Sourdough Sandwich Bread - that's not sour

From; Easy Sourdough Sandwich Bread | The Clever Carrot 

Make one loaf.  

500 g (4 cups) all purpose flour
60 g (4 tbsp.) unsalted butter, softened, cut into cubes
2 tbsp. sugar 
1 tsp sea salt 
1/2 cup active sourdough starter
1 cup warm water - or some milk and some water to total 1 cup

Baking Schedule: this is an overnight dough which takes approximately 10-12 hrs to rise @ 68 F. Start the night before, in the evening, and plan to bake the following day. If it’s warmer than 68 F the dough will take less time to rise. Alternatively, start in the morning and bake in the afternoon or evening. 

In a stand mixer fitted with the paddle attachment, mix the flour, butter, sugar and salt. Mix on low speed until combined; the butter should look like crumbs.

Add the starter and warm water. Mix until the flour is fully absorbed (get in there with your hands to finish mixing). The dough will feel slightly sticky and elastic at this stage. Cover with plastic wrap or a damp towel and let rest for 30 minutes.

After the dough has rested, switch to the dough hook and run the machine on medium-low (#3 on a KitchenAid) for 6-8 minutes. The dough will feel soft and supple and not stick to your hands.

Cover the bowl with plastic wrap and let rise overnight at room temperature (68 F) until double in size, about 10-12 hrs. 

In the morning, coat a 9×5-inch pan with butter.

Remove the dough onto a lightly floured work surface. Gently flatten the surface to release any large air bubbles.

Roll the dough into a log tucking the ends underneath. Rest for 5-10 minutes. With floured hands, gently cup the dough and pull it toward you to tighten its shape. Using a bench knife, place the dough into the loaf pan seam side down.

Cover the dough with lightly oiled or buttered plastic wrap. Let rest at room temperature until it has risen to about 1-inch above the rim of the pan, about 1 1/2-2 hours depending on temperature and the amount of sourdough starter used. Check the height by looking at the domed centre portion of the dough.

Preheat your oven to 375 F. Note: For higher oven spring, preheat to 500 F instead. Reduce to 375 F once the dough goes into the oven and bake on the centre rack for about 45-50 minutes, or until golden brown.