Kirin Holdings has announced the development of a pioneering cultivation technique that strengthens hops’ resistance to heat while preserving their aroma, bitterness, and flavor, according to The Asahi Shimbun. The company has already filed a patent for the method and presented its findings at the International Hop Growers’ Convention in Germany this June.
The approach, based on the principle of “heat acclimation,” pre-treats hop seedlings at 25°C, enabling them to thrive even when temperatures rise to 30°C. Tests with Czech Saaz and German Hersbrucker hops showed strong growth despite simulated drought conditions, with pre-treated plants outperforming untreated seedlings in field trials in Iwate Prefecture. Importantly, the quality of the hops’ aroma and flavor remained unchanged.
According to Riko Imahori from Kirin’s Research and Development Division, the method could help maintain yields under increasingly challenging weather conditions. “From next fiscal year, we plan to start similar field trials overseas,” Imahori said.
The urgency is underscored by declining global hop output. The International Hop Growers’ Convention estimated 2024 production at 110,000 tons, down 13 percent from five years earlier. A 2023 Nature Communications study warned that by 2050, yields in Europe’s main hop regions could fall by up to 18 percent, while alpha acid content could drop by as much as 31 percent.
Japanese hop farmers are also facing hotter summers and more frequent “guerrilla rainstorms,” which disrupt water absorption and damage crops. In Tono, a major hop-growing region, daytime temperatures that once averaged 27–28°C now regularly surpass 33°C, causing premature flowering and yield losses.
Compounding the challenge is the dwindling number of hop growers in Japan. National production fell from 2,513 tons with 6,682 growers in 1970 to just 123 tons and 96 growers in 2023. Kirin sees its heat-resilient hops as a key measure to counteract climate change and demographic pressures. “Even as global warming worsens, we want to maintain hop yield and quality through this research to continue making delicious beer,” Imahori emphasized.
