Potato Bread
["1 cake packaged yeast", "1/2 c. warm water", "1 medium sized potato, boiled and mashed", "1 c. potato water", "1 1/2 c. plain flour", "4 Tbsp. sugar", "4 Tbsp. salt", "4 Tbsp. shortening", "about 1 1/2 qt. flour"]
["At night, make a sponge of the first 5 ingredients.", "Cover and let stand overnight in warm place.", "In the morning, add to the sponge the remaining ingredients.", "Mix and knead to medium stiff dough.", "Let rise until doubled.", "Shape in loaves or rolls.", "Let rise until doubled again.", "Bake from 40 to 60 minutes in moderate oven at about 400\u00b0.", "Cool on rack."]
["cake", "warm water", "potato", "water", "flour", "sugar", "salt", "shortening", "flour"]