This is a great base sourdough method which, once mastered, can be adapted to include other heritage flours.
Mix starter and water with fingers until starter has mostly dissolved and mixture is frothy.
Mix in flour with your hands just until it is well incorporated and there are no dry pockets of flour. Dough should feel slightly sticky, but not overly wet or sloppy. Add additional flour or water if needed. Let rest, covered for 20-30 minutes.
Sprinkle salt evenly over the surface of the dough. With wet hands, dimple and pinch in salt to mix evenly, gently squishing and folding the dough in on itself, while trying to avoid tearing the dough (if dough seems stiff, now is a good time to add a small amount of additional water.) Let rest, covered for 20-30 minutes.
Gently stretch and fold the dough over itself four times, rotating 90 degrees after each fold. Repeat four sets of stretch and folds every 20-30 minutes.
Allow dough to rest, covered, at warm room temperature for a total of four to eight hours until it has a slightly domed top, visible bubbles on the surface, and has increased slightly in volume (in a clear container, dough should have evenly dispersed bubbles throughout)
Gently ease dough out onto a lightly floured surface. Shape into desired shape and place into proofing bowl or basket, lined with a generously floured towel, or directly into greased loaf pan. Allow to proof, covered, at room temperature for 1-3 hours, until visibly increased by 25-50% in size and the surface of the dough springs back slowly when poked.
Place in refrigerator to proof overnight (8-16 hours), remove from fridge immediately before baking.
Preheat oven and baking vessel (if using) to 500 degrees for 30 minutes.
Turn out shaped loaf onto crumpled parchment paper, score with a bread lame or sharp knife, and carefully transfer into hot baking vessel (lifting the edges of parchment like a sling.)
Immediately reduce temperature to 475F and bake, covered, for 20 minutes.
Remove lid and bake for an additional 20-25 minutes, until desired colour is reached, and the loaf sounds hollow when tapped on the bottom.
Allow to cool for at least one hour before slicing.