The characteristic of Gyokuro is totally different from Sencha. Gyokuro shouldn’t be defined as the superior version of Sencha; it is a completely different category of Japanese green tea.
What are the distinctive characteristics of Gyokuro?

Firstly, the Gyokuro tea leaves are very deep green in color. Secondly, its flavor is like seaweed and has a mellow, sweet and full bodied taste.
In fact, the same cultivar that produced Sencha can be used to produce Gyokuro. The secret is that the farmer has a very special method when producing tea leaves for Gyokuro. About 20-30 days in advance before plucking of the tea leaves, the entire tea garden will be covered by sheet. Under the sheet, the tea trees are shield from direct sunshine. When seriously lacks sunshine, tea trees will trigger a chain of physiological changes within itself in order to survive. The tea leaf is not only physically changing, the chemical composition in the leaves also changed.  As a result, tea leaves produce the typical flavor substances of Gyokuro and extremely rich in minerals. We select our Gyokuro from Shizuoka, Okabe Town of Shizuoka Prefecture where it is surrounded by clean air and transparent alpine water. We call it Asahina Gyokuro.

Above is just an ordinary introduction of Gyokuro. We selected the “Hon Gyokuro”. “Hon” in Japanese means genuine or authentic. Perhaps authentic is more suitable for this meaning. The name Hon Gyokuro is given only for the tea that is produced from the tea garden covered with “straw”. This is a traditional method applied for the production of Gyokuro and it is hardly practiced in most of the modern tea gardens nowadays. At present, almost more than 90 percent of the Gyokuro tea gardens are covered by black sheet that is called “Kanreisha”.

In general, there are 3 major categories of tea that is grown under coverage.

1. Tea tree is directly covered with sheet. The sheet is almost rested right on top of the tea tree and there is no headspace between tea tree and sheet. This type of tea is called Kabuse Cha.
2. A framework is built around the tea garden and it is covered with black sheets. This is the most common type of modern Gyokuro garden. Due to the black color of the sheets, the temperature inside Gyokuro garden tends to be very high. Tea grows much faster and plucking is carried out earlier in season.
3. A framework is built around the tea garden. But the headspace between tea leaf and sheet is much closer than ordinary Gyokuro that mentioned in category 2. Tea leaves almost touches the ceiling. The farmer strictly uses straw to cover the tea garden. This is called Hon Gyokuro. The temperature inside garden is relatively lower and plucking is carried out much later than ordinary Gyokuro.

The taste and flavor of Hon Gyokuro is remarkably different from ordinary Gyokuro. Hon Gyokuro gives a very strong aftertaste. Once drink, you find its flavor amazingly long lasting and taste lingers on your throat for a long time. You feel a kind of sweetness that stays very long in your throat. For ordinary Gyokuro, Umami characteristic is often being emphasized. Umami is contributed by amino acid content in tea leaves. However, Umami does not impress us unless it comes with deep aftertaste. Eventually ordinary Gyokuro gives a flat taste with overwhelming umami, while Hon Gyokuro gives a very long lasting flavor and taste on top of Umami characteristic.
The reason why the Hon Gyokuro gives a long lasting aftertaste is because of the straw used to cover the tea garden. These straws are very rich in minerals. When rain falls, water that soaked through the straws on top of the tea garden will supply additional minerals onto the ground. The extra minerals from the straw will drastically improve the quality of soil and eventually the quality of Hon Gyokuro becomes so much different.

Mr.Omura and his wife: There are only a few famialies who produce Hon Gyokuro at the moment. He worries if there is no one who continue Hon Gyokuro production in future since most of younger generation shift their production to the modern method.

For our Hon Gyokuro, there is another factor that makes our quality different. The tea garden that produces our Hon Gyokuro uses not just straw, but it must be fresh straw. According to Mr. Omura who is the owner of Hon Gyokuro tea garden, the fresh straw is a very crucial factor. According to him, when he chews the fresh straw, it tastes sweet as it is rich in minerals. On the other hand, the recycled straw from previous year does not retain sufficient minerals. Just because of he has to get sufficient supply of fresh straws every year, he also owns a rice field in large scale. It is his wife’s job to produce sheet using straws. Nowadays straw sheet is very expensive to purchase, yet if they produce it by themselves, it takes a lot of efforts and time. This is one of the reasons why most of tea gardens switch to using plastic black sheet.

