1. 1. Activate the Yeast: In a large mixing bowl, combine the warm water, sugar, and active dry yeast. Stir gently and let it sit for 5-10 minutes until foamy. This foaminess indicates your yeast is active and ready to work.

2. 2. Combine Wet Ingredients: Add the room temperature sourdough discard to the foamy yeast mixture. Stir well with a spoon or spatula until thoroughly combined.

3. 3. Mix Dry Ingredients: In a separate medium bowl, whisk together the all-purpose flour and salt.

4. 4. Form the Dough: Gradually add the dry flour mixture to the wet ingredients, mixing with a wooden spoon or your hands until a shaggy dough forms. Once most of the flour is incorporated, turn the dough out onto a lightly floured surface.

5. 5. Knead the Dough: Knead the dough for 8-10 minutes until it becomes smooth and elastic. If the dough is too sticky, add a tiny bit more flour, a tablespoon at a time, but try not to add too much. The dough should spring back slowly when poked.

6. 6. First Rise: Lightly grease a clean large bowl with a little melted butter or oil. Place the kneaded dough in the bowl, turning it once to coat the top. Cover the bowl tightly with plastic wrap or a clean kitchen towel and let it rise in a warm place for 60-90 minutes, or until doubled in size.

7. 7. 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 loaf by gently flattening it into a rectangle, then rolling it up tightly from one of the long sides. Pinch the seam closed and tuck the ends under.

8. 8. Second Rise and Bake: Grease a standard 9×5-inch loaf pan with butter. Place the shaped dough into the prepared pan, seam-side down. Cover the loaf pan loosely with plastic wrap or a kitchen towel and let it rise again in a warm place for 30-45 minutes, or until it has nearly doubled in size and looks puffy. Preheat your oven to 375 F (190 C) during the last 15 minutes of the second rise. Bake for 30-35 minutes, or until the crust is golden brown and the internal temperature reaches 200-210 F (93-99 C) with an instant-read thermometer.

9. 9. Cooling: Once baked, immediately remove the bread from the loaf pan and place it on a wire rack to cool completely before slicing. This prevents the bottom from getting soggy and allows the internal structure to set.