**Activate the Yeast:**
- In a large mixing bowl, combine warm water and sugar. Stir until dissolved. Sprinkle yeast over the top and let it sit for 5-10 minutes until it becomes frothy.
**Mix the Dough:**
- Add oil and salt to the yeast mixture. Gradually mix in 3 cups of flour, stirring until smooth. Continue adding flour, ½ cup at a time, until a soft dough forms that pulls away from the sides of the bowl but is still slightly sticky.
**Knead the Dough:**
- Turn the dough onto a floured surface and knead for 8-10 minutes, or use a stand mixer with a dough hook for 5-7 minutes, until the dough is smooth and elastic.
**First Rise:**
- Place the dough in a greased bowl, turning it to coat the surface. Cover with a clean kitchen towel and let it rise in a warm place for about 1 hour, or until it doubles in size.
**Shape and Second Rise:**
- Punch down the dough and divide it into two equal portions. Shape each portion into a loaf and place them into greased 9x5-inch loaf pans. Cover and let rise again for 30-45 minutes, or until the dough rises about 1 inch above the edges of the pans.
**Bake the Bread:**
- Preheat the oven to 350°F (175°C). Bake the loaves for 25-30 minutes, or until the tops are golden brown and the bread sounds hollow when tapped.
**Cool:**
- Remove the loaves from the pans and let them cool on a wire rack before slicing.