Is it common to brew Japanese tea in a gaiwan?

[Chip]

In my experience, not only are many Japanese infusion vessels not intended to be filled completely, there is an advantage to not doing so with fukamushi sencha. A slight graceful swirl in the wrist motion of the pour brings the smallest leaf particles to the surface and they wind up in the cup in the early infusions, not giving them time to develop bitterness.

I still maintain that with good Japanese greens you don't need anything but a cup and a strainer that fits the cup if you control the temperature and the pour properly. But it's not the easiest answer.

I see you have taken Advanced Brewing 301 and 302.

Having been there and done that with brewing Japanese teas in many contraptions during a time when there were no kyusu to be found for a Westerner, it is still such a pleasure to pick up a fine kyusu and go through the motions.

It was like a revelation from the very first time I finally had the opp to use a kyusu, and it was even a crappy one. But I was sooo thrilled to finally have one.

[Chasm]

I see you have taken Advanced Brewing 301 and 302.

Otherwise known as what happens when a research engineer turns their focus on tea. Some of my Japanese pots just don't handle like they were meant to be filled all the way. Experimenting with the pour gives an idea of how far the pot was meant to be filled. So why would someone make the pot that way? Well, why not, for teas that can easily be cooked instead of infused? It's not like you need optimal heat retention. What happens if you pour it in any of a hundred different ways you can think of if you try hard enough?

Yeah, I take lab notes too. Not all the time, but enough of the time. I'm like a kid with a chemistry set.

[David R.]

Some of my Japanese pots just don't handle like they were meant to be filled all the way.

I agree. I buy kyusu that are twice the size I wanna use, usually around 20cl. It was an advice given to me by an advanced japanese tea drinker. I have always followed it blindly, and I am quite happy with it. Doesn't say, it wouldn't work otherwise, but it seems easier to deal with filter/pouring issues.

[Chip]

... not to mention when filling significantly less than full, the leaves are much less apt to find their way onto the lid.

For sencha in a kyusu, I fill 2/3-3/4 full, sometimes a bit less.

For gyokuro however, I might fill more than 3/4 and after a steep or two, taking into account the now fully reconstituted leaves, the houjin may be virtually full.