Start by feeding your starter around 3 or 4 PM on Thursday afternoon.
When the starter is bubbling and doubled in size, you can begin to make your bread.
Weigh out the starter and water on the food scale. MIx together with a fork.
Add in both flours and salt and mix until combined. You may wet your hands and use them to mix, if that works for you. Make sure all the flour is incorporated. The dough will be very shaggy at this point. Cover the bowl with a towel and set aside to rest for 30 minutes.
When 30 minutes are up, wet your hands and fold the dough by taking a piece from the outside and bringing it towards the middle. Do this until you've come full circle, or the dough begins to resist.
Cover the bowl with a towel and set aside to rest in a warm place (about 71 F) for 8-10 hours.
Go to sleep!!
In the morning, the dough should have risen up the bowl, doubling in size. You may leave it for another couple of hours if it's not at that point yet.
Wet your hands and gently ease the dough from the bowl onto a floured surface. Fold the dough again, starting from the outside and bringing it towards the middle. Once you've come full circle, flip the dough over with your bench scraper and use it to shape the dough into a nice round loaf. Let the dough rest on the counter for 10 minutes.
Flour a proofing basket. When 10 minutes are up, lift and flip the dough into the floured proofing basket using the bench scraper. The bottom part of the dough should be facing you with the rounded end in the basket.
Set the dough aside to rest for 30-1 hour.At this point, you may also place your dough in the fridge for up to 24 hours before proceeding to the next step.
Place your cast iron pot, covered, in the oven and preheat to 450F.
After 30 minutes -1 hour invert the basket onto a small-medium sheet of parchment paper. Score.
Carefully remove the pot from the oven and take off the lid. Gently lift the parchment paper and place the loaf inside of the pot. Cover and bake for 20 minutes.
After 20 minutes, remove the lid and continue to bake for 30 minutes.
When 30 minutes are up, carefully remove the loaf from the pot and set on the oven rack to crisp up for an additional 5-10 minutes.
When the loaf is ready, remove it from the oven and cool on a cooling rack for at least 1 hour before slicing.