Instructions

1. Begin by preparing your roasted potatoes. Preheat your oven to 200°C (400°F). Wash and peel the potatoes, then cut them into chunks. Toss the potato chunks with a drizzle of olive oil, salt, and pepper. Spread them out on a baking sheet and roast in the oven for about 25-30 minutes, or until golden and tender. Allow them to cool slightly before mashing.
2. Once the potatoes are roasted, mash them until smooth. Measure out 300g of the mashed potatoes and set aside to cool completely. This will ensure that the heat does not kill the active cultures in your sourdough starter.
3. In a large mixing bowl, combine 500g of bread flour and 10g of salt. Mix them together thoroughly to ensure that the salt is evenly distributed throughout the flour.
4. In a separate bowl, mix 350g of water with 100g of your active sourdough starter. Stir until well combined. If your starter is cold, you may want to let it come to room temperature before mixing to ensure a good fermentation process.
5. Pour the water and sourdough starter mixture into the flour and salt mixture. Add the 300g of cooled mashed potatoes and the chopped rosemary. Use a wooden spoon or your hands to mix the ingredients together until a shaggy dough forms.
6. Once the dough starts to come together, transfer it to a clean, lightly floured surface. Knead the dough for about 10-15 minutes until it becomes smooth and elastic. If the dough is too sticky, you can add a little more flour as needed, but be careful not to add too much.
7. After kneading, place the dough in a lightly oiled bowl. Cover it with a damp cloth or plastic wrap to prevent it from drying out. Allow the dough to rise at room temperature for about 4-6 hours, or until it has doubled in size. This is the bulk fermentation stage.
8. Once the dough has risen, gently deflate it by pressing down on it. Turn it out onto a lightly floured surface and shape it into a round loaf. To shape, tuck the edges of the dough into the center and flip it over so the seam is on the bottom. Use your hands to create tension on the surface of the dough by rotating it against the surface.
9. Place the shaped loaf into a proofing basket or a bowl lined with a floured kitchen towel, seam side up. Cover it with a damp cloth and let it proof for another 2-3 hours at room temperature, or until it has puffed up noticeably.
10. About 30 minutes before baking, preheat your oven to 230°C (450°F). If you have a Dutch oven or a baking stone, place it in the oven to heat up as well. This will help create steam for a better crust.
11. Once the loaf has finished proofing, carefully turn it out onto a piece of parchment paper. You can score the top of the loaf with a sharp knife or a razor blade to allow for expansion during baking.
12. Using oven mitts, carefully remove the preheated Dutch oven from the oven. Lift the parchment paper with the loaf and place it inside the Dutch oven. Cover with the lid and return it to the oven.
13. Bake the loaf covered for 30 minutes. Then, remove the lid and bake for an additional 15 minutes, or until the bread is golden brown and sounds hollow when tapped on the bottom.
14. Once baked, remove the bread from the oven and carefully transfer it to a wire rack to cool completely before slicing. This cooling period allows the crumb to set properly, ensuring a better texture.
15. Enjoy your homemade sourdough with roasted potato and rosemary potato bread fresh or toasted, with butter or your favorite spread!