Tea, a health beverage that already existed in ancient China, is loved by people for its mellow and fragrant flavor. However, drinking tea also requires a certain understanding; one should not drink tea incorrectly and cause physical discomfort.
I. Bagged tea is best brewed only once, while loose-leaf tea should not be brewed more than three times.
In daily life, some people like to brew tea repeatedly until there is no flavor left, while others change the tea after one or two brews. Which of these practices is correct? How many times should a cup of tea be brewed?
A researcher from the Tea Research Institute of the Chinese Academy of Agricultural Sciences said that while the number of times tea is brewed is closely related to personal taste—some prefer light tea and others strong tea—from a nutritional absorption perspective, bagged tea is best brewed only once, and loose-leaf tea should not be brewed more than three times.
He explained that tea contains nutrients such as tea polyphenols, which have anti-cancer properties; tea polysaccharides, which can lower blood sugar; caffeine, which stimulates the central nervous system; and various amino acids and vitamins. The amount of these nutrients that can be released is highly dependent on the number of brews. Generally speaking, the larger the tea particles, the slower the nutrients are released; the smaller the particles, the faster they are released.
Compared to loose-leaf tea, the leaves in bagged tea are cut and rolled during processing, which thoroughly breaks down the leaf cells, resulting in smaller particles. After the first 3-5 minute infusion, 80%-90% of the nutrients in bagged tea are released. After the second brew, the remaining 10% of nutrients are almost completely extracted. Therefore, it is best to brew bagged tea only once, as there is no significant loss of nutritional absorption, and it does not affect the taste and flavor. For loose-leaf tea, due to its larger particles, the first brew should be longer, about 5 minutes, during which 60%-80% of the nutrients are released. After the second brew, 80%-90% of the nutrients are extracted. After the third brew, the nutrient extraction rate will exceed 95%, and further brewing will offer no nutritional benefit.
As for the claim that multiple brews of tea can cause pesticides, heavy metals, and other harmful substances to leach out, experts say that while this claim has some merit, there is no need to be overly concerned. Most pesticides used in China's tea production have extremely low water solubility. Based on an average daily consumption of 10 grams of tea per person, even with tea containing 1 mg/kg of pesticide residue, the amount of pesticide ingested would only be 0.0001 mg, which is a few thousandths of the daily intake limit set by the World Health Organization. The leaching rate of lead, a heavy metal in tea, is also relatively low. As long as tea is purchased from regular manufacturers, its content will not exceed national standards.
II. The most suitable daily tea intake is 12 grams.
Jiang Heyuan, a researcher from the Tea Research Institute of the Chinese Academy of Agricultural Sciences, recommends that for the average person, a daily intake of about 12 grams of tea, brewed 3 to 4 times, is appropriate. People who consume a lot of greasy food or smoke and drink excessively can increase their tea consumption accordingly. However, pregnant women, children, individuals with neurasthenia, and those with tachycardia should reduce their tea intake. Han Chi also reminds that with the popularity of Gongfu tea, people are drinking tea "at increasingly higher temperatures," which is very wrong. "People drink tea for health benefits, but drinking very hot tea increases the risk of esophageal cancer and other cancers, which is得不偿失 (not worth the loss). The optimal temperature for drinking tea should be around 60°C and should not exceed 70°C."