How are Gastrodia elata processed and graded?

From early November to early April of the following year, Gastrodia elata is in its dormant period. During this period, Gastrodia elata can all be processed into finished medicinal material for sale. Generally, harvesting, planting and processing are done simultaneously, so that harvesting and planting are closely linked. The harvest period is divided into two seasons, winter and spring. The winter harvest is before the ground freezes, and the spring harvest is after the thaw and before sprouting (mid-April). To process the harvested Gastrodia elata, the following steps must be carried out:

Grading: Jianma (arrow-shaped Gastrodia) varies in size. Grade 1 Gastrodia elata should be above 150 g; Grade 2 Gastrodia elata 70 g to 150 g; Grade 3 Gastrodia elata below 70 g; Grade 4 Gastrodia elata is damaged or insect-bored.

Rinsing: Wash the graded Gastrodia elata clean in water, then immediately peel and steam or boil, which is called Xuetianma (snow Gastrodia) or Mingtianma (bright Gastrodia). If the skin is kept, it can be steamed or boiled directly after washing. Note that Gastrodia elata should not be soaked in water for a long time, otherwise the processed product will turn dark.

Steaming or boiling: After the Gastrodia elata is put into the steamer or boiled in water, note the following: A. Do not steam or boil too long. The boiling time for Grade 1 should be 10 minutes to 14 minutes, Grade 2 7 minutes to 10 minutes, and Grade 3 5 minutes to 8 minutes. B. Check the steaming or boiling condition at any time.

The center of the Gastrodia elata has an opaque white core, which should account for 1/5 of the diameter of the Gastrodia elata. In this way the drying ratio is high. Otherwise, if steamed or boiled too long, the drying ratio is low. C. For boiling in water, 20 g of alum can be added per 10 kg of Gastrodia elata. The processed Gastrodia elata is semi-transparent and of high quality.

Sulfur fumigation: The purpose of fumigating the steamed or boiled Gastrodia elata with sulfur is to make its appearance attractive, its color white and transparent, its quality good, and to prevent insect damage. Place the Gastrodia elata taken out of the pot on a bamboo curtain on the bed, cover tightly with plastic sheeting, light sulfur underneath the bed, fumigate for 5 hours to 6 hours, then put it on a heated kang to dry.

Drying in a heated kang or sun-drying: If the quantity of Gastrodia elata is large, it is best to build a huilong kang, place a bamboo curtain on it, and put the Gastrodia elata on the bamboo curtain. At the beginning, the temperature should be kept at 55°C to 65°C. After 30 hours, the temperature can reach 80°C, and must not exceed 85°C. Generally, 60 hours is enough for it to be completely dry. Alternatively, at 55°C to 65°C for 48 hours, it can be taken out of the kang and piled up, covered with sacks or similar to sweat for 8 hours, then pressed flat with a wooden board for shaping, and then put back on the kang to continue drying. The purpose of shaping is to make it look good without wrinkles.

Storage: Store the processed Gastrodia elata in plastic bags; as long as it does not get damp, it generally will not become moldy. During the hottest summer days it can be sun-dried. During storage, some Sichuan pepper wrapped in newspaper can be placed in the bag to prevent insect damage.

Grades: Grade 1 dried product is yellow-white, solid and semi-transparent, with no hollow center, no scorched or insect-bored parts, and no more than 26 pieces per kilogram.

Grade 2 dried product has a yellow-white surface, is solid and not easy to break, semi-transparent, with no hollow center, no insect damage, and no mold, and more than 26 pieces per kilogram.

Grade 3 dried product: the surface is yellow-white or brown, semi-transparent, with no mold and no insect damage, flattened, shrunken and curved, and no more than 90 pieces per kilogram.