從嗅覺到副交感神經：咖啡的「放鬆感」怎麼來的？ From Aroma to the Parasympathetic Nervous System: How Does Coffee Produce a “Relaxing Effect”?

JC咖啡小學堂

2025-08-08

從嗅覺到副交感神經：咖啡的「放鬆感」怎麼來的？

目錄:
1. 香氣是最早打開的放鬆開關
 2. 溫熱、柔和的咖啡，也能安撫神經
 3. 咖啡因的「雙面性」
4. 情境與儀式感：心理上的「條件反射」
5. 為什麼精品淺焙更容易帶來放鬆感？

對喜歡淺焙、單一莊園咖啡的手沖愛好者來說，沖煮咖啡不只是日常，更像是一種儀式。你也許會發現，儘管咖啡因具有提神作用，整個手沖過程卻常常讓人感到「放鬆」，甚至有點療癒。這種矛盾的感受，其實蘊藏著來自嗅覺、神經系統與心理經驗的多層次互動。

For pour-over enthusiasts who enjoy light roasts and single-origin beans, brewing coffee is more than just a daily routine — it’s almost a ritual. You may notice that, although caffeine is stimulating, the entire pour-over process often feels relaxing and even a little therapeutic. This seemingly contradictory experience actually reflects a multi-layered interaction between your sense of smell, nervous system, and psychological perception.

一、香氣是最早打開的放鬆開關

手沖咖啡最迷人的，往往是那一開始熱水落在粉層上時，噴湧而出的香氣。淺焙咖啡中常見的花香、果香、蜜香，實際上都與許多揮發性芳香化合物有關。例如：
* 茉莉、橙花、白桃：來自呋喃類與酯類芳香分子。
* 蜂蜜、香草、紅糖：可能含有香草醛、苯乙醇等化合物。

這些香氣透過嗅覺神經傳導，直接進入大腦的邊緣系統，也就是掌管情緒與記憶的區域。嗅覺是唯一一條不經視丘、直接進入大腦深處的感官通道，因此，香氣能快速激發情緒反應，喚起「愉悅、放鬆、安全感」等感受。

對咖啡人來說，熟悉的香氣，往往比咖啡因本身更有「情緒安撫」的力量。

1. Aroma: The First “Relaxation Switch” to Turn On

One of the most captivating moments in pour-over coffee is when hot water first hits the coffee grounds, releasing a burst of fragrance. Common floral, fruity, and honeyed notes in light roasts are actually linked to numerous volatile aromatic compounds. For example:

Jasmine, orange blossom, white peach: derived from furan and ester compounds.

Honey, vanilla, brown sugar: may contain vanillin, phenylethyl alcohol, and other molecules.

These aromas travel through the olfactory nerves directly to the brain’s limbic system — the area responsible for emotion and memory. The sense of smell is unique in that it bypasses the thalamus and reaches deep into the brain, allowing aromas to trigger emotional responses quickly, evoking feelings of pleasure, relaxation, and security.

For coffee lovers, familiar aromas often provide a greater “emotional comfort” than caffeine itself.

二、溫熱、柔和的咖啡，也能安撫神經

許多淺焙手沖咖啡的口感，並不強烈，而是帶有清甜、滑順、甚至像茶湯般的清透感。這種溫潤的液體進入口腔與食道，會刺激舌頭與喉部的感覺神經，進一步活化副交感神經系統。

副交感神經主導的是「休息與修復」的身體狀態，包括：降低心率與呼吸頻率、放鬆肌肉與促進消化、穩定情緒與思緒。

因此，當在早晨或午後，靜靜啜飲一杯溫熱的淺焙手沖時，不僅身體進入較平靜的狀態，大腦也同步接收到「此刻可以放鬆」的訊號。

2. Warm, Gentle Coffee Can Soothe the Nervous System

Many light-roast pour-over coffees have a subtle, delicate profile — sweet, smooth, and even reminiscent of tea. When this warm, gentle liquid enters the mouth and throat, it stimulates sensory nerves on the tongue and pharynx, further activating the parasympathetic nervous system.

The parasympathetic system governs the body’s “rest and repair” state, including lowering heart rate and breathing, relaxing muscles, promoting digestion, and stabilizing emotions and thoughts.

Therefore, when you quietly sip a warm light-roast pour-over in the morning or afternoon, not only does your body enter a calmer state, but your brain also receives the signal that “it’s time to relax.”

