STIR yeast into potato water in a large mixing bowl. Let stand 10 minutes to dissolve.
MIX in 3 cups flour, stirring well with a wooden spoon. (Or mix with paddle attachment of an electric mixer). Cover and let stand at room temperature overnight, or until risen.
HEAT milk in a saucepan or microwave-able container, just until little bubbles break the surface; add sugar, lard or butter and salt. Cool to lukewarm.
MIX milk with the yeast mixture. Gradually stir or beat in 6 cups flour to make a stiff dough, about 10 minutes.
ADD raisins; knead on a lightly floured surface until dough is smooth and elastic. Place in a large, lightly oiled bowl. Cover and let rise at room temperature until doubled, about 1-1/2 hours.
PREHEAT oven to 350°F.
SHAPE into 2 loaves. Place in greased 9x5-inch loaf pans.
BAKE 1 hour or until golden brown and bread sounds hollow when tapped. Cool in pans 15 minutes; remove to a wire rack to cool completely. For a softer crust, brush tops with water and sprinkle lightly with granulated sugar.