Desert wines. How to grow grapes where the ground is a griddle
May 14th 2016 Economist
Daniel Kish once speared fish for a living. Now he makes wine in Israel’s Negev desert. Sipping on Shoshanna, a spicy blend of petite sirah, zinfandel, merlot and shiraz named after his mother, he explains why winemaking there can be so hard. The ground is rocky and parched. The sun is fearfully hot. And the local Thomson’s gazelles adore grapes. “You’ve opened a restaurant in the desert. So of course animals are going to eat,” he says. Mr Kish produces between 6,000 and 7,000 bottles of wine a year; he reckons each costs 45 shekels ($12) to make. They sell for just over twice that at his vineyard on Kish Farm. Keeping the process kosher is costly.
A region’s climate determines its terroir—the environmental elements that affect the quality of grapes, such as rainfall, temperature and soil conditions. Consequently, vineyards and their produce serve as a particularly sensitive means of measuring climate change. Most grapes grow between temperatures of 12°C and 22°C. So research in recent years suggests that, in a warmer world, grapes will cope better at higher latitudes and elevations.
A study published last month in Nature Climate Change, a journal, found that grapes across France are now harvested two weeks earlier than they were 500 years ago. This trend could mean that wine gets worse, as it did after Europe’s heatwave in 2003. Grapes exposed to too much sun become sweeter and less acidic; eventually, they become raisins. Some spots, such as California’s Napa Valley, may get too hot for vines altogether. This will squeeze the juice out of an industry that generates more than $1 billion a year in taxes in America.
Israel’s deserts can serve as laboratories for growing vines in warmer conditions. Intense sunshine there can mean that one side of a grape can warm to 50°C in the summer, while the side in shadow will experience temperatures of just 30°C. Aaron Fait, an Italian academic at Ben Gurion University, is using nets of different densities and colours to protect the growing clusters. The temperature, weight, size and chemical composition of the grapes are monitored and conditions tweaked accordingly.
Dr Fait also researches the combinations of cultivars and root stocks that will allow water to be used most efficiently; certain Australian types are particularly hardy. And trimming, or using trellises to force vines into different growth-patterns, can help manage the efficiency of their water use. Dr Fait already advises vintners in Bordeaux on how to beat the heat. “These new strategies for irrigation and shading will keep the wine industry going,” he reckons. L’chaim!