Mix all Ingredients: Start with a nice bubbly active starter. To a bowl of a stand mixer, add all of the ingredients. I like to add the flour last, so I can add a bit less or more depending on my starter's hydration.
Knead Dough: Knead until dough is stretchy and smooth. You want it to pull away from the sides of the mixing bowl and be smooth and elastic – about 10 minutes. It should pass the windowpane test.
Bulk Rise: Place the dough in a large bowl with a little olive oil. Allow to bulk rise for 10-12 hours in a warm place like on top of a stove or refrigerator covered with plastic wrap, a tight lid, or beeswax wraps. Rise time will depend on the temperature of your home and how active your sourdough starter is.
Shape and Second Rise: Grease a loaf pan or add parchment paper. On a lightly floured surface, shape the dough by rolling it flat with a rolling pin into a rectangular shape. Then roll it up and add your shaped dough to the greased loaf pan. Cover with a tea towel. Let the dough rest for the second rise for 2-4 hours in a warm spot, or until doubled. Again this depends on the temp! It could be as little as 1 hour if the house is warm and the starter active. You can add an optional egg wash to the top of the dough for more browning.
Score your bread with a lame: This step is totally optional! Before baking, use a lame (a sharp razor blade or knife) to score the top of your dough. Scoring allows the bread to expand properly during baking and creates beautiful patterns on the crust. Hold the lame at a slight angle and make quick, confident cuts about ¼-inch deep.
Bake: Bake at 375 for 45 minutes, or until golden brown on top. Allow to cool completely before slicing.