When fresh ginger is sun-dried or dried at low temperatures, it becomes gan jiang (dried ginger). However, due to the varying content of active ingredients in different varieties and regions, the primary medicinal production area for gan jiang is currently Qianwei County in Leshan, Sichuan.
Fresh ginger can be used directly or dried; when fresh ginger is sun-dried or dried at low temperatures, it transforms into gan jiang.
The active component of ginger is primarily gingerol. Although all types of ginger contain gingerol and have certain medicinal values, the content of gingerol varies significantly among different varieties and regions.
Therefore, not all ginger can be used as a medicinal material, and not all dried ginger can be used as gan jiang. The content of gingerol must meet the standards set by the Chinese Pharmacopoeia to be used medicinally.
1. Sources of Medicinal Dried Ginger
There are mainly two sources of medicinal dried ginger:
1. From Mother Ginger
After the ginger harvest each year, farmers will keep the complete and plump ginger rhizomes as seed ginger. In the following spring, after warming and sprouting, when the seed ginger is covered with ginger sprouts, it is cut into small pieces and planted in the ground. The sprouted small ginger pieces are referred to as mother ginger.
As the ginger seedlings grow, many new zi jiang (young ginger) will sprout around the mother ginger, which will also continue to grow.
Before the frost in autumn of the following year, both the mother ginger and fully matured young ginger are harvested again. The young ginger can be used for cooking various dishes, while the mother ginger, being older and more pungent, is more suitable for making medicinal dried ginger.
However, due to the low yield of mother ginger, it is actually difficult to become the main source of medicinal dried ginger. Most of the medicinal dried ginger used clinically actually comes from medicinal ginger.
2. From Medicinal Ginger
There are many varieties of ginger, which can be divided into culinary ginger and medicinal ginger based on their uses, and their cultivation methods differ.
The ginger we commonly use for cooking is primarily culinary ginger, also known as cooking ginger, characterized by its low gingerol content and milder spiciness. Due to its high moisture content, it is prone to spoilage and is not suitable for medicinal use or for processing into gan jiang, mainly used for cooking various dishes.
Medicinal ginger, also known as medicinal ginger, is a classification of ginger that can be used for both food and medicine. It is characterized by a higher content of gingerol and stronger spiciness, and due to its lower moisture content, it is more solid and less prone to spoilage, making it more suitable for medicinal use or for processing into gan jiang.
This type of dried ginger is of good quality, high yield, and abundant supply, making it the most commonly used dried ginger in clinical practice.
3. From Inferior Ginger
Some unscrupulous individuals may collect inferior ginger that is difficult to sell and process it into dried ginger for sale. This type of dried ginger is considered counterfeit and inferior products and should not be used as medicinal materials.
2. Medicinal Production Area of Dried Ginger
Qianwei County in Leshan, Sichuan Province has been a traditional production area for medicinal ginger in China for over 1,700 years. The white ginger produced here is classified as both food and medicine.
The white ginger from Qianwei is large, plump, rich in starch, low in fiber, and has a strong spicy flavor, with gingerol content exceeding the standards set by the Chinese Pharmacopoeia. The quality of the dried ginger produced is excellent and its medicinal properties are stable. It was approved as a “National Geographical Indication Product” in 2018, also known as bai gan jiang (white dried ginger).
Postscript:
When selecting medicinal dried ginger, it is best to choose those with a white cross-section, sufficient powdery texture, and strong spicy flavor.
Author: Zhang Changhai (Owner of Menglaoer Dried Goods Taobao Store, National Public Nutritionist, specializing in dietary health and chronic disease management, wx120355029)