Some people may be particular about tea leaves and/or techniques to brew tea, but how many of you even care about how to store tea leaves right?

The storage of tea leaves is very important to prevent the cause of flavor deterioration.


What happens to tea leaves after opening?

It may be thought that the quality of tea leaves would hardly change because they are dry, but that’s totally wrong. It does deteriorate drastically as soon as the bag/package is opened.

Once tea leaves are exposed to the air, the aromas would change as the aromatic components volatilize. Also, moisture causes flavour deterioration because tea leaves are vulnerable to humidity.

Causes of flavor deterioration

Flavours and aromas of tea leaves would drastically deteriorate if tea leaves are not stored properly.

In short, they would be able to be kept well to the end if tea leaves are stored right.

The deterioration of tea leaves is mainly caused by these three; oxigen (oxidation), sunlight and moisture.

Oxigen (oxidation)

Oxigen causes the flavor deterioration as it oxidizes the compounds of tea such as catechin and vitamin C. It also affects the color of tea and tea leaves, which makes them look worse.

Therefore, it is important to make sure to seal the bag/package thoroughly as squeezing the air out from the bag/package before sealing.


UV rays and sunlight fade the pigment chlorophyll that makes tea leaves green, which changes the color of tea and tea leaves from green to brown.

Also, sun exposure may cause the sun-struck flavor on tea leaves as tea leaves have a characteristic to easily absorb odors from others.

Therefore, tea leaves should be stored either in a dark place with no sun exposure or a container that blocks sunlight.


The oxidation of tea leaves would accelerate as tea leaves get more moist, which significantly affects the taste, colour and flavor of tea. So, leaving the bag/package of tea leaves is a big no-no.

Make sure to store tea leaves either in a dehumidified place or an air-tight container.

No refrigerated after opening?

Many people may refrigerate tea leaves after opening, that’s actually not good.

Refrigeration seems to be the best way to store tea leaves as it blocks sunlight, has no moisture and maintains a low temperature. However, refrigeration may cause tea leaves to absorb odors from other foods in the fridge, as mentioned before, tea leaves have a characteristic to easily absorb odors from others.

Besides, tea leaves may absorb moisture from the mist made in the fridge while the fridge opens and closes and that causes the temperature gap.

When taken out of the fridge, the freshness of tea leaves would also be deteriorated drastically as tea leaves absorb the moisture beads caused by the temperature gap.

Therefore, make sure to store tea leaves in a dark and dehumidified place like a cabinet instead of the fridge.

But it would be no problem storing unopened tea leaves in the fridge or freezer.

Suitable tools to store tea leaves.

Chadutsu (tea caddy)

Chadutsu (tea caddy) is the most suitable tool to store tea leaves.

It becomes air-tight as the body and lid are thoroughly sealed, which keeps tea leaves away from the air and moisture and blocks sunlight.

There are so many sizes of tea caddies, but we recommend the size for the amount of tea leaves that you can finish in a month. If the size is too big, the tea leaves would be exposed to the air in the caddy and that accelerates the deterioration.

Caddies made out of glass and plastic should be avoided because they let sunlight through.

Aluminum bag

Aluminum blocks the sunlight and moisture from the outside. You can store tea leaves in aluminum tea-leaf-storage bags that have lately been sold in stores.

There are also tea leaves sold in aluminum bags. If you purchase tea leaves in an aluminum bag, it can be stored as-is as long as it’s air-tight sealed.

January 09, 2023