Mix starter, honey, butter, milk, and water in a large mixing bowl. Add in flours and salt.
Mix well and knead until fully combined, 5-10 minutes
Take the dough’s temperature to gauge how long the dough is going to bulk ferment. 70 degree dough will need 10-12 hours, 75 degree dough will need 5-7 hours, 80 degree dough will need 3-5 hours.
Allow to rest 30-60 minutes after fully combining, then stretch and fold the dough (Think of this as folding an envelope, you bring up one quarter of the dough and fold it over the whole ball. Then turn, and repeat 3 more times until four sides are pulled up and folded over).
Repeat the stretching and folding 3 more times, about every 30 minutes.
Allow the dough to rest until it is finished fermenting (from the total time you determined by temp), it shouldn’t be too sticky to the touch.
Dump the dough on your counter and split into two equal balls. Shape and place in loaf pans.
Cover and let rise until doubled.
Before baking, preheat the oven to 450°F.
Score the bread as desired. Bake for 40 minutes or until 200°F internal temperature is reached.