In a large bowl or the bowl of a stand mixer, combine the water, salt, and sourdough starter.
Add 4 cups of the flour and mix. Add the remaining flour 1 cup at a time until the dough separates from the side of the bowl and is slightly sticky. You may need to add a bit more flour depending on how hydrated your starter is.
Allow the mixer to knead the dough for about 7 minutes, until smooth an elastic.
Place dough in a large greased bowl, cover with a damp towel, and set it in a warm place to rise for 5-6 hours or until doubled.
Shape dough into loaves and place them in lightly oiled (or parchment paper lined) loaf pans or on a sheet pan, cover with a damp towel and allow to rise for 1½-2 hours.
Bake in 350℉ oven for 28 minutes or until it reaches an internal temperature of 180℉.
Notes
For a softer crust, place a damp towel over the loaves after removing from the oven.