咖啡萃取不足是什么原因

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萃取不足（Under-extracted Coffee）

萃取不足是指没有将咖啡粉中足够多的风味物质溶解出来，咖啡粉中依然有大量物质没有被萃取出来。咖啡粉中的物质原本可以被萃取出来更多，来平衡掉不好的风味。

在你的印象中也许你曾经喝到过萃取时间过短的Espresso，比如说一杯用时下流行的精品咖啡烘焙度做的Ristretto。它会有刺激的酸、不足的甜感，怪异的咸味和令人失望的短暂余韵--这四个特征是萃取不足最明显的信号。接下来我们从细节层面逐一探讨一下。

Under-extracted Coffee

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.

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.

尖酸（sourness）

尖酸（sourness）是一个微妙的存在，特别是我们总想在咖啡中寻求好的酸质（acidity）的时候。很多人问我"尖酸（sourness）和酸（acidity）是不是一回事？"其实这个问题也在情理之中，因为在很多语言中"sourness"和"acidity"就是同一个词"酸"。因此你可以想象得出这样的情况会让不同语言的杯测变得有多么的不便。

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.

为了区别起见，我通常把"尖酸"（sourness）定义为负面的。尖酸（sourness）是一个非常迅速和强烈的感受。它会迅速地让你产生生理反应，你会噘起嘴唇，舌头两侧会有强烈而又尖锐的感觉。尖酸（sourness）是一种让人不愉悦的味觉感受。

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.

无论何时我讨论酸（acidity），它既可能是好的也可能是不好的。更恰当地说，它是一个风味范畴同时包含了正面和负面的特性。举个例子，"那杯咖啡的酸非常让人愉悦"（That coffee's acidity isdelightful）和"那杯咖啡的酸非常尖锐"（That coffee's acidity isvery sour）这两种说法对我来说都说得通。酸（Acidity）里包含了尖酸（sour）/果汁般的酸（juicy）/明亮的酸（bright）/刺激的酸（tart）等诸多内容。关于酸（acidity）我还有很多很多内容可写，不过本周的内容主要是关于萃取，酸的话题姑且打住。

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.

缺少甜感（Lacking Sweetness）

在我看来，咖啡风味里最重要的一个方面就是它的"甜感"。甜感即是奥义。你可曾听过有人抱怨过"这杯 espresso太甜了"？你尽可好好想一想。我深信我们应该始终追寻甜感。它是我所追求的终极目标，想要实现是非常困难的，不过一旦你达到你将获得超乎想象的回报。萃取不足是没有甜感的，且与之相去甚远。萃取不足总是会留下一些空洞的感觉让你无法满足，喝了一杯后会觉得"远远不够"。缺乏甜感的一个好处就是它会使尖酸（sourness）更加容易辨识，从而使萃取不足更容易被发现。

Lacking Sweetness -
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.

咸（Salty）

很多人也许都不太认同这个观点，但我一定会据理力争："萃取不足的咖啡是会咸的"。这种咸不是那种"抱歉我不小心放了盐"的咸，萃取不足的咖啡总是会带有咸咸的触感和味觉。从口腔触觉的角度来说，这种咸和碱性溶剂会带来的滑腻感很相似。（千万别为了证实这点去试喝氨水。相信我就好）

Salty -
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).

#注释--酸和盐的溶解性比糖要来得高。这也就是为什么萃取不足的咖啡会是尖酸和咸的-萃取时间不够长无法让糖类完全溶解出来。（欢迎指正）

#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]

余韵短暂（Quick Finish）

一杯理想萃取的咖啡余韵会持续数分钟（甚至数小时，如果你够幸运的话）。这种回味就像你刚吃了一块黑糖，或者是刚吃了一块太妃糖一样，非常美味！

一杯萃取不足的咖啡则无法提供这些回味。当咖啡液体被你喝下去后，一切旋即消失，你不会感受到多少令你愉悦的回味。吞咽后，一切戛然而止，这种意犹未尽的体验，真的不是那么美妙。

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!

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.

当然会有其他一些风味表现也会揭示出萃取不足的情况，但以上四个方面是最为显著的。当你尝到了这四个风味表现时，你可以确认你的咖啡存在着萃取不足的情况。

接下来，让我们把注意力转移到萃取之路的另一端--萃取过度。

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!

Let's now cast our attention to the opposite end of Extraction Street.