In a large mixing bowl, combine:Active sourdough starterFiltered waterMix until the starter is dissolved in the water.Add:FlourSaltStir until a shaggy dough forms. It’s okay if it looks a little rough—just make sure there are no dry patches of flour.Cover the bowl and let the dough rest for 15–30 minutes.
First Stretch & Fold
Gently pull one side of the dough up and fold it over the top.Rotate the bowl slightly and repeat.Complete four folds total, pulling from each side and bringing the dough up and over.Cover and let sit for 1 hour.
Second Stretch & Fold
Repeat the four folds.Cover and let sit for 1 hour.
Third Stretch & Fold
Repeat the four folds.Cover and let sit for 1 hour.
Fourth Stretch & Fold
Repeat the four folds one last time.
Shape & Counter Rest
Shape your dough into a round or loaf shape.Let it sit on the counter for a few more hours to continue rising.(You mentioned you usually start yours mid-morning and put it in the fridge after dinner — that timing works great.)
Cold Proof
Place the dough in the refrigerator.It can proof in the fridge for up to 48 hours.
Baking
When ready to bake, preheat your oven to 450°F.Place your Dutch oven inside the oven while it preheats.Put a cookie sheet on the rack underneath the Dutch oven (this helps prevent the bottom from over-browning).Once preheated, carefully place your dough into the hot Dutch oven with 4 ice cubes for steam and bake for 35 minutes. Remove the lid and bake an additional 15 minutes, until golden brown.