Feed your starter and wait until it is at peak activeness **(see note below)**
Combine the starter, water, flour, and salt in a bowl or container, and leave to rest for 30 minutes at room temperature **(this is the autolyse part of the process)**.
Stretch and fold the dough by grabbing a portion from the edge, and folding over to the center. Do this several times around the dough until it begins to tighten. You shouldn't be ripping the dough as you stretch and fold, and it should look like a round ball when you're done.
Cover the dough with a damp towel and let rest for 1 hour at room temperature. This is the start of the "bulk rise".
Do 4 "stretch & folds" around the sides of the dough **(turning a quarter turn each time, and going up and over the top with each fold)**, then cover with a towel and wait another hour.
Do another 4 "stretch & folds", like before, then cover the dough and let it rise overnight **(at least 8-10 hours)**.
After the bulk rise, the dough should have roughly doubled in size **(I've had the best success with letting it get 2.5x times the size, but after it doubles, you start to run the risk of it overproofing)**. Once it has risen enough for your liking, do another 4 "stretch & folds" like before, then wait for 30 minutes.
Do a final 4 "stretch & folds", this time flipping the dough over once done so that the smooth side is facing upwards. Then, shape the dough ball by cupping and pulling around the sides with both hands, rotating and pulling towards you **(this technique is hard to comprehend without seeing it, so watch some videos of people "shaping dough" if you're confused)**.
Using a bench knife, flip the dough ball upside-down into a floured cloth-lined bowl. Cover with edges of cloth and let rest for an hour **(or optionally, overnight in the fridge)**. This is the "proofing" stage.
Preheat the oven to 450°F, with the baking vessel **(dutch oven ideally)** inside.
Cut some parchment paper to fit the baking vessel **(edges included)**. Invert the cloth lined bowl, flipping the loaf onto the parchment paper. Remove the cloth.
Sprinkle the dough with flour, and rub gently with your hands
Using the tip of a bread lame, or small serrated knife, make 4 shallow **(4 inch long, 1 inch deep)** cuts at 3, 6, 9, and 12 o'clock around the dough
Use the parchment paper to transfer the dough into the dutch oven, cover, and transfer to preheated oven
Bake with lid on for 30 minutes
Remove lid and bake for another 15 minutes
Remove from oven, and transfer to a wire rack to cool for 1 hour
Slice and eat!
notes
If you keep your starter in the fridge, you'll need to feed it prior to starting the bread making process. To do so, take the starter out of the fridge and discard most of it, leaving a thin layer at the bottom **(~50 grams)**. Add a 1:1 ratio of flour to water to feed it **(ex. 60 grams all purpose flour, 20 grams whole wheat flour, 80 grams water)**. Mix well so that all the flour is wet, and there are no dry patches on the sides/ bottom of the container. Wait until the starter has doubled in size... this is when it is at peak activity, and will produce the best bread.
We use fine sea salt in the recipe, but regular table salt will work too as long as it isn't iodized. Iodized salt tends to add a bitter taste to bread when baked.
An easy way to check when the starter has doubled in size is to put a rubber band around your starter container at the level it is right after you feed it.
Over time, you'll get a sense of how wet the dough should be after the initial rest **(soft and stretchy, not wet, overly sticky, or soupy)**. This is the best time to adjust the texture by adding a little **(1 tablespoon or so)** water or flour as necessary, and mixing it in thoroughly.
The "stretch & folds" routine is to develop and strengthen the gluten structure, as well as to incorporate air into the dough. This will result in a more open crumb.
Baking with the lid on lets the dough steam as it cooks. When you take the lid off, you're letting the steam escape, and allowing for proper crust development. Tweaking the lid on/ off times will allow you to impact crust formation.
It is amazing how many home bakers make dense, gummy loaves, but because they spent all the time doing the work, act like their sourdough is the best thing since sliced bread. Buy a sourdough loaf from a bakery to taste side by side with your own and be honest about how it came out... that's the only way to improve and avoid people having to politely force down a shitty slice of your "masterpiece".
To me, the bread gets noticeably worse after around 2 days **(no matter how airtight of a container you store it in)**. It's best right out of the oven **(by which I mean an hour after, since it has to cool)**, pretty good the next day, and from then on it's no better than regular store bought bread, and I tend to start utilizing the great equalizer and toasting it.