People who often drink black tea should know that there is an obvious "golden circle" black tea on the edge of the black tea soup, which means that this black tea is of good quality and belongs to the top black tea. The better the quality of black tea, the brighter the golden circle. So many friends have to ask, is the "golden circle" of black tea a kind of pigment or an optical phenomenon?

The golden circle of black tea is an important factor for testing the quality of black tea. The main substances that form the "golden circle" of black tea are theaflavins, which are formed by oxidation of polyphenols. They are soluble in ethyl acetate and have benzophenones. The general term for compounds with phenolic ketone structure, including theaflavins, theaflavin monogallate, theaflavin digallate, etc., which play an important role in the color, aroma, taste and quality of black tea. Generally speaking, the thicker and brighter the "golden circle", the better the quality of black tea.

Theaflavins are orange-yellow substances dissolved in ethyl acetate in black tea. Theaflavin is an important component of black tea. Its content plays a decisive role in the color, aroma, taste and quality of black tea. It is the main component of the brightness of black tea soup, the important component of taste intensity and freshness, and it also forms the golden circle of tea soup. The most important substance.

Black tea has a high content of tea buds, thin and tight strips (small-leaf species) or fat and firm (large-leaf species), black and shiny in color, and more golden vellus hair on the tea strips; sweet and fragrant, with a sweet and mellow taste, and the soup is red in color Yan, there is a golden circle at the contact between the bowl wall and the tea soup, commonly known as the "golden circle". If it is a mid-range black tea, the sprout content is small, and the golden circle will be less yellowish.

There are many types of black tea. The two important sensory indicators for identifying the pros and cons of black tea are "golden circle" and "cold and muddy". There is a ring of golden glow along the tea cup attached to the tea cup, which is called the golden ring. The thicker the golden ring, the more golden the color, the better the quality of black tea.

Therefore, the main substance that forms the "golden circle" is formed by theaflavins in tea. Most of the black tea we drink usually can see that the "golden circle" is generally black tea of ​​excellent quality.