Increasing the Quality and Diversity of Ontario Cider Through Characterization of Novel Saccharomyces Yeast and Nitrogen Supplementation Regimens
Cider has experienced a rise in popularity in the province of Ontario. Industrial fermentation of dessert apples (Malus domestica Borkh.) by domesticated Saccharomyces wine yeast is the preferred production method of Ontario cideries. Here, four novel Saccharomyces yeasts were isolated and characterized based on their ability to ferment apple must. The fermentation kinetics of all four novel strains were also compared under five different nitrogen supplementation regimens. The isolates differed in their consumption of cider sugars although all successfully completed fermentations. Supplementing with amino acids or diammonium phosphate (DAP) caused an increase in must attenuation compared to no nitrogen addition. The addition of amino acids or DAP 72 hours into the fermentation enabled several isolates and industrial yeasts to increase the production of fruity-associated flavour compounds such as higher alcohols and esters. Overall, the findings provide Ontario cideries with new resources to sustain continued growth of the already burgeoning industry.