What is a Kyusu

A kyusu (sometimes spelled kyuusu)is a Japanese teapot used for drinking Japanese green tea. The most common type of kyusu has a handle on the side, though it can have a handle over the top, or on the back. It is typical for someone to use the term kyusu to refer only to a teapot designed for sencha, and use more specific terms for teapots designed for other teas.

kyusu japanese teapot in nature

Basic Form & Style of a Kyusu

Kyusu teapots are small by most Western standards. A typical size is around 270ml (9 floz), but they can also be a lot smaller.

The style of a kyusu can widely vary. Colours, shape, handle placement can all be different, but one design feature that needs to always be addressed is that Japanese green tea needs lots of room to brew. With this in mind, most kyusu come with a built in filter, rather than an infusing basket.

Some do not have lids. These are called futanashi kyusu. In order to make up for heat loss, the walls of the lidless teapot are thicker.

lidless futanashi kyusu

The Filter of a Kyusu

Japanese green tea leaves can be very small. The filter needs to have small holes in order to prevent excessive amounts of leaf from passing through.

There are many different types of filters, but some of the most popular are:

Wrap Around/Belt Filter:

A wrap around filter is typically made of stainless steel. With a large surface area, a wrap around filter will have a fast pour time. The stainless steel design also has a fine mesh which keeps leaf from passing through, or getting stuck in it.

The term “belt filter” usually implies that the stainless steel mesh wraps 360 degrees around the inside of the teapot.


Sasame Filter:

Sasame filters are a series of small holes made directly in the ceramic of the kyusu. Some tea drinkers believe a sasame filter is more authentic, and more visually appealing. The downside to a sasame filter is that they may pour slower, and allow more leaf to flow through them.

Note that some sasame filters can have a more elaborate array of holes, and some may have been created with a folk art approach.

sasame filter japanese teaware

Swing Filter:

Between infusions, a few drops of tea may still be trapped inside of the kyusu. To prevent the leaves from infusing, a swing filter spans the bottom of the teapot, keeping the leaves above the extra liquid. However, some types of fukamushi sencha can make the pour time very long with this style of filter.

kyusu with swing filter

Glazed versus Unglazed

On the outside of a kyusu, glaze/unglazed is an aesthetic choice. On the inside, it changes the function.

Kyusu that are unglazed on the inside allow the tea to brew directly against the clay. As clay is porous, over time it will absorb some aspects of the tea. It is believed that this absorption process makes the taste of the tea better over a long period of time. However, if a tea drinker brews a different type of tea in an unglazed kyusu, they risk having the flavours of that tea absorbed into the clay, negatively changing the taste of what they usually brew.

A glazed kyusu is more versatile. Different types of tea can be brewed in it without worry. But, unlike its unglazed counterpart, it will not have the same positive effect over time.

More Facts & Tips About Kyusu Teapots

For such a simple device, there are a lot of intricacies in a kyusu. Here is a short list of some more facts:

  • Many kyusu have a dip around the bottom on the inside. This acts as a small gulley for excess water to go to between infusions, in order to prevent the leaves from brewing in the left over drops.
  • Often, a kyusu will come with a plastic ring around the spout. Some tea drinkers keep this on, as it helps prevent drips from happening while pouring.
  • A common type of clay that kyusu are made of is tokoname.
  • Kyusu designed specifically for fukamushi typically have a tall, narrow shape.
  • Kyusu teapots should never be cleaned with dish soap. It is debatable to whether it is okay to clean a glazed teapot with baking soda, but an unglazed teapot should never be cleaned with anything but water.