好英语网如何去掉咖啡中的咖啡因?
If you’re partial to a cup of coffee minus the caffeine, then next time you’ve boiled the kettle you should raise your mug in memory of Friedlieb Ferdinand Runge.
如果你偏爱一杯脱因咖啡，那么下次烧水煮咖啡时，应该举杯纪念一下朗格（Friedlieb Ferdinand Runge）。
Runge was a 19th-Century German chemist who had come to the attention of Goethe – the poet and statesman who was also a keen science scholar. Goethe had heard of Runge’s groundbreaking investigation into belladonna, otherwise known as nightshade. Runge had isolated the compound that caused eye muscles to dilate if it was ingested.
朗格是19世纪德国的一位化学家，他对颠茄(一种茄科植物)的研究取得了开拓性的进展，从中分离出了一种化合物，人一旦摄入这种化合物会导致眼部肌肉扩张。他引起了诗人、政治家歌德（Goethe）的注意，歌德同时还是一位对科学充满热情的学者。
Goethe had been recently given a case of coffee beans, and so he asked Runge to perform an analysis of the beans. What Runge discovered is arguably the most consumed drug in the modern world – caffeine.
歌德最近收到了一箱咖啡豆，因此他请朗格对咖啡豆进行分析。朗格从中发现了可能是现代社会消耗最多的药物——咖啡因。
Caffeine is present in other drinks and foods – notably tea and chocolate – but it is inextricably linked with coffee. It’s a stimulant and an appetite suppressant, a dependable pick-me-up for students cramming for exams, workers on nightshifts and anyone else needing a wake-up.
咖啡因也存在于其他饮料和食物中，尤其是茶和巧克力，但与咖啡密不可分。它是一种兴奋剂，能抑制食欲，对于那些为了考试而疯狂复习的学生、上夜班的工人以及任何需要醒神的人来说，咖啡因都是一种可靠的提神剂。
But caffeine has a darker side, too.
但咖啡因也有副作用。
It can cause anxiety, insomnia, diarrhoea, excess sweating, racing heartbeat and muscle tremors. For many people, the pleasure of drinking coffee is outweighed by the caffeine-fuelled negatives.
它会导致焦虑、失眠、腹泻、多汗、心跳加速和肌肉震颤。对许多人来说，咖啡因的负面影响超过了喝咖啡的享受。
咖啡的口感越来越好，脱因咖啡的味道也随之改善
Could caffeine be removed from coffee? The answer, as any supermarket aisle will tell you, is yes – but the process isn’t as simple as you might think.
那能把咖啡因从咖啡中去掉吗？看看超市的货架就知道，答案是肯定的，但过程并不像你想的那么简单。
The first person to hit upon a practical decaffeination method was another German, Ludwig Roselius, the head of the coffee company Kaffee HAG. Roselius discovered the secret to decaffeination by accident. In 1903, shipment of coffee had been swamped by seawater in transit – leaching out the caffeine but not the flavour. Roselius worked out an industrial method to repeat it, steaming the beans with various acids before using the solvent benzene to remove the caffeine. Decaffeinated coffee was born.
第一个找到实用的脱咖啡因方法的也是位德国人——哈克咖啡公司（Kaffee HAG）的负责人罗斯留斯(Ludwig Roselius)。罗斯留斯是在偶然间发现了去除咖啡因的秘密。1903年，一批咖啡在运输过程中被海水浸泡，滤出了咖啡因，却保留了咖啡的味道。罗斯留斯想出了模拟这一过程的工业方法：先用各种酸来蒸咖啡豆，然后用苯溶剂来去除咖啡因。脱因咖啡就这样诞生了。
Benzene, it turned out, was a possible carcinogen, so the search was on for new techniques that could prise out the caffeine from the beans – and yet leave the flavour intact.
但后来发现苯可能会致癌，所以又开始寻找新技术，既能安全无害地提取出咖啡因，又能保持咖啡风味不变。
Chris Stemman, the executive director of the British Coffee Association, says most of those techniques from decaffeination’s earliest days are still being used today. But the process isn’t as straightforward as you’d expect.
