Processing Sencha
The Art of Sencha Processing: A Dual-Phase Journey
Sencha is crafted by steaming fresh leaves and rolling them into needle-like shapes. Sencha requires two distinct rounds of processing before it is ready for sale. In general, tea, as a product, requires far more processing than typical agricultural crops before it’s ready for market.
Primary Processing: Creating Aracha
To prevent oxidation, primary processing must begin within hours of harvest. The goal is to deactivate enzymes, dry the leaves, and break down their cell structure so the flavor can be easily extracted. The result is Aracha (Crude Tea), which contains the "main" leaf along with stems and powder.
Steaming (Mushi)
Steaming is a crucial step to deactivate the enzymes in the tea leaves. The steaming time depends on the condition of the leaves but generally lasts about 30 to 90 seconds. If the leaves are under-steamed, they can develop a grassy smell, while over-steaming causes the tea's flavor to be lost. The length of steaming has a significant impact on the taste of the tea, so it is essential to carefully determine the optimal steaming time.
| Feature | Light-steamed (Asamushi) | Deep-steamed (Fukamushi) |
|---|---|---|
| Steam Time | 30–50 seconds | 60–90 seconds |
| Leaf Shape | Preserved, intact needles | Finer |
| Tea Color | Light yellow | Cloudy, deep green |
| Flavor | Retains the original taste of the tea leaves, allowing subtle differences between leaves to be enjoyed. | Less bitterness, making it easier to drink, though different teas tend to have a similar flavor profile. |
| Brewing Method | Takes longer to brew and requires more skill to properly brew. | Requires a shorter extraction time and is easier to brew. |
| Region | Common in Kyoto | Common in Shizuoka |
Primary Rolling
In this step, hot air is applied as the tea leaves are rotated using “kneading hands” and “leaf sorting,” allowing moisture to evaporate evenly and efficiently. Before primary rolling, excess moisture is sometimes removed using a leaf-beating machine to soften the tea leaves.
Kneading
This is the only step where the tea is kneaded without adding heat. Moisture is thoroughly kneaded out of the leaves, including the stems, to balance the moisture levels in the tea and shape it properly. This process takes about 15 minutes.
Intermediate Rolling
Here, the tea is further kneaded while being heated to roughly body temperature. This step lasts around 10 minutes.
Fine Rolling
Fine rolling shapes the tea leaves into needle-like forms, a process that takes about 40 minutes.
Drying
Finally, the tea is dried to 5-6% moisture. This completes the primary processing of sencha, resulting in Aracha (Crude Tea), which can be safely stored or sold to wholesalers for refining.
Secondary Processing: Shitate-kakō
Aracha is a raw material, not a finished product. It contains stems, old leaves, and powder. As such, secondary processing (shitate-kakō/finishing) is performed to sort, clean, and add the final aromatic character (fire-aroma) through secondary drying. Tea grown using covered cultivation (kabuse-cha) requires secondary processing. That’s because covered cultivation encourages stem growth, and in the arachá state, the tea contains too many stems, making it difficult to enjoy the true flavor of the tea.
Sorting
Using cutting machines and sieves, the leaves are sorted by size, and lightweight leaves are removed using air flow. Stems are removed using static electricity and color sorting machines. Through this process, the arachá is separated into two categories: “honcha” (main tea) and “demono” (byproducts).
Drying & Roasting
Moisture is reduced to 3-4%. Depending on the drying method, a distinct roasted aroma known as hi-ka can also be added. Some customers prefer tea with a strong hi-ka, and in some cases, it enhances the flavor of the tea depending on its original quality.
The Result of Sorting: Aracha Breakdown
Nothing is wasted. During secondary sorting, the crude tea is separated into these categories:
| Part Removed | Finished Product | Common Use |
|---|---|---|
| Main Leaf | Sencha (Honcha) | High-quality loose leaf tea. |
| Stems | Kukicha / Karigane | Sweet, mellow tea; can be roasted to make Hojicha. |
| Tea Powder | Konacha | Strong, sharp flavor; often served in sushi restaurants, or used in tea bags. |
| Low-quality Large Leaves | Bancha / Genmaicha | Lower caffeine; great for daily drinking or blending. |
