Caffeine in relation to water temp and steep time

Hello. So common sense tells me that the hotter the water and the longer the steep the more caffeine will be extracted. But someone told me that the hotter the water the more the caffeine burns off. So does that mean quicker steeps with cooler temps extract more caffeine? I realize if thats the case there is probably a temp threshold where if its too low it wont open the leaves and extract anything. Any Theories?

21 Replies
Keemun said

The tannin in tea leafs dissolve slowly in water and change the effect of the caffeine . Means as longer one infusion goes as more caffeine loses is impact in terms of awakening effects…as it is fading away in this dissolving process. A 5-min tea infusion there does not necessary calm…it simply does not awake the drinker anymore…so to speak.

Most green teas should be allowed to steep for about three minutes, although some types of tea require as much as ten.

The strength of the tea should be varied by changing the amount of tea leaves used, not by changing the steeping time.

The amount of tea to be used per amount of water differs from tea to tea but one basic recipe may be one slightly heaped teaspoon of tea (about 5 ml) for each teacup of water (200 ml) (8 oz) prepared as above. Stronger teas, such as Assam, to be drunk with milk are often prepared with more leaves, and more delicate high grown teas such as a Darjeeling are prepared with a little less (as the stronger mid-flavors can overwhelm the champagne notes).

The best temperature for brewing tea depends on its type. Teas that have little or no oxidation period, such as a green or white tea, are best brewed at lower temperatures, between 65 and 85 °C (149 and 185 °F), while teas with longer oxidation periods should be brewed at higher temperatures around 100 °C (212 °F).53 The higher temperatures are required to extract the large, complex, flavorful phenolic molecules found in fermented tea, although boiling the water reduces the amount of dissolved oxygen in the water.

Type Water Temp. Steep Time Infusions
White Tea 65 to 70 °C (149 to 158 °F) 1–2 minutes 3
Yellow Tea 70 to 75 °C (158 to 167 °F) 1–2 minutes 3
Green Tea 75 to 80 °C (167 to 176 °F) 1–2 minutes 4-6
Oolong Tea 80 to 85 °C (176 to 185 °F) 2–3 minutes 4-6
Black Tea 99 °C (210 °F) 2–3 minutes 2-3
Pu-erh Tea 95 to 100 °C (203 to 212 °F) Limitless Several
Herbal Tea 99 °C (210 °F) 3–6 minutes Varied

Some tea sorts are often brewed several times using the same tea leaves. Historically, in China, tea is divided into a number of infusions. The first infusion is immediately poured out to wash the tea, and then the second and further infusions are drunk. The third through fifth are nearly always considered the best infusions of tea, although different teas open up differently and may require more infusions of hot water to bring them to life.

One way to taste a tea, throughout its entire process, is to add hot water to a cup containing the leaves and after about 30 seconds to taste the tea. As the tea leaves unfold (known as “The Agony of the Leaves”) they give up various parts of themselves to the water and thus the taste evolves. Continuing this from the very first flavours to the time beyond which the tea is quite stewed will allow an appreciation of the tea throughout its entire length.

Black tea

The water for black teas should be added near boiling point 99 °C (210 °F). Many of the active substances in black tea do not develop at temperatures lower than 90°C (195°F). For some more delicate teas lower temperatures are recommended. The temperature will have as large an effect on the final flavor as the type of tea used. The most common fault when making black tea is to use water at too low a temperature. Since boiling point drops with increasing altitude, this makes it difficult to brew black tea properly in mountainous areas. It is also recommended that the teapot be warmed before preparing tea, easily done by adding a small amount of boiling water to the pot, swirling briefly, before discarding. Black teas are usually brewed for about 4 minutes and should not be allowed to steep for less than 30 seconds or more than about five minutes (a process known as brewing or mashing in Britain). It is commonly said that a steeping time above five minutes makes the tea bitter (at this point it is referred to as being stewed in Britain), but in reality the precise time depends on a number of factors, such as the type of tea and the water quality, and bitterness can occur as early as three minutes, or not at all even after prolonged steeping. When the tea has brewed long enough to suit the tastes of the drinker, it should be strained while serving. The popular varieties of black (red) tea include Assam tea, Nepal tea, Darjeeling tea, Nilgiri tea and Ceylon tea.

Thanks for the post. I’m very familiar with the temps required for teas. I was just curious about caffeine in relation to water temp. Your first paragraph confirmed what someone told me about the caffeine dissolving. thanks!

