Combine the milk, about 5 cups of the flour, the sugar, yeast, and salt in a mixing bowl. Mix on low speed to make a cohesive dough. Add enough of the remaining flour as needed to form a soft but workable dough. Using the dough hook, knead for about 3 minutes on medium-low speed to develop the dough., Once the dough is smooth and elastic, add the butter and continue kneading on medium-low speed until the butter is completely incorporated and the dough is smooth, shiny, and elastic., Allow the dough to rise in a covered bowl until it's doubled in bulk, about 90 minutes., Turn the dough out onto a lightly floured surface, and divide it in half. Working with one half at a time, divide each piece of dough into eight equal pieces. Round all of the pieces into smooth balls., Lightly grease two 8 1/2" x 4 1/2" loaf pans., Place half of the dough balls into each of the pans, lining them up side by side in two lengthwise rows of four (see photo above)., Cover the pans, and let the loaves rise until they're puffy and have a soft, marshmallow-like texture, about 90 minutes to 2 hours., Towards the end of the rising time, preheat the oven to 375°F., Uncover the loaves, and bake them for 28 to 32 minutes, until their crust is golden brown and they sound hollow when tipped out of the pan and tapped on the bottom., Remove the loaves from the oven, and turn them out of the pans onto a rack to cool. Store completely cooled bread, well wrapped in plastic, at room temperature for several days. Freeze for longer storage.