Preparing your dough for the bulk fermentation (first proofing stage).
Combine Ingredients: In a large bowl, mix together all-purpose flour, warm water, active sourdough starter, and salt. Stir with a wooden spoon or Danish dough whisk in a circular motion until the ingredients are roughly combined. The dough doesn't need to be fully mixed at this stage. Rest the Dough: Cover the bowl with a damp towel, plastic wrap, or a plastic bag and let the dough rest for 15 minutes. This allows the flour to fully hydrate and begins the gluten development process.
Stretch and Fold (First Set): After the resting period, sprinkle a little flour on top of the dough to prevent sticking. Use a dough scraper, bench scraper, or clean wet hands to gather the dough from one side of the bowl, stretch it out and fold it onto itself. Turn the bowl a quarter turn and repeat the stretching and folding process. The dough should form a somewhat square shape. Cover the bowl again with a damp kitchen towel and let the dough rest for another 30 minutes.
Repeat Stretch and Fold Process: After the 30-minute rest, perform another set of stretch and folds. This involves stretching out the dough from opposite ends and folding them over each other. Turn the bowl and repeat the process. Cover the bowl and let the dough rest for another 30 minutes. Repeat this step one more time for a total of three sets of stretches and folds. First Rise: After completing the stretch and fold process three times, cover the bowl again and let the dough undergo its first rise. Place the dough in a warm place or in your oven with the light on and door propped open. The light should provide enough heat (without being too hot) to help the dough rise faster. It should take about 3 hours for the dough to double in size.