Meet the Wine Consulting Team at Chai Consulting
Chai Consulting brings together a group of certified wine professionals whose combined expertise spans authentication, collection management, formal valuation, and dispute support. Based in the Bay Area and working with clients across the United States, Europe, and Asia, our wine consulting team is built around one guiding principle: independent, conflict-free guidance that serves the collection and the client, not an inventory position or a predetermined sales channel.
Wine Experts Bay Area and Worldwide
Specialist Knowledge Across Every Stage of the Collection Lifecycle
Our professional wine advisors hold credentials and hands-on experience across the full range of collection work: provenance research, TCM® wine authentication, USPAP-compliant appraisal, inventory organization, sourcing, liquidation, and expert witness testimony. The team includes wine industry specialists operating across multiple continents, giving clients with collections in different regions access to coordinated expertise and consistent standards. Every engagement is led by someone with direct, relevant experience in the matter at hand.
DipWSET, CWE Managing Member/Founder
Maureen Downey
Maureen Downey is the founder and Managing Member of Chai Consulting, established in 2005. She holds the DipWSET and CWE designations and has spent two decades at the forefront of fine wine authentication, fraud detection, and collection advisory work. Maureen developed the proprietary TCM® methodology and the Chai Vault digital provenance registry, and has assisted law enforcement in major wine fraud matters. Her practice has encompassed more than $120 million in fine and rare wine assets across private, estate, institutional, and fiduciary collections. She serves as an expert witness in criminal and civil disputes involving authenticity, valuation, loss, and fraud, and leads the Seminars & Training program for collectors, sommeliers, auctioneers, and other wine professionals.
Consulting Executive Director & Senior Consultant, Europe, UK
Siobhan Turner, MW
Siobhan has joined forces with Maureen Downey since 2013 and quickly emerged as one of Chai’s most trusted authentication experts. She played a key role analyzing physical evidence in the Rudy Kurniawan fraud case at the U.S. Department of Justice and continues to lead critical authentication cases across Europe. With a Master of Wine credential and a background in finance and board-level leadership, she brings precision, wisdom, and unmatched global insight to every project.
TCM Authenticator Hong Kong/UK
Domonal Yeung
Since establishing his wine business in Hong Kong in 1997, Domonal has grown from a single retail outlet to a full-service enterprise spanning import, wholesale, distribution, and premium wine services. A graduate in Business Administration and Marketing with WSET credentials and formal training in mediation and risk planning, he is the sole officially certified TCM Authenticator in Hong Kong. Trained by Maureen Downey, Domonal combines deep industry experience with unmatched authentication skill.
TCM Authenticator Consultant, Europe, France
Etienne Paumier, DipWSET
Born into a winemaking family in the Loire Valley and seasoned in both Burgundy and Hong Kong, Etienne heads Wholesale and Private Client sales at Watson’s Wine. A graduate of HEC Paris with a WSET Diploma (with Merit), he’s respected for his expertise, integrity, and passion for Burgundy.
TCM Authenticator Brazil
Andrew Cullimore
Andrew’s wine journey began in London, evolving from sommelier to cheesemonger, then to a decade at Berry Brothers & Rudd. Now based in Brazil, he brings his WSET Diploma and passion for wine collections to Chai’s authentication practice—combining refined industry knowledge with global authenticity standards.
TCM Authenticator Portugal
Olivier Roberto
A former professional basketball player turned wine specialist, Olivier earned degrees in Management, Marketing, and Logistics before diving into the world of Madeira and Port. Fluent in Portuguese, French, and English, he expertly supports private collectors across borders with precision and poise.
TCM Authenticator, USPAP Certified Appraisals USA
Carol Cohen, DipWEST
With a unique blend of journalism, culinary arts, and wine expertise, Carol began her career as a copywriter for Wine Enthusiast and later earned credentials from the French Culinary Institute and WSET. Trained under Maureen Downey, Carol applies forensic authentication skills and delivers USPAP-compliant valuations with trusted discretion.
TCM Authenticator Hong Kong
Angelina Cheuk
London-raised with a Biochemistry degree from Nottingham, Angelina has been immersed in Hong Kong’s fine wine industry since 2015. Currently pursuing WSET Level 3 and whisky certifications, she is committed to elevating wine authenticity awareness and combating fraud worldwide—one bottle at a time.
TCM Authenticator, CA, CFE, Licensed Private Investigator, Switzerland
Nickolas Harris
A forensic expert at EY in Zürich, Nick brings over 15 years of anti-fraud and financial crime experience. A qualified forensic accountant and Certified Fraud Examiner, he became a TCM Certified Wine Authenticator in 2025. His childhood near Tasmanian vineyards instilled a lifelong love for wine—now augmented with rigorous authentication expertise.
Collection Management Consultant, Celebrity Sommelier, USA
Chris Sawyer
Christopher Sawyer is an expert sommelier, having honed his skills at high-end restaurants in California, creating award winning wine lists, and hosting educational events for the masses. This extends to his work as a public speaker, wine competition judge and host of curated wine country tours. He keeps busy partnering with Sonoma County Vintners to host specialty varietal tasting events and as Adjunct Faculty in the Wine Studies department at Santa Rosa Junior College. To enjoy his wine adventures, follow his blog, The Sommelier Files, and his YouTube Channel featuring The Varietal Show!
