Bitterness

Tea itself naturally carries a bitter taste, but if a bitter and astringent flavor persists without dissipating quickly, the tea may not be of good quality. The main causes of excessive bitterness include tender young leaves, insufficient sun-drying, improper fermentation, or tea harvested during the summer season.

Green Flavor

The green flavor is a natural characteristic of plants. In tea, it primarily arises from insufficient sun-drying, improper fermentation, or inadequate fixation. Other contributing factors include:

1. Excessive nitrogen fertilizer during cultivation.

2. Improper sun-withering or stirring during processing.

3. Low room temperature or high humidity during indoor withering, hindering water evaporation.

4. Harvesting overly tender leaves or leaves with heavy dew, or improper stirring causing leaf damage and water retention.

Burnt Flavor

A burnt flavor in tea usually results from improper fixation or roasting. If the temperature is too high or the duration too long during fixation, the tea may develop a burnt taste. Similarly, excessive heat or insufficient stirring during roasting can also lead to this issue.

Stuffy Flavor

In oolong tea, a stuffy flavor can manifest in three ways: a yellowish-stuffy taste from piled-up leaves generating heat, a damp-stuffy taste from unspread wet leaves, or a reddish-stuffy taste from prolonged compression during rolling.

Moldy Taste

If tea is stored improperly or for too long, it may absorb moisture and develop mold, losing its original aroma.

Sour Taste

Partially fermented teas undergo a post-fermentation stage after fixation, rolling, and initial drying. If the leaves retain too much moisture during this stage, microbial activity can cause sourness. However, a naturally fruity sourness from the tea's freshness is not considered a flaw.