The Dual Mandate: Biochemical and Physical Objectives of Rounian

The Rounian step is defined by a dual mandate. It must simultaneously achieve a specific biochemical objective (for oxidative teas) and a universal physical-sensory objective. The success of the final tea hinges on the precise execution of both.

The Biochemical Imperative: Maceration and Controlled Oxidation

For black and oolong teas, rolling is a deliberate act of intentional cellular disruption. This controlled maceration is the primary biochemical purpose of the step. The tea leaf's cell structure is highly compartmentalized; key polyphenol substrates (catechins) are stored within the cell's vacuole, while the enzymes responsible for transforming them—polyphenol oxidase (PPO) and peroxidase (POD)—are held separately in the cytoplasm.

The mechanical action of rolling, whether by hand or machine, provides the shear force and "grinding and twisting action" necessary to rupture these cell walls and membranes. This "bio-activation" allows the previously segregated substrates and enzymes to mix for the first time, in the presence of oxygen from the air.

This mixing ignites the enzymatic oxidation cascade, a process often, though imprecisely, referred to as "fermentation". In this cascade:

• PPO and POD catalyze the oxidation of catechins.
• These are converted into Theaflavins (TFs), the compounds responsible for the tea's developing briskness, sharpness, and bright yellow-orange color.
• Theaflavins, in turn, polymerize into Thearubigins (TRs), the complex polyphenols that provide body, depth, mouthfeel, and the characteristic deep reddish-brown color of a fully oxidized tea.

The "degree of rolling"—a combination of applied pressure and duration—is the primary control lever for this entire process. A greater pressure and longer rolling time result in a greater number of broken leaf cells. This releases more tea juice, which, when exposed to oxygen, leads to a "deeper the degree of fermentation". This single parameter is what allows a tea master to define the tea's category, from a lightly bruised and gently oxidized oolong to a fully macerated and deeply oxidized black tea.

This entire biochemical mandate is, crucially, inverted for green tea. For green tea, the Rounian step occurs after fixation. Fixation is a high-heat step (steaming or pan-firing) that intentionally denatures (destroys) the PPO and POD enzymes, thereby preventing this oxidative reaction. Therefore, for green tea, rolling is a purely physical shaping process, entirely divorced from any biochemical oxidative goal.

The Physical Imperative: Managing Infusion via Surface-Area-to-Volume Ratio (SA/V)

The second, and universal, mandate of shaping is the physical programming of the leaf's infusion behavior. This is achieved by managing its final Surface-Area-to-Volume Ratio (SA/V).

The physics of this concept is fundamental:

• High SA/V: An object with a high ratio, such as a flat leaf or fine dust, exposes a large amount of surface area relative to its small volume. This configuration maximizes the rate of diffusion and heat transfer.
• Low SA/V: An object with a low ratio, such as a sphere or a tightly rolled pellet, has the minimum possible surface area for a given volume. This configuration minimizes and slows the rate of diffusion.

The tea master's choice of shape is, therefore, a deliberate act of "infusion programming."

• Low SA/V (Pellets, Pearls): Tightly compacted forms like Gunpowder or balled oolongs present a minimal surface area to the hot water. The water must first hydrate and unfurl the leaf, a process that can take several seconds to minutes. This creates a "progressive" or "staged" release of flavor, with the "aroma [being] durable and persistent".
• High SA/V (Strips, Flat): Open, flat, or strip-shaped leaves like Dragon Well or Sencha present a large, immediately accessible surface area. This allows for a "relatively fast" extraction, yielding a "brisk, pronounced liquor" with a high percentage of compounds released in the very first infusion.

This physical programming is specifically designed to match a desired brewing culture. A low SA/V "pearl" that unfurls slowly is functionally necessary for the Gongfu Cha (工夫茶) brewing method, which demands a tea that can withstand multiple, short infusions. The staged release of flavor is precisely what makes this possible. A high SA/V tea, by contrast, would be "spent" after one or two infusions, failing the method's core requirement. Conversely, the high SA/V of tea bag fannings or dust is optimized for a Western-style brew: maximum, rapid extraction in a single 2-3 minute steep.

Furthermore, this low SA/V shape serves a critical, non-brewing function: preservation. A tightly rolled pellet (Gunpowder) or ball (Oolong) minimizes the leaf's exposure not just to water, but also to oxygen, moisture, and light during storage and transport. This "preserves freshness" and "extend[s] its shelf life". This was a critical logistical innovation that allowed a high-value, perishable commodity to survive long-distance trade routes.

