It is widely known that the longer Pu’er tea is stored, the higher its drinking value and the more pronounced its health benefits. However, if improper storage damages the tea and allows harmful bacteria to grow, the tea should no longer be consumed.
Judging whether Pu’er tea has spoiled cannot be done by visual inspection alone; it requires professionals to assess it through tasting and texture evaluation. Nevertheless, you can make a preliminary judgment based on the following points!
Note: It is essential to distinguish “spoilage” from the normal, pleasant aromas of well-aged Pu’er tea, such as aged fragrance or medicinal fragrance.
1. Observe the Appearance
A well-aged, healthy Pu’er tea cake should be dry, glossy, and even lustrous. Its color will gradually and uniformly change from dark green to dark brown and chestnut red over time.
Spoiled tea will show obvious visual warning signs:
- White, green, or yellow fuzzy or flaky mold spots may appear on the cake surface.
- The entire cake may look gray, black, dull, and lifeless.
- If the tea feels soft and mushy, and crumbles into powder when touched (instead of retaining some flexibility), it is most likely damp and spoiled.
2. Smell the Aroma
This is the most critical and accurate step in all judgment processes. A normal Pu’er tea—whether dry or brewed—should emit a pure, pleasant aroma, such as aged fragrance, honey fragrance, medicinal fragrance, or sweet fragrance.
Spoiled tea will give off warning odors:
- The most typical is a pungent musty smell, similar to that of a poorly ventilated basement or damp old clothes.
- Other unpleasant odors include a sour smell like spoiled leftover rice, or a strange smell of rotten wood or chemicals.
It is important to distinguish between a mild “storage odor” (which fades with ventilation) and a persistent “musty smell” (which is hard to remove). The latter is definitive proof of spoilage.
3. Taste the Tea Infusion
If no serious issues are found in the first two steps, you can conduct a final check by tasting a small amount of the brewed tea.
A well-aged Pu’er tea will have a clear, bright, and even glossy infusion. When tasted, it should feel mellow, smooth, and sweet. Even if there is a slight acidity, it will quickly stimulate salivation, leaving a comfortable feeling in the body after drinking.
A spoiled tea infusion tends to be turbid and dull. When tasted, you may experience:
- An unpleasant sharp sourness or a numbing sensation on the tongue.
- A “throat-tightening” feeling—dryness and tightness in the throat.
- A bland taste with a “watery” quality, where the tea flavor and water feel separated rather than integrated.
4. Examine the Wet Tea Leaves (Leaf Bed)
Pour the brewed tea leaves (leaf bed) onto a plate and observe them carefully.
Healthy tea leaves will have an even color, mostly reddish-brown or liver-colored. They feel soft and elastic (like moist leather) and are not easily torn when pulled.
Spoiled tea leaves will be black or unevenly colored. When touched, they are either mushy and crumble when squeezed, or dry and hard with no vitality.
If your Pu’er tea shows one or more of the above signs—such as mold spots, a pungent musty smell, a strong sour odor, or a throat-tightening sensation—it is safest to discard it immediately for your health. Toxins produced by mold (such as aflatoxin) are heat-resistant and cannot be removed by ordinary brewing, posing health risks.
For tea with only a mild storage odor (no mold), you can try “awakening” it in a dry, well-ventilated, and clean environment to see if it can regain its vitality.