A kyusu (急須) is a Japanese teapot, traditionally unglazed or partly glazed, with a side handle and a fine internal strainer. A good kyusu — especially an unglazed Tokoname or Banko piece — is not just a tool. It slowly absorbs a small amount of the tea you brew in it, and over the years it develops a flavor memory that makes every cup a little richer. Taken care of properly, your kyusu can stay with you for decades.
Here is how we recommend caring for one.
After Each Use
- Empty the leaves right away. Tea leaves left in a warm, damp pot for hours will go sour and leave faint stains.
- Rinse with warm water only. No soap. No detergent. Unglazed clay absorbs scent very easily, and the smell of dish soap will show up in your tea the next time you brew.
- Leave it to air-dry fully. Stand the kyusu upside down on a dish rack or a dry cloth, with the lid off, until everything is completely dry. Putting a still-damp kyusu away is the single most common cause of mold and off-smells.
Occasional Cleaning
After weeks or months of use, a thin film of tea residue may build up inside. This is normal, and for many tea drinkers it is actually desirable — it is the beginning of the flavor memory we mentioned. If you want to refresh your kyusu, here are gentle options:
- Baking soda soak. Fill the kyusu with warm water and a teaspoon of baking soda. Let it sit for 30 minutes, then rinse thoroughly with warm water. Air-dry fully.
- Green tea refresh. If you notice any faint odor, put 5 g of green tea leaves in the kyusu, pour in hot water, and let it steep for 5 minutes before discarding. Tea neutralizes most lingering smells naturally.
- Avoid bleach. Even well-rinsed bleach leaves a scent inside porous clay that is almost impossible to remove. If a pot is truly beyond saving, it is better to retire it than to bleach it.
Cleaning the Strainer
The fine metal or ceramic strainer inside a kyusu is essential to a clean pour, and it is also the most likely part to clog over time. To keep it clear:
- After rinsing, check the strainer. A few small leaves or bits of dust are normal.
- Use a soft toothbrush or a cotton swab to gently loosen anything stuck in the mesh. Work from the inside out.
- Never use metal wire or sharp tools — ceramic strainers are fragile, and metal strainers can warp.
- If the strainer has become fully clogged with old tea film, a baking soda soak (as above) usually loosens everything.
What to Avoid
- Dishwashers. High heat and detergent are both damaging to unglazed clay.
- Microwaves. Thermal shock can crack the body, especially on thin-walled pieces.
- Strong-smelling kitchens. Store your kyusu away from onions, garlic, vinegar, or other strong-scent foods. Unglazed clay will absorb scent over time.
- Wet storage. As above — always air-dry fully before putting the kyusu in a cupboard or box.
A Note on Unglazed vs. Glazed Kyusu
If your kyusu is fully glazed inside (most porcelain Arita or Kutani pieces, for example), it is less absorbent and easier to clean. You can still follow the instructions above, but the pot is more forgiving.
If your kyusu is unglazed on the inside — classic Tokoname red clay, Banko ware, Ise Mino — the care above matters much more. The trade-off is worth it: an unglazed pot rewards you with a slow deepening of tea flavor that a glazed one cannot provide.
The Long View
A kyusu is an object meant to be used, not displayed. The small marks and warm patina that develop over years of tea-making are, in Japanese tea culture, signs of a pot well loved. Rinse it, dry it, let it breathe between uses, and it will last longer than any of us.
You can browse our full selection in the Japanese ceramics collection. For more on Japanese pottery traditions, see our complete guide to regional pottery styles.