Undoubtedly the most important viticultural region of the country of Argentina is Cuyo, the arid and red-soiled area within central-west Argentina which produces over eighty percent of the nation's wine each year. Cuyo represents the finest aspects of Argentinian wine making, with wineries in the region celebrating their traditions which stretch back to the sacramental wines first introduced to the country by Spanish settlers hundreds of years ago. As with much of Argentina, Cuyo is most famous for the production of Malbec wines, with Malbec grapes thriving prodigiously in the hot climate of the region, reaching full ripeness in ways they rarely could in their native France, and producing wines of exceptional flavor and quality. The Desaguadero River is the key water source in this otherwise dry and dusty region, and successful irrigation projects have helped bring water to even the driest vineyards within Cuyo. The green skinned grapes of the Sauvignon Blanc varietal had their origins in Southern France, where they are still widely grown and used for many of the excellent young and aged white wines the region is famous for. Today, however, they are grown in almost every wine producing country in the world, and are widely revered for their fresh and grassy flavors, full of tropical notes and refreshing, zesty character. Sauvignon Blanc grapes thrive best in moderate climates, and ripen relatively early in the year. This has made them a favorite for many wineries in the New World, where they can still produce healthy and high yields in the earlier part of the summer before the temperatures become too hot. Too much heat has a massively adverse effect on Sauvignon Blanc, as the grapes become dull in their flavor, and the wine produced from them loses all its unique character and high points. As such, Sauvignon Blanc farmers have had a lot of trouble from global warming and climate change, as they are being forced to harvest their crops increasingly earlier in the year when it is cool enough to do so.