Mixing the Dough: Start by combining your active sourdough starter with room temperature water in a large mixing bowl, ensuring the starter is evenly distributed. Add salt and sugar.
First Rise (Bulk Fermentation): Cover the bowl with plastic wrap or a damp kitchen towel. Let the dough rest and rise overnight at room temperature (8 – 12 hours).
Stretch and folds: About 30 minutes into the bulk fermentation, perform 3 rounds of stretch and folds, about an hour apart.
Shaping the Dough: The next day, once the dough has doubled in size and is full of air bubbles, gently transfer it onto a lightly floured work surface. Stretch it into a rectangular shape.
Rather than rolling it, just fold the upper third toward the center and the bottom third over it. Turn it seam side down into a parchment paper-lined loaf pan.