In a large mixing bowl combine 2 1/2 cups of the flour and the yeast; set aside. In a medium saucepan, stir the milk, sugar, butter and salt until just warm (120-130 degrees) and butter almost melts. Add milk mixture to flour mixture. Beat with an electric mixer on low to medium speed for 3 minutes. Using a wooden spoon, beat in as much flour as you can.
Turn dough out onto a lightly-floured surface. Knead in enough of the remaining flour to make a stiff dough that is smooth and elastic (6-8 minutes total). Shape dough into ball. Place in a lightly greased bowl, turning once to grease the surface of the dough. Cover and let rise in a warm place until double in size (45-60 minutes)
Punch dough down. Turn dough out on a lightly-floured surface; divide in half. Cover, let rest 10 minutes. Meanwhile, lightly grease two 8x4x2-inch loaf pans.