Coffee, Tea, Chocolate and Cocoa Tannin is in both coffee and tea. Tannin retards digestion, acts as an astringent and imparts a bitter flavor to tea. Coffee contains a volatile oil called caffeine, which gives coffee its delightful aroma and flavor.
Metals affect the flavors of coffee and tea.
They are best prepared in pots which are porcelain, china or glass. A cup of coffee contains 2-3 grains of caffeine and a small amount of tannin. Coffee is made from the seeds of berries of the coffee tree which is grown in all the tropical countries, though chiefly in Brazil. Roasting of the coffee develops the delightful aroma and flavor which makes the coffee so appetizing. The flavor of coffee is due not only to the kind but also to the blend and the degree of roasting.