Kyusu filter
The filter built into a Japanese teapot, and the property that most determines whether the pot suits your tea. Three types dominate: sasame, a field of fine holes moulded into the ceramic wall; obiami, a stainless band running round the interior; and a basket dropped into the neck. Filtration area is what separates them, and deep-steamed sencha needs all of it.
Identity
- Category
- Filter or infuser
- Native name
- 茶漉し
- Romanised
- sasame, obiami, chakoshi
- Also called
- integral teapot filter, ceramic mesh filter, band filter
- Material
- Moulded ceramic, stainless steel mesh, or a removable basket
- Skill level
- Beginner
Porosity
Not porous. It contributes nothing of its own to the liquor, so it can be moved between teas freely and washed with detergent without consequence.
Where it comes from
Japanese, and developed alongside steamed green tea, whose fine broken leaf will block anything smaller.
Named here rather than presented as generic equipment. The object belongs to a practice, and TeaHQ describes it from the outside.
If you do not own one
Pouring through a hand-held strainer, which handles any leaf size and needs no fitted part at all. A pot with a small basket and no wall filter is the arrangement to avoid for fukamushi.
This one is not marked essential. The tea can be made without it.
Brewing methods it is used for
- Kyusu brewing (Japanese style) — The Japanese domestic approach to green tea: a moderate quantity of leaf, water well off the boil, short steeps, and two or three infusions from the same leaf with the times adjusted each time.
- Low-temperature brewing (gyokuro style) — A great deal of shaded Japanese leaf in a very small volume of water that is deliberately far below boiling — cool enough that the vessel can be held bare-handed. It is the most extreme low-temperature steeping in common practice, and it exists to extract one part of the leaf while leaving another behind.
Tea types it suits
Care and maintenance
Rinse before the leaf dries into it. A ceramic sasame filter that has gradually slowed can be cleared by soaking in warm water and brushing from the outside; never push a wire through the holes, which chips the ceramic and enlarges them unevenly.
Other filter or infusers
Sources
This page is TeaHQ synthesis. No external source stands behind the description, the material or the account of how the object is cared for. Where the record names a tradition, that attribution is TeaHQ’s own reading of common practice rather than a citation.
TeaHQ names no maker, brand or shop and has nothing to sell. Nothing on this page should be read as advice to buy the object — the substitute note above exists because owning it is usually optional.