Feed your starter about 6 hours before you want to make the dough and let rest at room temperature (70-74°F). Depending on the activity of your starter and the temperature of your house, it should ripen 4-8 hours after feeding. Your starter is ripe when it passes the float test. Drop a small piece of starter into a glass of water and if it floats, it's ready to use!
Mix together all of the ingredients except the salt (by hand or with a dough whisk), cover, and let rest at room temperature for 30 minutes to 1 hour.
Add the salt and knead the dough until smooth and supple.Place back in the bowl, cover, and let rise at room temperature for 2 hours. While the dough is rising do a set of stretches and folds every 30 minutes (3 total).
Turn the dough out onto a lightly floured surface and shape into a tight boule.Place in a lightly floured proofing basket, cover, and let rise at room temperature until the dough is light, puffy, and doubled in size (about 2-3 hours).
Preheat oven to 450°F.
Turn dough out onto parchment paper and slash an X in the top with a sharp knife or lame (and score some fun designs if you want). Carefully place into your dutch oven using the parchment paper and cover with tight fitting lid.
Bake covered for 17 minutes, then remove the lid and bake for another 20-25 minutes or until the crust is deep golden brown.
Remove from the dutch oven and let cool on wire rack.
For best results, store your homemade sourdough in a stainless steel bread box for up to a week.