Mixing and storing the dough: Whisk together the flour, yeast, salt, and sweetener in a 5- to 6-quart bowl, or a lidded (not airtight) food container.
Add the water and mix with a spoon or a heavy-duty stand mixer fitted with the paddle.
Cover (not airtight), and rest at room temperature until the dough rises, about 2 hours.
The dough can be used immediately after rising, though it's easier to handle when cold. Refrigerate in a lidded (not airtight) container and use over the next ten days. Or freeze for up to 4 weeks in 1-pound portions and thaw in the refrigerator overnight before use.
On baking day: Dust the surface of the dough with rice flour, pull off a 1 pound (grapefruit-size) piece and place it on a pizza peel prepared with cornmeal (use plenty) or parchment paper. Gently press and pat it into a ball-shape, using wet fingers to smooth the surface.
Allow to rest for about 60 minutes, loosely covered with plastic wrap or a roomy overturned bowl. During this time, the dough may not seem to rise much, which is normal.
Preheat a baking stone near the middle of the oven to 450°F (20 to 30 minutes), with an empty metal broiler tray on any shelf that won't interfere with the rising bread.
Dust the top with flour, and then slash, about ½-inch deep, with a wet serrated bread knife.
Slide the loaf onto the hot stone. Pour 1 cup of hot tap water into the broiler tray, and quickly close the oven door. Bake for about 45 minutes, or until richly browned and firm.
Allow to cool completely on a rack before eating.