How to Store and Age Japanese Tea
How to Store Japanese Tea
Japanese tea is a non-oxidized tea, which means its quality can degrade significantly if not stored properly. Special care is needed to preserve it well.
Japanese tea is sensitive to oxygen, humidity, temperature, and light, so it must be stored in conditions that avoid these elements. It also easily absorbs odors from other foods, so it should be kept in an airtight container.
Don’t Forget Deoxygenation
Store the tea in bags made of materials that don’t let oxygen or light through, and use nitrogen flushing or oxygen absorbers.
Sometimes, cafés display Japanese tea in transparent glass jars for aesthetic reasons, but while it may look stylish, this kind of storage is not suitable for long-term preservation.
For Long-Term Storage, Use the Refrigerator
If you plan to store Japanese tea for an extended period, place it in the refrigerator. However, do not open it immediately after removing it from the fridge, as condensation caused by the temperature difference can moisten the tea leaves. Let it return to room temperature before opening.
In contrast, fully oxidized teas like black tea can be stored at room temperature. In fact, they’re more susceptible to moisture, so storing them in the fridge is not recommended.
Best-Before Date for Japanese Tea
Because tea leaves contain only about 5% moisture, they don’t really "spoil." However, without proper care, their quality will gradually deteriorate.
If stored with oxygen absorbers or in nitrogen-flushed packaging, they can last over a year without issue.
Once opened, however, it’s best to consume within a few months, even less for powdered teas like matcha, which oxidize quickly and are best consumed sooner.
The Concept of Aged Tea
Is freshly harvested tea always the best? Actually, not necessarily.
In fact, Japanese tea includes the concept of aged tea. Tea leaves rich in umami (savory taste) become even more delicious when aged properly.
Matcha in particular has a long tradition of being aged for over half a year before being consumed. Specifically, tencha (unmilled matcha) is stored in a cool, dark place and then ground into matcha after aging. Freshly harvested tencha tends to be bitter or astringent, but aging smooths the flavor and enhances the unique aroma of matcha.
Research also suggests that catechins—compounds responsible for bitterness and astringency—decrease slightly with time, contributing to the mellow taste.
Likewise, umami-rich teas like gyokuro and kabusecha also benefit from aging. On the other hand, teas with low umami and high catechin content are not suitable for aging, as they tend to degrade quickly over time.
The Unique Aroma of Freshly Harvested Tea
So why do Japanese people look forward to freshly picked shincha (new tea)?
Fresh sencha, especially sun-grown (unshaded) types, has a refreshing fragrance that’s only present right after the first harvest in spring. This scent, which evokes the feeling of new green leaves, is mainly composed of green leaf alcohol.
However, even with proper cold storage and oxygen removal, this aroma gradually fades. In my experience, it completely disappears within a few months.
This fleeting scent is why Japanese tea lovers eagerly await shincha each year.
(Incidentally, shaded teas like kabusecha, gyokuro, and matcha have a strong “covered aroma” similar to seaweed, which tends to mask the green leaf alcohol scent found in shincha.)
The subtle flavor shifts that occur depending on the season and timing make Japanese tea all the more fascinating.
Examples of Tea Quality Deterioration
- Matcha discolored by light exposure
- Sencha turning reddish due to poor storage