Table 1: Comparative Analysis of Tea Shape, SA/V, and Infusion Kinetics

Shape / Example	Manufacturing Process	Relative SA/V	Extraction Kinetics	Sensory Profile & Brewing Suitability
Flat Spear (Longjing / Dragon Well)	Simultaneous fixation and pan-pressing	High	Fast: Rapid, high-volume initial release of compounds.	Brisk, Pronounced: Full flavor and aroma (e.g., chestnut, umami) on the first infusion. Suited for glassware or Western-style cup brewing.
Twisted Strip (Sencha / Orthodox Black)	Post-fixation rolling (Sencha) or pre-fixation rolling (Black)	Medium-High	Relatively Fast: Large exposed surface allows for quick hydration and release.	Robust Character: Full-bodied liquor, ideal for single, strong infusions (Western-style) or the first few infusions in a gongfu session.
Rolled Pellet (Gunpowder / Zhū Chá)	Post-fixation steaming and mechanical rolling into tight pellets	Very Low	Slow & Progressive: Leaf must hydrate and fully unfurl before peak release. Delays extraction.	Durable, Staged: Releases flavor in layers. Suited for multiple infusions; aroma is "durable and persistent". Shape also preserves freshness.
Rolled Pearl/Ball (Taiwanese Oolong)	Iterative cloth-wrapping, heating, and rolling ( Bao Rou )	Low	Slow & Controlled: Gradual unfurling releases flavor and aroma over many infusions.	Layered, Complex: Ideal for Gongfu Cha brewing, where each subsequent infusion reveals new nuances. Shape provides stability for storage.

Process Parameters and Critical Control Points

Achieving the dual mandate of Rounian is not guaranteed. It is a sensitive operation that depends on two key sets of parameters: the physical state of the leaf entering the process and the thermal environment during it.

The Prerequisite State: Pliability, Moisture, and Process Timing

Rolling cannot be performed on a fresh, turgid leaf, nor can it be done on a dry, brittle one. The process absolutely requires the leaf to be "hot, soft, and pliable," as the initial query noted. A leaf that is not pliable will be "easily damaged" and shatter, resulting in a failed process.

This essential pliable state is achieved by the upstream step in the manufacturing chain:

• For Black and Oolong Teas: The withering process (both physical and chemical) causes the leaves to lose moisture and turgor, rendering them flaccid, "soft and pliable".
• For Green Teas: The heat from the fixation step (steaming or pan-firing) "evaporat[es] moisture" and "soften[s]" the leaf tissue, making it receptive to shaping.

This relationship leads to a critical timing divergence that fundamentally defines tea categories:

• Black/Oolong Tea Process Flow: Withering (pliable) → Rolling (maceration/oxidation) → Fixation/Drying (to stop oxidation). The goal is to roll a biochemically active leaf.
• Green Tea Process Flow: Fixation (pliable/inactive) → Rolling (shaping) → Drying. The goal is to roll a biochemically inactive leaf.

Within this pliable state, the precise moisture content is a high-tech critical control point. This is not a simple "damp" state; it is a "sweet spot" of (e.g., ≈68%) moisture that is so important, modern facilities employ advanced sensing technologies like micro-NIRS (near-infrared) spectroscopy to monitor it in real-time. Missing this sweet spot has severe consequences:

• Too Wet: The leaves will "clump" during the final drying phase.
• Too Dry: The leaves will be brittle, and the Rounian process will fail to express the necessary juices to initiate and sustain enzymatic oxidation.

The Thermal Paradox: Managing Heat Generation During Rolling

While the Rounian step for black tea requires a cool ambient environment, the process itself generates significant heat. This creates a thermal paradox that must be actively managed. This heat originates from two sources:

1. Physical Friction: The mechanical action of leaves rubbing against each other and the rolling machine surfaces.
2. Exothermic Oxidation: The "leavening"—the biochemical oxidation of catechins—is an exothermic reaction that releases its own heat.

This generated heat creates a dangerous positive feedback loop: rolling causes oxidation, which creates heat, which in turn "will accelerate the oxidation of tannins", creating even more heat.

