Independent Third-Party Auditors

Independent validation that you are meeting Napa Green Vineyard and /or Napa Green Winery practice and performance-based standards, walking the talk, is critical to marketplace assurance. Our network of third-party auditors have gone through training in the Napa Green programming, and will validate implementation of practices that our team has not been able to review. If you are interested in becoming a Napa Green Auditor, please reach out to wegotthis@napagreen.org.

Jill Brodt

An experienced sustainability auditor and California native who has called Sonoma County home for over 20 years. Jill’s previous role as Laboratory Director at Brelje and Race Laboratories, Inc. for over 12 years has given her a strong background in quality control, quality assurance and audit preparation. Her experience in the commercial laboratory sector provides her a unique perspective as a former auditee. She served as a member of the Environmental Laboratory Technical Advisory Committee working closely with members of the State Water Resources Control Board. Jill has an eye for interpreting regulation and choosing appropriate and decisive corrective action. She holds a B.A. in Environmental Studies, with an emphasis in Water Quality, from Sonoma State University.

Auditing Services: Napa Green Vineyard, Napa Green Winery, Accredited Sustainability Auditor for California Certified Winegrowers

Matthew Hoymak

Matthew holds an MBA in Sustainable Management from Presidio Graduate School and brings over 14 years of experience in the hospitality industry as the founder and CEO of Stag Dining Group.

As a certified sustainability practitioner with the Global Reporting Initiative (GRI), Matthew has conducted audits for Fortune 500 companies, including developing waste stream and recycling strategies for NASCAR and assessing Intuit’s energy usage in commercial real estate. For the past two years, he has worked with Deep Planet AI to provide precision agronomy analysis for wine businesses, enhancing vineyard productivity and promoting regenerative farming practices. His work has also included remapping New York’s American Viticultural Areas (AVAs) in collaboration with the New York Wine and Grape Foundation and their grower survey.

Auditing Services: Napa Green Vineyard, Napa Green Winery

Sierra Minchaca

Sierra Minchaca is an independent third-party auditor for Napa Green and LODI RULES with a background in sustainable viticulture, climate-smart farming, and soil health. She previously served as Climate & Soil Specialist for Napa Green’s Vineyard Program, where she conducted vineyard irrigation evaluations, on-site Carbon Farm assessments, and supported certification processes and practice verification. Sierra holds a B.S. in Conservation and Resource Studies from UC Berkeley, advanced training in Carbon Farm Planning through the Carbon Cycle Institute, and has been trained as a Regenerative Agriculture Technical Assistance Provider through Chico State’s Center for Regenerative Agriculture.

She has also contributed to industry outreach as a Napa Green brand ambassador and through the RISE Climate & Wine Symposium, helping elevate conversations on resilience and regenerative farming. Her technical strengths include carbon farm planning, irrigation system evaluation, and sustainability metrics tracking. As an auditor, Sierra ensures compliance with program standards through thorough and objective evaluation.

Auditing Services: Napa Green Winery, LODI RULES

Megan Newhall

A Sonoma County native with over 18 years of experience in management including developing and monitoring guidelines and standards for assuring compliance with state licensure, federal regulations (OSHA, HIPAA etc.) and accreditation. Experienced in quality and internal audits of clinical services, which also involved preparing material for legal inquiries, external audit engagements and corrective action plans. Extensive experience in Human Resource Management and employment law including training, policies and procedures, employee retention, compensation and hiring practices.
B.A. in Communications.

Auditing Services: Napa Green Vineyard, Napa Green Winery, Accredited Sustainability Auditor for California Certified Winegrowers