2017年4月10日 星期一

咖啡萃取&如何品嘗?

This post will cover some basic extraction theory and the tastes associated with over, under and ideal coffee extractions.
此文將以基礎的咖啡萃取理論,以及品嘗到過度萃取萃取不足以及理想萃取三種情況的咖啡作連結。
Extraction is arguably the most important and least understood aspect of coffee brewing. It's everything. Without extraction, you don't even get a cup of coffee. Here's my super simple and not 100% accurate definition:
萃取可說是咖啡沖煮中最重要卻最不為了解的部分,萃取代表一切。如果不萃取甚至無法獲得一杯咖啡,以下是最簡單但不是百分之百準確的說法:



萃取就是用水將咖啡的物質帶出來
It's pretty easy to sum up, but a lot more difficult to understand and apply.
要用談的都很容易,但是要融會貫通和應用卻難得多。
For now, I don’t want to delve into fats and lipids and the micro-componentry of extraction. I want to communicate useful and relevant information, like how to taste extraction and how to manipulate it. Chemical analysis can come later.
先不在這裡深入討論萃取時咖啡油脂及微量成分的影響,先討論較實用及貼切的資訊,像是如何品嘗萃取的咖啡並且做到熟練,至於化學分析這類的以後再說。
When you mix coffee and water, a lot of things happen. The most relevant and easy to understand of all these things is that water dissolves a lot of coffee's flavours. These dissolved flavours make up (almost) everything you taste when you drink a cup of coffee. The rest is undissolved stuff.
將咖啡與水混合時會發生不少事,最容易理解的說法,就是水溶解出許多咖啡的味道,這些溶解出來的味道幾乎就是你在咖啡杯中喝到的風味。
This is mostly very very small coffee grinds that affect mouthfeel, but can’t be included in extraction because they’re just floating around in the water.
只有研磨到非常細的咖啡粉才會影響口感,但在萃取時不考慮細粉,因為細粉在萃取時只是漂浮在水中。
Roasted coffee beans are ~28% (by weight) water-soluble. This means that you can extract ~28% of the coffee bean's mass in water. The rest is pretty much cellulose and plant stuff that forms the structure of the seed.
烘焙咖啡豆有約28%重量的物質,可被水溶解,這代表可以萃取咖啡豆約28%的物質到水中。其餘的物質幾乎都是咖啡豆的纖維及種子的組織。
Water is pretty good at dissolving those soluble chemicals, but it needs help. If you throw a handful of coffee beans in hot water, you don’t extract much more than the outside layer. This is because the coffee bean’s structure is incredibly dense and complex; water can’t just pass through and collect all the flavour on its way. To help, we have to increase the surface area of the coffee beans; we need to ‘open them up’ so the water can easily get at all of the flavour. This is achieved rather handily by the use of a coffee grinder. It crushes the beans into a powder, exponentially increasing their surface area and allowing the water to do its work.
水是可溶性物質很好的媒介,但是還是需要一些外力的幫助,如果將完整的咖啡豆丟入熱水,萃取出的物質比粉少得多,因為咖啡豆的結構非常密集和複雜,水無法穿過完整咖啡豆並溶解味道。所以我們必須增加咖啡豆的表面積,必須打開它好讓水能帶出咖啡的味道。透過使用磨豆機可以輕鬆萃取,將咖啡豆磨成粉狀,增加表面積使水能夠發揮效用。
In an ideal world, we’d crush the coffee into an extremely fine powder, throw water at it and dissolve all of its delicious flavours. Unfortunately, this results in a terribly bitter and awful cup of coffee. Not all of the coffee’s flavours are good, so we have to control the amount of flavour that we extract in order to make a palatable cup.
理想狀況下,我們將咖啡磨到非常細的狀態,丟入水中並溶解出美好的風味。可惜若這樣做,這就是一杯很苦很難喝的咖啡。並非所有的咖啡風味都是好的,所以我們必須控制萃取風味的數量,才得以沖煮出一杯美味的咖啡。
We also can’t just use more coffee grinds and extract less of them to avoid those over-extracted flavours. Under-extraction tastes terrible as well (more on this in a moment).
 同樣的我們不能磨很多咖啡豆並萃取一點點,為了避免這些過度萃取的風味,萃取不足的咖啡喝起來一樣很可怕(有時比過度萃取還難喝)
Most people understand extraction as a two-way street. A street where we always try to steer the coffee towards the middle; avoiding both over and under-extraction.
多數人了解萃取就像是雙向道路,而我們總是試著在這條路找到平衡點,避免過萃或萃取不足的情形。
For the next two Hustles, this simple analogy will be enough. Then once you’re all over it, I’ll be adding a layer of complexity that rounds everything out. Until then, we’re on two-way Extraction Street!
下面這個簡單的圖就可以解釋後續內容,當你能夠駕馭這些時,就可以讓煮出來的咖啡更豐富。而在那之前,我們都還在下圖代表的路口中駐足。
 


