爲何要將咖啡豆保存在冰箱中

Many of us keep our coffee beans in the fridge or freezer to keep them fresh, but a new study suggests there’s added benefit to this practice: more flavorful coffee.

我們許多人都喜歡將咖啡豆放在冰箱或者冰櫃中保持新鮮，但是一項新的研究表明這一做法還有其他好處：咖啡味道會更濃。

Scientists from the University of Bath, in collaboration with a local cafe, studied the effects of grinding beans at different temperatures—from room temperature all the way down to a chilly -196°C. (I guess they figured some people like to store their coffee beans in vats of liquid nitrogen.) As the researchers point out in their ensuing study, now published in Scientific Reports, we get more bang for the buck when we grind cold coffee beans. That’s because the particles within coffee beans get tighter as the temperature gets lower. So during the brewing process, we get more flavor from the same amount of coffee.

巴斯大學的科學家與當地的咖啡廳合作，研究了不同溫度之下的現磨咖啡的口感——從室溫一直降低到冰冷的零下196攝氏度。（我猜他們認爲一些人喜歡把咖啡豆存儲在液氮的桶中。）隨後進行的研究結果現在已經刊登在科學報告中稱，我們磨製冰冷的咖啡豆更加划算。這是因爲當溫度降低之後，咖啡豆的內部結構就會變得更緊湊。所以在衝咖啡的時候，與等量的咖啡相比，這種辦法會讓咖啡的味道更濃。

Like almost anything in the kitchen, brewing coffee is an act of chemistry. Ideally, we’re trying to coax as many tasty organic molecules from the roasted bean, which has been ground into tiny bits. The flavors that come of these coffee bean particulates depend on a number of factors, including water chemistry, the accessible surface area of the coffee, and as the new study shows, the temperature of the bean when it was ground. As the researchers point out, small and uniform coffee grounds allow for better extraction of the flavor compounds, which allows for more coffee per bean, and consequently more flavor.

就像廚房中的其他東西一樣，衝咖啡是一種化學反應。理想狀態下，我們都是慢慢調製，因爲許多有機分子都來自烤制咖啡豆，而且已經磨製成了小分子。咖啡豆顆粒產生的味道取決於許多因素，包括水化學和咖啡的可接觸表面，根據新研究顯示的結果，還與咖啡磨製時的溫度有關。正如研究人員指出的一樣，小量的統一咖啡的磨製要考慮到味道成分的提取，還要考慮到平均每顆咖啡豆能夠產生更濃的味道。