Green tea has various health benefits. In particular, catechins are known to have various health functions. One of them is antibacterial / sterilizing and antiviral action. The influenza virus gets into the nose and throat and multiplies, causing symptoms. Epigallocatechin gallate (EGCg), a catechin, suppresses the growth of the virus in small amounts. In other words, gargle with tea can block viruses on your nose and throat. In Japan, there are elementary schools in Shizuoka, Sayama (Saitama Prefecture), Kagoshima Prefecture, and other tea producing regions that encourage students to gargle with green tea in winter. There are also tea farmers who donate green tea to their local elementary schools to protect students from influenza.
But sometimes you may feel it is wasteful to use the green tea for gargle. There is a special tip in such a case. Enjoy the green tea as usual until the first or second cup of brewing. During this time, don’t forget to use hot water at 70-80C (158-176F) to maximize the umami and sweetness of the green tea. And use the third brewing tea for gargle. We would recommend to bring the water to boil this time, since boiling water extracts more catechins. And keep it in a cup. And when you come home from outside, gargle with the tea you have prepared.
One thing that you should keep in mind is , once a virus enters the body, it is ineffective, so it is important to use tea gargle as a preventive measure in daily habits.