Petaluma, Calif.—Justin Harmon is the new winemaker at Pfendler Vineyards, a producer of estate-grown Chardonnay and Pinot Noir wines in the Petaluma Gap area of Sonoma County. Harmon replaces founding winemaker Greg Bjornstad who will continue to work with Harmon on vineyard management through Bjornstad's new viticulture software startup eVit. Harmon also produces wine under his own label, Argot Wines, and has a chemical engineering degree from the University of Pennsylvania.