There is another reason why the most farmers choose to produce ordinary Gyokuro.
In Japan, ironically ordinary Gyokuro is highly priced. It is the dilemma and discrepancy exists in Japanese tea market. In Japan the earlier the tea is plucked in season, the better the price it is given. The growing speed of Hon Gyokuro is purposely slowed down in order to raise its quality. Somehow ordinary Gyokuro comes out much earlier in the season. This dilemma is also caused by the misunderstanding of Japanese tea merchants who believe that Umami is the index of quality. As a matter of fact, it is not Umami that sets the quality but the minerals.
Under the circumstances, Hon Gyokuro seldom comes out in the tea market. It is not worthwhile that the farmers spent a lot more time and effort in taking care of the crops, yet lower price is given. Usually Hon Gyokuro is directly sold to the specialty tea shop that understands and appreciates its value.

Ordinary Gyokuro Garden which is covered with black sheet		Hon Gyokuro Garden which is covered with straw

Okabe Town is located north west of Shizuoka Town. The alpine river called Asahina River runs through the town, and both sides are surrounded by very steep mountains. The Asahina District which is located at the north of Okabe Town has hilly lands, and thanks to the typical mountain weather, it is suitable for producing good quality tea. Tea is produced here since the Muromachi Era. The Gyokuro was invented in year 1835. In old days, Gyokuro tea garden was covered by the bundles rice straw. Nowadays, Asahina (Shizuoka), Uji (Kyoto) and Yame (Fukuoka) are three major Gyokuro manufacturing areas in Japan.

Around 30 days in advance before plucking the leaves, Gyokuro tea garden is covered. The penetration rate of sunshine in the beginning of 7-10 days is 65-70%, and from then onwards the penetration rate is 97-98%. The theanine which is a kind of amino acid is produced from the root and is transferred to the stem and leaves. Theanine is the substance contributing to the umami and sweet taste in green tea. Green tea which contains higher percentage of theanine gives a amino acid taste which is called Umami in Japanese and nowadays also in English. On the contrary, tea leaves which contain a higher proportion of polyphenol such as catechin gives a bitter taste. When tea leaves are exposed to sufficient sunshine, theanine is degraded and converted into catechin. Therefore, blocking out the sunshine will inhibit the biosynthesis of catechin and theanine is proportionally increased. In other words, the typical taste of Gyokuro is made by blocking out the sunshine from the tea leaves.

The typical aroma of Gyokuro which is often associated to seaweed is composed by the substance named dimethylsulphite. The precursor of dimethylsulphite is called methylmethioninesulphonyl. This substance is also accumulated in tea leaves when the tea garden is blocked from sunshine. During this process, the tea leaves get steamed, which in turn produces a substance called dimethylsulphite that gives typical seaweed flavor.

The brewed Gyokuro leaves are very deep green in color compared with Sencha which is yellowish green in color. When the tea garden is covered and no sufficient sunshine reaches the tea leaves, it will rise to the surface of the tea leaves and produce more of chlorophyll, the green pigment in tea leaves, in order to carry out photosynthesis. This is the reason why the color of Gyokuro is a deep green shade.

Hon Gyokuro Tea Garden		For covering tea garden, it is essential to use fresh straw. The one on the left is fresh straw, while the one on the right is old batch. The outcome is completely different depending on the quality of straw.

Asahina Gyokuro is mainly produced from the cultivar called Yabukita. The leaf is plucked by hand, therefore, the tea bush in the tea garden is not cut into “table-shape” but standing up.
Starting from the end of April till beginning of May, the first flush is plucked. For Hon Gyokuro, the timing of plucking is later than ordinary Gyokuro. The plucking is usually carried out in the middle of May. The plucking is based on the standard of one bud and 3 leaves. It is important to include the third leaf. The third leaf stay with tree much longer than young leaf. Hence it contains more minerals and polyphenols. This is essential to gives a strong flavor and thick body in taste.
The leaf is plucked after sunrise in order to avoid the morning dew. If morning dew remains on the leaves, the tea leaves will be over heated during the steaming process. As a result, the tissues of the tea leave will be excessively destroyed and will not be able to produce fine quality tea leaves.

Tea leaf at Gyokuro garden just before plucking		The tea leaf for Gyokuro turns into deep green color

The process of Gyokuro is basically the same as Sencha. However, the leaf of Gyokuro contains more moisture and is tender, therefore extra care is required during handling.