Add 4 1/4 cups flour and salt to yeast mixture and stir to blend well (dough will be sticky). Knead dough on floured surface until smooth and elastic, adding more flour by tablespoonfuls if dough is sticky, about 10 minutes. Form dough into ball. Oil large bowl; add dough, turning to coat. Cover with plastic wrap and let rise in warm area until doubled, about 1 1/2 hours. Punch down dough; knead into ball and return to same bowl. Cover with plastic wrap and let rise in warm area until doubled, about 45 minutes or less