Updated: Aug 6, 2019
Can the color of your tea tell you how much caffeine is in it? How about the taste? You probably believe that there is more caffeine in your cup of tea the darker its liquor or the stronger its flavor, right? Thus, a cup of white tea or green tea has less caffeine than a cup of black tea. However, recent research studies say that this may not be the case.
Caffeine occurs naturally in a variety of plants, including tea. It protects the leaves, especially the fresh buds, from insects, bacteria and fungi. The caffeine in a tea plant ranges between 1.4- 4% of the weight of the leaf. It is said to be in higher concentration in new shoots and buds. Given this, Silver Needle, a very expensive variety of white tea that uses only the top buds, may be said to have more caffeine in it than a black tea produced from mature leaves. This, then, dispels the belief that white tea has the smallest amount of caffeine among the teas being very light, sweet, delicate and the least processed.
So, in general, is there one type of tea that can be considered to have more or less caffeine in it compared with another? Let us just say that, regardless of the type, teas have caffeine in it but the caffeine level varies in each particular tea depending on several factors- the varietal of the plant (the leaves of the Camellia sinensis var. assamica is thought to contain more caffeine), the soil chemistry, the altitude, how young the leaves are when plucked (younger tea leaves contain slightly more caffeine), how much tea is used when brewing, the steeping time (the longer the brewing time, the higher the level of caffeine), and the steeping temperature (less caffeine is infused into cooler water).
References: Tea Sommelier Handbook, Victoria Bisogno and Jane Pettigrew; The Everything Healthy Tea Book, Babette Donaldson