In the celebrated Napa and Sonoma valleys, winemakers big and small are being forced to close facilities and lay off hundreds of people. Io Dodds explores the roots of the downturn — and meets the people trying to weather the storm A cross the rolling fields and sun-baked hilltops of California 's world-famous wine country, an economic crisis is unfolding. You might not know it as you browse through bottles in your supermarket or liquor store. But amid changing demographics and a cultural shift