Why should alum be added to handmade sweet potato vermicelli?

Alum will be added to sweet potato vermicelli during processing to make it chewy and not easy to break after cooking.

Judging whether vermicelli is pure sweet potato powder can be judged from the following points:

1. Q: The cost of sweet potato powder is relatively high. Generally, vermicelli with a particularly low price on the market is unlikely to be made of pure sweet potato powder;

2. Observation: Pure sweet potato vermicelli is transparent and shiny in color, while fake sweet potato vermicelli is dark in color;

3. Taste: When eating pure sweet potato vermicelli, there will be a faint sweet potato fragrance. When cooking, it will give off the unique fragrance of sweet potato and taste very smooth;

4. Burning: Burn a section of pure sweet potato vermicelli with a lighter. It will become fine powder after burning and can be blown away by blowing. The fake sweet potato vermicelli will become filaments after being burned.