Climate-induced decline in the quality and quantity of European hops calls for immediate adaptation measures

Abstract

A recent rise in the global brewery sector has increased the demand for high-quality, late summer hops. The effects of ongoing and predicted climate change on the yield and aroma of hops, however, remain largely unknown. Here, we combine meteorological measurements and model projections to assess the climate sensitivity of the yield, alpha content and cone development of European hops between 1970 and 2050 CE, when temperature increases by 1.4 °C and precipitation decreases by 24 mm. Accounting for almost 90% of all hop-growing regions, our results from Germany, the Czech Republic and Slovenia show that hop ripening started approximately 20 days earlier, production declined by almost 0.2 t/ha/year, and the alpha content decreased by circa 0.6% when comparing data before and after 1994 CE. A predicted decline in hop yield and alpha content of 4–18% and 20–31% by 2050 CE, respectively, calls for immediate adaptation measures to stabilize an ever-growing global sector.

N-Acetylglutamic Acid Enhances Tolerance to Oxidative and Heat Stress in Humulus lupulus

“…In hop cultivation, the yield and bitter acid (α-acid) content of hop cones decreased when the temperature in the growth period exceeded the annual norm in the Czech Republic [5]. Climate change accompanied by global warming is also predicted to cause reductions in hop yields and bitter acid content of 4-18% and 20-31%, respectively, by 2050 in Germany, the Czech Republic and Slovenia, whose microthermal climate represents suitable cultivation areas for high-quality aroma hops [6]. Interestingly, the flavour of some hop cultivars differs depending on the production area.…”

“…The combined analysis of meteorological measurements and projection models predicts that global warming, resulting in a 1.4 • C temperature Horticulturae 2024, 10, 484 2 of 13 increase, will induce early ripening of hop cones. This is expected to trigger hop yield reduction, accompanied by decreased α-acid content, in both the Czech Republic and Germany [6]. Furthermore, high temperatures cause reduced expression of various genes regulating secondary metabolite biosynthesis, with a marked decrease observed in the valerophenone synthase gene, which plays a crucial role in bitter acid production [7].…”

Micropropagation and Synthetic Seeds Production of Humulus lupulus L. var. Mapuche: Optimization, Advances, and Agricultural Applications

“…However, the specific combination of climate and soil required by hops increases its vulnerability to extreme weather events, which are expected to become more frequent in the current global context. The expansion of craft breweries has driven the demand for hops worldwide [2], posing new challenges and opportunities for producers in terms of expanding the area under cultivation, improving product quality, and achieving socioeconomic and environmental sustainability. Additionally, global climate change (GCC) is altering weather patterns and water availability, significantly affecting different agricultural sectors, especially crops with specific environmental requirements, such as hops.…”

“…In recent years, different studies have highlighted the adverse effects of GCC on hop production, impacting both quantity and quality [3,4]. In a recent study, Mozny et al [2] analyzed historical data from major European hop-producing regions and revealed that drought and high temperatures during the growth stage negatively affected hop crops, advancing their maturation and reducing the production and the concentration of alpha acids content, responsible for the bitter taste of beer. In addition, to the GCC impacts, the spread of pathogens like downy mildew, powdery mildew, and different viruses through contaminated material poses a significant threat to the brewing industry, evidenced by considerable economic and yield losses observed [5][6][7][8][9][10].…”

Assessing Genetic Diversity and Population Differentiation in Wild Hop (Humulus lupulus) from the Region of Central Greece via SNP-NGS Genotyping

“…Climate change is expected to have a major impact on commercial hop varieties, as a decline in both yield and acids content is predicted; therefore, new varieties that are better adapted to the new conditions will be needed [26]. Notably, the comparison of the average annual yield of European aroma hops between 1971-1994 and 1995-2018 revealed a significant decrease in the yield as well as in the alpha acids content [27]. Based on the data from 1971-2018, models predict a climate-induced decline in both the yield and in the bitter acids that give the beer its characteristic aroma.…”