The process for making Yunnan Black Tea (Dian Hong):
Primary processing: Picking—Wilt—Roll—Ferment—Dry—Rough tea—Inspect—Weigh—Store.
Refining: Rough tea—Blend rough tea for refining—Sieve—Wind sort—Pick over—Inspect—Final blending—Level heap—Supplemental firing—Weigh—Pack—Inspect—Store.
The Yunnan Black Tea (Dian Hong) Production Process
1. Fresh Leaf Picking
The quality of the fresh leaves is the foundation of the tea's quality. Yunnan Black Tea uses the fresh leaves of the Fengqing large-leaf tea, which are plump and covered with dense downy hair. Under optimal leaf variety conditions, the quality of the fresh leaves must consider tenderness, uniformity, freshness, and cleanliness.
2. Fresh Leaf Wilt
After picking, the fresh leaves undergo Wilting under certain temperature and Humidity conditions, spread out evenly to promote the activity of enzymes in the leaves, allowing for appropriate physical and chemical changes in the tea's contents; some moisture is released, causing the stems and leaves to wilt and turn a dark green color. The grassy smell dissipates and is replaced by a fragrant aroma, sometimes with notes of fruit or flowers. This results in a tea that is mellow without being bitter or Astringent.
Yunnan Black Tea not only needs excellent color, fragrance, and flavor, but also requires a tight and straight shape, complete peak and sprout, and an oily luster. Therefore, proper wilting of the fresh leaves is a prerequisite for the high quality of the Yunnan Black Tea (Dian Hong) rough tea product.
3. Rolling
Rolling is an important step in forming both the inner quality and outer appearance of black tea. Through the technical handling of rolling, the product achieves a tight and straight shape and a mellow taste.
4. Fermentation
Fermentation is the key step in the formation of black tea quality. It involves the enzymatic oxidation of polyphenols due to damage to the semi-permeable cell membranes, leading to a series of oxidation, polymerization, and condensation reactions of the leaf contents, resulting in the formation of colored compounds such as theaflavins and thearubigins, as well as substances with special aromas. The principle is to utilize oxygen from the air and the activity of Polyphenol oxidase to promote the profound oxidation and condensation of polyphenols, triggering other biochemical changes and collectively forming the unique qualities of black tea.
5. Drying
Drying, commonly known as baking, is the last step in the production of black tea. It can be done manually or mechanically. Even if the quality of the fresh leaves is high and the techniques for wilting, rolling, and fermentation are properly handled, if the final step of drying is not done well, it can result in a lower-quality product or even a defective one, negating all previous efforts. Therefore, mastering the drying process is crucial for improving the quality of the rough tea.
Drying typically consists of two stages: initial drying and final drying.
Initial drying, also called “pre-drying” or “first baking,” should leave the tea with a moisture content of 18% to 25%, evenly distributed between dry and moist areas, with no signs of smoke or scorching.
Final drying, also known as “second baking,” further dries the tea after initial drying. It is the second (and final) drying stage in the primary processing of various teas. The purpose of final drying is to ensure the tea is thoroughly dried; after final drying, the tea should have a moisture content below 7% and no smoky or scorched off-flavors.
To achieve good tea quality, the drying process must reasonably control parameters such as temperature, quantity of leaves (thickness of spread), time, number of times the leaves are turned (for hand baking), speed, and airflow, without any negligence. During the drying process, technicians not only need to endure hardship but also need to skillfully manage the “drying machine.”
Once the rough tea has completed final drying, the production of rough tea is finished. It then goes through grading and further processing into various finished teas before being marketed.
The process of making black tea is complex and meticulous. In the five steps of picking, wilting, rolling, fermenting, and drying, each step must be connected to the next, and every process is interconnected, interdependent, and mutually influencing as a whole.