When drinking Chenpi (dried tangerine peel) water, some users may find the tea soup has a sour taste. Since Chenpi is made from citrus peels, it contains natural organic acids, and a moderate sourness is normal. However, the quality and flavor of Chenpi are influenced by many factors; some are sweet with a lingering aftertaste, while others are noticeably sour. Below are several primary reasons why Chenpi tea might taste sour.
1. Natural Organic Acid Components
All Chenpi made from citrus peels contains Vitamin C and fruit acids. In the natural flavor profile of Chenpi, "limonoid-like" substances represented by limonin and bitter principles, as well as citric acid, create its "sweet and bitter" characteristics. These substances are easily soluble in water and aid in food digestion. As the aging years increase, these limonoid-like substances gradually decrease, which is why Chenpi has the characteristic of "the older, the better."
2. Variety Differences: Grafted vs. Original Stocks
- Grafted Chenpi (Bo-zhi): Because it uses lemon grafting technology, its aroma is slightly thinner than that of the original stock (Quan-zhi), and some peels may have a slight sour undertone.
- Original Stock Chenpi (Quan-zhi): It has a higher aroma and a sweeter taste without harshness. Due to the scarcity and low disease resistance of original stock citrus trees, the yield is lower, and the price is relatively higher.
3. Anaerobic Fermentation in Sealed Environments
If Chenpi is stored in a completely sealed, relatively oxygen-deficient environment for a long time, anaerobic fermentation reactions (such as lactic acid bacteria action) may occur. The sugars in Chenpi can produce lactic acid under anaerobic conditions due to the influence of lactic acid bacteria, resulting in a sour taste.
4. Insufficient Maturity of Citrus Peels
Sourness is closely related to the maturity at the time of harvest. "Qing-pi" (green peel, harvested when immature) has a higher citric acid content and tastes more bitter and sour. In contrast, "Er-hong" and "Da-hong" (ripe red) peels have higher sugar content as the fruit matures, leading to a more "sweet and fragrant" profile. This is why Da-hong peels are generally more popular than Qing-pi in Pubei Chenpi.
5. Processed Peels and Insufficient Aging
Not all Pubei Chenpi has a pronounced sour taste. Most peels with significant sourness are usually insufficiently aged (e.g., less than 3 years of aging), and the citric acid in the peel has not been fully transformed through natural aging and sun-drying. Furthermore, some "fake aged peels" on the market produced through artificial aging processes often retain untransformed organic acids, resulting in an unnatural sour taste when brewed.