Add the warm water and active bubbly starter to a large mixing bowl. Whisk well, then add in the warm milk, sugar, bread flour, salt, and all purpose flour. Mix until well combined and all flour is moist.
100 grams active sourdough starter, 235 grams warm water, 75 grams warm milk, 12 grams sugar, 360 grams bread flour, 140 grams all purpose flour, 6 grams salt
Cover with plastic wrap or a damp tea towel and let the dough sit for 40-60 minutes.
Work the dough into a ball by doing a few stretch and folds or simply rolling the dough into a ball. Cover.
Let the dough bulk rise for 8-10 hours or until doubled in size.
Set the dough on a lightly floured work surface. Gently press the dough to release air bubbles. Divide the dough into 12 pieces, weighing about 70-75 grams each. Line a baking sheet with parchment paper.
Roll each dough portion into a ball by tucking the four corners of the dough in, then rolling into a ball.
Set each dough ball onto a baking sheet lined with parchment paper. Cover with plastic wrap and let rise until the dough is noticeably larger and puffy, about 45-60 minutes.
Preheat the oven to 400 degrees and set the baking rack to the center.
Bake for 25-30 minutes or until the rolls are lightly golden brown. Cool on the pan.
Enjoy!