First of all, you can distinguish between old and new tea according to the color of the tea.
The green tea is green and verdant, and the soup is yellow and green, and the black tea is moist, and the soup is red and orange, which is the symbol of the new tea. During the storage process, some substances that make up the color of the tea will slowly decompose or 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 become dull and dull, while the increase of tea brown will make the color of green tea yellow-brown and lose its original fresh color; black tea is stored for a long time, and the tea polyphenols in tea will cause oxidation and condensation, which will make the color of the color gray, and the increase of tea brown will also make the color cloudy, which will also lose the freshness of the new black tea.
Secondly, new and old tea can be distinguished from aroma. Scientific analysis shows that there are more than 300 ingredients that make up the aroma of tea, mainly alcohols, esters, aldehydes and other substances. During the storage of tea, they can not only evaporate continuously but also slowly oxidize. Therefore, as time goes by, the aroma of tea will change from high to low, and the fragrance will become low and turbid from the fragrant fragrance of the new tea.
Third, you can also distinguish new and old tea from tea from tea. Because during storage, some of the phenolic compounds, amino acids, vitamins and other substances that make up flavors are decomposed and volatile, while some condensate into substances that are insoluble in water, thereby reducing the effective flavor substances that are soluble in tea soup. Therefore, no matter what kind of tea, the taste of new tea is mellow and refreshing, while the aged tea seems light and unpleasant.
The green tea is green and verdant, and the soup is yellow and green, and the black tea is moist, and the soup is red and orange, which is the symbol of the new tea. During the storage process, some substances that make up the color of the tea will slowly decompose or 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 become dull and dull, while the increase of tea brown will make the color of green tea yellow-brown and lose its original fresh color; black tea is stored for a long time, and the tea polyphenols in tea will cause oxidation and condensation, which will make the color of the color gray, and the increase of tea brown will also make the color cloudy, which will also lose the freshness of the new black tea.
Secondly, new and old tea can be distinguished from aroma. Scientific analysis shows that there are more than 300 ingredients that make up the aroma of tea, mainly alcohols, esters, aldehydes and other substances. During the storage of tea, they can not only evaporate continuously but also slowly oxidize. Therefore, as time goes by, the aroma of tea will change from high to low, and the fragrance will become low and turbid from the fragrant fragrance of the new tea.
Third, you can also distinguish new and old tea from tea from tea. Because during storage, some of the phenolic compounds, amino acids, vitamins and other substances that make up flavors are decomposed and volatile, while some condensate into substances that are insoluble in water, thereby reducing the effective flavor substances that are soluble in tea soup. Therefore, no matter what kind of tea, the taste of new tea is mellow and refreshing, while the aged tea seems light and unpleasant.