In the bowl of a stand mixer, add the water and sugar and stir or swirl to dissolve. Stir in the yeast and 2 cups of the whole wheat flour. Let sit for 10 minutes, until bubbles form. Add in the remaining cup of whole wheat flour, 2 cups of all-purpose flour, salt, and vegetable oil.
Using the dough hook attachment, turn the mixer on to the lowest setting until a cohesive dough forms. Add the remaining cup of flour over the sticky dough and mix on the next lowest until combined and a soft and smooth dough forms. The dough should hardly be sticky.
Transfer the dough to a large bowl greased with oil. Cover loosely with plastic wrap and set in a warm* location for 1 ½ hours, until doubled in size.
Deflate the dough and divide in half. Shape each half into an 8-inch log and place in greased 8 ½“ x 4 ½” loaf pans. Cover loosely with plastic wrap and set in a warm location to rise for an additional 30 minutes.
While the loaves are rising, preheat the oven to 375°Once the loaves are ready, remove the plastic and bake for 30 minutes, until the crust is golden brown and the internal temperature is 190°F.
Notes
*I placed my bowl in an off-oven with the light turned on.