For the pretzel sticks, dissolve the yeast in lukewarm water. Mix all dry ingredients well. Mix with the yeast water, the butter and the sourdough.
Knead for about 8 minutes to a smooth dough (rather by hand because it is a firmer dough). Cover and let rise for about 15 minutes. Divide dough into 9 equal sized pieces and grind (shape) into rounds.
Cover again and let rise for about 5 minutes. Roll out dough pieces into an oval shape about 10×15 cm and roll up with the flat of your hand. Place end down on a baking sheet and let rise, covered, for about 1/2 hour.
Preheat oven with an ovenproof container to 180 °C hot air. Coat well with baking soda (USE HAND SHOES ATTENTION!!) or dip in it.
Make several diagonal cuts with a knife and sprinkle with salt and caraway seeds. Pour plenty of water into the hot container – lye pastry needs a lot of steam when baking.
Bake Stangerl for about 15-20 minutes. Let cool on a kitchen rack.