Add warm water to a large bowl with yeast and sugar.

Mix until combined, stir in vegetable oil and set aside 5 minutes.

Next, add 2 cups whole wheat flour and 2 cups of all purpose flour along with the salt.

Stir together using a dough whisk or wooden spoon.

Add another cup of whole wheat flour, mixing together until dough forms a ball and pulls away from the bowl.

Using bread or all purpose flour, flour a clean surface. Pour dough onto the floured surface and knead the dough by folding it over itself, and then pushing it back to the center of the work space with the palms of your hands. Add a bit of flour as needed.

Knead for 3- 5 minutes or until dough is no longer sticky. Form dough into a smooth ball.

Grease a large bowl with vegetable or olive oil.

Place dough into the bowl and turn it over so both sides are oiled. Cover with a bowl cover or plastic wrap and set in a warm, draft-free place until doubled, about 1 hour.

Punch down the dough, removing the air. Place on a floured surface. Using a bench knife or sharp knife, cut the dough in half.

Line or grease 2 9 x 5 -inch loaf pans using parchment paper or vegetable oil.

Form each piece of dough into a loaf shape and place into the prepared loaf pans. Cover and set aside to rise, 1 - 1/2 hours. The bread should rise about 1/2"- 1" above the pan.

Preheat oven to 350°.

Remove the covers and bake for 35- 40 minutes. Test bread with a digital thermometer, cooking to 190°- 200°.

Remove from oven. Carefully remove from the bread pans, cooling on a wire rack.

When bread is completely cooled, slice with a serrated knife.