High-quality green tea soup color
Bright, clear soup color without impurities is always a necessary condition for measuring a high-quality green tea. Green tea retains more natural substances of fresh leaves, more than 85% of tea polyphenols and caffeine, about 50% of chlorophyll, and less vitamin loss, thus forming the characteristics of green tea "clear soup and green leaves".
After brewing green tea, the tea soup is mainly light green and emerald green, with yellow in the green, and the soup color is green leaves. There are certain differences in soup color for different varieties and grades of tea. For example, the soup color of Longjing tea of different grades can be light green, apricot green, emerald green, yellow green, etc. The luster also varies from clear to bright and dark.
Generally speaking, all high-quality green teas have a common principle: no matter what the color of the tea soup is, there must be no turbid or gray impurities, and clear is better.
Why does tea turn yellow?
A cup of clear green tea will lose its green color and increase the degree of yellowness when brewed at high temperature, especially for a long time. This is the oxidation of tea polyphenols in tea to form yellow-red and reddish-brown oxidation products, mainly theaflavins, theaflavins, theaflavins, etc.
The water-soluble components of green tea are the main substances of green tea soup, mainly flavonols, anthocyanins, flavanols and oxidized derivatives of flavanols. These components are highly soluble in water and appear yellow-green in aqueous solution, while flavanols are the main substances that constitute green tea soup.
Tea polyphenols is a general term for polyphenols in tea, including flavanols, anthocyanins, flavonoids, flavonols and phenolic acids. It is mainly flavanols (catechins), catechins account for 60-80%, so the tea soup of green tea will also be yellow.
In addition, for tea leaves that have been stored for a long time, or new tea that has been improperly stored for a short time, which leads to deterioration, the loss of chlorophyll in the soup color will also make the tea water appear yellow and the soup color turbid.
