Oolong with original flavor Oolong tea can be recognized by the color of the infused leaf - its darker, oxidized edges resemble a black tea leaf, the remaining, much lighter part of the leaf looks like a green tea leaf. Ollong is characterized by a high content of tannins and catechins and a small amount of caffeine. Oolong tea is brewed in an amount of about 2-3 grams per 170 milliliters of water for about 2-3 minutes. The water temperature in the case of green oysters should be around 95 ° C. We rinse the tea first, especially when we are not sure that the leaves have not been sprayed with pesticides or do not contain dust.