A recipe for Amish sourdough bread on Food.com recommends creating a dough from yeast, water, milk, honey and oil, as well as wheat flour, eggs, salt and white flour. You then knead the dough, oil it, allow it to rise, divide it into loaves and bake the loaves.
Combine 2 1/4 teaspoons of yeast, 1 cup of water, 1 cup of milk, 2 tablespoons of honey and 1/4 cup of oil, as well as 1 cup of whole-wheat flour, 2 cups of eggs, 2 teaspoons of salt and 6 1/2 cups of white flower into a stand mixer with a dough attachment. Knead the dough in the mixer for 10 minutes until it is slightly sticky. Flour a surface, and knead the dough by hand for two minutes into a large ball. Put the dough into a large bowl, and rub vegetable oil over the surface of the dough. Cover the bowl with a towel, and place it in a warm location to allow the dough to rise.
Remove the dough from the bowl, and divide it into two equal portions. Create a rectangle out of each dough ball, and roll the dough into a log to remove any bubbles. Insert the dough into pre-greased loaf pans, brush the tops with eggs whites, sprinkle them with poppy seeds, and bake the loaves for 25 minutes at 375 degrees Fahrenheit.