Jeff Onysko

Associate Winemaker
Napa Wine Company

Jeff Onysko earned his degree in Wine and Viticulture from Cal Poly San Luis Obispo, where he developed a strong foundation in both the science and business of winemaking. He began his professional journey in the research department at E. & J. Gallo Winery as an intern, followed by production and bottling coordination roles at Cakebread Cellars that deepened his hands-on experience. Jeff currently serves as Associate Winemaker at Napa Wine Company, where he oversees the Elizabeth Rose portfolio for Ghost Block Estate Wines. In addition to winemaking, he leads technical and business development initiatives across Napa Wine Company and Yount Mill Vineyards, with a focus on integrating emerging technologies—from fermentation tools and MicroOx systems to custom software that improves efficiency, traceability, and data-driven decision-making. He is passionate about bridging tradition with innovation to strengthen operations and drive sustainable growth. Jeff serves on the AVF Board because he believes research and collaboration are essential to the long-term success of the wine industry.