In large bowl of mixer, mix 1 1/2 cups flour, the yeast, sugar and 1/2 tsp salt. With mixer at low, add 1 1/2 cups very warm water.Beat 3 minutes at medium. Gradually add the rest of the flour. Turn out onto floured board and knead 5 minutes.,Place in a greased bowl, turn greased side up. CVover, let rise 45 minutes to an hour. Punch down, turn out onto board. Roll pieces of dough out into pencil shapeds and knot, forming preztel shape. Cover, and let rise on floured obard for 30 minutes. Boil 1 quart water and the baking soda in a skillet. Put each preztel in the water and simmer 20 seconds. Place on well greased cookie sheet, salt and bake at 400 F for 15 minutes.