TeaChat

I've been scouring the forum for studies measuring mg caffeine in tea. Normally I don't really care, but special circumstances make me much more curious right now.

I brew my black teas western style, so the http://elmwoodinn.com/about/caffeine.html study has convinced me that my 5g of black tea probably contains 100-150mg of caffeine in the first 3 minute steeping, and about half that in the second ~8 minute steeping.

However, I can't find anything satisfactory about sencha. The studies I've seen all seem to use either "green tea" or something else that evokes a Chinese green to me. I would love to see a study that says 5g of sencha contains X mg caffeine since I assume that my 5-7 steepings will extract nearly all of it. Help?

It's all so variable, I would be surprised if they can come up with a number that represents sencha as a whole within 100 mg or so

That's a good point, I'm sure there is a lot of variation based on level of steaming, etc. I'm still holding out hope for some ballpark numbers though.

You can send an e-mail to Camellia Sinensis. They had some of their teas analyzed in a lab.

If you check DOI: 10.1021/jf980223x they tested several types of Japanese green tea for caffeine content. You can see that they range from 6.90 to 9.57 mg per 100mg of dry leaf.

so for 5g that's 345mg-479mg

Bef wrote:You can send an e-mail to Camellia Sinensis. They had some of their teas analyzed in a lab.

Thanks, that's a great suggestion.

entropyembrace wrote:If you check DOI: 10.1021/jf980223x they tested several types of Japanese green tea for caffeine content. You can see that they range from 6.90 to 9.57 mg per 100mg of dry leaf.

so for 5g that's 345mg-479mg

Thanks so much for looking that up, that's really helpful! Looks like I'm going to being having some teeny tiny sencha sessions.

Devoted135 wrote:

Bef wrote:You can send an e-mail to Camellia Sinensis. They had some of their teas analyzed in a lab.

Thanks, that's a great suggestion.

entropyembrace wrote:If you check DOI: 10.1021/jf980223x they tested several types of Japanese green tea for caffeine content. You can see that they range from 6.90 to 9.57 mg per 100mg of dry leaf.

so for 5g that's 345mg-479mg

Thanks so much for looking that up, that's really helpful! Looks like I'm going to being having some teeny tiny sencha sessions.

Time to look for this teapot...

Just found the topic by chance but found it quite interesting!, , and the comments quite valuable.

I was sorry to learn that white and green teas has potentially as much caffeine as other teas.

Anyway, I would like to add a word of caution. When steeping the tea we are extracting water soluble compounds from the leaves, the amount we extract depend on the quantinty of leaves we use, the steeping time and the water temperature. So some of the data on caffeine on the caffeine content of the leaves give us a maximum value of the caffeine we may expect in our cup.

entropyembrace wrote:If you check DOI: 10.1021/jf980223x they tested several types of Japanese green tea for caffeine content. You can see that they range from 6.90 to 9.57 mg per 100mg of dry leaf.

so for 5g that's 345mg-479mg

Very interesting. While looking for it, I found a recent reference in the same journal (doi: 10.1021/jf202304z) that look at the content of the leaves depending on the position (age) of the leaves. The used leaves (yabukita) from a single tea garden, but found the amount caffeine increases from stem to first leaves. Maybe is common knowdledge but I found it interesting.

Hey I was right after all, imagine that