1. 1. Combine Wet Ingredients: In a large mixing bowl, combine the active sourdough starter, warm water, granulated sugar, and instant yeast. Stir gently until the sugar and yeast are mostly dissolved. Let it sit for 5 minutes to allow the yeast to activate and the starter to loosen up.

2. 2. Add Dry Ingredients: Add the salt and 4 cups of the all-purpose flour to the wet mixture. Mix with a wooden spoon or a sturdy spatula until a shaggy dough forms. It will look a bit rough and sticky at this stage.

3. 3. Knead the Dough: Turn the dough out onto a lightly floured surface. Begin to knead, gradually adding the remaining 1 cup of flour, a little at a time, until the dough is smooth, elastic, and no longer sticky. This should take about 8-10 minutes of continuous kneading. Alternatively, if using a stand mixer with a dough hook, knead on medium speed for 6-8 minutes.

4. 4. First Rise: Lightly grease a large clean bowl with olive oil. Place the dough in the bowl, turning it once to coat all sides. Cover the bowl tightly with plastic wrap or a clean kitchen towel. Let the dough rise in a warm place for 1.5 to 2 hours, or until it has doubled in size. You’ll know it’s ready when it looks puffy and springs back slowly when gently poked.

5. 5. Shape the Loaf: Gently punch down the risen dough to release the air. Turn it out onto a lightly floured surface. Shape the dough into a rectangular loaf that will fit comfortably into your standard 9×5-inch loaf pan. You can do this by gently patting it into a rectangle, then rolling it up tightly from one of the longer sides, pinching the seam closed.

6. 6. Second Rise: Lightly grease your 9×5-inch loaf pan. Place the shaped dough seam-side down into the prepared pan. Cover the pan loosely with plastic wrap or a kitchen towel and let it rise in a warm place for another 30-45 minutes, or until it has nearly doubled in size and looks puffy.

7. 7. Preheat and Bake: While the dough is on its second rise, preheat your oven to 375 F (190 C). Once the dough has risen, place the loaf pan in the preheated oven. Bake for 30-35 minutes, or until the crust is golden brown and the internal temperature reaches 200-210 F (93-99 C) when checked with an instant-read thermometer.

8. 8. Cooling: Once baked, immediately remove the bread from the loaf pan and place it on a wire rack to cool completely before slicing. This step is crucial for preventing a gummy texture.