The Craft of Lapsang Souchong: Birthplace of Black Tea

Lapsang Souchong is the world’s first black tea. Born in Tongmu Pass deep inside China’s Wuyi Mountains, its defining feature is a distinctive pine-smoke aroma — not the harsh industrial smoke of cured meats, but the sweet, resinous fragrance of slow-roasted Masson pine wood that clings to the leaf and unfolds in the cup like dried longan steeped in honey[1].

The craft’s secret lies in pine-wood smoke roasting. Fresh leaves are first withered, then rolled to break cell walls, then oxidised under controlled temperature and humidity until they turn red. Finally they are carried to the “qing lou” — not a place of entertainment, but a traditional multi-storey wooden building unique to Tongmu Pass. Pine firewood burns on the ground floor; tea leaves rest on the upper floors, slowly absorbing the rising smoke as they dry. Without this step, there is no true Lapsang Souchong[1].

Drag the sliders above to see how smoke aroma intensity changes with roasting temperature and duration across the five core stages from fresh leaf to finished tea.

What makes this tea special

Lapsang Souchong’s identity begins with geography and history. Tongmu Pass sits within the Wuyishan National Nature Reserve, at 1,000–1,500 m elevation, with an annual mean temperature of about 14–18 °C, persistent mist, high humidity and wide day–night temperature swings[1]. The dominant local cultivar is Wuyi Caicha — a seed-propagated population of small, tender leaves well suited to black tea production.

Local legend traces the tea’s origin to the late Ming or early Qing dynasty, when an army passed through Tongmu Pass. Tea workers, unable to process the fresh leaf as green tea in time, found it had naturally oxidised and turned red. To salvage the crop, they hastily dried the leaves over pine fires — and accidentally created a new tea with a smoky aroma and bright red liquor[2]. Whether or not the story is historically accurate, it captures the essence of the craft: Lapsang Souchong is a “happy accident” that revealed the path to fully oxidised tea, and the pine-wood roasting was a pragmatic use of abundant local Masson pine, whose resin-rich wood made smoke roasting almost cost-free.

By the early 17th century, Lapsang Souchong was being shipped to Europe by Dutch traders. It became a staple of British royal afternoon tea and directly inspired the planting and manufacture of black tea in India, Sri Lanka and elsewhere[3]. A thread of pine smoke from Tongmu Pass changed the global tea map.

Full processing flow

Traditional Lapsang Souchong passes through roughly twelve stages[1][4]:

Of these, withering, rolling, fermentation and smoke-roasting are the most quality-critical and are explored in detail below.

Withering: moisture loss and enzyme awakening

Withering is where Lapsang Souchong flavour begins. Fresh leaves are spread in thin layers on bamboo mats or withering troughs, 3–5 cm deep, for 8–18 hours depending on weather and equipment, reducing moisture from about 75% to 60–65%[1][4].

Traditionally, Tongmu Pass producers rely on natural indoor withering (locally called “liang qing”), exploiting the mountain’s cool, humid, well-ventilated climate for slow moisture loss. Modern factories also use warm-air withering troughs at 30–35 °C, cutting the time to 6–10 hours, though the resulting aroma is slightly less delicate than the natural method[4].

During withering, leaf cells gradually lose water, cell-membrane permeability increases, and the previously separated polyphenol oxidase (PPO) and catechins begin to meet. Proteins hydrolyse into amino acids and starch converts to soluble sugars, laying the groundwork for the sweet, mellow taste that follows. Under-withered leaf retains too much grassiness and astringency; over-withered leaf loses fragrance and ferments unevenly.

Rolling: breaking cells and shaping

Withered leaves move to a rolling machine, following a light–heavy–light pressure pattern for 60–90 minutes[4]. Because Lapsang Souchong uses relatively tender leaf, rolling must not be too aggressive — excessive juice extrusion and broken strips lead to uncontrolled, overly rapid oxidation.

Rolling serves three purposes:

1. Cell breakage: releases cell sap so PPO and substrate can meet, creating the oxidation interface;
2. Strip formation: the leaf is twisted and curled into tight, rope-like strips that hold their shape through drying;
3. Uniform mixing: enzymes, substrates and oxygen are evenly distributed, leading to consistent fermentation.

The sign of proper rolling: cell breakage rate around 70–85%, strips tight and slightly sticky with juice but not dripping, leaf colour shifting from dull green to dark red.

Fermentation: from green leaf to red liquor

Fermentation (in tea terminology, enzymatic oxidation) is the heart of black tea’s “reddening”. Rolled leaves are spread in bamboo baskets or fermentation rooms, 8–12 cm deep, at 22–28 °C and 90–95% relative humidity, for 3–6 hours[1][4].

Here, PPO catalyses the oxidation of catechins into o-quinones, which couple and polymerise into theaflavins and thearubigins — the former giving brightness and briskness to the liquor, the latter contributing the red, rich colour and mellow body[5]. Under-fermentation yields a yellowish liquor and lingering green notes; over-fermentation produces a dull brown colour, flat aroma and thin taste.

Because Tongmu Pass leaf is tender and chemically rich, fermentation time is usually slightly shorter than for large-leaf congou black teas. The tea maker watches the leaf colour and aroma closely: green → yellow-red → red-brown, with grassiness fading into floral and ripe-fruit notes, signals the right moment to stop[5].

Values are representative; real workshops adjust for leaf condition, weather, equipment and the tea maker’s judgement (drawn from GB/T 13738.3-2012 and Tongmu Pass processing practice)[1][4].

Smoke-roasting: where the pine aroma is born

Smoke-roasting is the single most distinctive step separating Lapsang Souchong from every other black tea — and the reason the “qing lou” exists.

