Yinghong No. 9 black tea after the cold muddy explanation: why the tea is cold turbid?

People who often drink black tea will find a very strange phenomenon. After a pot of high-flavor black tea has been placed for a period of time, a thick layer of yellow muddy water will accumulate at the bottom of the tea container and it is not easy to clean it. However, if hot water is injected, this substance will disappear quickly.

And this is the black tea, especially the British Red 9 most often appear on the unique cold after muddy phenomenon,"cold after muddy" professional scientific name called "tea cheese". The reason for its formation is theaflavins, thearubigins with chemical properties of relatively stable and slightly bitter caffeine complex formed. When at high temperature (close to 100℃), each is free and soluble in hot water, but with the decrease of temperature, they associate to form complexes. With the increasing of association reaction, the tea liquor changes from clear to muddy, showing colloidal characteristics, and the particle size continues to increase, which will produce coagulation. After cooling tea soup often milky precipitation, so that tea soup orange or brown, this is the black tea soup "cold after muddy", but also a sign of high quality black tea.

This is because tea contains tea polyphenols, and black tea in the fermentation of some tea polyphenols will be converted into theaflavins, thearubigins, theabrownin. At high temperature, caffeine and them are free, but with the decrease of temperature, they will form an association complex through association, and show the characteristics of colloid, so that the tea soup from clear to muddy and appear "cold after muddy" phenomenon. This is related to the strength of fresh and concentrated black tea. The stronger the freshness of black tea, the more obvious the phenomenon of muddy after cold.