Feed Starter– pick one of these two ways to do it:
Use a 1:1:1 ratio 
120 grams Sourdough Starter
120 grams Water
120 grams Bread Flour (unbleached)

OR eyeball it/approximate (what I do most of the time–I don’t get out the scale for feeding the starter)

First discard (remove about half or more) leaving about a 1/2 cup of starter in your jar
Feed starter with:
about 1/2 cup bread flour
enough water to create a very thick looking batter 

After you have fed starter leave on counter for a few hours (depends on the warmth of your kitchen) until bubbly and about doubled in size.  A good test is to drop a small bit into a cup of water. If the dough floats it is ready to bake with and proceed with recipe. If it sinks–then discard half the starter and feed it again.

Making the Dough:

Place a large bowl on the scale and zero it out (tare button) then add ingredients:

200 grams starter
525 grams water (room temperature to warmish)
700 grams bread flour
1 Tablespoon salt

Mix gently just until the flour is incorporated. It will be a rough, shaggy dough. Cover lightly and set aside for one hour.

After one hour, with a damp hand, fold 1/4 of the dough in on top of itself, turn to the next 1/4 of the dough and fold it on top again. Then repeat for a total of 4 times so that all the dough has had a chance to be folded over. Lightly cover and let rest for 30 minutes on the counter.  Repeat this folding process 4 times (will take 2 hours).

After 2 hours of folding and resting, cover the bowl and place it in the refrigerator overnight for 12-15 hours.

The next morning remove from the fridge and let the bowl sit on the counter until it comes to room temperature –about 2 hours.

Then gently dump the dough onto a clean countertop and divide in half using a dough scraper. Be careful not to touch the sticky dough.  Cover lightly with a clean dish towel and let sit for 30 minutes.

Pick up one dough ball and stretch it, using gravity to let it hang. Lay the dough (more like a rectangle shape now) onto the counter —{Optional–this is the time to sprinkle on add-ins like cheese cubes and herbs, cinnamon sugar, or white chocolate with pecans}—then fold it 1/3 way over, lengthwise, then the other 1/3 length over the fold.  Then 1/3 fold on  either end to fold over and tuck to create a ball.  

Repeat for second ball. Place both dough balls in separate bowls or proofing baskets. Cover with plastic grocery sack and place in fridge to rest for 4 hours. 

Baking Sourdough:
About 30 minutes before you are ready to bake the dough, heat your covered dutch oven in the oven set at 450 degrees to get it nice and hot.

Remove  dough balls from fridge and place on parchment paper. Use the lame (razor blade or very sharp knife) to slash the top in a pretty design.  

Carefully remove hot dutch oven from oven and place dough inside replacing the lid and returning to oven,

Bake for 30 minutes with the lid on then remove the lid and bake for another 5-10 minutes until loaf is golden brown.

Immediately after removing the pan from the oven, carefully lift the bread out and place on cooling rack. If you don’t have 2 pans to bake them simultaneously, then put the covered pan back in the oven to reheat for 10 minutes. Then repeat the process for the second loaf.