In a medium bowl, mix together the ripe sourdough starter, all-purpose flour, and water until well combined. Cover and let sit for 3-4 hours.

In a large mixing bowl, combine levain, water, maple syrup, and maple extract. Stir in whole wheat flour and bread flour with salt until a sticky dough forms. Rest for 30 minutes.

Perform stretch and folds every 30 minutes for 1.5 hours, wetting hands to prevent sticking. Incorporate chopped pecans in the second fold.

Cover the bowl and let the dough rise for 1.5 to 2 hours until visibly puffed.

Gently turn the dough onto a floured surface, pre-shape it into a tight ball, and let it rest for 30 minutes.

Shape the dough into a tighter round and place seam side up in a floured banneton. Cover for cold fermentation overnight.

Preheat oven to 500°F (260°C) with a Dutch oven inside. Transfer dough into the hot Dutch oven, cover, and bake for 25 minutes. Remove lid, reduce temperature to 400°F (200°C) for 20 minutes.

Transfer the bread to a wire rack to cool completely before slicing.