Stir the potato flakes, yeast, sugar, and warm water together with a wooden spoon.

Cover, and leave on the counter for 5 days.

Stir in the potato flakes, sugar, and warm water into the starter.

Allow the starter to rest for 2 hours until it becomes active and bubbly.

Scoop out 1 cup of starter for your bread, cover the remainder of the starer, and place in your fridge until next week.

In a large bowl, combine the flour, active sourdough starter, lukewarm water, oil, white granulated sugar, and salt, mixing until well combined.

Knead the dough until the flour is fully incorporated, and the dough is smooth and elastic.

Cover the mixing bowl with a damp kitchen towel or plastic wrap and allow it to rise in a warm place for 3-4 hours or in the fridge for an overnight rise until it doubles in size. This will be your first rise.

After the dough has risen, gently punch it down to release any air bubbles.

Transfer the dough to a lightly floured surface and divide the dough into two equal portions using a bench scraper and shape each portion into a loaf.

Place each of the loaves in a greased bread pan seam side down.

For the 2nd rise, cover the loaf pans with a damp kitchen towel or plastic wrap and let them rise for another 30-60 minutes, or until the dough rises above the rim of the pans.

Once the dough has risen, preheat your oven to 375°F and then remove the towel or plastic wrap.

In a small bowl, whisk together the egg with 1 teaspoon of water to create an egg wash.

Brush the egg wash over the loaves and place the loaf pans in the preheated oven.

Bake for 30-35 minutes, or until the bread is golden brown and sounds hollow when tapped on the bottom.

Remove the bread from the oven and let the bread cool in the pans for 5-10 minutes.

Then, transfer the loaves to a wire rack to cool completely before slicing.