In a large mixing bowl, dissolve yeast in warm water. Add sugar and oil, mix well. Stir in whole wheat flour, let stand until the mixture lightly bubbles, about 5 min.
In a small bowl, beat eggs and water. Remove 2T of egg mixture and set aside.
Add remaining egg mixture and salt to batter, mix until smooth. Add 4 cups of all-purpose flour and beat until smooth. Add enough remaining flour to form a soft dough. Turn onto a flourd surface and knead until smooth and elastic- about 6 min. Place in a greased bowl turning once to grease top. Cover and place in a warm place and let rise until doubled, about 20 min.
Punch down and divide in half. Divide each half into thirds. Shape each third into a rope about 15in. long. Place three ropes on a greased baking sheet and braid. Pinch ends firmly and tuck under. Brush with the reserved egg mixture and sprinkle with sesame seeds. Repeat with the remaining dough.
Let raise until double- about 20 min. Bake 350 20-25 min.