Hi Keemun,
I know this thread is old, but I still give it a chance.
You wrote “The tannin in tea leafs dissolve slowly in water and change the effect of the caffeine”. I’ve already heard that, but never found the “proof”. Do you know what’s the biochemical mechanism underlying this phenomenon ? Maybe you know a scientific paper talking about it ? I’d be very interested !
Thanks

Keemun said

Dear Sir
…I just found this. http://en.wikipedia.org/wiki/Talk%3ATannin
Read it throu and let me know what you think.

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I read this from heavenoftea.com:

To Decaffeinate your Tea: Steep your tea leaves at the temperature suggested for 20 seconds. Then drain the liqueur and resteep the leaves in fresh hot water for the recommended time. This first steeping removes the majority of the caffeine (it will still have a small amount).

I personally resteep at a slightly higher temperature for a shorter period of time, but you should try it a couple of ways to discover what works best with the specific tea you’re trying to decaffeinate. This is a great trick when you usually drink caffeinated teas, but really want a cup late at night. You can enjoy the tea while washing away the caffeine content!

So would that mean that the opposite of doing that would produce more caffeine?

Hello. I wasn’t trying to decaffeinate my tea. In fact caffeine is a big reason why I drink tea in the first place! I am simply wondering about the effect of water temp on caffeine extraction. And I don’t agree with people who claim that you can “decaffeinate” tea by steeping them a little to drain it off, becasue usually the leaves only partially unfurl during the first steep which means that part of the leaves haven;t even touched the water or only partly touched the water. So in my opinion each steep yeilds caffeine until the leaves are totally unfurled. Kanpai!

The first steep definitely contains the vast majority of the caffeine in the tea, and flushing the first infusion is definitely a good way to limit caffeine, if that is someone’s goal. I agree somewhat that for tightly rolled teas like ball oolongs this may not work quite as well. However, typical gong fu practice with these types of teas calls for a high-pour of water of the first infusion to “awaken” the leaves. The heat and pressure surely draws out a lot of the caffeine as well.

Cofftea said

I have a hard time believing a rinse of 30 sec or less gets rid of the majority of the caffeine, but maybe I’m wrong. Another thing to remember is sometimes you start off w/ more leaf for a tea you’d rinse vs. a tea you wouldn’t. For example, for pu erhs I tend to use 1g of tea per 1oz of water. 6g of tea has more caffeine than a cup w/ only 2.25g.

Ghostea said

This conversation is very interesting and insightful.
What I’m taking from this is basically that, if you soaked tea in cold water for around 10 minutes, then soaked for 1 minute in hot water and discard the liquid, we could actually achieve more realistic results of decaffeination that may match earlier estimates of the percentage removed.
I believe someone should research this method and publish the results!

This is from the tea subReddit:

How much caffeine is in tea?
There is a lot of good information out there about the caffeine content in tea, but there is also a lot of bad information out there. Here are some great resources to clear up some of the hype/myths surrounding caffeine levels in tea:

CAFFEINE AND TEA: Myth and Reality by Nigel Melican http://chadao.blogspot.com/2008/02/caffeine-and-tea-myth-and-reality.html

Debunking the At-Home Decaf Myth by Bruce Richardson (submitted by UnwashedMeme) http://elmwoodinn.com/about/caffeine.html

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Cofftea said

Here’s some great info. This is a company that exclusively sells Japanese greens, but maybe other teas are the same way?
http://www.denstea.com/index.php?main_page=perfect_brewing

Thanks Cofftea! That chart is very informative. Cheers!

Cofftea said

Glad it’s what you needed!

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IIIIII like the info being provided here.

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Might be a bit off topic, but I also read somewhere that most if not all the decaffeinated teas out there still have at least some caffeine in them, so do not trust decaffeinated ones too much!

Cofftea said

Yep. ~5-10mg.

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S said

This is off-topic, but OMG KITTY ICON <3

Hey Shanti. Glad you like my kitty icon. I like yours too! so cute!

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Small tidbit of information from
“The Tea Companion” by Jane Pettigrew:

“When hot water is poured on [tea], the tea solubles (caffeine, tea polyphenols, and various volatile components such as essential oils) are released into the water at a rate of concentration which gradually decreases over time.” (65)

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If you put tea leaves in boiling water, they will release their caffeine property within seconds, after which you can place them in a different pot an enjoy without fear of being up all night. Conversely, the longer you steep tea leaves, the more caffeine they will eventually release (although the bulk does go out in the first few seconds).

And zeitfliesst was right, even decaffeinated teas have a little pep in their step.

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Lilysmom said

If you cold steep black tea, do you think you get any caffeine? I doubt you get much, unfortunately…….

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