There are many factors that determine how much caffeine a tea contains. Some of these are: the region, climate where the plant is grown, nutrients contained in the soil, cultivation methods, altitude, when the leaves are picked, the variety of the plant, manufacturing methods, and how the tea itself is prepared.
The most popular teas are black, oolong, green and white, which all come from the same plant, the evergreen shrub (camellia sinensis). What makes these teas different is the processing they go through to arrive at the finished tea product. Following is a brief description of each type of tea and the level of caffeine it contains.
Black Tea – This is the darkest of the four types and contains the highest amount of caffeine. Black tea is the most processed tea of the bunch, which means that it undergoes full oxidation (a process of fermentation). After being picked the leaves are withered in the sun, then rolled / bruised in order to break the cell walls to release the enzymes, which start the fermentation process, and finally they’re dried. This process is basically the same for the other oxidized teas, the only difference is the fermenting time.
Oolong Tea – Is a semi-processed tea, meaning that the leaves are fired to stop the fermentation process. It contains the second highest level of caffeine.
Green Tea – Has the third highest content of caffeine and is unoxidized. The leaves are steamed, rolled and then dried.
White Tea – Is the least processed of the four and contains little caffeine. The leaves are harvested while very young and with the bud closed; only the top leaf is picked. They’re sun – dried and then packaged.
Ways to Decrease Caffeine In a Cup of Tea
If you are someone who cannot drink caffeinated beverages, sensitive to caffeine, or would like to cut back on caffeine here are some options for you.
You can use water that is cooler in temperature and to steep the tea for a shorter period of time. If you’re using loose leaf tea, you can use less leaf.
Another method is to steep the tea in hot water for approximately 1 minute, which releases 80% of the caffeine, dump it, and steep a second cup following the above guidelines.