How do you know whether the tea is new or old? What is the situation that the brewed tea has bubbles like beer?

Judging new tea and old tea can be comprehensively distinguished from the following four aspects.

First of all, we can distinguish old tea from new tea according to the color of tea. Generally speaking, the color of green tea is green, and the color of soup is yellow-green and bright; Black tea is a symbol of new tea. It is dark in color and bright red and orange in soup. During the storage of tea, some substances that make up the color of tea will slowly decompose and oxidize under the action of light, gas and heat. For example, the decomposition and oxidation of chlorophyll in green tea will make the color of green tea dim, while the increase of theabrownin will make the color of green tea soup yellow and brown, losing its original bright color; When black tea is stored for a long time, the tea polyphenols in tea will be oxidized and condensed, which will make the color darker, and the increase of theabrownin will also make the soup turbid and lose the freshness of new black tea.

Secondly, we can distinguish new tea from old tea by aroma. Modern scientific analysis shows that there are more than 300 kinds of tea aroma components, mainly alcohols, esters, aldehydes and other substances. In the process of tea storage, they can not only volatilize continuously, but also oxidize slowly. Therefore, with the extension of time, the aroma of tea will change from high to low, and the fragrance type will also change from the fragrance of new tea to low-boring.

Thirdly, we can also distinguish new tea from old tea from the taste of tea. This is because during the storage process, phenolic compounds, amino acids, vitamins and other substances that constitute the taste in tea, some decompose and volatilize, and some condense into water-insoluble substances, thus reducing the effective taste substances that can be dissolved in tea soup. Therefore, no matter what kind of tea, the taste of new tea is mellow and fresh, while old Chaze doesn't like it.

Fourth, all new teas give people the impression of fresh color, high fragrance and mellow taste. Even if the aged tea stored for more than 1 year is well preserved, it will inevitably appear black, fragrant and thin. Just because of the different storage methods, the degree of change is large and small. As for the change of tea tide or some peculiar smell caused by poor storage, that is another matter.