Global warming has been a boon for Riesling, last week’s Riesling Rendezvous conference in Seattle heard.
The conference, hosted by Ernie Loosen, Decanter’s Man of the Year 2005, and Ted Baseler, the president of Château Ste Michelle, was attended by well over 350 professionals from all four corners of the world.
Speakers suggested that warmer temperatures worldwide were opening up new regions for Riesling and guaranteeing consistency in more traditional regions – although in time growers will be forced to adapt, or move.
‘Where we once had two poor vintages and a couple of washouts each decade, we really haven’t had a bad year in almost a generation,’ producer Helmut Dönnhoff from the Nahe region of Germany said.
Maynard Amerine and Albert Winkler from UC Davis classified the optimum sites for Riesling as zones with average temperatures between 13.2 and 15.2 Celsius between 1 April and 31 October.
Temperatures in classical growing regions such as the Rheingau, Wachau and Alsace have risen by just over 1 degree in the past 30 years, engendering a welcome consistency in quality there.
At the same time temperature increases have fuelled a rise in production in areas hitherto little known for Riesling, such as the Finger Lakes in New York, Niagara in Ontario or the Old Mission Peninsula in Michigan.
While this development has been kind to cool climate fruit, Dr Greg Jones of Southern Oregon University and Professor Hans Schultz of Geisenhim presented new data on how global warming might affect Riesling’s future.
Rising temperatures mean optimum production sites are moving further north, to higher altitudes and cooler sites, while viticulturalists are forced to look to different forms of canopy management to guarantee fruit balance.
‘As clonal material, rootstock and vineyard management continue to improve, it is unclear that the upper boundary of 15.2 degrees is set in stone,’ added Dr. Jones.
‘But if temperatures rise by another 1.5 to as much as 5 degrees over the coming years, as we expect, and rainfall patterns change, warmer regions with lots of sunshine hours like the Clare or Eden Valleys in Australia will have to adapt.’
Climatologists predict that 2010 is predicted to be the hottest year on record worldwide. This will be due in large part to El Niño, the tropical climate pattern that warms the Pacific every five to seven years.
Written by Joel B Payne