The key point of making prunes is 1. First drying: the fresh vegetables are dried for about 2 days, so that the surface of the leaves is dried and shrunk (the shrinkage rate is about 75%-80%), and the stems are soft and constantly folded.

2. Finishing: Finishing the dried wild vegetables, removing the old rotten leaves, cutting the roots to see white, and then moving indoors.

3. Stacking fermentation: stacking below 50cm for 3-4 days in spring and below 100cm for 5-6 days in winter, and keeping the temperature in the pile at 30-40℃ until 70%-80% of the leaves turn from green to yellow.