Gundlach Bundschu Winery is California 's oldest continuously family-owned winery , and is the second oldest winery after Buena Vista Winery ( established a year earlier by Agoston Haraszthy ) . It is still owned and operated by the founder 's heirs and today led by the sixth generation , Jeff Bundschu . The winery 's estate vineyard , named Rhinefarm by Bavarian-born Jacob Gundlach in 1858 , is located within the Sonoma Valley AVA of Sonoma County , at the crossroads of the Sonoma Valley , Los Carneros AVA and Napa Valley AVA , along the Mayacamas Mountains . They specialize in estate-driven , sustainably farmed Bordeaux reds and cool climate varietal wines . The company was founded by Jacob Gundlach in 1858 . Charles Bundschu , from Mannheim , Germany , joined the company in 1868 , and became part of the family when he married Jacob Gundlach ’s daughter Francisca in 1875 . J. Gundlach & Co. grew significantly over the next 30 years , distributing Rhine wines from its factory at the corner of Second Street and Bryant Street in what is now the Soma District in San Francisco , California and its headquarters nearby on Market Street at Second . There was a New York branch as well . After Jacob ’s death in 1894 , the company was renamed Gundlach Bundschu . By the time of the great earthquake of 1906 the company was a major international wine producer , distributing over 250,000 cases of mostly fortified wine per year
great earthquake of 1906
1906 San Francisco earthquake
Gundlach Bundschu