1. Prepare Your Work Surface: Lightly dust your clean work surface with rice flour or all-purpose flour. Avoid using too much flour, as this can prevent the dough from sticking to itself and sealing properly. Have your proofing basket (banneton) ready and dusted with flour as well.

2. Gently Turn Out Your Dough: Carefully scrape your fermented sourdough dough out of its bulk fermentation container onto the lightly floured surface. Try to disturb it as little as possible to maintain the air bubbles developed during fermentation.

3. Preshape the Dough (Optional but Recommended): If your dough is particularly slack, a preshape can help. Gently pull the edges of the dough towards the center to form a loose ball or round. Let it rest for 15-20 minutes, uncovered, to relax the gluten. This step makes the final shaping easier and helps build tension.

4. Flatten and Gently Stretch: After the rest (or if you skipped preshaping), gently flatten the dough into a rough rectangle or oval shape. Be careful not to degas it too much. You want to create a surface area for folding.

5. First Fold: Top to Center: Take the top edge of the dough and fold it down towards the center, overlapping by about one-third. Press gently with the heel of your hand to seal this fold.

6. Second Fold: Bottom to Top: Take the bottom edge of the dough and fold it up over the previously folded section, extending past the center. Again, press gently to seal. At this point, your dough should resemble a cylinder or a short, thick log.

7. Create Tension: Roll and Seal: Starting from one end of the cylinder, gently roll the dough towards you, maintaining tension as you go. As you roll, use your thumbs to tuck the dough under itself, creating a tight seam at the bottom. This rolling and tucking action is crucial for building surface tension.

8. Final Sealing and Transfer: Once rolled, pinch the seam firmly along the entire length of the loaf to ensure it’s completely sealed. Gently cup the dough with your hands, rotating it slightly to further tighten the surface tension. Carefully transfer the shaped batard, seam-side up, into your well-floured proofing basket. This allows the dough to expand upwards during proofing and prevents the seam from bursting prematurely.