This led to a 6-month exchange at California Polytechnic State University, (in San Luis Obispo, California, USA). While on this exchange in California he was introduced and gained a curiosity into grapevines. Stewart then went on to study for a doctorate in viticulture at Charles Sturt University (Wagga Wagga, NSW, Australia) that also included a 6 month period at Trent University (in Peterborough, Ontario, Canada).
Stewart's research focussed on grapevine physiology, predominately on the effects of irrigation and nutrition management, carbohydrate and nitrogen reserve dynamics, and plant hormones on grapevine growth and development.
In 2009 he left the academic life to gain industry experience where he worked as a vineyard manager in the Wairarapa region and then in the Hunter Valley of Australia. After 5 years working in the industry, Stewart recognised that his future happiness lay in academia.
Since 2014, Stewart has been involved in tertiary education - first at Eastern Institute of Technology as a lecturer in viticulture. Stewart was appointed to NMIT in 2018 where he continues his passion for research and hopefully to pass on his enthusiasm for viticulture to the students studying Wine and Viticulture at NMIT, who will be the future of the New Zealand Wine Industry.