Why are Longjing leaves flat?

Start with the essentials

Three key points

1. Initial pan work has several jobsHeat controls oxidation while handling begins moisture loss and shaping.
2. Resting connects the stagesMoisture redistribution prepares leaves for further pan work.
3. Final work brings the result togetherHeat and movement affect drying, flatness and aroma according to material condition.

What to notice when tasting

What makes Longjing special

Longjing’s identity starts with place. Under China’s GB/T 18650-2008 standard, Longjing tea is produced in three zones[1]:

• West Lake zone: the core area around Hangzhou’s West Lake, source of true West Lake Longjing;
• Qiantang zone: Xiaoshan, Yuhang, Fuyang and Lin’an districts of Hangzhou;
• Yuezhou zone: Shaoxing, Xinchang, Shengzhou and Zhuji areas.

Only tea grown and processed within the West Lake zone by the traditional method may be sold as “West Lake Longjing”[2].

Cultivar and plucking also matter. The traditional Longjing population cultivar gives complex aroma but buds unevenly; the widely planted Longjing 43 buds early and produces uniform, elegant leaves. The finest grade is picked as one bud and one just-unfolding leaf.

Full processing flow

Traditional West Lake Longjing passes through roughly ten steps[2]:

Of these, spreading, qing guo and hui guo are the most quality-critical.

Spreading: letting the leaf wake up

Freshly picked leaves are spread in thin layers on bamboo trays for 6–12 hours at room temperature. Moisture falls from about 75% to around 70%[2].

This does three things:

1. Softens the leaf — making it pliable for shaping;
2. Dispels grassy notes — some low-boiling green volatiles evaporate;
3. Begins gentle conversion — proteins partly hydrolyse into amino acids, building the umami base.

Under-spread leaves retain too much grassiness and may scorch; over-spread leaves lose fragrance and yellow.

Qing guo: high-heat fixation and first shaping

Qing guo is the dramatic first act. Leaves are tossed into a pan heated to 180–220 °C and moved rapidly with the hands. A hand-fired batch uses 100–150 g of leaf for 10–15 minutes; 3–4 minutes is a condition-bound machine example, with settings varying by machine and leaf state[2][5].

Compare the two firing stages: qing guo emphasises fixation and first shaping; hui guo emphasises pressing, polishing and final drying. Switch stages to connect each movement with its purpose.

Heating reduces polyphenol oxidase (PPO) and peroxidase activity, limiting enzymatic oxidation and red discoloration. Their heat resistance and residual activity differ; the cited green-tea enzyme study does not measure every Longjing batch[6]. Heating also removes some grassy volatiles and promotes Maillard and other thermal reactions between sugars and amino acids. Roasted, chestnut-like and bean-like notes arise from a mixture of volatiles rather than a one-compound explanation[7]. Pan temperature is not leaf temperature: contact with the pan, leaf movement and evaporation all affect heating.

At the end of qing guo the leaf is 20–30% moisture and already partially flat — about 70% dry.

Resting: even out the moisture

After qing guo the leaves are spread again and rested for 40–60 minutes[2]. This lets internal moisture migrate to the surface, re-softening the leaf so it does not break during hui guo and so the final pressing can be even.

Both involve spreading leaves, but their main tasks differ. The simplified cross section below contrasts outward water loss with internal redistribution.

Hui guo: low-heat shaping and aroma finishing

Hui guo is where Longjing gets its flat, glossy identity. The pan temperature drops to 60–80 °C, following a low–high–low rhythm. Hand hui guo uses about 150 g of leaf and lasts 20–40 minutes; 8–10 minutes is one machine example, adjusted to equipment and leaf condition[2][5].

Movements emphasise pressing, rubbing and polishing against the pan wall, repeatedly flattening the leaf into the characteristic “bowl nail” form. The slow, gentle heat drives the last moisture out while aroma compounds concentrate and settle.

Finished leaf moisture drops to 5–6% and the strip snaps when bent; colour ranges from tender green to the distinctive “parched-rice” tone of some traditional West Lake lots.

