日本語版

pine smoke withering

process / process-pine-smoke-withering

松の煙による萎凋

Pine smoke withering is a distinctive step in the withering of (Lapsang Souchong) in which tea leaves are exposed to pinewood smoke.

On this page (8 sections)
  1. Overview
  2. Sources for this overview (2)
  3. Topic hubs
  4. Follow the connections
  5. Related entries (10)
  6. Sensory (1)
  7. Mechanism and receptors (1)
  8. How processing and cooking change it (1)
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Reading the bitterness

「正山小種」 (Lapsang Souchong) is a black tea made by a distinctive process: during withering and drying, tea leaves in bamboo baskets are hung over a pinewood fire to absorb its smoke. This is described as a traditional method originating in the Tongmu area of Wuyi Mountain, Fujian Province.

Exposure to pine smoke has been found to change the tea's bitterness itself, beyond adding aroma. A study combining electronic-tongue measurement, sensory evaluation, and cell-based calcium imaging reported that pine-smoke withering significantly reduced the bitterness of 「正山小種」 (Lapsang Souchong).

As a possible basis for lower bitterness, untargeted metabolomics was reported to find large decreases in major bitter phenolics after pine-smoke withering, including 10 monomeric catechins, 14 glycosylated flavonols, and 6 galloylated phenolic acids. This report has been checked only at abstract level; details such as panel size and electronic-tongue output values require reading the full text.

Pine-smoke withering also substantially reshapes aroma compounds. GC and GC-MS analysis reported decreases in tea-derived aroma compounds but marked increases in pine-derived terpenes and pyrolysis products including guaiacol, 4-methylguaiacol, and 4-ethylguaiacol; these were not detected in unsmoked 「正山小種」 (Lapsang Souchong). Lower bitterness and substantial aroma change arise from the same step.

The abstract shows that guaiacol and alpha-terpineol, aroma compounds from pine-smoke withering, suppressed TAS2R14 activation by a pre-withering tea extract by 37% and 21%, respectively, measured as changes in intracellular calcium signaling. Quantum chemical calculations indicate that these aroma compounds interact with bitter molecules mainly through intermolecular hydrogen bonds and van der Waals forces.

Sources for this overview

  1. Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong, a Special Chinese Black Tea with Pine Smoking Process

    Yao S; Guo W; Lu Y; Jiang Y / 2005 / journal article / abstract checked

    Checked for this overview: Confirmed the specific steps of withering under pine smoke. / Confirmed the pattern of changes in pine-derived aroma compounds.

  2. Role of smoke withering process in the bitterness amelioration effect on smoked Lapsang Souchong tea

    Su W; Ni L; Wang D; Lu Y; Liu W; Feng X; Liu Y; Liu Z / 2026 / journal article / abstract checked

    Checked for this overview: Confirmed significant bitterness reduction through multiple methods. / Confirmed the breakdown of decreased bitter phenolics. / A receptor-level mechanism involving direct suppression of TAS2R14 activation by aroma compounds.

Follow the connections

Lapsang souchong →is processed by→ pine smoke withering

bitterness →is reduced by→ pine smoke withering

pine smoke withering →reduces→ TAS2R14

Structured claims — open a section to read each claim's confidence, evidence and limits

Sensory (1)

bitterness is reduced by pine smoke witheringsupported

Scope: A comparison before and after the pine-smoke withering process for lapsang souchong (smoked tea)

Note: Using a method integrating electronic-tongue analysis, sensory evaluation, and a cell-based calcium-imaging assay, the pine-smoke withering process was confirmed to significantly reduce the tea's bitterness. The study reports that non-targeted metabolomics found pine-smoke withering to have greatly decreased the major bitter phenolics, including 10 monomeric catechins, 14 glycosylated flavonols, and 6 galloylated phenolic acids. The full text has not been confirmed; this is abstract-level information.

Electronic-tongue analysis, sensory evaluation, and a cell-based calcium-imaging assay are reported to have confirmed that the pine-smoke withering process significantly reduces the bitterness of lapsang souchong. Non-targeted metabolomics is reported to show that the major bitter phenolics, including 10 monomeric catechins, 14 glycosylated flavonols, and 6 galloylated phenolic acids, decreased greatly.
Limitations: Confirmation is at the abstract stage only; methodological details such as panel size, specific electronic-tongue output values, and statistics have not been confirmed this time. Re-evaluation after checking the full text is needed.
Source: Role of smoke withering process in the bitterness amelioration effect on smoked Lapsang Souchong tea (Su W; Ni L; Wang D; Lu Y; Liu W; Feng X; Liu Y; Liu Z, 2026) · abstract checked
Show datasensation-bitter —is_reduced_by→ process-pine-smoke-withering
claim: clm-lapsang-bitterness-reduced-by-smoke-withering / type: sensory / updated: 2026-09-02

Mechanism and receptors (1)

pine smoke withering reduces TAS2R14preliminary

Scope: Layer: cell. Effects on TAS2R14 were measured with a cell-based calcium-imaging assay.

Note: Full text not checked; confirmed from the full abstract as posted on Semantic Scholar. Separately from the 2 existing claims (confirmation of reduced bitterness, and the decrease in bitter phenolics), this adds a mechanism by which the aroma compounds themselves directly suppress the bitterness signal at the receptor level.

"key pinewood smoke odorants, guaiacol and α-terpineol, directly inhibited TAS2R14 activation by pre-smoke withered tea extract, reducing intracellular calcium signaling by 37% and 21%, respectively. Quantum chemistry calculations further demonstrated that these odorants readily interact with bitter compounds primarily through intermolecular hydrogen bonding and van der Waals forces."
Limitations: Full text not obtainable (an Elsevier journal; not open access in either Europe PMC or OpenAlex). Confirmed only from the full abstract posted on Semantic Scholar. Details of the measurement conditions for these figures (concentration, time, etc.) cannot be determined from the abstract.
Source: Role of smoke withering process in the bitterness amelioration effect on smoked Lapsang Souchong tea (Su W; Ni L; Wang D; Lu Y; Liu W; Feng X; Liu Y; Liu Z, 2026) · abstract checked
Show dataprocess-pine-smoke-withering —reduces→ receptor-tas2r14
claim: clm-w71c2-lapsang-guaiacol-terpineol-tas2r14 / type: mechanism / updated: 2026-09-07

How processing and cooking change it (1)

Lapsang souchong is processed by pine smoke witheringsupported

Scope: 「正山小種」 (Lapsang Souchong), a traditional production method originating in the Tongmu area of the Wuyi Mountains, Fujian Province.

Note: During withering and drying, tea leaves placed in bamboo baskets are suspended above a fire burning pinewood and exposed to its smoke. In this process, tea-derived aroma compounds decrease, while pine-derived terpenes (including longifolene) and pyrolysis products (including guaiacol, 4-methylguaiacol, and 4-ethylguaiacol) increase markedly; these are not detected in unsmoked Lapsang Souchong. The source does not give numerical values for smoking temperature or time.

It has been reported that, in the process of suspending tea leaves in bamboo baskets above pinewood smoke to dry and flavor them, tea-derived aroma compounds decrease while pine terpenes and pyrolysis products (including guaiacol, 4-methylguaiacol, and 4-ethylguaiacol) increase markedly, and these are not detected in unsmoked products.
Limitations: Because the full original text has not been checked, detailed information, including numerical values for temperature and time and whether bitterness is discussed, has not been confirmed in this review. The information remains at abstract level.
Show dataingredient-lapsang-souchong —is_processed_by→ process-pine-smoke-withering
claim: clm-lapsang-processed-by-smoke-withering / type: processing / updated: 2026-09-02

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