Mix together the active sourdough starter, flour and water. Cover loosely and let sit for 3–4 hours at 78–80ºF, until doubled in size, bubbly and at its peak.

Grate the fresh corn from the cobs. Add the grated corn and butter to a skillet and cook over medium-low heat, stirring frequently, for about 5 minutes until the excess liquid has evaporated and the corn thickens into a soft, pudding-like mixture.

In a large bowl, combine the cooled corn pudding mixture, ripe levain, water, sugar, cornmeal, salt and bread flour. Use a dough whisk or sturdy spoon to mix until all of the flour is incorporated and a sticky dough forms. Cover with plastic wrap and let the dough rest for 30 minutes.

After the dough has rested, perform 4 sets of stretch and folds, spaced about 30 minutes apart.

Cover the dough and let rise for another 2–2½ hours at about 78ºF.

Gently turn the dough out onto a clean counter and shape it into a round.

Let the dough rest uncovered for about 30 minutes.

Prepare a banneton or bowl lined with a kitchen towel and flour it generously with cornmeal. Shape the dough and place it seam-side up in the prepared banneton.

Cover and refrigerate overnight, or for about 14–20 hours.

Preheat the oven to 450ºF for 20-30 minutes.

When ready to bake, flip the loaf onto parchment paper, score the top, and transfer it to the hot Dutch oven.

Bake covered for 30 minutes, then remove the lid and bake for another 15-20 minutes until the crust is a deep golden brown and the center of the loaf registers 205–210ºF.

Let the bread cool completely before slicing.