Potato Bread

Name: Potato Bread
Prep time: 30 min
Cook time: 35 min
Total time: 4 h
Yield: 12 slices
Ingredients: Ingredients; 1 medium russet potato (about 8 oz); 3 1/4 cups bread flour; 1 packet (2 1/4 tsp) active dry yeast; 2 tablespoons granulated sugar; 1 1/2 teaspoons salt; 3/4 cup warm potato cooking water (reserved from cooking potato); 1/4 cup whole milk, warmed; 3 tablespoons unsalted butter, melted; 1 large egg, room temperature; 1 tablespoon butter for brushing (optional)