01 -
Combine 1/2 cup sourdough starter with 2 cups flour and 1 1/3 cups warm water. Let sit at room temperature for 4–6 hours until bubbly and active.
02 -
In a large bowl, combine 2 cups milk or buttermilk, 2 cups active sourdough starter, and 3 cups flour. Mix briefly on low speed until just combined. Cover and ferment overnight at room temperature.
03 -
The next morning, add 1/4 cup fat, 1/2 cup sweetener, 4 teaspoons salt, and 3 cups milk or buttermilk to the pre-ferment. Mix on low speed to incorporate. Add 5 cups flour and mix on medium speed for 5–10 minutes. Gradually add 4 to 6 more cups flour until dough pulls away but remains slightly sticky. Mix 2–3 minutes more.
04 -
Transfer dough to a large greased bowl. Cover and let rise in a warm spot for 2–3 hours until doubled in size.
05 -
Punch down dough and place on lightly floured surface. Divide into 4 equal portions. Flatten each into a rectangle, fold in corners, and roll into loaf shape. Place into greased loaf pans.
06 -
Cover loaves and let rise for 2–3 hours until dough rises just above pan edges. Avoid over-proofing to prevent collapse during baking.
07 -
Preheat oven to 375°F (190°C). Slash loaf tops with a sharp blade. Bake for 30 minutes or until internal temperature reaches 190°F (88°C).
08 -
Remove baked loaves from pans and transfer to cooling rack. Brush tops with butter for a softer crust. Cool completely before slicing.