Dr, (b. 1942), born in Cardiff, Wales, has been among the most influential brewing scientists of the past few decades. While heading up the research group at the Labatt Brewing Company in Canada, the team developed and implemented the use of high gravity brewing and ice beer. His research group at Heriot-Watt University in Scotland further increased the brewing industry’s understanding of yeast biochemistry as it pertains to the brewing process.

Stewart’s research group at Labatt did pioneering work that explained the mechanics of yeast flocculation and was also one of the first brewing groups to carry out advanced genetic research on constructing yeast strains with high temperature tolerance. These were later used in the fuel ethanol industry. Stewart held a number of technical positions with Labatt Brewing and from 1986 to 1994 was the Labatt Brewing Technical Director.

In 1994, Dr Stewart returned to the UK and to the university environment, where he held the position of Director and Professor, International Centre for Brewing and Distilling, at Heriot-Watt University (1994–2007). Many students in the brewing and distilling industry have been trained and mentored by him in this role.

Stewart has made a large contribution to the brewing literature with over 300 publications including books, patents, review papers, articles, and peer-reviewed papers.

He continues to work actively with students and researchers in the brewing industry as an Emeritus Professor in Brewing and Distilling, Heriot-Watt University.

See also flocculation and heriot-watt university.