That’s not just a clickbait title.
What you read below will surprise you.
That’s because so much of the information you find online regarding the caffeine content of various teas is flat out wrong.
Almost all sources tell you that black tea has the most caffeine. But that isn’t really true.
Black tea leaves actually tend to have less caffeine than other tea leaves. But a cup of brewed black tea has more, on average.
In the end, it’s actually up to you.
How is this possible? And how can you control the amount of caffeine in your tea? Let’s find out.
Table of Contents
- 1 Which Tea Has The Most Caffeine?
- 2 Caffeine Content Of Specific Teas
- 3 Daily Caffeine Limits
- 4 Tea With The Most Caffeine: Final Thoughts
Which Tea Has The Most Caffeine?
Generally, a tea’s caffeine level correlates with the steeping duration. Longer steeping times provide higher caffeine levels.
In practical terms, a cup of black tea usually has higher levels of caffeine, because it generally steeps for the longest period of time.
However, if you look at the original composition of the tea leaves, white tea leaves contain much more caffeine by weight.
But since you don’t usually steep it as long as black tea, the resulting cup of tea has less caffeine in it.
Factors Affecting Caffeine Levels in Tea
Did that answer surprise you? I know I was a bit shocked when I just started learning about tea.
Let’s explore the intricacies of tea to understand why any type of tea, be it black, white, green, etc. can have high levels or low levels of caffeine.
It depends on a number of factors. The type of tea is not one of those factors.
As mentioned, a cup of black tea has a higher caffeine content on average because of the longer infusion time. The higher steeping temperatures also extract more caffeine from the leaves.
But if you use cooler water and a shorter steeping time, the resulting cup of black tea will have far less caffeine than a cup of white tea or most green teas.
That’s because numerous other factors influence caffeine levels in your tea, from where you source the tea to how it is cultivated.
External conditions, like altitude, type of fertilizer, and the environment, can affect the caffeine level just as much as the grade of the leaf.
But remember that a long steeping time will always result in more caffeine. How long you steep the leaves has the largest impact on the amount of caffeine that actually ends up in your cup.
Let’s look at the main factors that affect how much caffeine is in a cup of tea.
Tea varietals are one significant factor. All tea comes from the same plant, called the tea plant.
It shows up in two primary forms: Camellia sinensis var. sinensis, generally found in China, and Camellia sinensis var. assamica, which tends to grow in India.
Typically, leaves of the assamica variety have higher levels of caffeine.
Harvest time is another consideration. Typically, if farmers harvest the tea in spring, it will have a higher caffeine level than teas harvested later in the year.
Teas that fall into this spring category include silvertip white teas, gold tipped black teas and the higher quality Darjeeling teas.
Since plants have smaller leaves and buds earlier in the year, you’ll find a higher caffeine concentration in the parts taken.
Changes in growing practices can also result in an effect on caffeine levels. One example is putting tea plants in the shade for several weeks before harvest.
Matcha is also made from shade grown leaves. Since the entire leaf is ground up to make matcha powder, and then consumed, a cup of matcha has a far higher caffeine content than other teas.
After harvest, processing plays into the total caffeine content as well. For example, tea leaves that are roasted to stop fermentation tend to have lower levels of caffeine than leaves that are steamed.
Japanese green tea leaves are usually steamed, while Chinese green tea leaves are roasted. Sencha is the most famous Japanese steamed tea and Dragon Well is probably the most famous Chinese roasted tea.
Finally, there’s the actual preparation and ingestion of tea in your home. As mentioned, this ends up having the largest impact on the amount of caffeine that ends up in your cup.
Specifically, a longer steeping time is the primary factor in determining how much caffeine is extracted from the leaves. But water temperature also plays a part.
Boiling water cool water pulls out more caffeine than cooler water. And of course, don’t forget the amount of tea leaves you use. More leaves means more caffeine. That should be obvious.
Additionally, pulling more caffeine (and along with it other particles like tannins) out of the leaves and into your cup can lead to your tea being cloudy when it cools down.
Measuring Caffeine Levels In Tea
There are many ways that caffeine is measured, depending on when in the lifecycle of a cup of tea you calculate it.
As a result, it’s hard to make an absolute determination on which tea has the highest and lowest amount of caffeine. All the factors mentioned above play a role in the chemical makeup of the tea you’re drinking.
Any tea manufacturer can choose to take one aspect and declare X-amount of caffeine in this tea bag or this loose-leaf tea. But where they’re taking their data from is essential.
They could be measuring the caffeine content at an ideal moment in time when it is exactly what they want, but it could change later down the line due to processing.