The qing lou is a traditional three-storey wooden building unique to Tongmu Pass. A fire pit on the ground floor burns Masson pine firewood; the middle floor acts as a smoke buffer and heat diffuser; the top floor holds the fermented leaves. Smoke rises through flues, and the temperature in the smoking chamber is held at 100–120 °C for 6–10 hours, slowly drying the leaf while it adsorbs volatile compounds from the pine smoke[1][4].

The main contributors to pine-smoke aroma are pyrolysis products of pine resin, especially guaiacol, 4-methylguaiacol and 4-ethylguaiacol, along with small amounts of terpenes[6]. At 100–120 °C these compounds are adsorbed onto the leaf surface and released gradually during brewing, creating the signature “pine-smoke aroma, longan-sweet liquor” profile.

Too low a temperature (below 90 °C) and the smoke aroma is weak, drying is slow and the leaf risks mould. Too high (above 130 °C) and burnt off-notes appear, theaflavins are damaged, the liquor turns dull and the taste becomes harsh. The fuel matters too: fresh pine gives dense, aggressive smoke; air-dried pine gives soft, lingering smoke. Traditionally, Tongmu Pass farmers harvest pine in autumn and let it dry for a year before use[4].

Traditional vs new-style: keeping or losing the smoke

From the late 20th century, as nature-reserve logging restrictions limited Masson pine supplies and some consumers found the smoke too intense, new-style Lapsang Souchong emerged[4].

New-style follows the same withering, rolling and fermentation steps, but eliminates or greatly reduces pine-wood smoke roasting, replacing it with smoke-free hot-air drying or light smoke baking. The finished tea shows floral, honey and sweet notes, with a bright red liquor and a mellow, clean taste closer to standard congou black tea — but it loses the signature pine-smoke aroma that defines traditional Lapsang Souchong.

Neither style is objectively better; they serve different flavour preferences and market segments. Traditionalists insist “without pine smoke, it is not Lapsang Souchong”; innovators counter that “tea aroma is diverse, why be bound to one thread of smoke?” Today, Tongmu Pass hosts both old factories that still fire the qing lou and younger workshops that have fully embraced the new style[4].

Flavour and quality formation

Lapsang Souchong’s flavour rests on three pillars:

1. Theaflavins and thearubigins: formed during fermentation, governing liquor brightness and body;
2. Amino acids and soluble sugars: accumulated during withering and fermentation, delivering sweetness and aftertaste;
3. Smoke-aroma compounds: guaiacol and related phenols adsorbed during smoke-roasting, creating the distinctive smoky note.

Research shows that traditional Lapsang Souchong contains significantly higher guaiacol levels than smoke-free black teas, and this correlates strongly with sensory scores for “pine-smoke aroma”[6]. Meanwhile, Tongmu Pass’s high altitude, cool temperatures and humid, misty environment slow tea-plant growth, allowing richer accumulation of amino acids and aromatic substances — a key source of the “longan-sweet” character[1][7].

The silhouette is relative; real cups vary by origin, craft (traditional vs new-style), season and storage. New-style Lapsang Souchong would score near 0–20 on pine-smoke.

Grades and brewing

Under GH/T 1118-2015 Lapsang Souchong tea and GB/T 13738.3-2012 Black tea—Part 3: Souchong black tea, the tea is divided into three grades: Special, Grade 1 and Grade 2[1][7]. Special grade demands tight strips, glossy black colour, bright red liquor, and either a high, long-lasting pine-smoke aroma (traditional) or prominent floral-honey fragrance (new-style), with a mellow, sweet taste.

Brewing guide:

Because traditional Lapsang Souchong carries an intense pine-smoke note, some drinkers rinse the first infusion quickly and discard it, beginning formal tasting from the second steep — the smoke and longan sweetness will be more harmonious. New-style Lapsang Souchong needs no rinse; the first steep is ready to drink.

Related entries

• The science of black-tea oxidation — the enzymatic science behind Lapsang Souchong’s fermentation
• Congou vs. CTC black tea — two different roads within the same black-tea family
• China’s six tea categories — where Lapsang Souchong sits in the bigger picture
• The craft of Longjing — another representative tea craft deep dive

Full process parameters

Values are representative; real workshops adjust for leaf condition, weather, equipment and the tea maker’s judgement (drawn from GB/T 13738.3-2012, GH/T 1118-2015 and Tongmu Pass processing practice)[1][4].

References

1. GH/T 1118-2015. 正山小种茶 (Lapsang Souchong tea). All China Federation of Supply and Marketing Cooperatives. https://www.spc.org.cn/online/
2. Chen Zongmao (陈宗懋) ed. 中国茶叶大辞典 (Encyclopedia of Chinese Tea). China Light Industry Press, 2000. — Entry on Lapsang Souchong origin and history.
3. Ukers, W. H. All About Tea. 1935. — Historical record of 17th-century Chinese black tea exports to Europe.
4. Shi Zhaopeng (施兆鹏) ed. 茶叶加工学 (Tea Processing Science). China Agriculture Press. — Traditional and new-style Lapsang Souchong processing parameters.
5. Subramanian N., et al. (1999). Role of Polyphenol Oxidase and Peroxidase in the Generation of Black Tea Theaflavins. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/10552528/ — Mechanism of PPO and theaflavin formation during black tea oxidation.
6. Wan Xiaochun (宛晓春). 茶叶生物化学 (Tea Biochemistry), 3rd ed. China Agriculture Press, 2003. — Formation and adsorption of phenolic aroma compounds during black tea smoke-roasting.
7. GB/T 13738.3-2012. 红茶 第3部分：小种红茶 (Black tea—Part 3: Souchong black tea). National Tea Standardisation Technical Committee (SAC/TC339). — Definition, processing flow and grading terminology for souchong black tea.