Tea 101
Caffeine of Tea – The Different Levels, Effects & More In Each Tea

Caffeine of Tea – The Different Levels, Effects & More In Each Tea

Caffeine of tea is more in depth than expected. Some common questions I get is, “How much caffeine is in this tea?” or “What is the best tea for me to drink if I am sensitive to caffeine?” or “is tea caffeine different from other (coffee, energy drinks, etc.) caffeine?”

In this article, let’s explore some of the science behind caffeine, what to caffeine level to expect in your cup, what effects the different levels of caffeine in tea, comparisons of caffeine in tea to other drinks and more!

Science of Caffeine

Caffeine, some people’s best friend, other’s worst enemy. It is the most common drug used (possibly abused?) in the United States. How does caffeine actually work and function in your body or more interestingly your brain?

The human brain consists of many tissues, cells and hormones that all play crucial roles in our bodies everyday functions. Our brain is constantly producing chemicals that alter our moods such as dopamine and serotonin, but the one we care about is adenosine.

Adenosine is the chemical our brain produces that, when accumulated, tellscaffeime-and-adenosine us to sleep and rest. Adenosine builds up and fills receptors thus giving us those sleepy feels. Introduce caffeine to the brain. Caffeine comes in and acts as a receptor blocker for adenosine. Thus, we do not feel sleepy! This feeling (fortunately or unfortunately?) does not last forever.

While caffeine is busy working and disrupting the normal processes of adenosine, the adenosine is not stopping production. Eventually that caffeine stops and in floods the reservoir of adenosine that has been building up. Thus, we experience the dreaded caffeine crash.

Caffeine of Each Tea Type

Just because something has caffeine does not mean it will react with your body the same some other beverage does with caffeine. A big determinant of how a cup of green tea vs a cup of black tea will affect you is based on its concentration.

Caffeine concentration is typically recorded in milligrams (mg). As a reference for the list below, the Mayo Clinic recommends caffeine be limited to 400mg or less per day. Below lists the caffeine level for one serving of different types of tea and other beverages for bonus!

Coffee and tea living in harmony!

  • Herbal Tea: 0mg
  • Green Tea: 15 – 30mg
  • White Tea: 15 – 30mg
  • Oolong Tea: 40 – 60mg
  • Pu’erh Tea: 50 – 70mg
  • Black Tea: 50 – 70mg
  • Kombucha: 5 –  15mg
  • Coffee: 90 – 110mg
  • Standard Energy Drink: 90 – 120mg

Each of the beverages above have a range. This is predominantly due to variations in the processing and others that will be described below!

Why There Are Different Levels

Caffeine varies from cup to cup when you have black tea or green tea. Sometimes there are even variations from a cup of green tea to another cup of green tea! So what’s the deal? These differences have to do with all these factors: oxidation, steep time, steep temperature, tea grades, farm geography, and style of growing.


Tea comes from the Camellia sinensis plant, so it should all have the same caffeine content, right? Wrong! When the tea is harvested it then undergoes different processes to turn the leaves into green, oolong, black, white or pu’erh. The major processing step is oxidation. The longer the oxidation the higher the caffeine content. Black and pu’erh are the longest, oolong middle and white and green the least oxidized.

Different levels of oxidation!

Steep time & temperature

Whether you know it or not, there is a right way to brew a cup of tea! Generally, a cup of tea should be brewed for 3 – 5 minutes. In order to get more caffeine you steep the leaves closer to the 5-minute mark. Temperature also plays a role too! The higher the temperature (~200 – 212 degree F) the more caffeine present. For more details on how to properly brew specific tea’s, check out Fresh Steeps’ “How Long to Steep Tea For” post here!

Tea Grades

Tea is classified into different grades. Those types include whole, broken and powdered. Whole leaf is a typical loose-leaf tea you buy. Broken is typically what you will find in tea bags. Powdered is the tea-leaf ground to a fine powder and consumed whole, like matcha! Whole leaves tend to be the least caffeinated, followed by broken, then powdered being the most caffeinated.

Farm Geography

Where the tea leaves are grown also has an effect on the caffeine! Assamica tea leaves grown in Assam India typically have higher concentrations of caffeine. Many of these make up black tea, while leaves grown in China are lower in caffeine. Typically, grown for green and white.

