Recently I’ve had a few tea curious people ask me about the amount of caffeine in tea. And honestly, the answer is not really that straightforward! But I thought I would pull together some information for you that will hopefully make it somewhat easier to understand where the various styles of tea roughly sit on the caffeine content scale. This info comes from a couple of sources which I’ve listed at the end of the article should you want to do further reading, and is certainly by no means exhaustive or definitive.
Background: A (Very!) Brief Science Lesson
- The unique properties of tea are due to the presence of alkaloids and polyphenols.
- The polyphenols in tea are commonly known as tannins.
- Tannins are responsible for the astringency and strength of a tea.
- Alkaloids are naturally occurring molecules which contain nitrogen and are found in amino acids.
- Three types of alkaloids are found in tea, with caffeine being the main one.
Caffeine in Tea vs Caffeine in Coffee
In 1838 it was found that the caffeine in tea and the caffeine in coffee are in fact one and the same. However, how the caffeine behaves in the body is where a significant difference arises.
When we brew tea, the caffeine combines with the tannins that we spoke about above. The bond that forms between the caffeine and the tannin means that the caffeine is slowly absorbed by the body as it first has to break the bond between the caffeine and the tannin. As a result, the body absorbs the caffeine over a longer period of time thus evening out the effects i.e. You don’t get a quick high and then a noticeable crash afterwards. In coffee however, no bonds need to be broken and the caffeine is quickly absorbed directly into the bloodstream, thus we get a noticeable spike in energy, followed by a dip.
So now that we have some basics out of the way, let us get on to comparing the caffeine content of different beverages. In this table we are looking at the amount of caffeine in 100ml of each particular beverage.
I hope this has helped you understand the caffeine content of tea in relation to a number of other beverages. The important thing to remember is that this is not definitive. Factors like the age of the leaf and processing methods can have an impact on the caffeine content of tea so remember this is just a ball park guide.
P.S The above is a synthesis of information from:
1. Tea: Histories, Terroirs Varieties. 2nd ed. by Kevin Gascoyne, Francois Marchand, Jasmin Desharnais and Hugo Americi
2. The Alcohol and Drug Foundation Caffeine Fact Sheet: https://adf.org.au/drug-facts/caffeine/