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【阚欧礼的回答(26票)】: 因为只了解瑞士水处理的脱因过程，所以就针对这个处理法回答题住，还好瑞士水处理脱因还是灰常灰常流行滴，全程只用到水，最终咖啡因含量含量低于干重的0.1%，符合ICO对低因咖啡的定义，低于0.3% 
生豆麻袋长下边这个样子~~ 
decaf确实是对生豆进行处理法处理的，所以要是足够土豪，题主的愿望还真的可以实现。 过程如下 给生豆洗个澡，浸泡在水中 
可溶性物质溶解入水（包含咖啡风味类物质与咖啡因）
木质纤维，绿原酸等等不溶于水，保留在生豆内，析出咖啡因。
关键的赖磊，水中有个变态的咖啡因终结者，把溶解的咖啡因不断的过滤掉，而溶液与生豆的浓度差也继续帮助咖啡因溶解入水。
8~10小时后，咖啡生豆泡舒坦了，咖啡因也已经只剩0.1%
最后猜测应该是进行烘干脱水。因为我手都有生豆，是这个样子的
最后说一下风味，因为我也没有条件跟精确同批次的未处理的生豆进行风味比对，主观上来说水处理的咖啡豆body（体质感）相较近似产区的弱，略有涩味（可能是我烘焙的问题，因为这个含水量明显不是很正常），风味的丰富程度较淡薄，冲泡后忘了用TDS测试，同等条件下是否水溶物会更低，主观上喝起来感觉更淡些，如果TDS偏低可以用更高的粉水比弥补。所以题主希望低因又风味不变恐怕现在技术还没发展到那步………… 【Yirgacheffe的回答(8票)】: 书上看过介绍，正好用来答题——有三类方法去除咖啡因。去除咖啡因会降低咖啡口感。 答第一问： 一、欧式（溶剂）处理，有两种细分。
二、瑞士水处理（敢死队先牺牲，后来者有福啦处理法）。第一拨生豆泡热水，能溶解的物质都溶入水中后，豆子扔掉。水中的咖啡因用碳滤方式去除，余下“风味饱和的液体”。此后再往里面加生豆，咖啡因会溶解，“风味们”就还留在豆子里。更棒的只要碳滤一下，咖啡因去除后的“风味饱和液”能继续使用。 三、二氧化碳处理法。拿高压之下呈半液态、半气态的二氧化碳去结合生豆里的咖啡因，最后用碳滤方式去除咖啡因（这个方法我从书中看得似懂非懂，希望更有学识的知友来科普）。 答第二问： 咖啡因本身存在与否不影响咖啡口感，但去咖啡因的暴虐过程会有负面影响。 以上是我用大白话转述的，追求严谨性的知友可以看下附原文。出处是Kenneth Davids大神的烘豆科普书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)】: 谢邀，我也只是了解其大致原理，详细的并不很了解……这个问题已邀请@梁齐，他是食品加工行业专业人士，他的解答应该会比我更专业…… 至于是否影响口味，据我喝过的低因来讲，没喝出太大的差别…… 【知乎用户的回答(0票)】: 曾经由于身体关系，只能喝低因的，几乎尝试了上海各个精品咖啡店的各种低因豆子。 个人体验结果是：只要是低因的 风味跟常规的咖啡都不能比 坦白的说 我觉得是差很多 最后只能挑了一个相对来说 风味保留得相对较好的。 【白姬沙的回答(0票)】: 我来废话一句…喝习惯了就没反应了…当然也可能产生一定的依赖…文不对题但是希望能帮（你逗我？）到题主…看完就请折叠吧嘤嘤嘤 【哈哈的回答(0票)】: 有一种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，本来就是低咖啡因豆子。 原文地址:知乎 |
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