In a large jar or bowl combine the levain ingredients well. Cover and let ferment 8-10 hours.
In a large mixing bowl, or in your electric mixer, combine the 662g water and the active bubbly levain. Stir well.
Slowly mix in the 1037g flour. Knead by hand 5-10 minutes, or put in the electric mixer with the dough hook attachment for 10 minutes.
Cover and let rest 15-30 minutes.
In a small bowl combine the salt and 1 tbls. of water. Add it to the dough and knead another 5-10 minutes. Cover and let it rest on the counter 45-60 minutes.
Begin the first series of stretch and folds. Pull one side of the dough up out of the bowl to stretch and then fold over itself. Turn the bowl another 90 degrees and repeat until you've stretched and folded the dough four times. Cover and let it rest on the counter another 45-60 minutes. Repeat this series of stretch and folds 3 more times, for a total of 4.
Cover and let it rise 8-10 hours at room temp (68-70 degrees) or in the fridge for up to 36 hours. The dough will almost double in size, and should appear less dense and very jiggly. If fermenting in the fridge, let it come to room temperature before moving on to the next step.
Divide the dough into 2. One loaf at a time stretch the dough out as much as it will allow without ripping (This is called lamination). Fold it back up to form a loaf. Push and pull the round loaf across the counter to build tension. Once you have a nice tight loaf set aside and repeat with the second loaf. Let both loaves rest on the counter, uncovered, for 10-20 minutes.
Repeat the lamination process a second time. Keep in mind the bread will remember it's shape and wont stretch as well the second time around. If you want to add any inclusions (cheddar + jalapeños, cinnamon + sugar, etc.) do it during the first lamination and skip right to the next step.
Flip the loaf upside-down and gently drop into your floured proofing baskets. Cover and let rise 1 - 1.5 hours.
Once proofed, place in the fridge for 4-6 hours, or freezer for 1 hour. (You can technically bake them now, but I like to score and bake them cold)
Preheat the oven to 500 degrees with the dutch oven(s) inside.
Remove loaves from the banneton proofing baskets. You'll want to flip them onto a piece of parchment paper or bread mats. Score with a razor blade or bread lame.
Gently drop into the preheated dutch ovens and cover with the lids. Place in the oven with a half sheet pan on the rack underneath (this will keep the bottoms from burning). Reduce the oven temp to 450 degrees and bake for 20 minutes.
Remove the lids and bake an additional 20-25 minutes, depending on how toasted you like your bread.
Let cool 30-60 minutes before slicing.
Store in the cooled dutch ovens or in a ziplock bag. If placing in the freezer double bag.
Notes
I like to do the expansion score 7 minutes into baking. I just pop the lids off real quick to add the expansion score, or to deepen the score, and put them right back in. This isn't necessary, but helps you to manipulate the way steam escapes so you can really make your designs pop.To log in your food dairy, search Myfitnesspal or the Macrosfirst app for Stay Fit Mom Sourdough. You can change the serving size to 1 gram and log your slice of bread, big or small. I love a toasted slice of sourdough with avocado, cottage cheese, a shredded hard boiled egg, a drizzle of honey, and red pepper flakes. Just TRUST ME.