There is a well-defined critical temperature ceiling. If the temperature of the leaf mass rises above approximately 82°F (28°C) or 35°C (95°F), the process fails. "Undesirable chemical and enzyme reactions" take over. This excessive heat causes "tannins with a higher degree of condensation," which "reduce the color and taste of the tea soup". Delicate volatile aroma compounds are "baked off," and the leaves are effectively "stewed" in their own heat, resulting in a dull, flat, low-quality tea.

The engineering solution to this paradox is to maintain a cool, well-aerated rolling room, typically between 20-25°C (68-77°F). The cool ambient air acts as a heat sink, continuously wicking away the frictional and exothermic heat generated by the process. This management allows the tea master to extend the rolling time—often 30 to 90 minutes—to achieve the desired degree of maceration without crossing the thermal "red line" and destroying the tea's quality.

Case Studies in Shaping: A Technical Deep-Dive

The principles of shaping are best illustrated by examining the diverse techniques used to create iconic tea styles.

Case Study: The "Pan-Fired" Flat Spear (Longjing / Dragon Well)

This is a critical distinction: Longjing (Dragon Well) does not undergo Rounian in the traditional sense. Instead, its fixation and shaping are a single, simultaneous process.

The mechanism involves placing fresh leaves into a large, heated wok. This intense heat is the fixation step, which immediately denatures oxidative enzymes. While the leaves are being fixed, the tea artisan uses their bare hands to press the leaves firmly against the hot metal surfaces of the wok. This is not a random action; it is a highly skilled craft with a specific vocabulary of hand techniques, including "push" (to flatten), "rub" (to smooth), and "hard press" (to forcefully flatten the stems).

The purpose of this action is the diametric opposite of black tea rolling. Black tea rolling is a wet, cool process designed to express juice for oxidation. Longjing shaping is a dry, hot process. The "gradual squeezing" is designed to force the leaf's internal juices "out in direct contact with the heat". This roasts the leaf's own juices—rich in amino acids and sugars—onto its surface. This process is more akin to a Maillard reaction or caramelization, and it is what creates the signature "toasted chestnut" aroma and "super rich umami" flavor profile for which Longjing is famous.

The use of the artisan's bare hand is not for tradition alone; it is a high-resolution sensor. The hand "feel[s] the gradual change of the leaves"—their moisture, rigidity, and temperature. This real-time data allows the master to instinctively modulate the "combination of shifting, pressure and heat" required for that unique batch, an intuitive flexibility a "dumb" machine cannot replicate.

Case Study: The "Rolled" Pellet (Gunpowder / Zhū Chá)

The process for Gunpowder tea is: 1) Withering, 2) Steaming (this is the fixation step, halting oxidation), 3) Rolling into pellets, and 4) Drying/Pan-Firing to lock in the shape.

The English name "Gunpowder" is a visual analogy, but the Chinese name zhū chá (珠茶), meaning "pearl tea" or "bead tea," is more descriptive.

As identified in Section I-B, the primary function of this shape is not aesthetics but logistics. Developed as early as the Tang Dynasty (618–907), this "process technology" was a revolutionary solution to the problem of transporting a perishable, high-value commodity. The tight, low SA/V pellet shape:

• Makes the tea "less susceptible to physical damage" and breakage during transport.
• "Preserves their freshness and flavor" by minimizing surface exposure to air and moisture.
• "Extend[s] its shelf life" dramatically.

This function directly dictates the quality metrics for Gunpowder tea. A "better" pellet is one that performs this preservative function more effectively. Therefore, "high grade gunpowder tea features very small, tightly-rolled pellets". "Larger looser pellets" are considered "a mark of lower quality tea", and a "shiny" surface is an indicator of freshness.

Case Study: The "Iterative" Pearl (Taiwanese Oolong / Tie Guan Yin)

This is perhaps the most complex and laborious shaping method, known as Bao Rou (包揉) or "cloth-wrapping". It is not a single action but a long, iterative, multi-stage cycle.

The cycle, which is repeated "10-50 times", proceeds as follows:

1. Heating: After the primary oxidation and fixation steps, the leaves are re-heated (e.g., to 50-60°C) to restore pliability.
2. Wrapping: A large batch of the warm tea is placed into a "tightly woven fabric bag".
3. Compression: The bag is "twisted up tightly", compressing the leaf mass into a "tight ball".
4. Rolling: This entire cloth-wrapped ball is then placed into a specialized machine that rolls and kneads it, further "compress[ing] the tea".
5. Un-bagging: The compressed "cake" of leaves is removed, and the leaves are "scattered" (broken apart) to ensure even re-heating and prevent clumping.
6. Repeat: The entire cycle is then repeated, over and over.

