During the storage process, if the storage conditions are not good, the quality of Tea can deteriorate quickly. Deteriorated tea will undergo significant changes in its color, aroma, and flavor—it loses its luster, the fresh tea fragrance disappears and the aroma becomes dull, the infusion turns darker, the taste is no longer fresh and pleasant, and there may even be a musty, stale Odor.

The essence of tea quality deterioration is due to changes in the chemical components that affect tea quality. For example, chlorophyll in Green Tea is a substance that is greatly influenced by heat and light; high temperatures and strong light exposure can cause chlorophyll to degrade and break down.

Ascorbic acid (Vitamin C) in tea, like polyphenols, will oxidize during storage. The oxidized form of ascorbic acid has a yellowish-brown color. Lipid substances in tea will automatically oxidize during storage, producing some stale and off-flavors, and sunlight exposure can also result in a sunned off-flavor.

In summary, many components in tea undergo a series of changes during storage, and the extent of these changes is closely related to the storage conditions. It has been determined that the main factors contributing to tea deterioration are temperature, humidity, oxygen, light, and odors.