Hops initially served as a flavouring agent, and then a preservative in unrefrigerated kegs of beer that European colonial powers shipped abroad on sailing vessels. The weedy plant is grown in lines up trestles, and a fruit-like cone is harvested to make hops for brewing. The plants currently grown in northern climates require moist soil, a hard-winter freeze and a hot summer. But, according to a report in Nature News, warming weather, a result of global warming, has disrupted this formula.
"I was absolutely sure it was affecting our hops by 1989," said Peter Darby, a hop breeder with Wye Hops in Kent, UK.
The country's meteorological office data shows that the country has had unusually hot years since the late 1980s, and that is clearly being felt in hop fields.
"Within the past half-dozen years, warm springs and milder winters began affecting the main varieties. Many hop vines sprouted early, went stagnant and produced little," explained Darby.
According to Jim Salinger of New Zealand's National Institute of Water and Atmospheric Research in New Zealand, environmental changes were set to cause a crash in malting-barley production in New Zealand and Australia, with other areas perhaps to follow.
As the changing conditions became more evident, biologists have started heading to hotter climates in search of hop varieties that flourish there.
After the record heat of 2003 in Germany, the nation with the world's largest number of hop-growers, plant breeder Elisabeth Seigner, of the Hop Research Institute in Hull, Germany, turned to Turkey for wild strains to create hardier new varieties.
Also, plant scientists from Europe are attempting to breed new varieties that can withstand warmer climates, and are planning to install major irrigation systems where traditionally the hop plants haven't needed additional watering.
German hop growers recently received 6 million Euros from the European Commission to build the first major irrigation systems for this crop in that country, helping the plants to withstand hot summers to come.
Last August, researchers from the Hop Research Institute Company in Saaz, Czech Republic, dug up records of a 50-year-old United States-led hop collection trip to identify wild strains with desired traits in Arizona and New Mexico.
Researchers at Washington State University are now working to develop hop seeds into suitable varieties for new climates, some of which eventually will be shipped to the Czech Republic.