Founded in 1994, WNC brings decades of winemaking, viticulture and business experience to its projects around Australia and the world. From its original base in Hawthorn, to today’s office in the heart of the Yarra Valley WNC has always held a forward-looking, global view of the wine world.

Its projects continue to take the team far and wide, and have included locations as diverse as China, India, England, Japan, New Zealand, Vietnam, Turkey and Thailand.

Each member of the Wine Network Team is a highly respected professional with extensive experience in their selected field, making Wine Networking Consulting one of the most recognised, regarded, and valuable resources for the Wine Industry both in Australia, and internationally.

Gary Baldwin AM

Director & Principal Consultant

With university qualifications in biochemistry and wine science and many years experience in senior winemaking and management roles, wine-show judging, wine research and extension, Gary is one of Australia’s most respected wine professionals.

As a Director and Senior consultant of WNC since 1994, Gary travels domestically and internationally, providing technical advice on all aspects of wine production, and remaining up to date with worldwide winemaking trends and viticultural issues.

Mark O’Callaghan

Managing Director

Mark joined WNC as a Director and Consultant in 2013 after working as a Senior Winemaker for one of the largest Australian wine companies. He works with wine businesses across Australia and around the world including China and England, with earlier projects in India and the Canary Islands.

Prior to this, Mark spent fourteen years with Accolade Wines (formerly BRL Hardy), including eight years as Senior Winemaker and Winery Manager for Yarra Burn. In addition to the Yarra Valley during that period, Mark made wines in McLaren Vale, Heathcote, Great Western and the Pyrenees, plus vintages in Austria and Sicily.

Mark is on the management committee and is the immediate past President of the Yarra Valley Wine Growers’ Association. He is a regular wine show judge at both capital city and regional shows, occasional author and lecturer, member of the Victorian Pinot Noir Workshop Committee and former Chair of the Committee for the Yarra Valley Wine Show and James Halliday Chardonnay Challenge. He was also a Scholar at the 2007 Len Evans Tutorial.

Mark holds a Bachelor of Applied Science (Wine Science) (Charles Sturt University), a Graduate Diploma of Business Administration (Deakin University) and a Bachelor of Science (Monash University).

Sandrine Gimon


Raised in Savoie, France, but now based in the Yarra Valley, Sandrine is the former Chief Winemaker for Rymill, Coonawarra.

As a youngster she was Inspired by her family’s vineyards in Ardèche and was one of 24 annual students accepted in Universite des Sciences de Reims for the Diplôme National d’Œnologue. She graduated in 1998 after a 6-month internship at Veuve Clicquot Ponsardin, then worked at various wineries in Entre-Deux-Mers, Romania, Houghton (Swan Valley, WA), the Languedoc Rousillon, Pomerol and Padthaway (SA), eventually settling in Coonawarra.

Her 13 year tenure at Rymill allowed her to follow the link between land, grapes and wine and to manage a meaningful portfolio of wines.

Sandrine is an active wine show judge, has completed the Len Evans Tutorial (2017), the AWRI’s Advanced Wine Assessment Course (2007) and enjoys sharing knowledge and critical thinking with clients.

Mavis Zhang


Qualified with a Bachelor of Viticulture and Oenology from the University of Adelaide, Mavis Zhang is one of the leaders of the emerging generation of Chinese-born wine professionals. Today she brings more than five years of professional production experience with top-flight producers such as Bass Phillip and Vasse Felix, along with Rob Dolan and Sunshine Creek in the Yarra Valley.

Her winemaking experience includes winery operation and management on a daily basis, technical and analytical skills, sensory evaluation and quality control. She has significant experience in liaison with contract clients, consultant winemakers and other third parties, Australian and Chinese.

Outside production, first and foremost a wine lover with a passion for knowledge, Mavis has achieved WSET Level 3 and is an accomplished palate, having won the championship for the 1st Australian Wine Blind Tasting Competition (Melbourne District) in 2016. Mavis also has a rounded wine background that includes industry liaison and technical translation work for noted Australian wine critic Jeremy Oliver, the creation of wine educational material and the provision of wine training sessions for clients and the operation of a boutique wine store. Furthermore, Mavis has co-founded a wine club business and has planned and hosted several major wine dinner events.

Conrad Speight

Engineering Consultant

A Mechanical Engineer by profession, Conrad has over 20 years experience in winery development, upgrades, relocations and detailed project management.
He is one of the most experienced Winery Engineers in Australia. Based in Adelaide, his recent projects include major upgrades to a 75,000 Tonne winery in Mildura and a high-end boutique winery in the Yarra Valley.
As the former National Engineering Manager for Accolade wines (previously BRL Hardy) Conrad has developed and managed winery building projects in Canberra, the Clare Valley, Yarra Valley, Riverland, McLaren Vale, Margaret River, Swan Valley and Tasmania. Internationally, he was also responsible for a winery in Chile and has toured extensively, giving him a very broad industry understanding.
Prior to specialising in the wine industry, Conrad spent 12 years in manufacturing and construction in the mining, food production and car sectors.


Nicole Esdaile

Winemaking, Wine Business

Nicole has been associated with WNC since 2009; is a qualified pharmacist & winemaker and has extensive production, strategic, operational and business management experience.

Nicole has been broadly involved in the Australian Wine Industry for almost 20 years, holding senior winemaking & management positions at Capel Vale wines in WA, Rutherglen Estates in Rutherglen, Victoria and most recently Coombe Farm in the Yarra Valley.

She is an experienced wine show judge and sits on several Wine Industry Boards & Committees.

Ray Guerin

Viticulture, Vineyard Management

Ray Guerin is a veteran with enormous cool climate experience. He was awarded Gourmet Traveller Wine magazine’s Viticulturist of the Year in 2013 and inducted into the  Yarra Valley Hall of Fame in 2018.

Ray worked with Hardy’s for 18 years, specialising in southern Victoria and Tasmania, with particular influence on Hardy’s Arras sparkling wines – where he worked with chief sparkling winemaker Ed Carr. Ray then joined Shaw & Smith as Group Viticulturist in 2011.

Early in his career, Ray left his family’s vineyards in McLaren Vale and moved to the Yarra Valley to establish Hoddles Creek vineyard. Much later, Ray established his own Yarra Valley vineyard, Applejack.

Peter Hayes AM

Education, Training, R&D Investment

Mr Peter Hayes has extensive experience across education and training, R&D investment and management, viticultural operations, irrigation sector and government and industry affairs in a 30+ year career in the wine industry.

Mr Hayes is a society ‘fellow’ of the ASVO, a title given to members who have made a particularly outstanding and meritorious contribution to the grape and wine industry. The criteria for this award include making a major contribution in an industry, scientific, educational or Society role and having been a member of the Society for at least 10 years.

Dr David Jordan

Viticulture Scientist

Dr David Jordan is a Viticultural Scientist. He has a Doctorate (PhD) in Viticulture from Oregon State University, USA and an Honours degree in Horticultural Science from Lincoln University, New Zealand.

He has developed significant commercial experience during his involvement in the international grape and wine industry since 1983, and established his consultancy business Vine to Wine to Market in 1994.

Based in New Zealand, David consults to many wineries, vineyards and wine businesses in Australia and internationally.