I am often asked questions such as the following.
> “I’m beat; I need a pick-me-up. Which one of your teas has the most caffeine?”
> “I don’t tolerate caffeine very well. Which one of your teas has the least caffeine?”
Unfortunately, these questions are not easy to answer. As our knowledge of tea cultivation, processing and brewing has increased, any generalizations about caffeine content in tea have become very murky.
The Only Two Things We Know for Certain
There are only two answers I can give with any certainty.
> If you want to avoid caffeine completely, you cannot drink anything containing tea leaves from the Camellia sinensis plant. The only “tea” with no caffeine is made with herbs and/or fruits. In other words, infusions or tisanes. (Please note that there are a few herbs such as yerba mate, yaupon and guayusa that do contain caffeine.)
> If you want a real tea (made with leaves from the Camellia Sinensis plant) but want to minimize caffeine, we recommend decaffeinated tea. Brews made with these teas have very low caffeine, but not zero.
What Actually Determines Caffeine Levels?
Apart from these two statements, it is nearly impossible to direct you to teas with higher or lower caffeine content. The caffeine content of a cup of tea depends on myriad factors, such as the age of the leaves, the variety of tea bush, how the bush was propagated, the amount of nitrogen fertilizer used, the growing season and the methods used in processing the tea. Here are some examples.
- It has been shown that green and black tea made from leaves plucked from the same bushes on the same day have virtually identical levels of caffeine.
- Green tea from a plant in Japan may have more caffeine than green tea from China.
- Younger tea leaves and buds tend to contain more caffeine than older leaves. Thus, teas made with these younger leaves, such as a 1st flush Darjeeling or Silver Needles, could have more caffeine than other teas.
- If you have read my Tea Primer, you will know that all “real” tea comes from the Camellia Sinensis plant. Still, there are two main varieties, the Sinensis variety and the Assamica variety. The leaves of the latter variety tend to have more caffeine than those made from the Sinensis variety. As a result, our Assam teas may be higher in caffeine than some of our other black teas that are made from the leaves of the Sinensis variety.
What the Research Says
In one of the most scholarly books about tea, the authors tested 30 teas brewed to very specific standards. In the list of the 10 teas with the highest caffeine concentration, there is one black tea, two puerhs, five green, one oolong and one white. Among the 10 teas with the lowest caffeine are one black, five green, three oolongs and one white. That demonstrates that there really isn’t much of a pattern when comparing tea types by caffeine content.
In a 2008 study published in the Journal of Analytical Toxicology, the authors tested the caffeine content in 20 different teas. According to the results, they found “no observable trend in caffeine concentration due to the variety of tea.”
How Brewing Affects Caffeine
The way we brew tea also affects the amount of caffeine that is in the cup. Factors involved are the amount of tea leaves we use, the water temperature and the brew length. The more tea we use, the hotter the water and the longer we brew it, the more caffeine will be in the cup.
The Decaf Brewing Myth
Another myth is that if you do a quick 30-second brew, throw that brew away and brew the leaves again, you will have basically produced a decaffeinated tea. Studies have shown that less than 10% of the caffeine is removed in a 30-second brew. It would take over 5 minutes to remove 80% of the caffeine and over 15 minutes to remove all of it. The problem is that it would also remove all the flavor, making the subsequent brew unpalatable.
Why Tea Both Energizes and Relaxes You
Tea is a unique beverage in that it claims to relax us while also sharpening our minds and focus. How can this be? It can certainly not be explained by caffeine alone.
Let’s contrast coffee and tea and how caffeine affects our bodies. Although the caffeine is identical in coffee and tea, in the latter, it combines with polyphenols/tannins. This results in the caffeine being absorbed into our bodies more slowly over a longer period of time. Thus, the effects of the caffeine last longer and are more regular. The effect is that tea can sharpen the mind, increase concentration and lessen fatigue. In contrast, caffeine in coffee is an excitant, causing a direct increase in heart rate and a jittery feeling. Just one great reason for recommending tea over coffee!
Besides caffeine, tea does contain other stimulants. These include theine, theobromine and theophylline. On the other hand, tea also contains L-theanine, an amino acid with calming and relaxing properties.
Recent studies suggest that this combination of caffeine and L-theanine is effective at helping one focus. These randomized controlled studies have shown that tea consumption can help with attention & alertness. It is believed this is due to consuming a high dose of L-theanine alongside lower levels of caffeine. Also, because L-theanine reduces the cortisol response to acute stress in humans, tea is considered an optimal beverage during periods of elevated stress and burnout.
Tips for Caffeine-Sensitive Tea Drinkers
A final point is that caffeine affects different people differently. If you think you are caffeine-sensitive, you may want to start logging what happens when you drink tea. Note the type of tea you are brewing, how many leaves you use, the temperature of the water, how long you brew it for, the time of day, and how it affects you. Armed with that information, you are going to be able to choose teas in a more informed way.
At Tea Journeys, we believe the best cup of tea is the one that works for you. Whether you’re seeking a gentle morning lift or a calming evening ritual, we’re here to help you find it. Peruse our collections, ask questions, and let’s explore together.