1. Cut potatoes into small pieces and place into blender or food processor.
2. Pulse until potatoes are chopped finely (like grated) but not smooth. You can add half of the milk while pulsing.
3. Transfer potatoes to a large mixing bowl and mix in the rest of the milk, salt and yeast mixture.
4. Gradually mix in the flour. You can use the dough hooks on the mixer if you wish.
5. Dough should be quite soft and sticky. Add more flour if necessary.
6. Place half of dough into each two greased loaf pans.
7. Place pans into a preheated 375deg F (190deg C) hot oven and bake for about one hour or until loaves are golden and sound hollow when tapped with knuckles.
8. Turn out of the pans and brush with soft butter. (crust will be very crispy) Cool and serve. Stays fresh for two or three days. Can be sliced and frozen too.
Note: A delicious version is to substitute 1 cup of the white flour with rye flour and add 1 tbsp caraway seeds. Proceed as usual. This creates a very fragrant light rye loaf.