01 - Combine bread flour and water in a large bowl, mixing until just incorporated. Cover the bowl and let rest for 30 minutes to allow gluten development.
02 - Add active sourdough starter and sea salt to the autolyse mixture. Mix thoroughly until fully integrated and the dough begins to develop structure.
03 - Complete four stretch and fold sessions at 15-minute intervals over one hour. Grab one edge of the dough, stretch upward, and fold toward the center. Rotate the bowl and repeat for all four sides.
04 - After the final stretch and fold, gently work the cubed cheddar and chopped jalapeños into the dough. Distribute evenly while being careful not to deflate the dough.
05 - Cover the dough and let rise at room temperature for 4 to 6 hours. The dough should double in size and show visible fermentation bubbles.
06 - Turn the dough onto a lightly floured surface. Shape into a tight round loaf using the edges of your hands to create tension on the surface. Transfer to a floured proofing basket or bowl, seam-side up.
07 - Cover and proof for 2 to 4 hours at room temperature, or refrigerate overnight for enhanced flavor development. The dough should show slight springback when pressed gently.
08 - Place a Dutch oven in the oven and preheat to 450°F for at least 30 minutes to ensure proper heat retention.
09 - Turn the dough onto parchment paper. Use a sharp knife or bread lame to score the top of the loaf with your desired pattern. Carefully transfer into the preheated Dutch oven.
10 - Bake with the lid on for 20 minutes to create steam and develop oven spring.
11 - Remove the lid and continue baking for 20 to 25 minutes until the crust achieves a deep golden color and sounds hollow when tapped on the bottom.
12 - Transfer the loaf to a wire rack and cool for at least 1 hour before slicing. This allows the internal structure to set and prevents gumminess.