Yield: 2 loaves
Prep Time: 30 min + rising time
Cook Time: 40 min
Two .25-ounce packages active dry yeast
4 tablespoons granulated white sugar, divided
1/2 cup warm water
3 tablespoons unsalted butter, melted
1 teaspoon salt
3 large eggs, separated
3 to 3 1/2 cups all-purpose flour
1/2 cup mashed sweet potatoes or yams
1 inch piece of grated fresh ginger
1. In a large bowl, combine the yeast with 1 tablespoon of the sugar and warm water in a mixing bowl. Let sit for 5 minutes until the yeast becomes foamy. Add the remaining sugar, butter, salt and 2 of the eggs to the yeast mixture and stir to blend well. Stir in the flour, 1 cup at a time, then stir in the sweet potatoes and ginger.
2. Turn the dough out onto a lightly floured board and knead for 2-3 minutes, adding only enough flour to prevent the dough from sticking to the board. The dough will be soft, so don't knead it too heavily. When the dough is smooth and springy to the touch, shape it into a ball. Put it in a greased bowl and turn to coat the surface. Cover with plastic wrap and let sit in a warm, draft-free spot until doubled in bulk, about 1 hour. This could take longer on cooler days.
3. Punch down the dough, then shape it into a ball and let it rest for 2 minutes. Turn out onto a floured board. Divide in half. Divide each half into thirds and roll out each third into an 8-inch log. Pinch each of the three pieces together at their tips and braid them to create the challah; then pinch the combined ends together. Repeat the process with the other dough half.
4. Cover the loaves loosely with a clean dishtowel and let them rise to almost double in bulk (again, in a warm place). Beat the remaining egg lightly, by hand. and paint the challah tops with it. Preheat oven to 375 degrees F. Bake 40-45 minutes.
*If using canned sweet potatoes, be sure to drain all of the liquid before mashing.
*Try adding raisins or other dried fruit with the sweet potato.