Feed your starter 4-6 hours before starting the dough. Feed your sourdough starter a few hours before making the dough, allowing it to double in size and become bubbly and active.
Mix the dough and let rest for 30 minutes. In a large mixing bowl, combine the active starter, lukewarm filtered water, and bread flour. Use a kitchen scale for accuracy. Mix with a dough whisk or your hands until fully incorporated. The dough will look shaggy, which is completely normal at this stage. Cover the bowl with plastic wrap or a clean kitchen towel and let it rest in a warm spot for about 30 minutes.
Add salt and start the stretch and folds. After resting, sprinkle salt evenly over the dough and gently press it in with your fingers. Begin stretching and folding by lifting one side of the dough, stretching it upward, and folding it over the center. Rotate the bowl 90 degrees and repeat, continuing until the dough has been folded from all sides. This process strengthens the dough and helps develop structure.
Add the pickled jalapeños and sharp cheddar cheese during the second stretch and fold. Pat the jalapenos dry with a kitchen or paper towel. Roughly chop them. Cube the sharp cheddar cheese. Add them to the dough right before you start the second round of stretch and folds. Continue with four stretches and folds, folding the dough over the inclusions.
Bulk fermentation (remaining 3-5 hours). Cover with a towel and place in a warm place. Repeat the stretch and folds every 30-60 minutes 1-2 more times. Then allow it to rest for 2-3 hours. The dough is ready to be shaped once it has increased in size, is jiggly, and has some bubbles on top of it.
Pre-shape. Gently scrape the dough out with a bench scraper onto a clean and lightly floured surface. I like to wet my hands before handling the dough. Gently push the dough ball away from you and back towards you to create tension. Allow it to rest for 30 minutes.
Shape the dough and overnight ferment (12-24 hours). After 30 minutes, the dough will have decompressed and flattened a bit. Heavily dust the inside of a banneton with rice flour and set aside. Use your hands to work in a circular motion pushing the dough ball away from you and guiding it back to you, working it into a round shape. Try to keep the jalapenos and cheese inside the dough ball. Use your bench scraper to assist you in flipping the dough ball upside down into the banneton. Cover it and place in the fridge overnight for 12-24 hours. Preheat oven (30 minutes). In the morning, preheat the oven to 450℉. Place your Dutch oven in the oven and allow it to heat up for at least 30 minutes.
Prepare bread. Cut a square of parchment paper and lay it down. This helps to prevent the bread from sticking to the Dutch oven and burning (this is especially important when baking with inclusions). If you use a bread sling, place it over the parchment paper. Remove the bread dough from the fridge and flip the banneton upside down over the parchment paper. Score the bread. Score the bread with your preferred design, just make sure to add at least one long expansion score.
Bake the bread (60 minutes). Carefully remove the Dutch oven and place the parchment paper and bread into it. Bake the bread covered for 30 minutes. After 30 minutes, remove the lid and bake uncovered for an additional 25-30 minutes.
Cool and enjoy! Allow the bread to rest for 30-60 minutes before you slice it. Enjoy!