Combine All Ingredients: In a large mixing bowl, whisk together the flour, sugar, yeast, and salt. Add the sourdough discard, warm water, and olive oil to the dry ingredients. Stir with a wooden spoon or use a stand mixer with a dough hook until a shaggy dough forms. The dough should be slightly sticky to the touch, but should not stick to the bowl. If it is too dry or too wet/ sticky, add more water or flour a few teaspoons at a time.
Knead the Dough: Turn the dough onto a lightly floured surface and knead for about 8-10 minutes until smooth and elastic. Alternatively, knead in a stand mixer for about 5 minutes.
First Rise: Place the dough in a lightly greased bowl, turning it once to grease the top. Cover with a kitchen towel or greased plastic wrap and let it rise in a warm, draft-free place (like a turned-off oven) for about 1 hour, or until doubled in size.
Shape the Loaf: Punch down the risen dough and shape it into a loaf. Place it in a greased 9x5 inch loaf pan.
Second Rise: Cover the loaf pan with a kitchen towel or greased plastic wrap and let it rise again in a warm place for about 1 hour, or until the dough rises about 1 inch above the rim of the pan.
Preheat Oven: Preheat your oven to 375°F (190°C) during the last 10 minutes of the second rise.
Bake: Bake the bread for 30-35 minutes, or until the top is golden brown and the loaf sounds hollow when tapped.
Cool: Remove the bread from the oven and let it cool in the pan for 10 minutes. Then, turn it out onto a wire rack to cool completely before slicing.