Why do some Pu er teas have an expiration date?

I also feel very strange when I see your question, I know very little, please forgive me if I am wrong!

There are only two kinds of Pu'er that I know (Shengpu, Ripe Pu), and they are all large-leaf teas unique to Yunnan, Shengpu is sun-dried green tea, and Ripe Pu is artificially fermented tea. They can all be stored for a long time.

The two-year shelf life you mentioned is not different in the pressing of raw materials, you can ask in detail about pressing raw materials! The raw materials of green tea are generally about one and a half years, and they will deteriorate after a long time.

Theoretically, any kind of food has a shelf life. It's just that the method of judging the shelf life of Pu'er tea is special. Pu'er tea is divided into raw tea and ripe tea, and raw tea is gradually and naturally fermented in the process of storage to become ripe tea.

Under normal circumstances, raw tea can be completely turned into ripe tea after eight years of storage. And after another twenty or thirty years, it will turn into dust. Therefore, Pu'er tea has a shelf life.

In general, eight to fifteen-year-old tea is best.

The new tea she said should be Yunnan green! Pu'er raw tea is a sun-dried green tea, the temperature is low, the microorganisms and enzymes on the surface of the tea are not inactivated, it can continue to ferment, and it can be stored for a long time! Yunnan green is made of Yunnan large-leaf tea stir-fried, should be high temperature, the tea has been inactivated, can not continue to ferment, so should be drunk as soon as possible!

Although there is a lot of controversy about whether raw tea is Pu'er, Yunnan Green is definitely not Pu'er, and I don't know if it is a scenic spot to fool people.

Each tea has a shelf life, but according to different regions, climatic conditions, and different preservation methods, the shelf life is different, and it cannot be generalized. For example, under the same storage conditions, tea leaves will have a longer shelf life in the north.

Tea can ensure the quality of tea for a long time under excellent storage and suitable reprocessing methods. Therefore, to some extent, for tea manufacturers, there is no strict or fixed shelf life for semi-finished tea that has not left the factory.

In fact, the national standard does not state whether tea must have a shelf life, but only stipulates that the shelf life must be marked on the outer packaging. According to GB7718-2011 "General Principles for the Labeling of Prepackaged Food in National Food Safety Standards", the shelf life must be marked on the outer packaging of tea. However, from the perspective of tea product standards, although there are provisions on the storage conditions of different types of tea, there is no provision for how long the shelf life of tea is.

At present, the shelf life of tea is marked by the merchant according to factors such as the type of product, packaging materials and storage conditions. Generally speaking, the shelf life of rock tea and black tea marked by manufacturers is between one and a half to three years; White tea, green tea, jasmine tea, and medium-poor fragrance Tieguanyin are generally about 18 months.

Pu-erh tea has an expiration date, which is often referred to as the "best before date". Tea leaves that have passed the "best before date" will change in taste, taste, and soup color. Expired tea leaves are also easy to react with air transport qi, resulting in the production of many microorganisms, and it is also easy to mildew when it comes into contact with moisture.

The most important thing to preserve tea is to prevent it from smelling and mildew, and it is best to store the tea in a dry, vacuum, and dark environment.

Tea has strong adsorption, easy to absorb the taste and moisture of the external environment, if stored in an environment with a large odor, it will affect the drinking feeling of tea.

The main reason for the deterioration of tea leaves is that after the tea leaves come into contact with the air, there is a chemical reaction, and the moisture in the air adheres to the tea leaves, causing the tea leaves to become damp.

Pu'er tea has a shelf life, but whether it is 60 years, or 100 years, or hundreds of years, there is no conclusive information, and often only rely on the intuition of tea drinkers to judge the degree of aging.

The appearance of new Pu'er tea is fresh, mostly yellow-green, with white hair, and strong taste; Due to the long-term oxidation, the appearance of the tea leaves will be jujube red, and the white tea will also turn yellow-brown. Usually, the white paper of the packaging of aged Pu'er tea has become old with time, and the paper is slightly yellow, so the age of Pu'er tea can be judged from the aging degree of the paper handmade cloth pattern and printing color. However, this can only be used as a reference, not an absolute basis, because some unscrupulous businessmen may take advantage of this psychology to package inferior products in stale yellow wrapping paper.

Store Pu-erh properly

Circulating air. There is more oxygen in the circulating air, which is conducive to the reproduction of some microorganisms in the tea, so it can accelerate the change of tea, but Pu'er tea cannot be hung on the balcony. There should be moderate circulation of air, but it should not be placed in the air outlet.

In addition, there should be no peculiar smell in the surrounding environment, otherwise the tea will change its taste. Therefore, it should not be placed in the kitchen or other environments with domestic or industrial odors.

Constant temperature. The temperature of Pu'er tea should not be too high or too low, the temperature should be based on the local environment, no need to deliberately artificially create the temperature, the normal indoor temperature can be, the best is to keep it between 20 and 30 degrees Celsius all year round, too high temperature will accelerate the fermentation of tea and become sour. Relatively speaking, the changes of Pu-erh tea in spring, summer and autumn will be faster than that in winter, and no matter when, Pu-erh tea should not be exposed to the sun, and it is better to be in a cool place.

Moderate humidity. Good Pu'er tea should be stored in a dry warehouse, which means that it is stored in a dry environment and avoid moisture. Too dry will slow down the aging of Pu'er tea, so there should be a certain amount of moisture.

In a drier environment, you can place a small glass of water next to the tea to increase the humidity in the air slightly.