Styles of Growing

Tea leaves are grown differently to form and develop our favorite teas. Some are grown in the shade rather than direct sunlight. This forces the leaves to produce more chlorophyll and ultimately other chemicals which lead to greater caffeine content.

Avoiding The “Caffeine Crash” With Tea

If you have ever had a (or 3) cup(s) of coffee you have experienced that caffeine crash making you feel worse than before. Now do the same with tea and you won’t get that. What’s happening?

Obviously, tea generally has more caffeine than coffee, so that plays a role, but many teas also have an added chemical compound that helps. This is known L-Theanine!

Matcha has some of the highest L-theanine concentrations of tea!

This amino acid is commonplace among the tea world. It is know as a nootropic (brain enhancer) and works in ways that give your brain a calm alertness. No jitters, no increased heart rate, just calm focus on the task at hand. It reduces mental fatigue by increasing the production of alpha wave lengths in the brain. These wave lengths promote that calm focus.

Combine this powerful amino acid with the rush of caffeine and your focus is even sharper and clearer. It doesn’t even crash on you like normal caffeine. It gradually lowers you back to a sedative state. Incredible!

The Right Caffeine For You

What have we learned about the caffeine of tea?

Well…caffeine is a powerful chemical that blocks our normal sleepy pathways in our brain allowing us to stay awake longer. Each cup of tea, coffee, or energy drink has different concentrations of caffeine. These different levels are affected by many factors (some of which you can control and experiment with in home!). Tea has a powerful aid in it known as L-Theanine that allows for a calmer focus when combined with caffeine than just plain old caffeine.

Next time you need a caffeine kick, try out tea! Experiment with it yourself and see what works best for your body. Overall, enjoy the experience!

8 thoughts on “Caffeine of Tea – The Different Levels, Effects & More In Each Tea

    • Author gravatar

      Very interesting article. I recently wrote a post on caffeine benefits and side effects, so I was somewhat more invested in this post as a result. I also have trouble sleeping sometimes, so I have been trying to decipher if tea or coffee is the lesser of two evils. Your comparison section above has clarified that for me. I’m also looking into decaf tea.

      • Author gravatar

        Sharon, thanks for the comment! There are a lot of amazing benefits with caffeine and as mentioned in the post, add L-theanine to it and it’s a power couple! If caffeine is affecting your sleep, I would recommend an herbal tea as it has no caffeine at all. Even decaf has a little caffeine (~5mg at most).

    • Author gravatar

      Great post! I honestly always wondered about the difference of caffeine in tea vs. coffee. Even though I heard that there was more caffeine in tea, I didn’t believe it because it never perked me up as fast as coffee. But, it is true that it gives a calm alertness rather than the jittery rush of energy you get from coffee. I usually drink my coffee in the morning and switch to tea in the afternoon. That way I stay alert without the crash or jitters.

      • Author gravatar

        It is amazing the differences! Coffee really does have a lot more and does not have those added friendly amino acid L-theanine. For coffee drinkers, it is definitely a good idea in my opinion to drink coffee in the morning and switch to tea later in the day if a caffeine boost is needed. Overall, you have to listen to your body and make the right choice from there!

    • Author gravatar

      Hi Vince, great in-depth post. Although I am a big coffee drinker and tea drinker I was not aware how caffeine works on our brain and how it blocks Adenosine. That’s great to know and it also makes sense. I was also unaware of the oxidation process tea goes through. I always thought green tea had the most caffeine but I am totally wrong on that. I drink coffee in the morning and tea in the early afternoon and it definitely helps me avoid the caffeine crash. Thanks for sharing this info.!

      • Author gravatar

        Justin, thanks for the comment! It is fascinating to learn how caffeine truly functions in the brain with adenosine. It opened my mind when I learned that as well! Many people believe tea has a higher level of caffeine, but typically that is not true. This is excluding decaffeinated beverages which still contain a trace amount of caffeine (~5mg). I am glad to hear this article helped!

    • Author gravatar

      Interesting and informative post. I’m actually starting to enjoy an occasional cup of tea! I find your posts easy to understand and just the right amount of content. Keep posTEAing and enjoy the brew!!

      • Author gravatar

        Mia, thank you for the comment! Love to hear that these posts are inspiring you to branch out and try something new. I am glad that the content is easy to understand and informative! I always appreciate the tea puns too!!!

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