Black tea is harvested around the world from the Camellia Sinesis plant. For Black Tea, the tea leaves are fully oxidized after being harvested. The Camellia Sinesis plant naturally contains caffeine. The amount of caffeine in Black Tea is generally around 40mg per 8oz cup. Most Black Tea should be prepared using boiling water and 1 teaspoon per 8oz cup. Each of the individual Serene Teaz Black Tea Infusions includes their own specific steeping instructions for best results.