This intensive process has two distinct goals. The physical goal is a "cold-forge" compaction. The process is analogous to "forging" metal: the material (leaf) is heated to become malleable, compressed (rolled in the bag) to shape it, and then re-heated when it becomes too hard to work. This gradual, iterative compaction is the only way to "forge" the leaves into "dense little balls" without shattering them.

The biochemical goal is a "perfume pump." This iterative rolling, which occurs after fixation, continues to "further break down cell walls". Since the oxidative enzymes are denatured, this does not create new oxidation. Instead, it serves to liberate volatile aroma compounds trapped deep within the cellular structure. Each rolling-and-compression cycle "pumps" out more of this essence, which develops the "strong, almost perfume-like fragrance" that defines high-mountain Taiwanese oolongs. The cloth bag itself is a key piece of process technology, wicking moisture while applying even, hydraulic-like pressure and protecting the leaves from being torn by the machine.

Craft vs. Code: Artisanal Skill and Mechanization in Modern Rolling

The "how" of Rounian is a study in contrasts, pitting the intuitive "feel" of the human hand against the brute-force efficiency of the machine.

The Artisan's "Feel": Flexibility and Intuition

Artisanal, "full handmade" processing remains the "gold standard" for "premium" and "superior grade" teas, commanding "astounding" prices. The value of the artisan lies in their use of "feel" and "experience" as a high-resolution, real-time data-collection system. This allows for "fine adjustments" to be made "on the fly," reacting to the unique moisture and rigidity of each specific batch of leaves. This is an adaptive flexibility that a pre-programmed machine "can not" replicate.

The drawbacks, however, are significant. The process is "labor-intensive", exceptionally slow (a Longjing artisan may only produce 1000g of finished tea per day), and "prone to inconsistency" as the artisan fatigues.

The Machine's "Consistency": Scalability and Efficiency

The reality of the modern tea industry is that most tea, even high-quality grades, is machine-rolled. These machines are designed to "mimic the hand-rolling process". The "Orthodox Roller," standard for strip teas, uses a rotating disc with "spiral guide ribs" and a "pressing cover" to create a "grinding and twisting action". Specialized machines exist for oolong (cloth-ball rollers) and Longjing (mechanical "paddles").

The advantages are undeniable: "efficiency", "scalability", and, for the mass market, absolute "consistency". A machine "does not show fatigue" and can increase output by an order of magnitude, processing 10,000g/day versus the artisan's 1000g/day.

A Comparative Analysis of Quality and Metabolite Impact

This trade-off between "craft" and "code" is no longer just a matter of opinion. For the first time, the chemical and sensory differences are being quantified. An untargeted metabolomic study (UPLC-QToF-MS) conducted on Tie Guan Yin oolong provided a direct chemical comparison between hand-picked and machine-harvested/processed teas. The results were staggering: the analysis "revealed a minimum 50% loss for over half of the chemicals in the machine-harvested group". This loss included the most critical quality-marker compounds: catechins, theaflavin, gallic acid, and chlorogenic acid.

This chemical "hollowing-out" was directly reflected in the sensory evaluation scores:

• Hand-picked: Only 9% of the finished products were graded as "low level."
• Machine-harvested: 66%—a full two-thirds—of the finished products "ended as low-grade tea".

It is important to analyze this data with nuance. The studies attribute this massive quality loss to "harvesting mechanization". The mechanical harvesters (plucking machines) "lack precision" and are often "rows of rotating blades" that non-selectively "collect older leaves and stems". This suggests a "Garbage In, Garbage Out" (GIGO) principle. The Rounian rolling machine itself may be highly efficient and consistent, but it cannot create quality that was already destroyed in the field by a non-selective, "dumb" harvesting machine.

The "premium" for "hand-made" is therefore not just for the artisanal rolling technique but for the entire artisanal chain, beginning with the "delicate work" and "precision" of hand-plucking the correct leaves.

Report Conclusion

The Rounian (shaping and rolling) step is definitively not an aesthetic afterthought. It is a sophisticated, multifunctional engineering step that forges the tea's final chemical, physical, and sensory identity. This analysis has deconstructed its Dual Mandate:

1. The Biochemical: A controlled mechanical maceration to initiate and modulate enzymatic oxidation, setting the tea's core chemical profile of theaflavins and thearubigins.
2. The Physical: A deliberate geometric "programming" of the leaf's Surface-Area-to-Volume ratio, which dictates its infusion kinetics and, consequently, the consumer's brewing experience.

