In a small saucepan, heat milk until bubbles form on the surface. Remove from heat and add sugar, salt and butter. Cool to lukewarm. While milk mixture is cooling, dissolve yeast in warm water and let stand until frothy.
Combine cooled milk mixture with yeast and water in a large mixing bowl. Stir in 315g of the flour, then add the remaining flour, a little at a time, to make a moderately stiff dough.
Knead on a lightly floured surface for 8 to 10 minutes, or until smooth and elastic. Place the dough in a lightly oiled bowl and turn to coat the dough.
Cover the bowl with a clean damp cloth and leave to rise in a warm place until the dough has doubled in volume (about 1 1/4 hours).
Lightly grease two 23x12cm loaf tins.
Punch down the dough and turn it out onto a lightly floured surface. Shape into two balls, cover and let rest 10 minutes. Shape dough into two loaves and place in pans; let rise until doubled (about 1 hour).
Preheat oven to 200 degrees C.
Bake for 35 minutes or until the top is golden and the loaf sounds hollow when tapped on the bottom.