科學(xué)家們說(shuō)，讓我們回到濃縮咖啡的制作上

科學(xué)家們說(shuō)，讓我們回到濃縮咖啡的制作上

The morning coffee is a sacred drink. Get it right and you’re set for the day, but if it’s wrong the hours stretch ahead of you. If your drink of choice is an espresso, you’re probably used to variation between your brews.

早晨的咖啡是神圣的飲料。如果做對(duì)了，你就為這一天做好了準(zhǔn)備，但如果做錯(cuò)了，你的時(shí)間就會(huì)延長(zhǎng)。如果你選擇的飲料是濃縮咖啡，你可能已經(jīng)習(xí)慣了不同的口味。

Katy Pallister

However, a study published in the journal Matter by a multi-disciplinary team from four countries has used mathematical modeling to help produce a more consistent espresso. The answer? Fewer coffee beans, ground more coarsely, and less water use.

然而，來(lái)自四個(gè)國(guó)家的一個(gè)多學(xué)科團(tuán)隊(duì)在《Matter》雜志上發(fā)表的一項(xiàng)研究已經(jīng)使用數(shù)學(xué)模型來(lái)幫助生產(chǎn)更一致的意式濃縮咖啡。答案是什么?咖啡豆越少，研磨越粗糙，用水量越少。

As Dr Jamie Foster, a mathematician from the University of Portsmouth and co-author of the research, explained: “The conventional wisdom is that if you want a stronger cup of coffee, you should grind your coffee finer. This makes sense because the finer the grounds mean that more surface area of coffee bean is exposed to water, which should mean a stronger coffee.”

正如樸茨茅斯大學(xué)數(shù)學(xué)家、該研究的合著者杰米•福斯特博士所解釋的那樣:“傳統(tǒng)觀點(diǎn)認(rèn)為，如果你想要更濃的咖啡，就應(yīng)該把咖啡磨得更細(xì)。”這是有道理的，因?yàn)榭Х仍郊?xì)，咖啡豆接觸到水的面積就越大，這就意味著咖啡越濃。”

Dr Jamie Foster, co-author of the paper, wanted to challenge the "common espresso wisdom". University of Portsmouth

Not only are coffee beans ground finely, but current brewing techniques rely on a relatively large mass of coffee beans, around 20 grams (0.7 ounces), to make an espresso shot.

不僅咖啡豆磨得很細(xì)，現(xiàn)在的沖泡技術(shù)也需要大量的咖啡豆，大約20克(0.7盎司)，才能做出一杯濃咖啡。

In practice, the team found that this method resulted in clogging of the coffee bed – what you find in the basket of an espresso machine – inhibiting the water’s passage. This spells bad news for a multitude of reasons. The amount of coffee dissolved in the water (extraction yield) is reduced, leading to a waste of raw material and a variation in taste.

在實(shí)踐中，研究小組發(fā)現(xiàn)，這種方法會(huì)導(dǎo)致咖啡床堵塞——就像你在咖啡機(jī)的籃子里發(fā)現(xiàn)的那樣——抑制水的流動(dòng)。從多方面來(lái)看，這都是壞消息?？Х仍谒械娜芙饬?萃取率)降低，導(dǎo)致原料的浪費(fèi)和口味的變化。

To find a solution, the team started by creating a mathematical model for a single grain of coffee. The extraction yield for the whole brew relies on modeling the extraction of millions of individual grains, which are placed irregularly on the coffee bed. Add to that the variability in the water pressure as it flows through the coffee, and the team had a real problem on their hands.

為了找到解決方案，團(tuán)隊(duì)首先為一?？Х葎?chuàng)建數(shù)學(xué)模型。整個(gè)咖啡的萃取率依賴于對(duì)數(shù)百萬(wàn)粒單獨(dú)谷物的建模，這些谷物被不規(guī)則地放置在咖啡床上。再加上流經(jīng)咖啡的水壓的可變性，團(tuán)隊(duì)面臨著一個(gè)真正的問(wèn)題。

In fact, Foster remarked that “you would need more computing power than Google has to accurately solve the physics and transport equations of brewing on a geometry as intricate as a coffee bed.” To simplify the equations, the researchers borrowed modeling methodologies from electrochemistry. Likening how caffeine dissolves out of coffee beans to how lithium ions are transported between the electrodes of a battery proved successful for the team.

事實(shí)上，福斯特評(píng)論道:“你需要比谷歌更強(qiáng)大的計(jì)算能力來(lái)精確地解決在像咖啡床一樣復(fù)雜的幾何圖形上釀酒的物理和運(yùn)輸方程。”為了簡(jiǎn)化方程式，研究人員借用了電化學(xué)中的建模方法。將咖啡因如何從咖啡豆中溶解出來(lái)比作鋰離子如何在電池的電極之間運(yùn)輸，這個(gè)研究小組被證明是成功的。

Coupling the maths with many shots of espresso, the researchers reached their conclusion. “One way to optimize extraction and achieve reproducibility is to grind coarser and use a little less water, while another is to simply reduce the mass of coffee," said Dr Chris Hendon (aka Dr Coffee), a computational chemist at the University of Oregon and co-author of the paper.

把數(shù)學(xué)和許多杯濃縮咖啡結(jié)合起來(lái)，研究人員得出了他們的結(jié)論。俄勒岡大學(xué)的計(jì)算化學(xué)家克里斯·亨登博士(又名咖啡博士)是這篇論文的合著者，他說(shuō):“優(yōu)化提取并實(shí)現(xiàn)重現(xiàn)性的一種方法是磨出更粗的咖啡，用更少的水，而另一種方法是簡(jiǎn)單地減少咖啡的質(zhì)量。”

The team's espresso method for success. Cameron et al. 2020/Matter

When the findings were put into practice at a small US coffee shop, the new recipe was found to save them thousands of dollars every year. If applied to the whole of the US coffee industry, the total savings could stand at $1.1 billion each year.

當(dāng)研究結(jié)果在美國(guó)一家小咖啡店付諸實(shí)踐時(shí)，人們發(fā)現(xiàn)這種新配方每年能為他們節(jié)省數(shù)千美元。如果應(yīng)用于整個(gè)美國(guó)咖啡行業(yè)，每年可節(jié)省11億美元。

“A good espresso beverage can be made in a multitude of ways,” Hendon concluded. “The point of this paper was to give people a map for making an espresso beverage that they like and then be able to make it 100 times in a row.”

“一杯好的濃縮咖啡有很多種制作方法，”亨登總結(jié)道。“這篇論文的目的是給人們提供一張制作他們喜歡的濃縮咖啡飲料的地圖，然后讓他們能夠連續(xù)制作100份。”