The scent is the most immediate aspect to greet you before drinking Tea. A pleasant aroma refreshes the mind, while an off-odor is displeasing and makes the tea uncomfortable to drink. If you detect any of these unpleasant odors, be cautious.
Charred Odor in Tea
The charred odor is produced when leaves are carbonized during tea processing.
A charred odor in tea typically occurs in two situations: First, if some old leaves are mixed in during stir-frying, or if the leaves aren't stirred evenly, or if there's too much Leaf debris, they can easily become charred. Another common situation is with Wuyi Rock Tea where, if the roasting isn't properly controlled, or if the roasting is intentionally overdone to mask some defects in the leaves, it can lead to carbonization. The result is a charred odor and a bitter taste.
In daily life, many people don't pay much attention to the charred odor in their tea. However, charred tea should not be consumed. Most of the nutrients in charred tea have been lost, so from both a nutritional and food hygiene perspective, charred tea leaves should not be drunk.
Water-Stagnation Odor in Tea
The water-stagnation odor refers to a dull and unpleasant smell. When we talk about tea, we use terms like “fresh and brisk” or “sweet and brisk.” “Stagnant” is the opposite feeling – a very uncomfortable mouthfeel.
The water-stagnation odor can occur for three main reasons: First, if rain-soaked leaves are not promptly processed to remove surface moisture; second, if the leaves are left to pile up before being killed to increase temperature and promote fermentation, or if the initial processing doesn't allow enough drainage; third, if the drying temperature is too low, preventing the complete evaporation of moisture. If proper techniques such as “more tossing and less piling” and “tossing and piling combined” are not used during the killing process, the tea can become spoiled.
Teas with this odor lack freshness, have a murky appearance, and a stagnant taste. After smelling them, one might feel a stuffy sensation in the nose and chest, unlike the sweet and brisk experience of good tea.
Grassy Odor
The grassy odor is similar to the smell of freshly cut grass.
The grassy odor in Green Tea may come from inadequate pre-processing or incomplete killing, or some manufacturers might deliberately reduce the degree of killing to maintain a fresh green color. Be cautious of particularly bright green teas, as they often have a high likelihood of having a grassy odor. In black tea, the grassy odor might be due to insufficient rolling or incomplete fermentation. In oolong tea, the grassy odor could be caused by incomplete processing or rehumidification after roasting.
Tea with a grassy odor affects its freshness and briskness. The leaves tend to be dark green, lacking aroma and flavor, with a prominent grassy taste.
Sour Odor in Tea
The sour odor is a severe defect indicating spoilage. Teas with a sour odor smell sour and stale, producing an unpleasant and dull scent.
This odor is commonly found in low-quality black tea. If the withering, rolling, and fermentation processes are not well-controlled, the tea will give off an “over-fermented” odor. It could also be caused by the accumulation and overheating of fresh leaves, leading to partial spoilage, or by damp storage conditions that introduce a sour smell.
Teas with a sour odor emit a sour smell when hot and cold, and the taste is also sour. The dry tea, liquor, and infused leaves appear murky and rotten. Such severely spoiled tea should not be consumed.
Moldy Odor in Tea
The moldy odor is an off-odor produced when tea becomes moldy due to dampness, which is relatively easy to identify.
When storing tea, it is crucial to keep it dry. Once tea becomes damp, reaching a certain level of moisture content, it is highly susceptible to mold growth, producing a moldy odor. Another situation is when Compressed tea hasn't been thoroughly dried; it may look dry on the surface but is wet inside, making it prone to mold quickly.
Moldy tea should not be consumed. In cases of slight mold, the moldy odor may not be apparent in the dry leaves, but once brewed, the tea's natural aroma is low and stagnant, with a moldy odor. Severely moldy tea has a noticeable moldy odor when dry, and when brewed, it can cause discomfort and nausea. Mold flowers and fungal threads may appear on the tea, indicating bacterial contamination. Drinking moldy and spoiled tea can lead to mild symptoms such as dizziness, blurred vision, abdominal pain, and diarrhea, or more severe issues like liver, kidney, and brain damage. It is advisable to avoid drinking such tea.
The aroma is a direct reflection of a tea's quality. A fragrant scent invigorates the spirit, while an off-odor causes discomfort. Tea enthusiasts can match the actual condition of the tea to the descriptions provided. Only by choosing well-made and properly stored teas can one ensure Health benefits.