In a large bowl thoroughly mix 1 1/2 cups flour, sugar, salt and undissolved yeast. Combine potato water and margarine in saucepan. Heat over low heat until liquid is warm - the margarine does not need to melt. Gradually add to dry ingredients and beat for 2 minutes at medium speed with electric mixer, scraping bowl occasionally. Add eggs, potatoes and 1/2 cup flour, or enough flour to make a thick batter. Stir in raisins and enough additional flour to make a soft dough. Turn out onto floured board. Knead until smooth and elastic, about 10 minutes. Place in greased bowl, turning dough to grease. Cover and let rise until doubled in bulk. Punch dough down. Turn out onto lightly floured board. Divide dough into 4 equal pieces. Shape each piece into a slender loaf, about 8 1/2 inches long. Put 2 loaves, side by side, in each of 2 greased 8 1/2 x 4 1/2 x 2 1/2 inch loaf pans. Cover. Let rise in warm place, free from draft until doubled in bulk. Bake in preheated 375 F oven for 35 minutes, or until done. Remove from pans and cool on wire racks.
Colorado Cache Cookbook (1978) From the collection of Jim Vorheis