萃取不足的咖啡
Under-extraction occurs when you haven’t taken enough flavour out of the coffee grinds. There’s still a lot left behind that could balance out the following undesirables.
萃取不足是指水帶出的咖啡粉物質不夠多,咖啡粉還有許多殘留的物質,可以增加這杯萃取不足咖啡的風味。
Cast your mind to a shot of espresso that was far too short; a ristretto of a typical Specialty espresso roast. It’s sour, lacking sweetness, weirdly salty and has a disappointingly quick finish. These four things are the most obvious indicators of under-extraction. Let’s go through them in a little more detail.
想像一杯萃取時間太短的濃縮咖啡,也就是精品義式濃縮ristretto,有臭酸味、缺乏甜味、奇怪的鹹味以及讓人失望的短餘韻。這四個特徵是萃取不足的明顯跡象,讓我們再來仔細看萃取不足的現象。

Sourness 
臭酸味
This is a tricky one, especially with our desire for acidity in coffee. I hear lots of people ask “Aren’t sourness and acidity the same thing?” and it’s a very valid question; in a lot of languages ‘sourness’ is the same word as ‘acidity’. As you can imagine, this makes multilingual cuppings a little difficult.
咖啡的臭酸味很棘手,尤其是期望得到咖啡的酸質時。有許多人問作者酸味sourness跟酸質acidity不是一樣嗎?”,這是個好問題;許多語言表達酸味跟酸質是一樣的用詞,你可以想像當說不同語言的人在一起杯測時,會有多困難。
To clear this up, I always define sourness as being negative. A sour flavour hits you quickly and aggressively. It creates an immediate physiological reaction, you might pucker your lips or it might feel electric or sharp on the sides of the tongue. Sourness is undesirable and distracting.
為了澄清這部分,會定義臭酸味為負面的味道。舌頭會很快並強烈地感受到酸味,這會造成立即的生理反應,你可能會皺起嘴唇,或是在舌頭兩側有觸電、尖銳的感受。臭酸味會令人不舒服而且破壞了你的味覺,且不會是你想要的味道。
Whenever I talk about acidity it can be either good or bad. It’s more of a category of flavour than a positive or negative attribute. Example: “That coffee’s acidity is delightful” or “That coffee’s acidity is very sour” are both logical to me. Acidity is the umbrella under which lies all sour/juicy/bright/tart things. I could write volumes about acidity, but this week is all about extraction. Back to it.
當談到酸質時,它可以是好或壞,比起用好壞來形容,酸質更像是風味的一種。例如:咖啡的酸質令人愉悅,或是這咖啡的酸質強度很高都很合邏輯。酸質跟酸味/果汁感/酸質明亮/刺激的酸這些都可做連結,可以專門寫一篇酸質的文章,但此文是探討萃取。回歸正題。

Lacking Sweetness 
缺乏甜味
In my opinion, the most important aspect to a coffee's flavour is its sweetness. Sweetness is the best. Have you ever heard someone say 'this espresso is too sweet!'? Think about that for a second. I strongly believe that we should always be chasing sweetness. It’s my holy grail: something that’s really difficult to find and stupendously rewarding once you get it. Under-extraction isn't sweet. It's far from it. It almost always displays an emptiness that leaves you with an unsatisfying 'I-want-more' feeling after drinking. The good thing about this lack of sweetness is that it also accentuates the sourness, making under-extraction much more obvious.
以作者的觀點,咖啡風味最重要的就是甜味。甜味是最棒的。你曾經聽過有人這樣抱怨嗎?”這濃縮咖啡太甜了!”。讓我們想想,我很相信我們應該都是在追求咖啡的甜味。甜味就如非常難找到的聖杯般,而一旦尋求到了就會有驚人的報償!萃取不足是不會有甜味,且相距甚遠。萃取不足會顯示出喝完咖啡後的不滿足,讓人有我想要更多咖啡那種空虛感。值得一提的是,欠缺甜味這件事的,反而可以凸顯出咖啡豆的臭酸味,讓人更明顯感受到萃取的不足。


