Overnight tea is generally not recommended to drink, will lead to nutrient loss, at the same time may affect your health.
Tea contains tea polyphenols, tea polyphenols are easily oxidized in air and water to form tea rust, overnight tea due to longer exposure in the air, the amount of newborn tea rust is also higher. Tea polyphenols are oxidized when exposed to air, losing their biological activity and nutritional loss.
Overnight tea may harbor various bacteria and fungi causing spoilage due to prolonged exposure to air. If you drink overnight tea may lead to gastrointestinal function decline in vomiting, abdominal pain, diarrhea and so on. Especially the elderly, children and teenagers with poor function of spleen and stomach should not drink overnight tea.
Therefore, we suggest drinking tea as much as possible to drink fresh tea water, and do not make too strong.