Sift the flour. Sifting aerates the flour and makes for a lighter loaf.
In a large bowl dissolve 12 tsp yeast mixed in 2 cups of warm water (1 cup hot and 1 cup cold is perfect) plus 2/3 cup of the sugar.
When the yeast becomes foamy, add the flour to the bowl and knead.
Lightly beat the egg together with the oil and salt and add to bowl.
Add the remaining sugar and 2 1/2 cups of warm water and knead for about ten minutes.
Add a bit more warm water as needed. The dough should be a bit sticky because the whole wheat flour needs more time to absorb the water.
Let the dough rise, covered, in a warm place. Punch down the dough every 20 minutes for an hour. By this time it should be risen and ready for shaping.
Preheat oven to 350 degrees F. "Take challah" with a brocha*, shape and let rise. Coat with egg wash, seeds, etc . as desired.
Bake at 350 degrees for about 45 minutes to 1 hour (depending on the size of the loaves/rolls) or until dark golden brown.