Sweet potato vermicelli noodles and noodles with alum re-powdered not sticky

Sweet potato flour noodles and noodles with alum re-powdered not sticky. Due to the production of sweet potato vermicelli, sweet potato flour itself mixed with water can only be a paste can not be shaped, and alum and water reaction has increased the effect of sweet potato flour gluten, can help the vermicelli shaped into a strip, so the folk handmade vermicelli will add alum.