Roll each portion of dough into a ball. Roll each ball into an evenly thick rope about 16 inches long. Line up 3 of the ropes, 1 inch apart, on a greased baking sheet. Starting in the middle, braid by bringing left rope underneath center rope; lay it down. Then, bring right rope under new center rope; lay it down. Repeat to end. Starting at the middle again, braid the other end by bringing outside ropes alternately over center rope. (Braid the ropes loosely, so the bread has room to expand.) Press rope ends together to seal. Repeat braiding with remaining three ropes for a second braid. Cover the braids and let rise until almost doubled (about 30 minutes).