We have analyzed the Critical Parameters of this process: the non-negotiable prerequisite pliable state and the management of the Thermal Paradox—the operational challenge of cooling a process that, through friction and exothermic oxidation, generates its own destructive heat.

Our Case Studies have revealed the sheer diversity of this "shaping" philosophy, demonstrating that it is a flexible solution to different processing goals:

• Longjing: A "hot-press" roasting of juices, distinct from oxidative rolling.
• Gunpowder: A "preservation" technology, invented for logistics and shelf-life.
• Oolong: An iterative "cold-forge" compaction that also acts as a "perfume pump" to release volatile aromas.

Finally, we have quantified the "Craft vs. Code" debate. The artisan's "feel" produces a chemically and sensorially superior product. This is not romanticism; it is a measurable fact. The "efficiency" of mechanization, particularly non-selective harvesting, comes at a quantifiable "cost" of up to 50% of the leaf's key chemical compounds. The shape of the tea in the cup is the physical-chemical-logistical solution to a centuries-old equation, representing the final, decisive act of the tea master.

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Works Cited

1. Surface area to volume ratio part I - Muggswigz, accessed November 12, 2025, https://www.muggswigz.com/index.php/mugg-s-buzz/25-hodgepodge/55-surface-area-to-volume-ratio-part-i
2. Surface-area-to-volume ratio - Wikipedia, accessed November 12, 2025, https://en.wikipedia.org/wiki/Surface-area-to-volume_ratio
3. Several Methods Of Tea Fixation Processing, accessed November 12, 2025, https://www.delijx.com/faqs/several-methods-of-tea-fixation-processing.html
4. The Purpose And Method Of Tea Rolling - Wit Tea Machinery, accessed November 12, 2025, https://www.teamachinerys.com/news/the-purpose-and-method-of-tea-rolling/
5. Tea Harvesting and Processing Techniques and Its Effect on Phytochemical Profile and Final Quality of Black Tea: A Review - MDPI, accessed November 12, 2025, https://www.mdpi.com/2304-8158/12/24/4467
6. Morphological Types of Green Tea Leaves: Needle, Rolled (Pearl), and Twisted (Strip) – Implications for Extraction and Sensory Profile - NAM SON, accessed November 12, 2025, https://nam-son.com/morphological-types-of-green-tea-leaves-needle-rolled-pearl-and-twisted-strip-implications-for-extraction-and-sensory-profile/
7. Rolled vs. Open Tea Leaves: Does a Tightly Rolled Form Affect the Infusion Time?, accessed November 12, 2025, https://blog.englishteastore.com/2013/05/28/rolled-vs-open-tea-leaves-does-a-tightly-rolled-form-affect-the-infusion-time/
8. What's So Special About Dragon Well Green Tea?, accessed November 12, 2025, https://jingtea.com/blogs/tea-in-detail/what-s-so-special-about-dragon-well-green-tea
9. Modern Balled-Oolong Rolling Process (“Gunpowder" tea) in Taiwan - Reddit, accessed November 12, 2025, https://www.reddit.com/r/tea/comments/twkra0/modern-balledoolong-rolling-process_gunpowder_tea/
10. Tea Processing Step: Oxidation, accessed November 12, 2025, https://teaepicure.com/tea-leaves-oxidation/
11. The Step-by-Step Orthodox Tea Manufacturing Process - Halmari Tea, accessed November 12, 2025, https://www.halmaritea.com/blog/orthodox-tea-manufacturing-process/
12. Enzymatic Reaction-Related Protein Degradation and Proteinaceous Amino Acid Metabolism during the Black Tea (Camellia sinensis) Manufacturing Process - PMC - NIH, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC7022896/
13. Tea Rolling Machine: Working Principles and Structural Analysis - longi, accessed November 12, 2025, https://www.longi.net/tea-rolling-machine-working-principles-and-structural-analysis/
14. Understanding the Rolling Process in Orthodox Tea Manufacture - Agriculture Institute, accessed November 12, 2025, https://agriculture.institute/post-harvest-mgt-value-addition/rolling-process-orthodox-tea-manufacture/
15. Enzymatic Oxidation of Tea Catechins and Its Mechanism - PMC - NIH, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC8840101/
