Modern Jewish Baker: Whole-Grain Challah

Ingredients

• 1 1/2 tablespoons dry active yeast
• 1 teaspoon sugar
• 1 1/4 cups lukewarm water
• 2 1/2 cups unbleached bread flour (preferably King Arthur)
• 1 1/2 cups whole-wheat bread flour (can also use regular whole-wheat flour)
• 1/2 cup oat bran
• 1 1/2 teaspoons salt
• 1/2 cup sugar
• 1/4 cup vegetable oil
• 2 large eggs
• 1 egg yolk (or 1 whole egg)
• 1 teaspoon water
• 1/4 cup whole oats (optional)
• 2 tablespoons whole flaxseed (optional)
• 1/4 teaspoon coarse sea salt (optional)
• 1/4 cup sunflower seeds (optional)
• 1/4 cup sliced almonds (optional)