Make the Dough: In the evening, whisk the starter and water together in a large bowl with a fork. Add the flour and salt. Combine until a still dough forms, then finish mixing by hand to fully incorporate the flour. The dough will feel dense and shaggy, and it will stick to your fingers as you go. Scrape off as much as you can. Cover with a damp towel and let rest for 30 minutes. Replenish your starter with fresh flour and water, and store according to preference.
After the dough has rested, work the mass into a fairly smooth ball. To do this, grab a portion of the dough and fold it over, pressing your fingertips into the center. Repeat, working your way around the dough until it begins to tighten, about 15 seconds.