Salty 
鹹味
Not everyone agrees with me here, but I’ll argue til I’m red in the face that under-extracted coffee is salty. It’s not quite ‘sorry I added table salt’ salty, but under-extracted coffee almost always has the mouthfeel and/or taste of saltiness. From a tactile point of view, it’s kind of similar to the slipperiness you get from alkalinity (Don’t go and drink ammonia to learn this one. Just trust me).
目前 並非所有人都同意作者的觀點,但這部分必須堅持說,萃取不足的咖啡會是鹹的。這並不像是抱歉我加了鹽到咖啡裡那種鹹,而是萃取不足的咖啡,幾乎都會有嚐到鹹味時的那種口感。以觸覺感受來看,就像是接觸到鹼性食物那種滑溜感(拜託不要喝阿摩尼亞來感受這個味道,相信我)

#PocketScience - Acids and Salts are more soluble than Sugars. This is why an under-extracted coffee is sour and salty - the sugars haven’t had enough time or chances to dissolve completely just yet. [citation needed]
#科學小講堂-酸味及鹹味比甜味更容易溶解出來,這也是為什麼萃取不足的咖啡會有酸味及鹹味,甜味的物質沒有足夠時間或機會來完全溶解出來。 


Quick Finish
餘韻短

A well extracted coffee has a finish that lingers for minutes (or hours if you're lucky). This finish can feel as though someone has left dark brown sugar on your tongue, or as though you've just finished a toffee. Yum!
良好萃取的咖啡的餘韻可延續好幾分鐘(甚至幸運可到幾小時),這個餘韻可以想像有人放了塊紅糖在你舌頭上,或是想像你剛吃完一塊美味好吃的太妃糖。

An under-extracted coffee doesn't have this finish. Once you swallow, it disappears straight away. You're not left with any pleasant lingering sensation. It's an abrupt and unsatisfying end to your coffee experience. Less Yum.
而萃取不足的咖啡沒有這種餘韻。當你吞下咖啡時,風味也隨之消散。你口中不會殘留任何令人愉悅的感受,這讓你體驗這杯咖啡讓你感受短暫且不滿意的口感,難喝又不美味。

There are other flavours that indicate under-extraction, but these four are certainly the most obvious. Whenever you taste them, be sure that some part of your coffee is under-extracted!
還有其他不佳感受代表萃取不足,但上面這四個項目是較明顯且確定的。不管什麼時候喝到這些特性,都可以確定你喝到的是萃取不足的咖啡。

Let's now cast our attention to the opposite end of Extraction Street.
接下來我們來看萃取不足的另一個極端。

Over-extracted Coffee
過度萃取的咖啡
Over-extraction occurs when you take too much of the soluble flavours out of the coffee. This level of extraction results in unfavourable flavours.
過萃的咖啡代表將咖啡中太多的可溶性物質帶出來,這種萃取結果帶來的是不好的風味。
Cast your mind now to an espresso of a typical specialty espresso roast that brewed for 40-50 seconds. Don’t pretend like you didn’t taste it when this happened once. It’s bitter, drying and hollow. These three things are the most obvious indicators of over-extraction. Let’s shine some light on them as well.
想像一杯萃取時間達40-50秒的精品義式濃縮咖啡,不要假裝你沒有喝過這種過萃的咖啡。這樣的咖啡會很苦、乾燥感且空洞,這是代表過度萃取咖啡最明顯的三個特徵,讓我們再來看看這些特徵。

