Part 4 - Refining Matcha: The Finishing of Tencha

Finishing Process

Matcha manufacturers take the crude tea produced through the tea farmer’s primary processing of fresh leaves and further process it into finished products. Taking into account flavor, production cost, and yield, the tea is processed for consumers and food manufacturers. This is referred to as the "finishing process." The key points are the three steps of "shaping," "sorting," and "blending (gogumi)." Among them, "blending (gogumi)" is so important that is explicitly defined in the criteria for Uji tea. Matcha manufacturers in Uji make full use of blending techniques to create flavors that meet customer needs.

When finishing crude tea into tencha — the raw material of matcha —, in the “shaping” step adjusts the particle size of crude tencha so that it can be ground by stone mill. In the "sorting" step, the shaped crude tea is separated into the portion that will become matcha, called "honcha," and other components such as stems, leaf veins, and powder, known as "demono." In the "blending (gogumi)" step, multiple honcha that have undergone the shaping and sorting processes are combined to create finished tencha that suits desired flavor and cost requirements. Blending is especially emphasized in Uji, where each tea field is small compared to other production areas.

Shaping

Using a cutting rotary sieve machine, crude tencha with various sizes is adjusted to a grindable size of 5mm to 8mm, suitable for stone milling. After blending, the finished tencha proceeds to the next milling step, where it enters the central shaft connecting the upper and lower millstones. As the millstones rotate, the tea is gradually becomes finer as it moves outward under centrifugal force and along the radial grooves. Finally, it is finely ground between the upper and lower millstones, and matcha is produced. The shaping process is the preparatory stage to enable this.

Cutting Rotary Sieve Machine

This machine is used in the shaping process. First, crude tea is dropped from the top of the machine. The rotary sieve at the top removes powder. The remaining crude tea is transfered to a lower box containing the cutting machine, where it is shaped to 5mm–8mm. Separation and shaping of leaves and leaf veins are also processed here. If large leaves or stems remain, the process is repeated. The shaped crude tea then falls to the side, is lifted by a conveyor belt, and transferred to the intake of the neighboring wind-powered sorting machine for the sorting process.

Sorting

Shaped crude tea includes not only the honcha that becomes matcha, but also powder, honcha with leaf veins, old leaves, stems, and other parts known as demono. These are sorted by weight using a wind-powered sorting machine called a Toumi. Inside the machine, air flows in a fixed direction, and as shown in the photo, heavier crude tea drops closer, and lighter parts fall farther away. This sorting process is repeated to improve the precision of the honcha.

The number of sorting passes through the machine is determined by factors such as yield (desired quality), tea price, and cost. If the crude tea is of high quality, fewer sorting steps may be required. If the tea includes hard stems and leaves, such as in second flush tea, the process may be repeated multiple times. The number of sorting steps also depends on the condition of the crude tea and the type of product the manufacturer aims to create. This step is deeply related to the product design by the tea manufacturer.

Tencha Stems

In tencha, stems and leaf veins are referred to as “hone” (bones). Hard stems and leaf veins cannot be crushed by the pressure of the upper millstone during the grinding process. Worse, they lift the upper stone, making it impossible to grind the actual honcha. Therefore, removing hard stems and veins beforehand is critical.

Reuse of Tencha Stems

While stems from sencha, gyokuro, and kabusecha are valuable as stem tea, tencha stems, which have a distinctive sourness, were considered largely useless. However, with the advancement of extraction technology in bottled green tea beverages, there are now cases where the theanine content is extracted for reuse. The reason tencha stems considered less flavorful is that, unlike other teas, tencha crude tea is not not kneeded during processing. As a result, the flavor does not fully develop when infused, resulting in a milder taste.

Yield

The yield indicates the proportion of honcha obtained through the sorting process relative to the total crude tea input and is a key factor in product development. For hand-picked crude tea, the yield is about 60%–65%, and for machine-cut tea, about 65%–70%. The picking method affects the yield: hand-picking tends to result in more leaves per bud, leading to lower yield compared to machine-cut harvesting.

Blending (Gogumi)

By ideally combining multiple honcha, finished tencha (the raw material for matcha) is produced that meets the required quality and cost. This is the key part of matcha product design. In Uji, where manufacturers place great importance on blending, they make a comprehensive assessment based on not only the quality of individual crude teas , but also their color, taste, and aroma.

The blending process begins with the tea master creating a small "prototype" using various components, which is then used to prepare a final instruction sheet. Following this instruction sheet, all selected honcha are placed into a hexagonal blending tank, as shown in the photo. Here, the tea is thoroughly mixed, and finished tencha for matcha is completed.

Storage Until Just Before Grinding

Finished tencha is stored in refrigerators at 10°C or lower to minimize quality deterioration due to temperature and humidity. Before grinding with stone mills, it is moved to a "preparation room" at room temperature from half a day to a day in advance. Opening bags of tencha in an environment with a large temperature difference can cause moistue to enter the bag when it is resealed, which may compromise quality. Special care is required, especially from the rainy season through summer when humidity is high.

Role of the Matcha manufacturer

In Uji, matcha manufacturers assess the characteristics of crude tea by farmers and perform optimal finishing processes to match their company’s flavor, quality, and style. During finishing, they place carefully balance cost and quality, aiming to maintain consistent quality and ensure stable supply throughout the year.

https://matchadirect.kyoto/blogs/matcha-insight/cultivation-method

https://matchadirect.kyoto/blogs/matcha-insight/part-2-harvesting-matcha-selecting-the-finest-leaves

https://matchadirect.kyoto/blogs/matcha-insight/part-3-processing-matcha-from-fresh-leaves-to-tencha