***This makes 4 loaves of bread
Scald the milk. Add the butter, sugar, molasses and salt. Let it cool for about 10 minutes and add the sour cream, beating with a wire whisk to mix it all thoroughly. Pour it into a large bowl.
When the liquid is cool enough so that a drop on the inside of your wrist is not hot enough to hurt, add the yeast. (if you add yeast to the hot mixture, you will kill the yeast and the bread will not rise.) Add about 5 cups of flour, 1 cup at a time, and mix it well with the liquid, breaking up lumps as you mix. Add raisins and walnuts.
Add flour, 1 cup at a time, until the dough is no longer very sticky; it should be right when you have added about 12 cups. Sprinkle out about 1/4 to 1/2 cup flour onto a clean board or countertop. Dump the dough onto the floury place and scrape out the bowl onto the dough. Wash, dry and grease the bowl.
Now, knead the dough for about 15 to 20 minutes using up the last of the flour. It should feel stretchy and elastic. Put the dough into the greased bowl and grease the top. Cover it will a damp cloth and set it in a warm place to rise. It may take as much as 2 hours until it is double in bulk. When it has doubled in bulk, flour a place on the counter, dump it out and knead it again for about 5 minutes.
Divide the dough into 4 equal parts and grease 4 bread pans. Shape the dough into loaves and put 1 in each pan. Cover the pans with a damp cloth and let the dough rise until about double in bulk, about 1 hour. Preheat the oven to 325 degrees, brush the tops of the loaves with beaten egg, and put them in the oven. Bake at 325 for 30 minutes and then at 300 degrees for another 30 minutes. The loaves will sound "hollow" when tapped when they are done. Take them out of the oven as soon as they are done. Turn them out of the pan onto cake racks.
The bread is best served warm, but it may be cooled and then frozen to save.