Fresh versus Aged Japanese Tea: How Time Changes Flavor

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.