China may soon be the world’s biggest producer of wine. In his father’s hometown, a prominent architect — and unlikely winemaker — sees a new Napa. ... When Ma Qingyun visits Yushan, a rural town an hour outside of Xi’an, in China’s Shaanxi province, he travels in a chauffeured black Mercedes-Benz. His car speeds eastward along the newly paved roads ... “How about we chug the first glass?” Frank Fu, a Shanghai-based venture capitalist, suggests, holding up his full wineglass and looking around. Laughs ripple among Ma’s guests, unsure if the suggestion is serious. Ma nods and laughs. “Sure!” Fu clinks glasses with his neighbors before tilting his head back and downing the wine. A few of the other guests join in. ... Baijiu is still the most popular alcohol in China (and accounts for about 38 percent of worldwide alcohol consumption), but the past few decades have seen a rapid expansion of the country’s wine market. China is now the fifth-largest wine-producing nation in the world, and it nearly tripled its consumption of red wine between 2008 and 2013, becoming the world’s largest consumer of the beverage. But old drinking habits linger, and Ma has acquired a benevolent patience with potential buyers who swig his painstakingly crafted pinots as if they were baijiu.