1. Combine flour and 310 g water in a bowl, mix until no dry spots remain, and rest for 30–45 minutes (autolyse).

2. Add sourdough starter, salt, remaining water, lemon zest, and poppy seeds; mix gently until incorporated.

3. Perform 3–4 stretch and fold cycles every 30–45 minutes during a 3–5 hour bulk fermentation at 24–26°C.

4. Pre-shape the dough into a rough ball, rest for 15 minutes, then shape into a boule or batard and place seam-side up in a floured proofing basket.

5. Refrigerate the dough for 8–12 hours for a cold proof.

6. Preheat a Dutch oven at 245°C for 45 minutes. Remove dough from fridge, score the top with a lame or razor blade.

7. Transfer dough to the preheated Dutch oven using a silicone sling or parchment, cover, and bake at 245°C for 20–25 minutes.

8. Remove the lid, reduce oven to 230°C, and bake uncovered for another 20–25 minutes until golden brown.

9. Cool the loaf on a wire rack for at least 1–1.5 hours before slicing.

10. Store at room temperature in a breathable bag for up to 3 days or freeze wrapped for up to 2 months.