Can we make the tea first and then pour it into the thermos

It is possible to brew the tea first and then pour it into a thermos, but it should be noted that soaking the tea leaves at high temperatures for a long time may affect the taste and nutrition. The components such as tea polyphenols and vitamin C in tea are prone to oxidation and decomposition under sustained high temperatures. It is recommended to control the insulation time within 2 hours and prioritize using glass insulated cups. When tea leaves are continuously soaked in an environment above 80 ℃, the color of the tea soup will gradually deepen and the taste may become bitter. This is because high temperature accelerates the oxidation and polymerization of tea polyphenols, while some aromatic substances will evaporate and be lost. Unfermented teas such as green tea are particularly sensitive, and prolonged insulation may lead to a decrease in freshness and vitamin C content by more than half. If stainless steel insulated cups are used, tannic acid in tea may react weakly with metal materials, but will not produce harmful substances. Special precautions should be taken to avoid overnight storage, as tea soup is prone to microbial growth if stored in a sealed environment for more than 6 hours. Pu erh tea and other post fermented teas are relatively resistant to steeping, but it is also not recommended to keep them warm for more than 4 hours to avoid excessive extraction and excessive concentration of the tea soup.

For daily tea drinking, it is recommended to brew and drink immediately. When using a thermos, try to finish drinking within 2 hours. You can choose a separate tea layered thermos cup, or use a teapot to brew first, filter out the tea leaves, and then keep warm. Pay attention to the suitable water temperature for different types of tea: green tea at 80 ℃, black tea at 90 ℃, black tea at 100 ℃, and avoid repeated heating. Clean the thermos cup promptly after drinking tea to prevent the accumulation of tea stains from affecting subsequent use.