低因咖啡是怎麼製作出來的?會降低咖啡的口味麼? | 知乎問答精選

 

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低因咖啡是怎麼製作出來的?會降低咖啡的口味麼?

2019年04月14日 知乎問答精選 暫無評論 閱讀 1 ℃ 次

【闞歐禮的回答(26票)】:

因為只瞭解瑞士水處理的脫因過程,所以就針對這個處理法回答題住,還好瑞士水處理脫因還是灰常灰常流行滴,全程只用到水,最終咖啡因含量含量低於干重的0.1%,符合ICO對低因咖啡的定義,低於0.3%

生豆麻袋長下邊這個樣子~~

decaf確實是對生豆進行處理法處理的,所以要是足夠土豪,題主的願望還真的可以實現。

過程如下

給生豆洗個澡,浸泡在水中

可溶性物質溶解入水(包含咖啡風味類物質與咖啡因)

木質纖維,綠原酸等等不溶於水,保留在生豆內,析出咖啡因。

關鍵的賴磊,水中有個變態的咖啡因終結者,把溶解的咖啡因不斷的過濾掉,而溶液與生豆的濃度差也繼續幫助咖啡因溶解入水。

8~10小時後,咖啡生豆泡舒坦了,咖啡因也已經只剩0.1%

最後猜測應該是進行烘乾脫水。因為我手都有生豆,是這個樣子的

最後說一下風味,因為我也沒有條件跟精確同批次的未處理的生豆進行風味比對,主觀上來說水處理的咖啡豆body(體質感)相較近似產區的弱,略有澀味(可能是我烘焙的問題,因為這個含水量明顯不是很正常),風味的豐富程度較淡薄,沖泡後忘了用TDS測試,同等條件下是否水溶物會更低,主觀上喝起來感覺更淡些,如果TDS偏低可以用更高的粉水比彌補。所以題主希望低因又風味不變恐怕現在技術還沒發展到那步…………

【Yirgacheffe的回答(8票)】:

書上看過介紹,正好用來答題——有三類方法去除咖啡因。去除咖啡因會降低咖啡口感。

答第一問:

一、歐式(溶劑)處理,有兩種細分。

  1. 直接溶劑法。蒸氣打開生豆孔,直接噴咖啡因溶劑,繼續用「蒸」的方式去除溶劑和咖啡因。

  2. 間接溶劑法。熱水浸泡生豆,把一切能泡的東西都泡出來。水豆分離。用溶劑取出熱水中的咖啡因,剩下的「味道」噴回淡而無味的豆子軀殼上……

二、瑞士水處理(敢死隊先犧牲,後來者有福啦處理法)。第一撥生豆泡熱水,能溶解的物質都溶入水中後,豆子扔掉。水中的咖啡因用碳濾方式去除,餘下「風味飽和的液體」。此後再往裡面加生豆,咖啡因會溶解,「風味們」就還留在豆子裡。更棒的只要碳濾一下,咖啡因去除後的「風味飽和液」能繼續使用。

三、二氧化碳處理法。拿高壓之下呈半液態、半氣態的二氧化碳去結合生豆裡的咖啡因,最後用碳濾方式去除咖啡因(這個方法我從書中看得似懂非懂,希望更有學識的知友來科普)。

答第二問:

咖啡因本身存在與否不影響咖啡口感,但去咖啡因的暴虐過程會有負面影響。

以上是我用大白話轉述的,追求嚴謹性的知友可以看下附原文。出處是Kenneth Davids大神的烘豆科普書Home Coffee Roasting, Revised, Updated Edition: Romance and Revival (2003)。

原文:

Coffees are decaffeinated in their green state. Three principal processes are used today in specialty coffees to remove caffeine: the traditional or European process, the water- only or Swiss- water process, and the CO 2 process. All are consistently successful in removing all but a trace (2 to 3 percent) of the resident caffeine.

The European or Solvent Process.There are two variants of the solvent method. The direct solvent process opens the pores of the beans by steaming them and applies the solvent directly to the beans before removing both solvent and caffeine by further steaming. The indirect solvent process first removes virtually everything, including the caffeine, from the beans by soaking them in hot water, then separates the beans and water and strips the caffeine from the flavor- laden water by means of the caffeine- attracting solvent. The solvent- laden caffeine is then skimmed from the surface of the water, and the water, now free of both caffeine and solvent, is reunited with the beans, which soak up the flavor components again.

