Mix 350g water, 100g active starter, and 10g salt. Add 500g bread flour and mix well. Cover and let rest for 30-60 minutes.
Do 3-4 rounds of stretch and folds, spaced 30-60 minutes apart. Your dough will get smoother and more elastic with each round. After the final stretch, cover it and let it rest on the counter to complete bulk fermentation.
Turn the dough onto a lightly floured surface and preshape by gathering it to the middle, flipping it over, and dragging it to create tension. Place your dough in a banneton or bowl, cover, and refrigerate for 12-24 hours.
When ready to bake, turn it out onto a silicone baking sling or parchment paper. Score, and bake at 460°F—22 minutes covered, 16-18 minutes uncovered.