16. Gunpowder tea - Wikipedia, accessed November 12, 2025, https://en.wikipedia.org/wiki/Gunpowder_tea
17. Tea Harvesting and Processing Techniques and Its Effect on Phytochemical Profile and Final Quality of Black Tea: A Review - PMC, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10743253/
18. Several Methods Of Tea Rolling Kneading Processing, accessed November 12, 2025, https://www.delijx.com/faqs/several-methods-of-tea-rolling-kneading-processing.html
19. Different tea, different processing: The 8 main tea processing methods and how a delicious cup is made, accessed November 12, 2025, https://australianteamasters.com.au/tea-processing-methods/
20. The 6 Steps of Tea Processing - Red Blossom Tea Company, accessed November 12, 2025, https://redblossomtea.com/blogs/red-blossom-blog/the-6-steps-of-tea-processing
21. Surface area to volume ratio of cells (video) - Khan Academy, accessed November 12, 2025, https://www.khanacademy.org/science/ap-biology/cell-structure-and-function/cell-size/v/surface-area-to-volume-ratio-of-cells
22. The Oolong Compendium - Tea Epicure, accessed November 12, 2025, https://teaepicure.com/oolong-tea-guide/
23. Swelling and infusion of tea in tea bags - PMC - NIH, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC5502043/
24. (PDF) Swelling and infusion of tea in tea bags - ResearchGate, accessed November 12, 2025, https://www.researchgate.net/publication/317747255_Swelling_and_infusion_of_tea_in_tea_bags
25. How to Make Gunpowder Green Tea - Fermentaholics, accessed November 12, 2025, https://fermentaholics.com/how-to-make-gunpowder-green-tea/
26. Unleash the Explosive Flavour of Gunpowder Tea in Your Cup - The China Teapot, accessed November 12, 2025, https://www.thechinateapot.co.uk/blogs/chinese-tea-education/unleash-the-explosive-flavour-of-gunpowder-tea-right-in-your-cup
27. Green Tea Production: Roasting - Tea Guardian, accessed November 12, 2025, https://www.teaguardian.com/what-is-tea/green-tea-production-roasting/
28. Proper roasting is key to the classic taste of a fine Longjing - Tea Hong, accessed November 12, 2025, https://www.teahong.com/proper-roasting-is-key-to-the-classic-taste-of-a-fine-longjing/
29. Processing of Sencha - Spring - Takezawa, accessed November 12, 2025, https://www.takezawa.jp.net/spring/copy_processing_of_sencha.html
30. Manufacturing Process of Semi-oxidized Tea (Chinese&Oolong tea) - far east tea company, accessed November 12, 2025, https://fareastteacompany.com/blogs/fareastteaclub/manufacturing-process-of-semioxidized-tea
31. Why tea leaves are rolled | Magazine | Avoury. The Tea, accessed November 12, 2025, https://www.avoury.com/at/en/magazine/why-tea-leaves-are-rolled
32. Black Tea Manufacturing Process, Health Benefit, and Application in Food Industry: A Review - Herald Scholarly Open Access, accessed November 12, 2025, https://www.heraldopenaccess.us/openaccess/black-tea-manufacturing-process-health-benefit-and-application-in-food-industry-a-review
33. Moisture contents and product quality prediction of Pu‐erh tea in sun‐drying process with image information and environmental parameters - PMC - NIH, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC9007301/
34. (PDF) An Approach for in-Line Control of Moisture Content During Green Tea Processing, accessed November 12, 2025, https://www.researchgate.net/publication/340151572_An_Approach_for_in-Line_Control_of_Moisture_Content_During_Green_Tea_Processing
35. Prediction Method of the Moisture Content of Black Tea during Processing Based on the Miniaturized Near-Infrared Spectrometer - MDPI, accessed November 12, 2025, https://www.mdpi.com/2311-7524/8/12/1170
36. Monitoring Moisture Content for Various Kind of Tea Leaves in Drying Processes Using RF Reflectometer-Sensor System - MDPI, accessed November 12, 2025, https://www.mdpi.com/2410-390X/2/3/18
37. Tea Manufacturing Process - Zesta Ceylon Tea, accessed November 12, 2025, https://www.zestaceylontea.com/blog/about-tea/tea-manufacturing-process/
