The tin
A note on how to use, care for, and keep the tin your ceremonial grade comes in.
The tin was made to endure
The tin your ceremonial grade comes in was made to endure. It was not made to be thrown away.
Kato Seisakusho — the workshop in Asakusabashi, Tokyo, that makes each of ours — has been making tea caddies since 1895. They make things where the container matters as much as what's inside. What follows is a note on how to keep yours.
Before opening
Store the sealed tin at room temperature, away from direct sunlight. The tin has two lids — an outer lid and an inner one — and together they seal against air and light. Until you open it, the tin itself is the environment. Nothing more is needed.
The inner lid is the harder part to make. We are told only two workshops in Japan still produce them in tinplate. Kato Seisakusho is one of them.
About your tin: no two are the same
Each tin is formed by hand from a single sheet of tinplate, sprayed with paint by hand, and screen-printed by hand at Kato Seisakusho. Because of this, no two tins are exactly alike.
You may find slight variations in the depth of the color, small differences in the position of the printed mark, faint traces where the painter's hand paused. These are not defects. They are the record of a tin being made by a person rather than a machine.
Your tin is one of a kind.
Opening the tin for the first time
Because the fit between the lid and the body is precise, the lid may be difficult to open at first. Do not try to lift it straight up.
Instead, turn the lid at a slight angle as you lift it, and close it the same way — at a slight angle, turning as you press down.
With use, the lid and the body settle into each other. After some time, the tin will open and close smoothly with a straight motion. In Japanese, this settling is called najimu — the way an object grows familiar with the hand that uses it.
A note on the lid edge
To create the tightest possible seal between the lid and the body, the edge of the lid is left unfinished. This is a technical choice, not an oversight.
Please handle the lid edge with care. It can feel sharp against the fingertips, particularly when the tin is new.
Pouch in, or powder in?
Your matcha arrives in a sealed pouch inside the tin. What you do next is up to you.
Leave the pouch in the tin. Roll the top down tightly after each use and set it back inside. You keep a second barrier against air, and nothing spills. Many people prefer this.
Or empty the powder into the tin. Easier to reach with a chashaku, and the tin does what it was made to do. Cut the pouch straight across the top, turn the tin upside down over the opening, then turn the whole thing back over and lift the pouch away slowly. Doing this over a bowl catches anything that escapes.
Neither is wrong. What matters more than either is keeping the tea cool and away from air — which is the next section.
After opening: pouch and tin
Once opened, your ceremonial grade is best kept cool. The tin itself, however, should not be refrigerated.
If you have a refill, this is simple. The two 30 g pouches can be kept in the refrigerator. The tin stays at room temperature and holds only the matcha you are using in the days ahead. When one pouch is finished, transfer the next.
If your ceremonial grade came in the tin alone, keep the tin at room temperature and finish it within approximately 15 days after opening. This is shorter than the six months stated on the product page — that figure applies to matcha kept sealed in its pouch. Once matcha sits in the tin with air reaching it, it is best used soon. Matcha oxidizes slowly, and the flavor stays truest when it is used soon after air first reaches it.
The tin is for using. The pouch is for keeping.
Caring for the tin
A few things to keep in mind:
Do not wash the tin with water. Water can lead to rust. If it needs cleaning, wipe it with a soft, dry cloth and let it air until fully dry.
Do not keep the tin in the refrigerator. Cold air and moisture are hard on the metal.
Handle without your fingernails. The paint is softer than it looks. Small scratches are easy to make and difficult to undo.
Do not apply adhesive stickers or tape to the surface. Removing them can lift the paint.
If you enjoy it, run your palm across the tin from time to time. Over months and years, this brings out a quiet luster in the surface — a change you will notice more than anyone else.
The tin over time
The tin will change. Small marks will appear where it has been set down, held, and lived with. The paint may soften. The sheen may deepen.
None of this is loss. The tin was made to hold something you return to. Its wear is the record of that returning.
When the tin is empty, our refill comes in two 30 g pouches. The tin can be used again. And again.
Made by Kato Seisakusho
Kato Seisakusho was established in 1895 in Asakusabashi, Tokyo — a district of small workshops and wholesalers, not the tourist quarter of Asakusa a few stops to the north. Kato Shunji is the current president. The tins are formed, sprayed and printed by hand by the craftsmen there.
Read more about the workshop in our Story.