Quantity is a significant factor, too. Obviously, the more you drink, the more caffeine you will be getting.
And keep in mind that tea isn’t just caffeine. It also contains many other ingredients that are often much more beneficial, like EGCG and L-theanine. Some of these ingredients can also increase awareness and concentration without giving you the trademark caffeine buzz.
Caffeine Content Of Specific Teas
Now that we’ve covered some general rules around tea and caffeine content, we can dive more into each variety of tea and how they differ, as well as what makes each unique.
First, you need to know that three parts of the tea plant are used to make tea.
The tea bud is the youngest and most caffeinated part of the plant. From the bud, a young tea leaf develops. It is bright and fresh, and contains a good amount of caffeine, but less than the bud. The mature tea leaf has the lowest amount of caffeine.
Green tea is a popular variety made from the Camellia sinensis plant. Most green tea is made from younger leaves, meaning they have a somewhat higher caffeine content.
Steamed green teas have more caffeine in their leaves than roasted and shade-grown leaves have more than those grown entirely in the sun.
Green tea does not typically steep as long as black tea, because the leaves are more delicate and easy to scald. For the same reason, cooler water (around 80 degrees Celsius) is used in brewing.
Brewing the leaves for too long and with water that is too hot results in an overly bitter cup (but one with more caffeine).
This is why a cup of brewed green tea generally contains less caffeine than a cup of black, despite the green tea leaves containing more caffeine on average.
Oolong tea varies greatly. Some is lightly fermented like green tea, while other varieties are fermented much longer, close to black tea. Steeping times vary as well, with darker oolongs steeping longer, resulting in more caffeine in the cup.
Most oolong teas are made from older leaves, which means lower caffeine. The leaves are also usually roasted, not steamed, which also means less caffeine.
White tea has the most caffeine by weight and leaf amount of any type of tea. That’s because it is made from young leaves.
Because these parts of the plant are more delicate and white leaves are not fermented, you need to use shorter steeping times and cooler water. This results in lower amounts of caffeine in your cup.
By now, you know that a cup of black tea generally has the highest caffeine level of all teas because of its long steep times and high temperatures. But most other types of tea have more caffeine in the leaves.
But there is a lot of variation among black tea types. Most use old leaves, which contain much less caffeine.
But some varieties are made from the young buds, just like white teas. The difference is that the black teas are fermented. The leaves contain more caffeine than other black teas. And they are also steeped for a longer time, so teas like this, Golden Monkey for example, have high levels of caffeine.
As mentioned, the assamica variety of tea plant contains more caffeine naturally, so teas made from this type have a higher caffeine content on average.
Assam black tea is made from this plant, but it is made from older leaves, so the caffeine content does not end up being too much higher in the end.
Herbal teas don’t come from the caffeine-rich tea plant. Instead, they’re made from various other plants, most of which do not contain caffeine.
Common herbal teas are peppermint, chamomile, fruit teas, and even stronger-tasting ginger teas. None of these contain caffeine.
But if those herbs are combined with regular tea leaves, then the resulting herbal tea contains the caffeine of the underlying tea. Read “Does Black Currant Tea Have Caffeine?” for more on this.
Yerba Mate is also from a completely different plant: the Ilex paraguariensis. It is found in South America and is known for its generally high caffeine content, beating out most regular teas.
Daily Caffeine Limits
When drinking caffeinated beverages, it’s crucial to stay within a safe limit for your body. Too much caffeine can lead to anxiety, insomnia, and even digestive issues.
The general daily recommendation is that you should only consume 400 milligrams per day — a figure I have no trouble hitting on a busy day. While this amount equals about four cups of coffee, it is around 8 cups of tea, depending on the type and brewing method.
Suppose you’re looking for the energy-boosting effects of tea. In that case, I highly recommend matcha, or a black tea, if you do not like the taste of matcha (not everyone does).
If you are trying to temper the amount of caffeine, use a tea made from older leaves and a shorter steeping time.
There is nothing wrong with a shorter steeping time for black tea, as long as you don’t mind the milder taste. Similarly, you could steep white or green tea longer, if you want more caffeine and you don’t mind a more bitter flavor.
You could also mix different types of tea leaves. Mixing green tea leaves with black tea leaves means you can use a shorter steeping time and still get plenty of flavor.
Tea With The Most Caffeine: Final Thoughts
While you might be surprised that black tea leaves generally contain the least caffeine out of all the tea types, you are probably not surprised that a brewed cup of black tea usually ends up stronger.
In the end, it is the steeping time that has the biggest impact. Use that knowledge to your advantage to increase or decrease the amount of caffeine in your cup to your preference.