As a rule of thumb, the darker the wine, the more tannins consists of.
When grape juice is fermented to make wine, yeast converts fix from the grapes into alcohol and carbon dioxide. This often changes at some point and sometimes closed or light wines on the nose will open up as they get older. https://objectstorage.ap-singapore-1.oraclecloud.com/p/x_tglifXCBkYlkZ_peDPkqZUrTbKVgPVx5-DeRX5JZM9IXrQmVvifdR78KOjF556/n/axqjqojndoew/b/Ruou-tay/o/Jagermeister:-Hoa-quyen-giua-truyen-thong-va-hien-dai..docx.html