Mix water, starter, salt, and 2 c flour in your Kitchen Aid or stand mixer. You can also easily make this loaf by hand –a danish dough whisk can be used if you don't have a mixer.
Allow the shaggy dough to rest for 20 mins to allow the flour to soak up as much moisture as possible.
Add more flour (up to 1 and 1/4 cups more) as needed to form a soft, slightly sticky dough that pulls away from the sides of the mixer & forms a ball.
Knead until dough comes together in a slightly sticky ball (a few minutes by hand).
Spray the bowl with olive oil before so it is lightly greased. Then place the dough in it and cover with a kitchen towel & set a timer for 15 mins.
When the timer goes off, return to the dough with wet fingertips & gently pull one side up & into the center, turning the bowl 1/4 turns & repeating all the way around the dough ball. Repeat every 15 mins for the first hour.
Fold dough this way every hour for the next 4-6 hours. (It’s okay if you forget – even that first hour of this folding technique will help!)
After the long rise, place your dough on a lightly floured surface & fold one more time. Then let it rest 5-10 mins.
Flip dough over & gently tuck it around & under as you rotate it, to create a nice firm surface. Try to get the top of the dough really tight. This will help your dough rise up in the oven more effectively.
Place dough seam side up in a greased bowl (or a well-floured banneton if you have one!). Cover lightly with a towel or greased plastic wrap & set aside.
Preheat your oven to 500 degrees, with the dutch oven inside for 45-60 mins. If your dutch oven can’t withstand that heat, preheat to 450.
Allow loaf to rise while the oven is heating or until a fingertip pressed into the surface causes the dough to slowly fill back in.
Place dough onto a piece of parchment paper. Immediately before adding the dough to the dutch oven, slash the top with a sharp knife. Make quick, confident strokes about ¼” deep.
Place dough in the Dutch Oven with the lid on, reduce the heat to 430 degrees, & bake for 20 mins.
Remove the lid & bake another 15-20 minutes or until the top is golden brown & the bottom sounds hollow when tapped.
Cool completely before slicing – this is important – the bread continues to build structure as it cools, so if you cut into it hot it may appear underbaked or doughy inside.