For some reason, it seems like I write a lot about caffeine on this blog. My three-part series on the subject is the most popular thing I’ve ever posted. My recent post about theanine talked about caffeine as well. One thing I haven’t addressed in detail is what happens to caffeine content when you blend tea with something else.
The first thing we have to do is clear our minds of preconceptions. Remember that there’s no simple formula saying that one kind of tea has more caffeine than another (see my caffeine myths article for details). And resign yourself to the fact that there’s no way short of spending a couple of thousand dollars on lab tests to determine how much tea is in a commercial blend, for reasons I’ll explain in a moment.
Let’s start with an example. Assume you have a tea you enjoy. You use two teaspoons of tea leaf to make a cup, and we’ll say this tea gives you 20mg of caffeine. You decide to use this tea in a blend. What happens to the caffeine level?
If you blend with other bulk ingredients, the caffeine calculations are simple ratios. If you blend the tea 50/50 with peppermint, then instead of two teaspoons of tea (20mg of caffeine), you’re using one teaspoon of tea (10mg of caffeine) plus one tablespoon of mint (no caffeine). You’ve cut the amount of caffeine in half. If your blend is 1/3 ginger and 2/3 tea, it will have 2/3 as much caffeine as the straight tea.
If you’re blending tea with other tea, the ratios work the same way. Blend together two tea styles with equivalent caffeine levels and the result will have the same amount of caffeine as the original tea blends.
All of this is contingent upon your measuring techniques. It becomes more complicated if you blend by weight instead of volume. Put together a cup of green tea and a cup of peppermint, and two teaspoons of the blend will contain (about) one teaspoon of tea and one teaspoon of mint. If you put together an ounce of gunpowder green tea and an ounce of peppermint leaves, the result is very different. Gunpowder tea is very dense, and peppermint leaves are light and fluffy. Two teaspoons of that mixture might only have a half teaspoon of tea, which means a quarter of the caffeine.
Extracts and oils
In many commercial tea blends whole ingredients like chunks of berry, flakes of cinnamon, and bits of leaf are more for looks than flavor. Soak a strawberry in hot water for three minutes and you’ll see what I mean. The real flavoring in those blends comes from extracts and essential oils that are sprayed on the tea leaves. In that case, the caffeine content is pretty much unaffected. A teaspoon of flavored tea leaves has the same caffeine as a teaspoon of unflavored tea leaves.
A little tea blending secret: sometimes the chunks of fruit in the tea really are chunks of fruit, but they’re not what you think they are. Tea blenders can purchase small chunks of dried apple that are sprayed with (or even soaked in) flavorings or extracts. Your piña colada blend might just be apple bits flavored with coconut and pineapple extracts. There’s very little flavor in the dried apple, so all you’re getting is the flavoring that was added. Why use them at all? Because it’s easy to experiment with, it doesn’t require the tea company to invest in leaf-spraying equipment, and it adds some visual variety to the blend. The chunks can even be colored.
A couple of real-world examples
Let’s start with genmaicha. This is a classic Japanese blend of green tea and roasted rice. I started with a tablespoon of my favorite genmaicha:
The base tea in this blend is sencha, which is fairly easy to recognize from the color and needle shape of the leaves. I don’t know the exact caffeine content of the sencha, but I can do a bit of Googling and come up with an estimate. Let’s go with 30mg per cup. Now, we’ll separate the tea leaves from the rice:
The main thing I learned from this exercise is that I don’t have the patience to pick all of the rice out of a tablespoon of genmaicha! The separation I did showed that a tablespoon of this particular genmaicha contained about 1/3 tablespoon of rice and 2/3 tablespoon of sencha. Since rice has no caffeine, that means a cup of this genmaicha probably has about 20mg of caffeine in it.
I was going to try the same experiment with a Moroccan mint tea, but found that the one I have on hand has no peppermint leaves. It appears to contain only tea leaves and mint extract. That means it has the same caffeine level as the tea used to make it — in this case a gunpowder green tea.
Doing the math
I don’t think you actually have to do much math to estimate caffeine levels. It’s imprecise at best because tea leaves don’t come labeled with their caffeine content. But if you look at a tea blend and it appears to be about half tea leaves and half something else, it’ll have about half the caffeine of the tea alone. Some blends I’ve looked at lately appear to have very little tea leaf — those might as well be decaffeinated tea! Others, like the Moroccan mint I mentioned a moment ago, are almost entirely tea, so treat them just as you would unflavored tea.
Back in my days in the software industry, I used to put on a lot of educational seminars. One day, I was teaching an all-day session and noticed one of my customers, a gentleman by the name of Ken Combs, sitting about fifteen rows back in the audience. At the first break, I went over to him and said, “What are you doing here, Ken? You could be teaching this seminar!” I absolutely loved his response: “I figure if I can learn one new thing, then the whole day is worth it.” Before using this insightful little anecdote to segue into the subject of this blog, I have to tell a little tale of that seminar. It was, as I said, an all-day seminar. I’m pretty good at projecting my voice, and when I’m dealing with small groups, I usually eschew microphones. This particular day, however, I had an audience of about 120 people and we were in a hotel ballroom with dubious acoustics, so I had a sound system. Like most hotel ballrooms, this one had accordion-style dividers that could separate it into smaller rooms, and we were using about a third of the room. The morning session went well, but the afternoon became Public Speaker Nightmare #23 ™: there was a wedding reception in the other part of the ballroom. They had a live DJ. He had a much more powerful sound system than I did. After about an hour with my sound system cranked up all the way, shouting into the microphone, I called a quick break and strolled over to the reception, where I asked the DJ if he’d mind taking the volume down a bit because he was making my job impossible. “Not my problem, dude,” he said as he cranked his volume up higher. We tried everything. We appealed to the bride. We called the hotel’s booking desk. We tried to find the weekend manager. And throughout it all, I shouted my voice raw trying to be heard in the back of the room. I couldn’t talk for two days after that (I’m not sure whether my wife wrote a thank you note to the bride for that or not), and we did end up getting a portion of our rent for the room refunded, but it made for one miserable seminar. Despite all of that, Ken learned his one new thing and I applied his philosophy from my side of the lectern and got much more careful about room bookings for future events. Remember I promised to bring this back to tea? Well, fast forward twenty years or so, and here I am at the World Tea Expo. I still try to follow Ken’s philosophy, and it serves me well. I attended two good educational sessions yesterday, which I’ll probably be writing more about: “Le Nez du Thé” (the nose of tea) and a tea blending workshop. I certainly learned more than one thing in each. After the exhibit hall closed, I went to the Tea Bloggers Roundtable. Mostly, I went for networking purposes, to meet some of these people I know only through their blog posts and tweets. It was a wonderful networking event, but even without that I learned something.
Yes, there was a bit of the mutual admiration society going on there, and the interplay was fun to watch (Godden and Coffey should take their show on the road), but it was also a very worthwhile session. There were more bloggers in the audience — including yours truly, of course — and the format was flexible enough that the distinction between panelist and audience member blurred. As everyone talked and questions were asked (and sometimes answered), it became clear that no two bloggers in the room really had the same objectives. For all of us, the blog is a representation of our personality enveloping the world of tea. Some of the blogs consist almost entirely of tasting notes (e.g., Nicole Schwartz’s “AmazonV” blog) and some have no tasting notes at all. We talked about tea, but mostly about the art of blogging, the expectations of our readers, and the trials and tribulations of trying to keep up any kind of a schedule for blog posts. I hope there’s another blogging event like this one again very soon!