Mix yeast,sugar,salt and water together. let stand until salt sugar and yeast are dissolved. Gradually add flour to liquid and mix thouroughly, until dough pulls form bowl sides. Turn ontofloured work surfaceand knead 5 minutes, Let dough rest while you grease bowl. Knead dough again 2-3 minutes, Place dough in bowl, turn once to grease top. Cover with damp towel and keep warm until doubled in bulk(1-2 hours) Punch down dough and knead briefly to get out any air pockets. Cut in half, shape into 2 Italian or french style loafs. Put on cookie sheet sprinkled with cornmeal. Rest 5 minutes. Lightly slash tops 3 times diagonally and brush with cold water. Place on rack in cold oven with roasting pan full of boiling water below.Bake 400 F for 30-45 minutes until crust is golden brown and sounds hollow to the touch,