Climate breakdown is already changing the taste and quality of beer, scientists have warned. The quantity and quality of hops, a key ingredient in most beers, is being affected by global heating, according to a study. As a result, beer may become more expensive and manufacturers will have to adapt their brewing methods. Researchers forecast that hop yields in European growing regions like Germany, Czech Republic and Slovenia will fall by 4-18% by 2050 if farmers do not adapt to hotter and drier weather, while the content of alpha acids in the hops, which gives beers their distinctive taste and smell, will fall by 20-31%. “Beer drinkers will definitely see the climate change, either in the price tag or the quality,” said Miroslav Trnka, a scientist at the Global Change Research Institute of the Czech Academy of Sciences and co-author of the study, published in the journal Nature Communications. “That seems to be inevitable from our data.” Beer, the third-most popular drink in the world after water and tea, is made by fermenting malted grains like barley with yeast. It is usually flavored with aromatic hops grown mostly in the middle latitudes that are sensitive to changes in light, heat and water. In recent years, demand for high-quality hops has been pushed up by a boom in craft beers with stronger flavors. But emissions of planet-heating gases are putting the plant at risk, the study found. The researchers compared the average annual yield of aroma hops during the periods 1971-1994 and 1995-2018 and found “a significant production decrease” of 0.13-0.27 tons per hectare. Celje, in Slovenia, had the greatest fall in average annual hop yield, at 19.4%. In Germany, the second-biggest hop producer in the world, average hop yields have fallen 19.1% in Spalt, 13.7% in Hallertau, and 9.5% in Tettnang, the study found. Beer-brewing in central Europe dates back thousands of years and is a cornerstone of the culture. The study found the alpha acid content of hops, which give beer its distinct aroma, had fallen in all regions. Andreas Auernhammer, a hop farmer in Spalt in southern Germany, said the total rainfall in his fields had changed little but that now “the rain does not come at the right time.” “With climate change affecting a vast number of agricultural crops, I’m not surprised,” said Douglass Miller, a senior lecturer in food and beverage management at Cornell University who is not involved in the study. “Hops are also finicky plants and there might be some crop failures,” Miller said, which could lead brewers to work with different flavor profiles from other types of hops. Words to Learn 相關詞匯 【啤酒花】píjiǔhuā hop the ripe dried flower clusters of a hemp plant used to impart a bitter flavor to beer 【精釀啤酒】jīngniàng píjiǔ craft beer a beer made by independent breweries with a focus on new flavors and varied brewing techniques 科學家警告稱，氣候惡化已經(jīng)在改變啤酒的味道和品質(zhì)。研究指出，多數(shù)啤酒中的重要原料啤酒花的數(shù)量和品質(zhì)正受到全球變暖的影響。啤酒可能會因此變得更貴，啤酒生產(chǎn)商也將不得不調(diào)整釀造方法。 研究人員預測，如果農(nóng)民不調(diào)整種植策略來適應更加炎熱干燥的天氣，到2050年底前歐洲的啤酒花種植區(qū)，例如德國、捷克和斯洛文尼亞，將減產(chǎn)4%到18%，而啤酒花中賦予啤酒獨特口感和氣味的α酸含量也將減少20%到31%。 該研究的合著者、捷克科學院全球變化研究所的科學家米羅斯拉夫?特蘭卡稱：“喝啤酒的人肯定會從價格標簽上或啤酒品質(zhì)上看到氣候變化。從我們的數(shù)據(jù)來看，這似乎是無可避免的。”該研究發(fā)表在《自然-通訊》期刊上。啤酒用大麥等麥芽谷物加入酵母發(fā)酵制成，是世界上僅次于水和茶的最受歡迎的飲料。在啤酒中通常會加入啤酒花來增加芳香。啤酒花主要在中緯度地區(qū)種植，對光、熱和水的變化十分敏感。 近年來，隨著味道濃烈的精釀啤酒變得流行，人們對高品質(zhì)啤酒花的需求也增加了。然而研究發(fā)現(xiàn)，溫室氣體的排放卻對啤酒花構成了威脅。 研究人員對比1971-1994年間和1995-2018年間的香味啤酒花年均產(chǎn)量后發(fā)現(xiàn)，每公頃減產(chǎn)0.13至0.27噸，“產(chǎn)量顯著下降”。斯洛文尼亞的采列市啤酒花年均產(chǎn)量降幅最大，達到19.4%。研究發(fā)現(xiàn)，在世界第二大啤酒花產(chǎn)地德國，斯伯特地區(qū)的啤酒花年均產(chǎn)量下降了19.1%，哈勒陶地區(qū)下降了13.7%，泰特南地區(qū)下降了9.5%。 中歐的啤酒釀造有數(shù)千年歷史，早已深深根植于文化當中。研究發(fā)現(xiàn)，中歐各地區(qū)啤酒花中賦予啤酒獨特風味的α酸含量都下降了。德國南部斯伯特地區(qū)的一名種植啤酒花的農(nóng)民安德里亞斯?奧恩漢默表示，他的農(nóng)田里總降雨量變化不大，但是現(xiàn)在“雨水來的不是時候”。 康奈爾大學食品和飲料管理高級講師道格拉斯?米勒說：“氣候變化影響了大量農(nóng)作物，我并不感到驚訝。啤酒花也是很挑剔的植物，可能會出現(xiàn)歉收。這可能會促使釀酒師使用其他類型啤酒花釀造不同風味的啤酒。” 米勒未參與此項研究。 (chinadaily.com.cn) | 