Ordinarily tea has about 1/3 the caffeine of coffee and decaffeinated tea has even less. There is no such thing as a caffeine free tea. Even the best decaffeinated tea on the market still contains as much as .4% of caffeine by dry weight. The type of leaves used can further influence this. The longer a teal leaf has fermented or the smaller the leaf, the more caffeine is present. Decaffeinated tea can be processed four different ways: 1), soaking the tea in methylene chloride, 2) using ethyl acetate, 3) carbon dioxide or 4) processing it in water. The first two methods are the same, except that they use different chemicals. Both can leave a chemical aftertaste. The latter two methods are the most common way to produce decaffeinated tea. Regardless of how the caffeine is extracted, to be labeled decaffeinated tea the product must contain less than 2.5% of the original caffeine level. A lot of people choose to drink decaffeinated tea because caffeine keeps them awake or makes them feel jittery. If you're a tea drinker, you can enjoy any flavor of decaffeinated tea, as the amount of residual caffeine is the same, whether you're enjoying a cup of green, black, white or oolong.
The decaffeination process doesn't affect the levels of antioxidants in the tea either, which researchers are discovering plays an increasingly important role in your health. Feel free to drink as much decaffeinated tea as you like the health benefits are worth it. One study even suggested that smokers significantly reduced DNA damage if they drank four cups of decaffeinated tea (specifically green tea) a day for four months. Drinking decaffeinated tea certainly can't hurt you. And more and more types of decaffeinated tea are making their way to market these days, including some of the more exotic flavors of tea that until now, weren't decaffeinated. As a result, tea drinkers can enjoy their favorite beverage late into the day, never having to worry about getting a case of the jitters or staying up all night again.