Bitter 
苦味
We’ve all been here. Coffee is bitter. Over-extracted coffee is really bitter. Unless I’m drinking Campari, I don’t want that much bitterness. A lot of this bitterness comes from caffeine, but there’s many other chemicals in coffee that contribute. A darker style roast that has achieved dry distillation will have many more of these bitter chemicals.
我們都喝過很苦的咖啡。過度萃取的咖啡真的很苦,除非我在喝金巴利苦酒,不然我不想喝到這麼苦的味道。許多的苦味來自咖啡因,但苦味也跟許多其他化學作用有關係。深焙的咖啡會達到焦炭化狀態,而形成更多苦味的化學物質。

#PocketScience - There are thousands of chemicals (pretty much all poisonous) that trigger the exact same bitter signal from our taste buds. This is our body’s way of saying ‘don’t eat that’.
#科學小講堂 有成千上萬的化學物質(絕大多是是毒物)會觸發我們味蕾的苦味訊號,警告我們的身體不要吃這個東西。


Drying 
乾澀感
Dryness in coffee is so incredibly bad because it’s such a strong sensation, and it can last a long time. This sensation is called astringency and is the same as you get from unsweetened black tea, young red wine or white wines with extended barrel time. In wine, this effect is caused by polyphenols: chemicals that are readily found in plants, seeds, bark etc. These are arguably the same chemicals that cause dryness in coffee.
在咖啡中喝到感覺乾澀的咖啡是非常不舒服的,因為乾澀感是很強烈且會持續很久的感覺。這種感覺稱為澀味,就如你喝到不加糖的紅茶、新釀葡萄酒、釀過頭的白葡萄酒一樣。在酒中的澀感是來自多酚效應:這是很容易在植物、種子與樹皮發現的化學物質,而這也可能是造成咖啡喝起來有乾燥感的化學物質。
Polyphenols are bitter and bind to your saliva’s proteins. In layman’s terms, they de-lubricate your tongue, creating a sandpapery or dry sensation in the mouth (This shouldn’t be confused with the wine versions of ‘crisp’ and ‘dry’ - these are terms that denote bright acidity or low sweetness; not necessarily mouthfeel).
多酚是苦的且會跟你唾液的蛋白質結合,以一般人懂得話來說,就是多酚會吸乾你的舌頭,在口中產生沙沙的或是乾燥的感覺(這不應該與葡萄酒中的混淆,這些形容詞表示鮮明的酸質或是低甜味,不一定是表示口感)

Hollow and Empty
空洞感
This is a personal descriptor I like to use for over-extraction. The coffee just feels empty and lifeless, like you’ve extracted the living daylights out of it and killed everything in the process.
Well extracted coffee fills your mouth with richness. It’s luscious, smooth and, well, mouthfilling. Over-extracted coffee is empty, hollow, rough and just plain-old yucky. It’s this lack of flavour and character (rather than the presence of a particular flavour) that leads me to use the word ‘hollow’.
作者喜歡用空洞來形容過度萃取的咖啡,咖啡感覺就是空虛且沒有生命,就像是萃取時把咖啡中的光亮抽離,過程中扼殺了美好的物質。良好萃取的咖啡會讓你喝到濃郁感,是美味、滑順且讓人垂涎三尺的。而過度萃取的咖啡就是空洞、粗糙、讓人厭惡的平淡無味。正是這種缺乏風味和特性的咖啡(此特性並非指風味的特性),讓作者用空洞一詞形容。
Those are the key over-extracted flavours. Of course there are more, but these are super simple to identify, and should have you identifying over-extraction in no time!
這些是過度萃取風味的味道特徵,當然還有更多形容詞,但這些是最容易辨認,這也提醒你不要沖出過度萃取的咖啡。
The most important thing to note about all of these flavours is that they are generic. You can get them from the most expensive Gesha in the world, and you can get them from sub-commodity grade rubbish. These flavours aren’t desirable. Most of us here are in Specialty Coffee, which means we’re trying to create a product special enough for the customer to want to pay more for it. Extraction-related faults are anything but special.
這些空洞風味最重要的,就是它們很常見,可以從世上最高貴的瑰夏咖啡中萃取出有空洞感的咖啡,也可以從次等的難喝咖啡中萃取出這樣的特性。這些風味並不討喜,大部分看此文的人都是追求精品咖啡,代表我們試著為消費者創造特別的咖啡,這樣消費者會願意花更多錢品嘗,而萃取不足這種誤失就是那麼突兀。
Now for the sweet spot, the yum-zone, the goods.
現在來看好料的,達到甜蜜點、美味的好咖啡。


