Since ancient times, people have been accustomed to brewing tea with hot water, believing that only hot water can extract the flavor and beneficial components from tea leaves. In fact, cold water brewing is no less effective. As long as you have enough patience, the tea's fragrance and nutrients will slowly seep out from within. As a Xiangxi folk song sings: "Cold water brews tea, slowly it becomes strong..."

So-called cold brew tea involves steeping tea leaves in cool boiled water or mineral water. Office workers, drivers, hikers, and others can enjoy this delicious and health-beneficial "cold brew tea" anytime, anywhere, as long as they can buy mineral water.

Research shows that after 2 hours of cold brewing, the infusion amounts of water-soluble components like tannic acid and free catechins from the tea leaves exceed those of hot-brewed tea. After 8 hours of cold brewing, the infusion amounts of components insoluble in water, such as ester-type catechins, can reach about 70% of those in hot-brewed tea.

Furthermore, studies have found that tea contains a polysaccharide substance that both promotes pancreatic islet function and removes excess sugar from the blood. However, this polysaccharide is heat-sensitive. If tea is brewed with hot water, it is severely damaged, whereas cold brewing avoids this problem. From this perspective, drinking "cold brew tea" can help people control their blood sugar.