The ten hand movements and hand vs. machine

The ten traditional hand movements of West Lake Longjing are:

Grab, shake, lay, press, smooth, push, fold, flick, rub and flatten

(Chinese: 抓、抖、搭、拓、捺、推、扣、甩、磨、压)

Different stages favour different movements: qing guo relies more on shaking to cool and dissipate green notes, while hui guo relies on rubbing and pressing to create the flat, polished surface. The master’s hands never leave the tea, and the tea never leaves the pan.

Machine processing offers efficiency and batch consistency, while hand work and combined methods allow finer adjustment to the leaf. Cui et al. (2021) compared four processing methods: in that experiment, one machine fixation followed by hand finishing produced aroma and taste comparable to fully handmade tea and better than fully machine-made tea[5]. This supports a combined route under the studied conditions, rather than a universal rule that handmade tea is superior. Judge fixation, shaping and final dryness alongside the actual leaf and infusion.

Flavour and quality formation

Longjing’s typical aroma spectrum includes:

• Fresh / tender notes: early spring bud character;
• Chestnut / bean aroma: from pyrazines and pyrroles formed during pan-firing;
• Orchid fragrance: occasionally found in high-grade West Lake lots.

Li et al. (2019) observed increases in some glycosidically bound volatile precursors (GBVs) during the studied green-tea pan-firing process[3]. Bound precursors are not the same as free aroma: enzyme activity, heat, water and volatile losses affect subsequent release. This result does not establish identical enzymatic aroma release during brewing in all Longjing teas. Amino acids, including theanine, contribute alongside other taste compounds; composition and perceived quality should be considered together[4].

The silhouette is a qualitative illustration, not a measured sensory score; real cups vary by origin, cultivar, grade and season.

Grades and brewing

GH/T 1115-2015 divides West Lake Longjing into four grades: Premium, Special, Grade 1 and Grade 2[2]. Special grade demands tender, uniform, flat, smooth leaves with a tender green colour, clear high aroma and fresh mellow taste.

Brewing guide:

Water that is too hot or too long a steep will dull the briskness and bring out bitterness.

Related entries

• The science of green-tea fixation — the enzyme science behind Longjing’s qing guo
• China’s six tea categories — where Longjing sits in the bigger picture
• Congou vs. CTC black tea — another representative tea craft deep dive

Full process parameters

These are condition examples, not a measured batch curve. Pan, room and leaf temperatures differ. Product standards and processing comparisons serve different purposes and do not define one universal recipe; workshops adjust to leaf, weather and equipment[1][2][5].

References

1. R-066 — GB/T 18650-2008.《地理标志产品 龙井茶》(Product of geographical indication—Longjing tea). 国家质量监督检验检疫总局、国家标准化管理委员会.
2. R-067 — GH/T 1115-2015.《西湖龙井茶》(West Lake Longjing tea). 中华全国供销合作总社.
3. R-068 — Li, P., Zhu, Y., Lu, M., et al. (2019). Variation patterns in the content of glycosides during green tea manufacturing by a modification-specific metabolomics approach: Enzymatic reaction promoting an increase in the glycosidically bound volatiles at the pan firing stage. Food Chemistry, 279, 80–87. https://doi.org/10.1016/j.foodchem.2018.11.148
4. R-069 — Wang, K. B., & Ruan, J. Y. (2009). Analysis of chemical components in green tea in relation with perceived quality, a case study with Longjing teas. International Journal of Food Science & Technology, 44(12), 2476–2484. https://doi.org/10.1111/j.1365-2621.2009.02040.x
5. R-070 — 崔宏春, 张建勇, 敖存, 黄海涛, 郑旭霞, 赵芸, 师大亮, 余继忠 (2021). 不同加工工艺西湖龙井茶品质差异特性分析. 食品工业科技, 42(13), 268–273. https://doi.org/10.13386/j.issn1002-0306.2020070165
6. R-060 — Öztürk, B., et al. (2016). Change of enzyme activity and quality during the processing of Turkish green tea. LWT-Food Science and Technology, 65, 318–324. https://www.sciencedirect.com/science/article/abs/pii/S0023643815300852
7. R-029 — 宛晓春 主编 (2003).《茶叶生物化学》(第3版). 中国农业出版社. ISBN: 978-7109066274.