三、咖啡因的「雙面性」

我們常以為咖啡因只會刺激中樞神經、讓人亢奮，但事實上，它的作用與劑量與環境密切相關。

在高劑量（>200mg）時，咖啡因確實會促使交感神經活性上升，使人心跳加快、注意力提高。但在低劑量（約50–100mg）下，咖啡因反而能促進多巴胺與血清素釋放，提升情緒與愉悅感，卻不會造成焦慮或緊繃。

一杯15克咖啡粉沖出的手沖咖啡，咖啡因含量大約在80–120mg之間。若在熟悉、放鬆的場景中飲用，反而會進入一種「清醒而平靜」的狀態。
3. The “Dual Nature” of Caffeine

We often think of caffeine as simply stimulating the central nervous system and making us more alert, but its effects actually depend on dosage and context.

At high doses (over 200 mg), caffeine does increase sympathetic nervous activity, raising heart rate and heightening alertness. However, at lower doses (around 50–100 mg), caffeine can promote the release of dopamine and serotonin, enhancing mood and feelings of pleasure without causing anxiety or tension.

A pour-over brewed from 15 grams of coffee grounds typically contains about 80–120 mg of caffeine. When enjoyed in a familiar, relaxed setting, it can lead to a state of being both alert and calm.

四、情境與儀式感：心理上的「條件反射」

除了香氣與生理反應，還有一個常被忽略但極為關鍵的因素：你的大腦記住了這段時間是「放鬆時間」。

當你習慣每天在相似的時間、地點沖煮與品嚐咖啡，這個行為會逐漸被大腦標記為「儀式性放鬆行為」。這種透過重複建構的心理條件反射，會讓你一坐下沖煮、聞到香氣，身體自然進入放鬆狀態。

也就是說，咖啡變成了一種訊號，提醒你：「現在，是你與自己的時光。」

4. Context and Ritual: The Psychological “Conditioned Response”

Beyond aroma and physiological reactions, there’s another often-overlooked but crucial factor: your brain remembers this time as “relaxation time.”

When you routinely brew and enjoy coffee at the same time and place each day, your brain gradually labels this activity as a ritual of relaxation. This psychologically conditioned response, built through repetition, means that as soon as you sit down to brew and smell the coffee, your body naturally enters a relaxed state.

In other words, coffee becomes a signal reminding you: “Now is your time for yourself.”

五、為什麼精品淺焙更容易帶來放鬆感？

相比深焙或義式濃縮，淺焙手沖咖啡所營造的體驗更加溫和、複雜與內斂。

淺焙豆的香氣細膩多變，更容易啟動嗅覺與情緒系統。明亮清爽的酸甜平衡，類似水果與花茶的舒緩感官印象。手沖動作本身節奏穩定動作重複、專注流動，有助冥想與放鬆。無壓力的環境（家、咖啡館）促進副交感神經活動，減低交感活性。

放鬆，不只是味道。咖啡之所以能放鬆身心，其實是一場由分子 → 感官 → 神經 → 情緒 → 習慣的連鎖反應。對愛好手沖淺焙的你來說，每一杯咖啡不只是「飲品」，而是一種與自己對話、讓神經鬆一口氣的媒介。下次當你坐下來手沖，不妨留意這個歷程，香氣升起的那一刻，你的放鬆就已經開始了。

若你對提升「放鬆系風味」有興趣，推薦你嘗試帶有茉莉花、桃子、蜂蜜香氣的淺焙藝伎，像是衣索比亞水洗藝妓、哥倫比亞藝妓及泰國藝妓豆等，它們不只風味迷人，更能讓你在日常的時光中找到片刻寧靜。

5. Why Do Specialty Light Roasts Make It Easier to Feel Relaxed?

Compared to dark roasts or espresso, light-roast pour-over coffee offers a gentler, more complex, and introspective experience.

The delicate and varied aromas of light-roast beans more easily stimulate the olfactory and emotional systems. Their bright, balanced acidity and sweetness evoke soothing sensory impressions, reminiscent of fruit and floral teas. The rhythmic, repetitive motions of pour-over brewing encourage focus and mindfulness, supporting relaxation. A low-stress environment — at home or in a café — further activates the parasympathetic nervous system while reducing sympathetic activity.

Relaxation isn’t just about taste. Coffee’s ability to calm the mind and body is actually a chain reaction: from molecules → senses → nerves → emotions → habits. For light-roast pour-over enthusiasts, each cup is more than a drink — it’s a medium for self-reflection and a gentle way to let your nervous system unwind. Next time you sit down to brew, notice this process: the moment the aroma rises, your relaxation has already begun.

If you’re interested in enhancing the “relaxation profile” of your coffee, try light-roast Geisha beans with jasmine, peach, or honey notes, such as Ethiopian washed Geisha, Colombian Geisha, or Thai Geisha. These beans not only offer captivating flavors but also help you find a moment of calm in your daily routine.