Lightly oil a large bowl; set aside. In a large bowl, dissolve the yeast in the water. Add 5 cups flour, and stir to combine. Stir in the sugar and salt. Add remaining flour, 1 cup at a time, stirring until a sticky dough forms. When the dough becomes too stiff to stir, turn it out onto a well-floured work surface. Knead, incorporating only as much flour as needed to make a smooth and elastic dough, 8 to 10 minutes. Transfer to prepared bowl, cover with plastic wrap, and let rise until doubled in bulk, 1 1/2 to 2 hours.