The truth about the caffeine content of green tea

Contrary to popular belief, the caffeine content of green tea may be higher than that of black tea. It really depends on the type of green tea you are drinking.

Oxidation does not increase the caffeine content. In fact, some studies have found that the longer tea is oxidized, the lower the caffeine content.

The color is a poor guide to the amount of caffeine in the tea. The best Japanese green tea, Gyokuro, contains more caffeine than black Lapsang Souchong.

So what influences the caffeine content of green tea?

variety of plants

Camellia sinensis has two sub-varieties: Chinese sinensis and Indian Assamica.

Chinese green tea is a slow-growing shrub that produces small, narrow leaves. It is typically grown from seed and has less caffeine, ranging from 1-3% dry weight.

Indian black tea is a fast-growing tree that produces large, broad leaves. Usually grown using the vegetable propagation method, it contains more caffeine, ranging from 3% to 5% by dry weight.

It’s the variety of the plant, not the oxidation, that makes black tea about twice as caffeinated as green tea.

But not all parts of the tea plant have the same amount of caffeine.

leaf style

Many high-quality green teas are made from the bud and its two adjacent leaves. These tender sprouts are the sweetest, tastiest and healthiest.

They are the richest in catechins, which contain all the antioxidants, and the sweet, fresh-tasting theanine, which soothes and calms the mind. Unfortunately, they also contain the most caffeine.

The younger the leaf, the more caffeine it contains. According to Upton Tea, the top and first leaf contain 5% caffeine by dry weight, the second leaf 3.5%, the upper stem 2.5%, and the lower stem 1.4%.

It is no coincidence that the best green tea from China (Longjing or Dragon Well) and Japan (Gyokuro) has one of the highest caffeine contents.

The tea bags have less caffeine content than green tea and a poorer flavor to match.

Black tea is made from larger, more mature leaves. This means that a high grade loose leaf green tea can have as much caffeine as black tea, sometimes even more.

Growth and production conditions

We are now in the realm of uncertainty.

Local growing conditions can influence the caffeine content of green tea. An often-cited example is Japanese Gyokuro, which is shaded from the sun to preserve its theanine and caffeine content.

Other less obvious contributing factors are the soil, the weather, and when the tea is harvested. The processing method, such as wilting and oxidation, also play a separate role. The longer the leaves are allowed to wither, the higher the caffeine. But the longer they are left to oxidize, the less caffeine will be.

Now do you see why depending on who you ask, the caffeine content of green tea can range from 8 to 75 milligrams per cup?