1. Fresh leaf moisture. With the continuous loss of fresh leaf water, a large amount of its contents will be decomposed, oxidized and lost, which will affect the quality of tea at a slight degree, and will lead to deterioration of fresh leaves and lose economic value in severe cases. Therefore, in order to keep the tea fresh, the spray method is usually adopted to keep the fresh leaf storage place at a higher humidity.

2. Temperature. The external temperature mainly affects the respiration of fresh leaves. The higher the temperature, the stronger the respiration of fresh leaves, and the higher the leaf temperature, the stronger the enzyme activity, which is not conducive to the quality of tea. Therefore, the appropriate low temperature is conducive to maintaining the freshness of tea leaves.

3. Oxygen. If ventilation is poor during storage, the anaerobic respiration of tea will increase enzyme activity, accelerate the decomposition of organic matter, and increase the oxidation of polyphenols. In the process of hypoxia, fresh leaves will gradually produce foul smell or rancid sour taste, which will adversely affect the aroma of the finished tea. Therefore, in the fresh leaf picking, transportation, and storage of traditional Chinese medicine, maintain air circulation to prevent anaerobic respiration of fresh leaves and affect the quality of tea.

4. Mechanical damage. After the fresh leaves suffer mechanical damage, on the one hand, the respiration of the fresh leaves becomes stronger and the leaf temperature rises rapidly; on the other hand, it causes the enzymatic oxidation of polyphenols, which is prone to leaf red change.