Start your sourdough by measuring out sourdough starter into your bowl along with cold water, kosher salt and bread flour, and mix with a wooden spoon into a very sticky dough. Cover and ferment for 4 hours, giving a good fold after 2 hours. Then prep a banneton (wooden proofing basket) or bowl with a dusting of rice flour. Using just a touch of flour, knock the air out of your dough ball and roll into a ball, then transfer smooth-side down into a banneton. Sprinkle with flour and refrigerate overnight for a long, slow fermentation to develop flavor. Let the loaf rise at room temperature again and transfer onto a parchment-lined baking sheet. Score, spritz with water, bake, cool and slice! The satisfaction of homemade sourdough is like no other. Enjoy! Get the recipe for Chef John's Sourdough Bread.