In a large saucepan, bring the milk just to a boil. Turn off the heat and add the butter, mashed potatoes, and the 1/3 to 1/2 cup honey; stirring vigorously with a wire whisk to blend. Let sit until it has cooled to lukewarm.
In a large mixing bowl, dissolve the yeast in the warm water with the 1/2 teaspoon honey or sugar. Let it sit until frothing. Add the lukewarm potato mixture to the yeast, along with the ginger, eggs, and salt; beat well.
Add 2 1/2 cups flour and beat 2 minutes with an electric mixer or at least 200 strokes by hand. Stir in the wheat germ, if using. Gradually add more flour, as much as it take to make dough that leaves the sides of the bowl. Turn the dough out onto a lightly floured board and knead until smooth and elastic. Sprinkle on a little more flour if it remains insistently sticky, but expect some stickiness because of the potatoes. When it has become elastic, especially if blisters appear on the surface, you can stop kneading.
Put the dough in a buttered bowl, turn it over or brush the top with melted butter, cover with a kitchen towel and let rise until it has doubled in size.
Punch the dough down, turn it out onto the board, knead a few times to press out air bubbles, and cut in half. Cover with the towel and let rest about 10 minutes.
Grease two medium to large loaf pans. Shape the dough into loaves, put in pans, and brush the tops with melted butter. Cover and let rise again until about doubled in size.
Preheat oven to 375 degrees F.
Bake for 35 minutes. About 5 minutes before you expect bread to be done, take the loaves out of the oven and brush with a egg beaten with 2 tablespoons milk or cream; return to the oven. They are done when the bottoms sound hollow when tapped. A good check is to use an instant digital thermometer to test your bread. The internal temperature should be between 200 and 210 degrees F.
Remove from pans to cool on a wire rack.
Makes 2 loaves.
* Wheat Germ: The embryo of the wheat kernel, which is flattened into a yellowish, oily flake. Because it's high in oil, it is usually toasted to extend its shelf life. It has a nutty flavor and can be sprinkled over cereal or used in baked goods.
Farmhouse Potato Bread Recipe: https://whatscookingamerica.net/bread/farmhousepotbrd.htm