Development of lightly rolled Japanese green tea

Japanese green tea is less lasting in brewing

Many people find that the taste and flavor of Japanese green tea do not last through multiple infusions. The first infusion is strong and flavorful, but by the second or third infusion, the tea often becomes light and plain. Regardless of brewing style, this is mainly because the tea leaves are rolled very tightly. As a result, flavor and components are extracted very quickly during brewing. Many people accept this as the nature of Japanese green tea. However, it raises a question: why is the tea rolled so tightly? If Japanese tea were rolled more lightly, it could potentially last for many more infusions.

The appearance of tea leaves influences the process

In Japan, the shape of tea leaves is considered an important quality factor. Needle-shaped leaves are especially valued, and hand-rolled teas can command high prices. Generally, the slimmer the leaf, the greater the pressure applied during rolling. This stronger rolling causes more cell breakage, allowing more components to be extracted during brewing. However, rolling itself does not determine the fundamental character of green tea. That is mainly defined by steaming time and heat treatment in later stages. Therefore, tight rolling primarily serves to increase extraction efficiency.

White tea is produced without rolling

Some teas, such as white tea, are produced without rolling. The process is as follows: Withering >> Heating to stop fermentation >> Drying >> Moderate baking Despite the absence of rolling, white tea still delivers rich flavor and aroma. Because the leaves are not heavily processed, their freshness lasts across many infusions. In comparison, raw pu-erh tea is generally rolled very lightly. Occasionally, tightly rolled pu-erh is found, but its flavor tends to fade more quickly than lightly rolled versions.

The rolling is important for black tea

In black tea production, rolling is a critical step. It breaks the leaf cells, allowing enzymes and substrates to mix and initiate enzymatic fermentation. This process directly affects fermentation consistency and final quality. However, green tea is not fermented. So why is tight rolling so important for Japanese green tea?

The role of umami in tightly rolled Japanese green tea

One reason may be the emphasis on umami, which is often regarded as a key quality indicator of Japanese green tea. Umami mainly comes from the amino acid theanine. Why do elderly people miss the tea they drunk before? Umami in tea was identified by Dr. Sakado in the 1950s. Since then, it has been widely associated with tea quality. This concept also aligned well with modern agricultural practices, as increased fertilizer use leads to higher amino acid content and stronger umami. As a result, tightly rolled tea became advantageous, as it enhances the extraction of umami during brewing. However, higher umami often correlates with increased fertilizer use. In tea, there is generally an inverse relationship between umami and aftertaste—teas rich in umami tend to have a shorter aftertaste. In contrast, teas from China, Taiwan, and India often prioritize long-lasting aftertaste as a key quality factor.

Developing lightly rolled Japanese green tea

I have been focusing on teas produced through natural farming, meaning no nitrogen fertilizer is used—not even organic sources. Compared to conventionally grown tea, these teas contain less theanine but higher levels of polyphenols and minerals. Because of the lower amino acid content, there is less need for tight rolling. The key characteristics of natural farming tea are strong aftertaste and floral flavor. Light rolling helps preserve these qualities and allows the tea to last through many infusions. With lighter rolling, less mechanical energy is applied, and the leaf surface is less damaged. This reduces oxidation during processing, resulting in a more floral and refreshing profile. Based on this concept, I have been developing a new style of Japanese green tea with very light rolling to enhance floral characteristics. Trials began last tea season in Tsukigase, and if all goes well, we hope to introduce this new style this year.