Arrow hemp and big white hemp can be processed into commercial hemp. Gastrodia elata should be processed with time. Gastrodia elata will become empty if it is stored for too long.

(1) classification

According to the size of gastrodia elata, it is divided into 3-4 grades. Generally, the fresh weight of Gastrodia elata is Grade I, Grade II, 45-85g and Grade III. Then the soil should be cleaned to avoid affecting the efficacy.

(2) steaming

Steam the cleaned fresh gastrodia elata for 15 ~ 20 minutes, and steam thoroughly, without seeing black hearts. You can also blanch in boiling water for 5 ~ 15 minutes. Then put it into a fumigation room and fumigate it with sulfur 10 ~ 12 hours. The smoked gastrodia elata is bright and white in color, good in quality, and can prevent moth and mildew.

(3) drying

Smoked gastrodia elata should be dried immediately. The temperature should be controlled at 50 ~ 60℃, and the initial temperature should not be too high to prevent the water in Gastrodia elata from evaporating too fast and the sugar core and epidermis in the middle from forming a hard shell; If the temperature is too low (40℃), drainage is needed to prevent mildew; Bake with slow fire until 70% to 80% dry, take it out and flatten it, then raise the temperature to about 70℃ and continue to dry completely. Check frequently when drying to prevent scorch deterioration or foaming.