Black tea is allowed to wither, which precedes a process called oxidation (sometimes incorrectly referred to as fermentation) during which water evaporates out of the leaf and the leaf absorbs more oxygen from the air. Black teas usually undergo full oxidation, and the results are the characteristic dark brown and black leaf, the typically more robust and pronounced flavors of black teas, and when brewed appropriately, a higher caffeine content compared to other teas (50-65% of coffee, depending on the type and brewing technique).
Dark Tea is from Hunan and Sichuan provinces of China and is a flavorful aged probiotic tea that steeps up very smooth with a natural slightly sweet note. Learn more about Dark Tea.
Oolong tea (also known as wulong tea) is allowed to undergo partial oxidation. These teas have a caffeine content between that of green teas and black teas. The flavor of oolong (wulong) teas is typically not as robust as blacks or as subtle as greens, but has its own extremely fragrant and intriguing tones. Oolongs (wulongs) are often compared to the taste and aroma of fresh flowers or fresh fruit.
Green Tea is allowed to wither only slightly after being picked. Then the oxidation process is stopped very quickly by firing (rapidly heating) the leaves. Therefore, when brewed at lower temperatures and for less time, green teas tend to have less caffeine (10-30% of coffee). Greens also tend to produce more subtle flavors with many undertones and accents that connoisseurs treasure.
White teas are the most delicate of all teas. They are appreciated for their subtlety, complexity, and natural sweetness. They are hand-processed using the youngest shoots of the tea plant, with no oxidation. When brewed correctly, with a very low temperature and a short steeping time, white teas can produce low amounts of caffeine. Of course, steeping with hotter temperature and longer time will extract more caffeine. But by definition, white tea does not have less caffeine than other teas.