Some days ago a Japanese friend send me a picture.
It looked like crystals that had grown on top of some of the tea leaves.
She told me that it was caffeine.
Caffeine? I was skeptical at first.
But as I searched online, I became convinced.
It turns out that she was using a chakōro (茶香炉, tea leaf burner).
It’s just like an incense burner, but you add tea leaves instead of incense.
I’ve never actually used one, but it’s on my wish list.
Anyway, the explanation that I saw online was that caffeine sublimes (starts as a solid and turns into a gas) because of the heat.
But then it turns back into a solid as it cools, and that’s how the crystals form.
If you taste the crystals, you’ll notice that they are bitter.
That’s because caffeine itself is very bitter.
While it rarely happens, you might end up with these crystals inside your newly bought tea.
I imagine that this happens during the hiire (firing) stage of the process.
Last week I received a message about this from a reader. What a coincidence.
There’s no need to worry.
Since the caffeine crystals come from the same tea leaves, they do no harm.
I’ve never seen them in real life, unfortunately.