Caffeine In Tea
OK before you shout, “It’s Theine!”, let me explain. It was originally called Theine when caffeine was first discovered in tea in 1827, but as it’s essentially the same thing, so we all now talk in terms of caffeine.
Caffeine’s not a bad thing sent by the devil to destroy humankind. It has its place in our lives and taken in moderation, can be very useful to us. It increases alertness, has a stimulating effect on our metabolism and can also help to increase the dopamine levels in the blood, which lift our mood. Remember, we are talking about moderate amounts of caffeine here, but be aware that too much caffeine can ruin all this loveliness and may produce a less positive outcome.
I’d like to start by exploding some caffeine in tea myths:
#1- “Black tea has more caffeine than green tea”
As Jimmy Somerville would sing “It ain’t necessarily so”. Some of the factors that contribute to the levels of caffeine found in tea are explained a little later.
#2- “The darker the colour of the tea, the more caffeine it contains”
Er…rubbish! Some white and green teas that have pale infusions contain more caffeine than some black teas which infuse to a much darker colour.
#3- “ You can decaffeinate tea by infusing for 30 seconds, then pouring away the first infusion!”
This is a biggie. This has been branded around for years but is simply not true. What is true is that the first infusion does remove some of the caffeine. Here are the facts:
In 1996, Hicks et al published a research study in Food Research International concluding that, to remove 100% of the caffeine from tea, you need to infuse it for 15 minutes and then re-infuse the leaves. Unfortunately, that would probably take most of the flavour from the tea too. However, if you steep a black tea for 5 minutes and then infuse the leaves again, that would reduce the caffeine content by around 70% and still keep a good level of flavour.
Here is the data from their research, which displays how much caffeine is reduced after initially steeping the tea for the time shown:
30 seconds – 9%
1 minute – 18 %
2 minutes – 34%
3 minutes – 48%
4 minutes- 60%
5 minutes – 69%
10 minutes – 92%
15 minutes – 100%
It is important to add at this point that the antioxidants and other health benefits of tea tend to be extracted more quickly than the caffeine. As a result, if you quickly infuse the leaves for 30 seconds or so and then pour it away, you are reducing the healthy elements found in tea and just a small amount of the caffeine.
How Much Caffeine Is In Tea?
This is a tough question because there is no straight answer, but I’ll do my best.
All teas, Black, Green, Oolong and White, come from the same plant, Camellia Sinensis and therefore, all have similar amounts of caffeine content, around 28 – 68 mg per 200ml cup. That probably doesn’t mean much until you compare it to coffee, which contains around 135mg for the same cup. Obviously, it doesn’t have to be the same cup, you can use another cup, but you get the idea.
Other Factors That Contribute to Caffeine Levels in Tea
The new buds and younger leaves tend to contain more caffeine than the more mature, lower leaves of the plant.
Also, the region where the tea is grown, the terroir and the variety of the tea plant, all have an effect on the caffeine content.
For example, the large leaves of the Indian Assam tea plant, Camellia Assamica, have higher caffeine levels than the smaller leaves of the China tea plant, Camellia Sinensis.
More caffeine will be transferred to your cup when the tea is brewed with water at a higher temperature and also when steeped for longer. So, because Black tea is infused with boiling water for 3-5 minutes, it will extract more caffeine than say a Green or White tea, which is typically steeped for 1-3 minutes in cooler water.
This goes some way to explaining the misconception that black tea has more caffeine than other teas because it is fully oxidised. In fact, it’s more to do with its preparation and nothing to do with the amount of oxidisation.
Typical Steeping Temperatures
Black teas – 3-5 minutes in Boiling water (100°C)
Green & White Teas – 1-3 minutes in slightly cooler water (75-85°C)
Caffeine in Tea vs Coffee
I’d just like to get something straight, this isn’t a competition between tea drinkers and coffee drinkers. I know some coffee drinkers that are perfectly decent people. Now that’s off my chest, on with the story…
You may find it strange to know that dried tea leaves and dried coffee beans can both have very similar amounts of caffeine per kilogram, and some tea leaves actually have more than coffee. However, when you consider that you need about 10-12g of coffee to make a cup of coffee, yet only 2-3g of dried tea leaves to make the equivalent cup of tea, you can see why we intake less caffeine from tea.
The caffeine in coffee, apart from being more in a typical cup than tea, is absorbed more rapidly by the body. This can cause an immediate increase in blood circulation and cardiovascular activity.
Conversely, L-theanine, an amino acid found only in tea, has a relaxing effect that counteracts the jitteriness of caffeine without reducing the increase in alertness.
Certain polyphenols in tea also slow down the absorption rate of caffeine, meaning you get the benefits more gradually and a sense of revitalisation for longer periods of time, without the dreaded crash.
So let’s do some calculations:
3 x 6 = 18
24 – 23 = 1
45 + 3 = 48
I feel better now. OK, back to tea and the final question…
Caffeine – How much Can I Take?
The recommended amount is not more than 6 cups.
You should remember though that we are all different. I personally can drink all day and all night and still sleep like a baby, figuratively speaking, not in a cot and I certainly don’t need a nappy (despite the rumours).
You know your body better than anyone else, so recognising how your body reacts to caffeine, will determine how much you should consume.
Caffeine Free-Tea Choices
Decaffeinated tea, in fact, is not caffeine free at all. It still contains around 5-10mg per cup, so if you are Caffeine intolerant or just prefer caffeine-free beverages, there are lots of wonderful and delicious Tisanes to choose from including Rooibos, Nettle, Red Fruits, Pinacolada, Peppermint, etc.
There is a good reason why tea conjures up images of relaxation and Zen. If you were planning to marry a drink, tea is the one you would take home to meet your parents. It’s gentle, kind and good for you, but it also provides you with stimulation when your parents aren’t looking. Just remember what I said at the beginning, although caffeine has a bad boy reputation, it has lots of good qualities too.
If you are worried about the effects of caffeine, you should always consult a professional medical person for advice.
What About You?
Are you sensitive to the effects of caffeine? Can you drink all day or night without a worry? Will this information help you to decide which teas to drink at certain times of the day? Don’t make me beg you – just leave a comment below 🙂
If you enjoyed this article, please rate it with the stars or better still, share it with someone, day or night, using the lovely decaffeinated buttons below.
Also, don’t hesitate to contact me if you need any other information or advice…but don’t ask me where to buy coffee…I don’t know!
Have a Steeping Time