Saccharomyces cerevisiae (brewer's yeast) strain BY-989
In 2025, Health Canada received a submission to allow the sale of genetically modified Saccharomyces cerevisiae strain BY-989 to impart tropical fruit flavours and aromas in beer by converting flavourless conjugated thiols naturally present in barley and hops into free thiols. A liquid and dried commercial preparations of this strain will be sold as Tropics London and Dry Tropics London, respectively, and are intended to replace yeast from other available commercial sources in the fermentation of beer.
In order to determine whether S. cerevisiae strain BY-989 could be sold in Canada for the production of beer, the scientists at Health Canada conducted a scientific assessment that ensured that it is safe for consumption. Our scientists considered how the yeast strain was develop, produced, and whether it can be toxic or cause allergic reactions.
Scientists with expertise in molecular biology, microbiology, toxicology, chemistry, and nutrition conducted a thorough analysis of the data and the protocols provided by the applicant to ensure the validity of the results.
Following this assessment, it was determined that the changes made to this yeast strain do not pose a greater risk to human health than other yeast strains currently available on the Canadian market. In addition, Health Canada also concluded that this yeast strain would have no impact on allergies, and that there are no nutritional concerns with its food use.
Health Canada's assessment of S. cerevisiae strain BY-989 preparations was conducted according to the Guidelines for the Safety Assessment of Novel Foods. The approach taken by Health Canada in the safety assessment of novel foods is based upon scientific principles developed through expert international consultation over the last 20 years with agencies such as the World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO), and the Organization for Economic Co-operation and Development (OECD). The approach taken by Canada is currently applied by regulatory agencies around the world in countries such as the European Union, Australia/New Zealand, Japan, and the United States.