours.
Position the oven rack in the center of the oven.
Place a heavy dutch oven—about 4 to 6 quarts in size—in the oven. Include the lid if you are sure the knob is oven-safe to 500 F, or if you have removed the knob.
Preheat the oven to 500 F.
Carefully remove the hot dutch oven from the oven and place it on a metal rack.
Reduce the oven temperature to 425 F. (Most dutch oven lids are safe to 425 F, but if you aren't sure, check the manufacturer's website.)
Lifting by the ends of the parchment paper, lower the dough, parchment paper and all, into the hot dutch oven. Place the lid on the pot and put it back in the oven. Alternatively, if you're using an enamel coated iron dutch oven, you can flip the dough over and into the ungreased hot pot, leaving the seam-side up. It makes for a nice texture on top.
Score the loaf if you like.
Bake for 30 minutes with the lid on.
Remove the lid and bake for about 20 minutes longer.
When the bread is golden brown on top and registers at least 200 F on an instant-read thermometer inserted in the center, remove it and place it on a rack to cool before slicing and serving.
Tips:
Try to weigh ingredients, but if that isn't possible, measure the flour, beer, and water as accurately as possible. The final dough should be fairly soft and somewhat ragged looking, unlike the typical smooth yeast dough.
Parchment paper works for all kinds of baking, but if you don't have it, you can still make this bread. Generously flour a plain cotton kitchen towel (not terrycloth, it will stick). Place the dough round on the towel seam-side down, flour the top, and cover with the ends of the same towel or cover with another towel. After the 2 hour rise, flip it over into the hot dutch oven, seam side up.
Use an enamel-coated cast-iron dutch oven or a large oven-safe pot or casserole with a lid. There's no need to grease the enamel-coated cast-iron pot.