Combine water, yeast and sugar and let stand untiil yeast has dissolved and is foamy. Mix in flour and knead for 7-8 minutes. Let dough rise covered, in a greased bowl in a warm place, until double in bulk. Form into sticks or pretzels and place on greased cookie sheets. Apply a thin egg wash (1 egg yolk diluted with 1-2 tablespoon water or milk) Sprinkle with coarse salt. Allow pretzels to rise until almost double in bulk. Bake in preheated 250ºC oven for about 10 minutes. Cool and serve.