The Swiss Water or Water- Only Process. In this commercially successful process there are two phases. In the first, start- up phase, green beans are soaked in hot water, which removes both flavor components and caffeine from the beans. This first, start- up batch of beans is then discarded, while the caffeine is stripped from the water by means of activated charcoal filters, leaving the flavor components behind in the water and producing what the Swiss water- process people call 「flavor- charged water」— water with the flavor but without the caffeine. This special water becomes the medium for the decaffeination of subsequent batches of green beans. When soaked in the flavor- charged but caffeine- free water, new batches of beans give up their caffeine but not their flavor components, which remain more or less intact in the bean. Apparently the water is so charged with flavor components that it can absorb no more of them, whereas it can absorb the villainous caffeine. Having thus been deprived of their caffeine but not their flavor components, the beans are then dried and sold, while the flavor- charged water is cleaned of its caffeine by another run through charcoal filters and sent back to decaffeinate another batch of beans.

The CO2 Process.In the CO2 method, the green beans are bathed in highly compressed carbon dioxide (CO2 ), the same naturally occurring substance that plants consume and human beings produce. In its compressed form the carbon dioxide behaves partly like a gas and partly like a liquid, and has the ability to combine selectively with caffeine. The caffeine is stripped from the CO2 by means of activated charcoal filters.

DECAFFEINATION AND FLAVOR

However powerfully it may affect our nervous systems, caffeine has very little effect on flavor. Isolated, it is a bitter, almost tasteless white powder. Coffee without it should taste virtually the same as coffee with it. Nevertheless, soaking green coffee beans in hot liquid and drying them out again is not a gentle process. It definitely affects the flavor of the abused beans. Affects how much? Depending on how careful the decaffeination process and how attentive the subsequent roasting, from a little to a lot. If you buy decaffeinated beans to roast at home you may notice that they are no longer the common gray- green to blue- green color of unroasted coffee, but instead range from a rather sallow yellow to a light brown. This color change is due to the soaking and drying to which the beans have been subjected during decaffeination. The result for roasting purposes is delicate beans that roast much less predictably than untreated beans. The combination of the loss of some flavor agents in the soaking process with the difficulty in roasting accounts for the fact that decaffeinated coffees purchased in the store may not taste as consistently good as coffee from untreated beans. The main message for the home roaster is to buy green decaffeinated beans from a reliable source, and roast them carefully. See Chapter 5 ( here ) and the instructions following that chapter for suggestions on handling decaffeinated coffees. You might also consider making blends of decaffeinated and untreated coffees. The untreated beans bolster the taste of the decaffeinated beans, yet still limit the amount of caffeine. Remember, however, that you may need to roast the decaffeinated beans in a separate session before blending, since they typically reach the same degree of roast 15 to 25 percent faster than untreated beans.

【巴松的回答(1票)】:

謝邀,我也只是瞭解其大致原理,詳細的並不很瞭解……這個問題已邀請@梁齊,他是食品加工行業專業人士,他的解答應該會比我更專業……

至於是否影響口味,據我喝過的低因來講,沒喝出太大的差別……

【知乎用戶的回答(0票)】:

曾經由於身體關係,只能喝低因的,幾乎嘗試了上海各個精品咖啡店的各種低因豆子。

個人體驗結果是:只要是低因的 風味跟常規的咖啡都不能比 坦白的說 我覺得是差很多 最後只能挑了一個相對來說 風味保留得相對較好的。

【白姬沙的回答(0票)】:

我來廢話一句…喝習慣了就沒反應了…當然也可能產生一定的依賴…文不對題但是希望能幫(你逗我?)到題主…看完就請折疊吧嚶嚶嚶

【哈哈的回答(0票)】:

有一種咖啡就是叫低因咖啡

【斗彩的回答(0票)】:

星巴克的低咖啡因是有另外的豆子,本來就是低咖啡因豆子。

標籤:-咖啡館 -咖啡 -咖啡機 -咖啡豆 -法壓壺


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