May 29, 2020
Manufacturing Process of Unoxidized Tea(Green Tea)

Do you know how your daily green tea and Fukamushi-cha (deep steamed steeped green tea) are manufactured before reaching you hand? The word “unoxidized” is deeply involved with the process, in which a lot of time and effort are hidden. Let us take a look one by one at why the word “unoxidized” is related to green tea and what makes the difference between green tea and Fukamushi-cha.

Characteristics of manufacturing process of unoxidized tea (green tea)

Unoxidized tea is produced by heating and deactivating enzymatic fermentation (oxidization) in the leaf, i.e. halting the action of the enzymes, so that fermentation does not proceed. “Deactivation” is unique to unoxidized tea. There is no deactivation to make fermented teas. Although green tea is a representative unoxidized tea, the original color of Japanese tea was yellow or brown, not green. However, the “aosei-sencha” method was invented to give the liquid such a beautiful green color as you see today. In this way, with an elegant sweet flavor and aroma, green tea was born.

From plucking fresh leaves to shipment

Plucked fresh leaves are processed near the production area to “Aracha (crude tea)”, which have undergone kneading and drying. Then, after the “finishing” process, the tea is shipped as a product throughout the country

How to make Aracha

Aracha plays a role of “groundwork” to make delicious green tea. The tea leaves undergo the steps of plucking (picking fresh leaves), steaming, rough rolling, rolling/twisting, medium rolling, fine rolling, and drying in this order to be Aracha.

1. Steaming

Fresh leaves are steamed to deactivate oxidative enzymes. Non-pressured and equalized steaming retains the green color and aids in removing the grassy smell. This process is very important for green tea because the color, aroma, and flavor depend on how long the leaves are steamed. Longer steaming makes a darker color and reduces the astringency and smell.

2. Rough rolling

The leaves are vigorously kneaded and dried with hot wind under an appropriate pressure. This process softens the leaves and reduces their moisture.

3. Rolling/twisting

Rough rolling does not knead the leaves enough. Now the leaves are kneaded only with pressure, with no heat. This process equalizes the leaf moisture and breaks up the leaf cells so that the ingredients come out easily.

4. Medium rolling

Rolling/twisting leaves the leaves shrunk and unshaped. By further kneading in hot wind, the leaves become easy to shape at the fine rolling process.

5. Fine rolling

The leaves are dried and at the same time kneaded in one direction. This process gives green tea’s characteristic slender shape.

6. Drying

The shaped leaves still contain 10–13% moisture. By drying them thoroughly with hot wind, the number decreases to about 5%. Finally, Aracha is ready.

Finishing

In the phase of Aracha, the leaves are still irregularly-shaped and moist. It is difficult to maintain the quality. Here comes the need of the finishing process. In this process, “pre-firing, sorting/shaping, firing, and blending” take place in this order. Shipment follows measuring, checking, and packaging. Finishing enables longer storage and enhances the tea flavor.

7. Pre-firing

Prior to sorting/shaping, the entire Aracha leaves undergo firing (roasting, etc.).

8. Sorting/shaping

Aracha is sieved to remove fine stems and sort the leaves by the size. And the following processes such as cutting shape the leaves.

9. Firing

Drying once again with fire improves the shelf life of the leaves and brings out the tea aroma.

10. Blending

As the final adjustment, blending can equalize the composition and quality of the tea. Blending makes a well-balanced tea.

What is Fukamushi-cha?

Fukamushi-cha is a Sencha (steeped green tea) that has been steamed 2–3 times longer than normal Sencha. It goes through almost the same process as normal Sencha. Tea leaves are different in thickness between their areas and cultivars. The time required for steaming differs accordingly. There are no specific rules about it. Astringency and sweetness go together in normal Sencha with its characteristic light green liquid. However, some areas used to produce Sencha that was too astringent to be palatable to consumers. This is why they started deep steaming to bring out less astringency and more sweetness. Prolonged steaming made tea leaves more slender and deepened the green liquid color. This vibrant liquid color soon gained publicity and Fukamushi-cha became popular in no time.