Activate Yeast: Mix 2 g active dry yeast with warm water at 100°F until it becomes foamy.
Mix Dough: Add 500 g bread flour and additional water to the activated yeast. Mix for about 20 seconds until combined. Add 10 g salt and incorporate by hand until sticky but fully mixed.
Initial Rest: Let the dough rest in the bowl for 1 hour.
Stretch and Fold: Perform four stretch and folds every 30 minutes by grabbing a side of the dough, stretching it up, folding it over itself, and rotating the bowl to repeat.
Shape Dough: After the last stretch and fold, shape the dough into a ball using the 'batard' method: fold the bottom, sides, and top into the center, braid three small folds to secure, and place seam side up in a proving basket.
Cold Proof: Refrigerate the dough for an overnight cold proof of about 12 hours or until it passes the poke test (poke slowly fills back). If underproofed, continue proofing at room temperature.
Preheat Oven and Cast Iron: Preheat the oven to 475°F with the cast iron skillet inside.
Prepare for Baking: Carefully transfer the dough to the hot cast iron skillet, dust the top with rice flour or normal flour, and score the top lightly.
Bake Bread: Bake in the cast iron for about 25 minutes. Remove from cast iron and bake directly on the oven rack for another 15 to 20 minutes.
Cool Before Cutting: Allow the bread to cool completely before cutting to let the crumb set.