38. From leaf to cup : A journey through energy-efficient tea processing - CAG, accessed November 12, 2025, https://www.cag.org.in/blogs/leaf-cup-journey-through-energy-efficient-tea-processing
39. Longjing Green Tea - REAL Alcohol Free, accessed November 12, 2025, https://realalcoholfree.com/pages/longjing-green-tea
40. Dragon's Well Tea: The Ultimate Guide to Longjing Tea - Sencha Tea Bar, accessed November 12, 2025, https://senchateabar.com/blogs/blog/dragons-well-tea
41. Tea Time: All's Well That's Dragon Well - Serious Eats, accessed November 12, 2025, https://www.seriouseats.com/tea-time-all-about-dragon-well-tea-how-to-brew
42. What Is Long Jing Tea? Taste, Origins, Brewing Tips, and Two Premium Styles to Try, accessed November 12, 2025, https://roseveartea.co.uk/blog/long-jing-tea-guide/
43. Longjing Tea: The Ultimate Guide To Chinese Dragon Well Tea, accessed November 12, 2025, https://enjoyourtea.com/green-tea/longjing-tea/
44. How Artisans Use Machines To Craft The Best Teas - Red Blossom Tea Company, accessed November 12, 2025, https://redblossomtea.com/blogs/red-blossom-blog/how-artisans-use-machines-to-craft-the-best-teas
45. Everything You Need To Know About Gunpowder Tea: Making, Taste, Brewing, And History, accessed November 12, 2025, https://jyyna.co.uk/gunpowder-tea-guide/
46. Gunpowder Tea,origin and production,preparation methods - Vicony Teas, accessed November 12, 2025, https://www.viconyteas.com/directory/tea-encyclopedia/gunpowder-tea.html
47. Why Keep Stems In Taiwan Oolong? - Teavivre, accessed November 12, 2025, https://www.teavivre.com/info/why-keep-stems-in-taiwan-oolong.html
48. Tie Guan Yin Production - Wan Ling Tea House, accessed November 12, 2025, https://www.wanlingteahouse.com/blogs/tea-articles/tieguanyin-production
49. Production of Taiwan Oolongs | Chazhidao Chinese Tea Traditions School, accessed November 12, 2025, https://chazhidao.org/en/fourth-circle/production-taiwan-oolongs
50. The difference between full handmade and semi handmade Dragon Well tea - Teavivre, accessed November 12, 2025, https://www.teavivre.com/info/the-difference-between-full-handmade-and-semi-handmade-dragon-well-tea.html
51. Man versus Machine - Tea & Coffee Trade Journal, accessed November 12, 2025, https://www.teaandcoffee.net/feature/19005/man-versus-machine/
52. Is Hand-Picked Tea Really Better? From Machine Harvesting in Japan to Hand-Picking in Taiwan - Yoshantea, accessed November 12, 2025, https://www.yoshantea.com/m/news.php?id=231026653a15dc44a06&lang=en
53. Hand Processing vs. Machine Processing - Mauna Kea Tea, accessed November 12, 2025, https://maunakeatea.com/hand-processing-vs-machine-processing/
54. Meet the Tea: Dragonwell - Longjing - Green Tea - Tea for Me Please, accessed November 12, 2025, https://www.teaformeplease.com/meet-tea-dragonwell/
55. Tea Rolling Machine: Revolutionizing Tea Production, accessed November 12, 2025, https://www.delijx.com/new/Tea-Rolling-Machine-Revolutionizing-Tea-Production.html
56. (PDF) The Evolution of Tea Harvesting: A Comprehensive Review of Machinery and Technological Advancements - ResearchGate, accessed November 12, 2025, https://www.researchgate.net/publication/385115155_The_Evolution_of_Tea_Harvesting_A_Comprehensive_Review_of_Machinery_and_Technological_Advancements
57. How Smart Tea Brewing Machines Help Tea Shops Improve Consistency and Efficiency | Dasin News and Events, accessed November 12, 2025, https://www.dasin-tw.com/en/news/Dasin-news-2025008.html
58. The Impact of Harvesting Mechanization on Oolong Tea Quality - PMC - NIH, accessed November 12, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10892732/
59. Hand-Picking Vs. Machine Harvesting - River & Stone Tea, accessed November 12, 2025, https://www.riverandstonetea.com/blogs/news/hand-picking-vs-machine-harvesting
60. Tea Harvesters vs Manual Harvesting: Efficiency Comparison Analysis | mrteamachinery, accessed November 12, 2025, https://mrteamachinery.com/tea-estate-equipment