Caffeine and Tea
Contrary to what you may have thought, Tea does have caffeine. An 8 oz. cup of black tea can contain 25-48 mg. of caffeine and an 8 oz. cup of brewed coffee contains 95-165 mg. of caffeine.
The actual caffeine content of a cup of tea can vary considerably because of factors such as origin, processing and the preparation method, including the steeping time.
The caffeine in tea and coffee are technically, identical but the experience of the caffeine is different because tea contains L-theanine, an amino acid found only in tea. It reduces stress and promotes relaxation. This works with the caffeine in tea in a synergistic way to calm the body without reducing caffeine alertness. There are also, high levels of antioxidants found in tea that slow the absorption of caffeine and provide a longer period of alertness without the horrible crash your body feels after coming down from the caffeine jolt it experiences in coffee.
You can "make your own" decaf tea by briefly steeping the tea for 30 seconds and throwing away the liquor. It is believed that most of the caffeine is washed away in this initial steeping. The truth is, caffeine is extracted over time, and so the first 30 seconds of a five minute steeping cycle may only extract 20 to 30% of the caffeine (the amount depends on the leaf and processing style). But, the antioxidants and other health benefits of tea tend to be extracted more quickly than the caffeine. Therefore, that first quick steeping or "washing" removes both some of the caffeine AND the healthy elements found in tea.
All tea is made from the same plant, Camellia sinensis, if you want to eliminate caffeine completely, you should switch to Herbal blends made from botanicals not related to the Camellia sinensis plant because they are naturally caffeine free.