1. First, prepare a large container, add a proper amount of salt, but don't put too much salt, because it will be too salty to soak the vermicelli after adding too much salt, and then add white vinegar to the salt.

2. Then slowly pour warm water into a clean bowl. At this time, add the water in the basin, it must be warm water. Never use hot water, preferably between 40 and 50 degrees, that is, warm water with just the right taste. Otherwise, soaking the vermicelli in boiling water will easily cause the vermicelli to be cooked outside and taste particularly soft and rotten, but the core inside is still raw. After adding warm water, stir with chopsticks.

3. Soak the prepared sweet potato vermicelli in this warm water for 5 minutes. After 5 minutes, you can take out the fans. You can see that the original dry powder strips have been soaked very soft, not rotten. It is tough when pulled by hand and chewy when eaten.