John completed his BSc in Winemaking in 1984 and was awarded the prestigious Ron Potter Scholarship after being encouraged into the wine world by Australian winemaking legend Brian Croser, whilst he was studying Geology at Adelaide University.

After working as Assistant Winemaker at Campbells' winery in Rutherglen, and Saltrams in the Barossa Valley, John embarked on a five-year world tour. By hemisphere-hopping he rapidly built his knowledge of world wine production practices. As one of the first "flying winemakers" John worked for Yalumba, Penfolds (Nooriotpa, Yenda and Loxton) in Australia, Clos du Bois in California, Hugels in Alsace, and Domain Tim Marshall in Nuits St Georges, Burgundy during the 1980s.

Settling in England in 1990, John set up Harvest Wine Consultancy based at the Thames Valley Vineyard in Twyford, Berkshire. He developed a client base of English vineyards and wineries, and helped transform the English wine industry. The succeeding years saw Harvest's clients win many English wine awards, including the Gore-Brown trophy - the top accolade - five out of six years. Following this success, John formed the Harvest Wine group, a co-operative marketing venture, which worked to cement the place of English wines on British high street retail shelves.

In 1993 John began consulting to wineries worldwide. His first venture was to the Czech Republic. Since then winemaking and consultancy projects have taken him to Australia, Canada, USA (California and Texas), Mexico, Peru, Brazil, Uruguay, Chile, China, France (Provence, Bordeaux, Alsace and the Loire), Germany, Spain (Valencia and La Mancha), Italy (Friuli, Tuscany, Campania, The Marche, Sicily, Sardinia and Trentino), Portugal, Romania, Hungary, Moldova, Bulgaria, Ukraine, Israel, Turkey, Serbia, Russia, Moldova, India and South Africa.

Today John is a sought after wine business consultant and works with wineries and winery investment groups the world over. As well as consulting to wineries through Worontschak Wine Services Ltd he is Managing Director of Litmus Wines Ltd , a director of Elevage Ltd , a non executive Director at Casa Madero winery in Mexico, Winemaker at Denbies Wine Estates and a panel chairman at the International Wine Challenge. He is a regular contributer to industry debates and a commentator to the trade and on radio and TV. John travels widely to international wine fairs, symposium and to his global client base.

John lives in Notting Hill Gate, London with his wife and two sons.