1. Combine Starter and Water: In a large mixing bowl, gently whisk together the active sourdough starter and the warm water until the starter is mostly dissolved. The mixture should look milky and slightly bubbly.

2. Mix Dry Ingredients: Add the bread flour, granulated sugar, and fine sea salt to the bowl. Mix with a wooden spoon or your hands until a shaggy dough forms and no dry spots of flour remain. Cover the bowl with a damp towel or plastic wrap and let it rest for 30 minutes (this is called autolyse, which helps gluten development).

3. Incorporate Add-ins: After the rest, gently knead the dough in the bowl for a minute or two. Then, add the dried cranberries and orange zest. Fold them into the dough until they are evenly distributed. Be careful not to overmix, as this can tear the gluten strands.

4. Bulk Fermentation with Folds: Cover the bowl again. Over the next 4-6 hours (or longer if your kitchen is cool), perform 3-4 sets of “stretch and folds” every 30-60 minutes. To do this, lightly wet your hand, grab a portion of the dough from the edge, stretch it upwards, and fold it over the center. Rotate the bowl and repeat 3-4 times. This builds strength in the dough. The dough should become noticeably smoother and more elastic. Alternatively, you can place the covered dough in the refrigerator for 8-12 hours for a slower, cold bulk fermentation.

5. Shape the Loaf: Gently turn the dough out onto a lightly floured surface. Shape it into a round or oval loaf. For a round loaf, gently pull the edges towards the center, then flip it over and use the tension of the surface to create a tight ball. For an oval, gently roll and tuck the sides.

6. Final Proofing: Place the shaped dough into a floured banneton basket or a bowl lined with a floured kitchen towel, seam-side up. Cover it loosely with plastic wrap or a clean towel. Let it proof at room temperature for 1-3 hours, or refrigerate for 8-12 hours. The dough should look visibly puffy and feel soft but still have some resistance when gently poked.

7. Bake the Bread: Preheat your oven to 450F (232C) with a Dutch oven inside for at least 30 minutes. Carefully remove the hot Dutch oven, invert the dough into it (seam-side down), and score the top with a sharp knife or razor blade. Cover the Dutch oven and bake for 30 minutes.

8. Finish Baking and Cool: Remove the lid from the Dutch oven, reduce the oven temperature to 400F (200C), and continue baking for another 10-15 minutes, or until the crust is deep golden brown and the internal temperature reaches 200-210F (93-99C). Carefully remove the loaf from the Dutch oven and transfer it to a wire rack to cool completely for at least 1-2 hours before slicing. This cooling time is crucial for the crumb to set properly.