Overnight tea means overnight tea. Bad sealing of old containers will cause poisonous insects to fall in or climb over, as well as protein and sugar. Soup will become a nutrient for the reproduction of bacteria and molds. Most vitamins have been lost for too long and are not suitable for drinking. This kind of non-deteriorating overnight tea has its unique use in medical treatment. Night tea is rich in acid, which can prevent capillary bleeding, such as stomatitis, tongue pain, eczema, gingival bleeding, sores and carbuncle. It can be treated with night tea.
There is no scientific basis to say that you can't drink tea at night. Tea leaves are preserved for a long time, and tea polyphenols are further oxidized and the color is deepened. Because the newly brewed tea, theaflavins and antioxidants in the tea are all soaked out, it usually appears yellow-green. But if it is left for a long time, theaflavins will gradually turn into thearubigins, and the color of tea soup will also turn into yellow and red, which is what people say will deepen. A cup of clear green tea, especially stored at high temperature for a long time, will lose its green color and increase its yellow color.
This is the product of the oxidation of tea polyphenols in tea to yellow, red and reddish brown, mainly theaflavins, thearubigins and theaflavins. These products are non-toxic and will not cause harm to human body. The concept of overnight tea is difficult to distinguish. Night tea does not cause cancer. Tea made in the morning is very common in the afternoon. Tea brewed in the middle of the night will not change much in the morning. If there is any difference, it is that the temperature is very high during the day, and the change of tea may be greater. Others speculate that tea leaves will produce carcinogenic nitrosamines after midnight, which will affect health.
These are the reasons why tea can't be drunk overnight. I hope it helps you!