Caffeine in Tea. Basic facts

One of the most discussed topics in the tea world is the question about caffeine in tea. Let's shed some light on what caffeine is, what it does to the human body, and whether there is such a thing as most / least caffeinated tea.


What is caffeine

Caffeine is an alkaloid from the group of purines. It is one of the three main alkaloids found in tea. It is also a main ingredient in tea leaves, affecting tea's taste and quality. Caffeine acts as a stimulant for the nervous system. It relieves fatigue, stimulates the heart, has a diuretic effect, and promotes the work of the respiratory system. 

Caffeine in tea vs coffee - is it the same thing?

Yes, it is the same molecule, only it was first discovered in coffee. When scientists discovered it in tea, they first called it "theine". When they confirmed it's identical to the one found in coffee, people started calling it "caffeine" altogether.  


Do not confuse "Theine" with "Theanine". While Theine is another name for caffeine, Theanine, or L-theanine, is an important amino acid in tea leaves.


Tea vs coffee - which one has more caffeine?

The amount of caffeine found in dry leaves is more in tea than in coffee. However, the amount of coffee we use for brewing a cup of 150ml is almost twice as much as the tea leaves we would use for the same cup. Hence, a cup of coffee loads us with more caffeine than the same cup of tea would do. 


Although tea has more caffeine as % of dry weight, it might provide less caffeine than coffee in terms of personal intake.


Furthermore, caffeine in tea has a different stimulating effect on the human body. It is because of the L-Theanine we mentioned above.

L-Theanine is an important amino acid in tea. According to a number of research, it acts as a powerful neurotransmitter that impacts the serotonin and dopamine brain levels. By increasing the "alpha activity" in the brain, it decreases the stress level and puts us into a state of relaxation and awareness. That explains the consistent use of tea in meditative and spiritual practices across cultures.


tea vs coffee


Which tea is most / least caffeinated?

Unfortunately, there is no short answer to this question. One of the main reasons is that the caffeine level in tea is largely defined by factors other than the processing of the six tea types. 

However, you can still estimate whether your tea is more or less caffeinated by considering these important factors.


The real factors behind caffeine in tea

Tea tree variety

Levels of caffeine vary in different tea tree varieties. Various research will define different varieties as the most caffeinated. The Top 3 include the original Camelia Sinensis var. Sinensis, and two Yunnan large-leaf varieties: Camelia Sinensis var. Taliensis and Assamica.


Sunshine, soil, altitude, moisture, and tea tree tending are all among the factors that impact the tea leaves' inner content. More fertilization and trimming, a higher amount of sunlight, and growing in the lowlands as opposed to the high mountain increase the caffeine levels in tea leaves. 

Tea plant parts

Different parts of the tea tree contain different levels of caffeine too. The younger the part of the tea plant, the more caffeine it contains. Thus, bud-only teas are usually the most caffeinated. 


Tea growing in spring and summer contains more caffeine than the one harvested during autumn or – where that applies – in winter.

Brewing time

Caffeine is highly soluble in water. The longer we steep the tea leaves, the higher the caffeine amount in our tea soup.


Is Pu-erh really the most caffeinated tea?

It depends on which type of Pu-erh we refer to. Indeed, Sheng Pu is a reputedly potent tea with strong energy and an intense taste. However, Ripe Pu-erh, although produced from the same variety, impacts the human body in a different manner.

Ripe Pu-erh is the only tea that TCM doctors claim is suitable to drink late in the evening or before falling asleep.


Can I Decaffeinate My Own Tea?

Another popular myth is that we wash away most, if not all of the caffeine by rinsing our tea leaves. 

Decaffeinating tea is a serious process requiring special equipment, not something we can do at home. 

Studies show that if we rinse the tea leaves for at least 15 minutes, we will get rid of almost all the caffeine. And of all the flavor, nutrients, and benefits along with it. Not recommended. 

To learn more about the caffeine content in tea, check out our caffeine tag