英国咖啡协会(British Coffee Association)执行理事斯坦曼(Chris Stemman)表示，许多早期的脱咖啡因技术至今仍在使用，但过程并非你想的那么简单。
“It isn’t done by the coffee companies themselves,” says Stemann. “There are specialist decaffeination companies that carry it out.” Many of these companies are based in Europe, Canada, the US and South America.
斯坦曼说：“咖啡公司不会自己来做，有专门的公司来去除咖啡因。”其中许多位于欧洲、加拿大、美国和南美。
You might think that it would be easier to roast the coffee, grind it into the required powder (espresso, filter or instant) and then begin the decaffeination process. Not, so says Stemman.
你可能觉得，先将咖啡豆烤好磨成需要的咖啡粉(意式浓缩咖啡粉、过滤咖啡粉或是速溶咖啡粉)，再去掉咖啡因会容易一些，但斯坦曼表示并非如此。
“It takes place when the coffee is green, before roasting.
“当咖啡豆还是绿色的时候，即烘烤前,就要去除咖啡因了。”
“If you were to try and decaffeinate roasted coffee you’d end up making something that tastes a bit like straw. So that’s why with 99.9% of decaffeinated coffee to this day, the process is done at the green coffee stage.”
“如果先烘烤再去除咖啡因，味道会像稻草。所以现在99.9%的脱因咖啡都是在生豆阶段去除咖啡因。”
There are several ways to decaffeinate coffee but the most prevalent is to soak them in a solvent – usually methylene chloride or ethyl acetate. Methylene chloride can be used as a paint stripper and a degreaser as well an agent to remove caffeine.
去除咖啡因的方法有几种，最常用的是将豆子浸泡在溶剂中，通常是二氯甲烷或乙酸乙酯溶剂。二氯甲烷可以用作脱漆剂和脱脂剂，也能去除咖啡因。
Ethyl acetate, meanwhile, is a natural fruit ether usually made from acetic acid – the building block of vinegar – and it’s also used to make nail polish remover (it has a distinctive sweet smell, much like pear drops).
而乙酸乙酯则是一种天然果醚，通常由乙酸（醋的基本成分）制成。它还被用来制作洗甲水（它有一种独特的甜味，很像梨汁）。
The beans are first soaked in water and then covered in a solution containing either of these solvents. The caffeine is then drawn out by the solvent.
先将豆子浸泡在水中，然后加入二氯甲烷或是乙酸乙酯溶液，来去除咖啡因。
The solvent-laced water is then reused again and again until it is packed with coffee flavourings and compounds – pretty much identical to the beans, except for the caffeine and solvent. By this stage in the process the beans lose very little flavouring because they’re essentially soaked in a concentrated coffee essence.
溶液会被反复使用，直到充满了咖啡的味道和化合物——除了含有咖啡因和溶剂之外，和咖啡豆的味道几乎一模一样。至此，咖啡豆的风味得到了极大保留，因为它们基本上是泡在浓缩的咖啡精华中。
Soaking coffee beans in solvents doesn’t sound like a particularly healthy enterprise, but both of these agents have got a clean bill of health. In 1985 the US’s Food and Drug Administration said the likelihood of any health risk from methylene chloride was so low “as to be essentially non-existent”. (FDA rules allow up to 10 parts per million of residual methylene, but coffee decaffeination usually uses solutions with one part per million).
用溶剂浸泡咖啡豆听起来似乎不太健康，但这两种物质都对健康无害。1985年，美国食品药品监督管理局(Food and Drug Administration，简称FDA)表示，二氯甲烷损害健康的可能性非常低，“几乎不存在”。(FDA允许百万分之十的亚甲基残留，但脱咖啡因使用的溶液，亚甲基浓度通常都低至百万分之一)。
Two other methods use water. The Swiss Water method sees the beans soaked with water; the caffeine rich solution (full of flavours) is then strained though activated carbon which captures the caffeine. Starting in Switzerland in the 1930s, the process was first used commercially in 1979. It gained favour because it was the first decaffeination method not to use solvents.