Ideally Extracted Coffee
良好萃取的咖啡

A well extracted coffee is a little miracle. A lot of work has gone into balancing countless variables to produce a tiny cup of deliciousness, and it’s imperative to know what this tastes like.
良好萃取的咖啡有些可遇不可求,大家投注許多功夫來平衡無以計數的變因,只為創造一杯美好風味的咖啡,而我們必須知道這樣的咖啡喝起來怎麼樣。
Cast your mind to the best damn cup of coffee you’ve ever had. It’s sweet and ripe! There’s a clarity to the flavour, like it’s transparent. The acidity is balanced and positive, perhaps complex if you’re lucky. And the finish goes for ever. This is the jam, and you want to know more about it.
想像你喝過最好喝的咖啡,就是甜美及成熟的風味!澄澈的風味就像透明一般。酸質平衡並且帶來正面感受,如果你夠幸運,酸質還會很豐富,而且餘韻綿長。這是讓大家趨之若鶩的咖啡,而你會想更了解它的咖啡。

Sweet and Ripe 
甜美與成熟

As I said, the Holy Grail. I’ve spent countless hours teasing more ripeness out of coffees. It never gets old.
作者花了無數的時間,不厭其煩地從咖啡中理出更多咖啡最成熟的風味。
Think of a plum or similar stonefruit as it ripens. At first there’s a lot of acidity and tartness, then it gradually gets sweeter. The sugars are developing and becoming richer, heavier, more cloying. Then it hits a point where just holding the fruit near your nose enables you to smell the sweetness. Right there. That’s the sweetness and ripeness you want from coffee. If you’ve never had that, you’re in for a treat one day soon!
想像李子或類似的核果類水果成熟時,一開始會擁有豐富及強烈的酸質,接著越成熟會越來越甜,水果的糖分發展且變得更濃郁、厚重、甚至膩口。然後達到一個點,就像你拿著水果湊近鼻子聞到的甜香。這就是你會想從咖啡喝到的甜美與成熟風味,如果你從沒喝過這樣的咖啡,你可能會很容易就被滿足。

Clarity and Transparency
澄澈與透明感
George Howell has a way with words. He describes the processing method of coffee as being ‘the window through which you see the coffee’. I like to extend this analogy by thinking of the extraction (and roasting) as another pane in that window. If you have over or under-extraction muddying up your glass, it’s harder for you to ‘see’ what the coffee really tastes like. Generic extraction faults are distracting and can impair the provenance of the coffee you’re serving.
George Howell描述咖啡處理法為:從咖啡之窗窺視咖啡,而作者喜歡將這句話延伸為想像萃取與烘焙為咖啡之窗的其他窗格",如果你杯中的咖啡是過度萃取或萃取不足的咖啡,你會很難到咖啡實際風味。常見的萃取失誤會讓你分心,並且會白費你品嘗的咖啡在前端處理時的苦心。


Acidity 
酸質
Fine, complex and definable acidity is truly something to behold in coffee. Acidity is something that’s incredibly beguiling, but also frustratingly flighty. When you get acidity that reminds you of a specific fruit, or even a wine, you’re in the green. If that acidity is so definable and intense that you can pinpoint a variety of fruit and remember the last time you ate it, you’re nailing it.
細緻、豐富與鮮明的酸質,是咖啡背後最重要的元素。酸質讓人陶醉卻也會讓人幻想到洩氣,當你喝咖啡時,酸質讓你聯想到特定水果甚至是葡萄酒。如果這個酸質可以被清楚定義,你可以專注在回想上次你吃到這種水果的感受。


Finish for Days
餘韻綿長
This is self explanatory. A good finish goes nearly forever. A sure sign of good extraction.
本身的字義以說明了一切,好的餘韻可以留存許久,也就是萃取良好咖啡的象徵之一。
  So thats the good, the bad, and the ugly of extraction and flavour. Hopefully now you will notice a few of these flavours in your day to day coffee tasting, and be able to link them with the appropriate level of extraction.
以上就是咖啡萃取及風味的好、壞或更差,期望現在你可以注意這些平常你喝的咖啡,並能夠連結到不同萃取結果的咖啡特性。

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