How to do simple processing of Gastrodia elata? Detailed method and steps

In the processing of Gastrodia elata, the residual stems must first be removed, taking care to keep the arrow buds, wash off the mud and sand, rub off the rhizomorphs and scales, wash clean with clear water, and then steam in a steamer. The heat must be strong and the steamer lid must be tight, so as to quickly kill the cells of the tuber, inhibit enzyme activity in the tuber, and prevent the leakage of sap. Steam large tubers for 30 minutes and small tubers for 15 minutes, until thoroughly cooked (no white core). If any are excessively swollen with gas, pierce them with a raw needle to release the gas, then place them on a heated kang or in a drying room, or sun-dry them. Generally, 4-5 kg of fresh Gastrodia elata is needed to process 1 kg of finished product.

1. When drying on a heated kang, the temperature must be strictly controlled. At the beginning, the fire must not be too fierce (coal or firewood is best as fuel), so that the kang temperature rises evenly and is kept at 50-60°C. After 2-3 hours, gradually raise the kang temperature to 70-80°C, so that the moisture inside the tubers evaporates rapidly. If the temperature is too high at the beginning, the outer layer of the tubers will form a hard shell due to rapid evaporation of moisture, and the outward escape of internal moisture will be blocked, making it difficult to dry them thoroughly for a long time. When the tubers are 70-80% dry, press them flat with a wooden board, but do not use too much force, to prevent sap loss and loss of medicinal efficacy, then continue drying on the kang. At this time, a temperature of 50-60°C is suitable, to prevent scorching and deterioration (scorched kang). When they are 80-90% dry, remove them from the kang for moisture return (sweating), that is, pile them in a low-temperature place, cover them tightly with a cotton quilt or double-layer gunny sacks, and let them sit for more than 10 hours, so that the moisture inside the tubers moves outward, then continue drying on the kang until completely dry, with the kang temperature at about 50°C.

2. Drying room drying: place the thoroughly steamed medicinal tubers flat in drying trays (be careful not to overlap them), close doors and windows tightly, control the temperature at 40-50°C at the beginning, gradually raise it to 70°C, and vent moisture at appropriate times according to changes in room temperature and humidity. When they are 70-80% dry, press them flat, stop venting moisture, and dry until completely dry.

(1) Processing method of Tongjiang County, Sichuan

Wash the commercial tubers clean with clear water, then rub off the scales with straw or rice husks. After washing, while still wet, put them into a smokeless closed drying kang, and dry with fast steam until the tubers become soft (thoroughly cooked) with no hard core. Then open the closed opening and continue drying with gentle steam (40-50°C). At the same time, while they are soft, pinch the tubers flat. If any are too large and swollen with gas, pierce them with a bamboo needle to release the gas. When they are dried until the tubers become hard, remove them from the kang for moisture return (sweating). After they become soft again, put them back on the kang and dry with gentle steam until hard and dry, so that they make a crisp sound when knocked against each other. Then take them out of the pit and pile them for about 1 week. If the tubers no longer become soft, it means they are thoroughly dry, and they can be boxed and stored.

(2) Processing method of Fubao, Lichuan, Hubei

First remove the residual stems of the commercial tubers, taking care to keep the arrow buds, wash off the mud and sand, scrape off the outer skin with a thin iron sheet (be careful not to damage the flesh), and immediately put them into clear water. After the water boils, add 100 g of white alum per 5 kg to the boiling water, with the amount of water just enough to cover the Gastrodia elata. While boiling, stir gently with a wooden pestle to heat them evenly, and boil until there is no core (test by piercing with a bamboo needle or holding them up to the light). When boiling the tubers, it is best to classify them as large, medium, and small and boil them separately. According to tests, large medicinal tubers need 15-20 minutes and small medicinal tubers need 7-9 minutes to be thoroughly boiled. Appropriate cooking degree can significantly increase the dry-to-fresh ratio of the finished medicinal tubers. If any expand too much during boiling, pierce them immediately with a bamboo needle, press them lightly flat, and remove the water vapor. The boiled medicinal tubers should be immediately taken out and put into clear water to cool, then taken out and dried by heat or sun. When they are 80-90% dry, fumigate once with sulfur balls (add sulfur balls to charcoal fire, that is, 70%-80% yellow mud and 30%-20% sulfur, add water and form into balls the size of duck eggs, and dry them), so that the medicinal material turns yellow-white in color and can also be protected from insect damage. Air-dry until completely dry, and it is then the finished product.

(3) Processing method of Yun County, Hubei

Put fine sand or red-hot fire ash from firewood and grass into a large wok, heat it over a fire, then add the Gastrodia elata and stir-fry. When the Gastrodia elata continuously makes a crackling sound, immediately take it out of the wok and put it into a basin of cold water. While hot, scrape off the coarse skin and scales with a bamboo knife. After washing, rinse briefly in alum water, then wash clean with clear water, and steam in a steamer for 30-40 minutes, until thoroughly cooked. Take out and sun-dry or dry on a heated kang until 60-70% dry, press flat with a wooden board (but do not use too much force, to prevent sap loss), and if there are bubbles, pierce them with a bamboo needle to release the gas, then dry over charcoal fire or in a sulfur-fumigation kang until completely dry.

(4) In the area of Hunjiang, Jilin Province, there is a method of boiling millet together with Gastrodia elata until the millet is cooked, then taking out the Gastrodia elata, rinsing off the foam on the tubers with clear water, and placing them on a heated kang to dry.