In the bowl of a stand mixer, combine all pre-fermented dough ingredients. Place in a warm place for 1 hour.

When it has doubled in volume, is bubbly, and has an acidic smell, add the bread flour, milk, salt, and sugar and place it in a stand mixer fitted with a hook attachment. Knead on medium for 3 minutes or until the dough looks more homogenous and pulls easily from the sides of the bowl, but still sticks to your hands.

Then add half of the butter and knead until it’s completely incorporated (the dough can look like it’s disintegrating but will come back together eventually). Then, add the rest of the butter and knead the dough for 10-12 minutes on medium until it pulls away from the sides of the bowl and you can stretch a small piece of it into a square, creating a film thin enough for light to pass through (windowpane test). The dough won’t stick to your hands anymore and it will look hydrated, silky, and smooth.

Place the dough into a large bowl lightly greased with olive oil. Cover with plastic wrap and leave at room temperature to proof for 1.5 to 2 hours, depending on how warm it is in your kitchen, until it doubles in volume.

Grease an 8" by 5" (20cm by 13cm) loaf pan with butter.

Remove the dough onto a lightly oiled working surface and deflate it. Roll it into an 8" by 15" rectangle. Then, roll the dough tightly into an 8" log and place it into the prepared pan. Cover it with plastic wrap and leave at room temperature to proof for 1 hour or until domed about 1" above the top of the pan.

Meanwhile, preheat the oven to 350F (175C).

Remove from the oven and let the bread rest in the pan for 3 minutes. Then, remove onto a cooling rack to cool down completely.