Tea leaves are one of the richest sources ofTannin. Black tea leaves contain 2-4% tannins by dry weight, while oolong tea leaves contain 1-2% and green tea leaves contain 0.5-1.5% tannins. The tannin content in tea leaves depends on factors like variety, processing, and growing conditions. Different types of teas also have varying tannin composition profiles. https://prachicmi.livepositively.com/understanding-tannins-and-their-role-in-food-and-drink/new=1