Better brewing

Alex Speers holding beer

Thanks to Heriot-Watt research, brewers worldwide can make up to 50 per cent more beer in the same size plant. Professor Graham Stewart and his team have enabled more cost-effective and quality-enhanced brewing by solving problems that dogged the introduction of new production processes.

Brewers can make huge cost savings if beers are made from more concentrated worts. (Wort is the liquid extracted from the initial grain-mashing process and contains the sugars that will be fermented to produce beer.) In high gravity (HG) brewing, wort is concentrated from a traditional value of about 12 per cent solids to upwards of 18 per cent. But companies’ first attempts at HG brewing could not achieve the same flavour as traditional gravity methods, and foam consistency and yeast fermentation performance were also poor.

Fifteen years of research by Prof Stewart’s team has led to substantial improvements in the HG brewing process. Prof Stewart has been honoured by the Master Brewers of Americas, the American Society of Brewing Chemists and the Institute of Brewing and Distilling primarily for his work on understanding and providing industrial solutions to problems with HG brewing.

Take the problem of flavour-matching a brand of beer produced by normal strength wort to the same beer brewed with HG-wort and then diluted. Prof Stewart’s team discovered that using maltose-based syrups and increasing other wort nutrients improved flavour matching. This breakthrough has led most large brewers to switch to maltose-based syrups for their HG-worts.

Distilleries as well as breweries worldwide have benefitted enormously by switching to HG methods. Being able to expand production without building new production facilities both makes financial sense and helps sustainability, through savings on energy, effluent and cleaning.

Key information

Graham Stewart

Graham Stewart