Measure the flour into a large bowl that has a tight-fitting lid.
In a medium bowl, combine the sourdough starter, water, and salt. Mix with a dough whisk or sturdy wooden spoon until the starter is about half dissolved into the water.
Dump the starter mixture into the bowl with the flour, and mix with the dough hook or wooden spoon until most of the flour is incorporated and a shaggy dough begins to form.
Take off your rings and get your hands in there, squishing the dough in your fists, turning it over, and squishing again until all of the flour is incorporated into the dough. At this point, the dough will be rather sticky.
Once all the flour is incorporated, dust your hands with flour and use the heel of your hand to knead the dough into a smooth ball. (Press down on the dough with the heel of your hand, fold the dough up and over, turn, and repeat, dusting your hands with more flour as needed. You are done when the dough has morphed into a smooth-looking ball.)
Cover the bowl with its lid and let it rise at room temperature for 12 to 20 hours or until it has doubled in size.
After the dough has finished rising, scrape it out onto an unfloured work surface. Use a bench scraper to divide the dough into 2 equal-size pieces, and form each piece into a ball. Place the two balls in one large rectangular airtight container or two separate airtight containers (they will need extra space to spread out as they rise).
Seal the container(s) and let the dough rest at room temperature until the balls have spread out and puffed up and are very pliable, 1 to 3 hours. (Alternatively, seal the container(s) and refrigerate the dough balls for 24 to 48 hours. Or, place each dough ball in a separate zip-top bag and freeze for up to 3 months.)
Transfer the dough balls to a floured work surface. (If you refrigerated your dough, let it come completely to room temperature before you stretch it; this will take about 2 hours. If you froze your dough, take it out of the freezer the morning of your pizza night, and let it defrost on the counter until dinner time.)
Stretch out each dough ball to a 12- to 14-inch circle, then transfer it to a floured peel or parchment-lined baking sheet. Top and bake the pizza until the crust is golden and charred in spots (at 500°F for about 10 minutes on a baking sheet; at the hottest your oven will get for 6 to 8 minutes on a baking steel/stone).