In mixing bowl, dissolve yeast in water. Add sugar, salt, and about half the flour. Beat thoroughly 2 minutes. Add egg. Gradually beat in shortening then flour until smooth. Cover with damp cloth; place in refrigerator. Punch down occasionally as dough rises in refrigerator. About 2 hours before baking, cut off amount needed & return remaining dough to refrigerator.
Shape into rolls & place on greased baking sheet. Cover. Let rise until light (1 1/2 to 2 hours). Heat oven to 400 (moderate hot). Bake 12 to 15 minutes. Makes 4 dozen medium rolls.