Can a thermos cup be used to brew tea leaves?

Thermos cups are common drinking cups, especially in the cold winter. Carrying a thermos cup with you allows people to drink hot water at any time. Many people like to drink tea, and some people like to use thermos cups to drink tea, thinking that this can keep the temperature of the tea, and they can also drink tea anytime and anywhere. In fact, drinking tea with a thermos cup is an incorrect practice. Drinking tea with a thermos cup will cause the loss of nutrients in the tea.

Is it harmful to brew tea in a thermos cup?

People advocate drinking tea for health preservation. Tea can invigorate spirits, improve thinking, quench thirst and relieve fatigue. It is known as the "king of recreational drinks". However, it is not wise to choose to use a thermos cup to make tea. Because tea is brewed in a thermos cup, the tea leaves are soaked in high-temperature, constant-temperature water for a long time, just like simmering tea over low heat. In this way, the vitamins in the tea will be destroyed in large quantities, the aromatic oil will evaporate in large quantities, and tannic acid and thealkali will precipitate in large quantities, which will not only reduce the nutritional value of the tea, but also make the tea bitter and affect the taste. In addition, the vitamins and flavonoids in tea are not resistant to high temperatures. If soaked in high temperatures for a long time, the nutrients will be destroyed in large quantities, reducing the nourishing and health-care functions of the tea. At the same time, the aromatic oil in the tea will evaporate quickly, reducing the tea aroma.

It is best to drink tea after soaking for 4 to 6 minutes. At this point, 80% of the caffeine and 60% of other soluble substances have been soaked out. However, long-term high-temperature soaking in a thermos cup will cause too much caffeine, theanine, and tannic acid to leach out of the tea, which is too irritating to the gastrointestinal tract and is not good for health.

Be careful when brewing tea in a thermos cup

The thermos bottles sold on the market have the same functions, but the materials of the linings are different, including ceramic, porcelain, stainless steel, plastic, etc. These materials will cause different chemical reactions when dealing with contents with different acidity and alkalinity. Therefore, this is also what you should pay attention to when brewing tea in a thermos cup, brewing various Chinese herbal health teas, or even brewing fruit juice, milk, etc.

In principle, Chinese medicinal materials cannot be stored in metal products to prevent chemical reactions. I believe everyone has a unified understanding of this. For other foods such as honey water, milk, juice, and of course tea, try to avoid using metal or plastic-lined thermos cups. In addition, some people use enamel tea sets to make tea, which is also inappropriate. Enamel tea sets are prone to wear and tear after being used for a long time, exposing the iron sheet. The metal components will dissolve with the tea, making the tea turn yellow and lose its original flavor. Moreover, enamel tea sets dissipate heat and transfer heat quickly, and the tea fragrance is easy to spread.

How to use a thermos cup to drink tea

In daily life, it is indeed not advisable to use a thermos cup to make tea directly. But if you want to keep choosing a thermos cup so that you can drink tea and various health liquids at any time, there is still a way.

Choose a high-quality thermos cup, glass cup, porcelain cup, or purple clay teapot to brew hot tea (remove the tea leaves) or health-preserving medicine first, and then pour it into the thermos cup. It can be consumed at any time, but it is not recommended to keep it overnight.