另外两种方法用的是水。瑞士水处理法是把豆子浸泡在水里，然后把富含咖啡因的水(咖啡味道浓郁)用活性炭过滤掉咖啡因。这种工艺源自上世纪30年代的瑞士，并于1979年首次投入商业使用。它之所以受到人们的青睐，是因为它是第一种不使用溶剂的脱咖啡因方法。
There is another method, Stemman says, which involves the use of “super critical carbon dioxide”. Beans that have been soaked in water are put in a stainless-steel extractor which is then sealed, and liquid CO2 blasted in at pressures of up to 1,000lbs per square inch. Like the Swiss Water method, it’s the C02 which binds with the caffeine molecules, drawing them out of the unroasted bean. The gas is then drawn off and the pressure is lowered, leaving the caffeine in a separate chamber.
斯坦曼说，还有一种方法则使用了“超临界二氧化碳”。将在水中浸泡过的豆子放入不锈钢萃取器中，密封后注入液态二氧化碳，然后把容器内压力加至每平方英寸1000磅。与瑞士水处理法的原理类似，这种方法是用二氧化碳和咖啡因分子结合，将咖啡因从未烘烤的咖啡豆中提取出来，最后抽走气体，降低压力，咖啡因就跟着抽走了。
It’s an ingenious method but it does have one big drawback, according to Stemman. “It can be enormously expensive.”
斯坦曼认为这种方法十分巧妙，但也存在一个很大的缺点，太贵。
Decaffeination became much more widespread as instant coffee became a staple, says Stemman. But the early incarnations of instant decaff coffee were not a roaring success.
斯坦曼说，随着速溶咖啡成了家常便饭，脱咖啡因也变得更加普遍。但是，早期的脱因速溶咖啡并不太成功。
“If you look back 20 or 30 years ago, we [in the UK] really were a nation of instant coffee drinkers,” he says. “And the one thing that instant coffee didn’t really taste of was coffee. Decaff was even worse.”
他表示：“二三十年前，我们（英国人）很爱喝速溶咖啡。速溶咖啡没什么咖啡味，脱咖啡因的味道更糟。”
Stemman says that as people have become more used to quality coffee – for instance, the UK now boasts some 24,000 coffee shops – this has forced coffee-making companies to find ways of enhancing flavour even in decaffeinated instant coffee.
斯坦曼表示，英国目前有约2.4万家咖啡店，人们越来越习惯于高品质的咖啡，咖啡公司不得不想方设法提升咖啡味道，即便脱因的速溶咖啡也是如此。
“Decaffeination can be a complicated piece of chemistry, which is why there are these very sophisticated companies doing it.”
“脱咖啡因是个十分复杂的化学过程，所以会由非常成熟的公司来做。”
The centenary of decaffeination – 2006 – went by with little in the way of public fanfare. In the UK at least, the number of people stumping for a decaff coffee has fallen markedly even as the quality has improved – while as many as 15% of coffee drinkers chose decaffeinated brews in the 1980s, that’s fallen to about 8% today.
2006年是脱咖啡因方法诞生100周年纪念，却几乎没有引起公众的注意。尽管脱因咖啡的质量有所改善，但购买人数却显著下降，至少英国如此。上世纪80年代，15%的人喝咖啡会选择脱咖啡因的，如今已降至8%左右。
And does Stemman drink decaffeinated himself? “Generally, no, if I don’t want the caffeine, well I just won’t have a coffee or a tea.”
斯坦曼自己会喝脱咖啡因的吗？“一般不会，如果我不想摄入咖啡因，就干脆不喝咖啡和茶。”
And there’s another thing. While each of these methods will take most of the caffeine away, there’s no such thing as a completely decaffeinated drink. If you really want to avoid any caffeine at all, it’s probably better to drink something that never had a trace of it in the first place.
还有一点，虽然上述方法都会除掉大部分咖啡因，但并不完全。如果你真的一点咖啡因都不想摄入，最好是喝原本就不含咖啡因的饮料。
