Malt Whisky Fermentation Impact on New-Make

During the production of Scotch malt whisky, metabolism of carbohydrates in wort is responsible for the production of both alcohol and flavour. This impacts the character of the new-make spirit produced. Therefore, it is of importance to the distiller to understand and control the fermentation process and how changes to raw materials (malt, yeast) may both positively and negatively impact the character and flavour of new-make spirit.<brA 4-parameter logistic model was developed to describe industrial fermentations at the Glenmorangie and Ardbeg distilleries. This model was then used to study lab based fermentations where several parameters were altered in comparison to a control. This includes the use of novel yeast strains, pre-fermentation of wort with Lactobacillus plantarum and high-gravity fermentations. The spirit produced from these fermentations was then analysed using a suite of analytic techniques including GC/MS, GC-FID and HPLC. Furthermore, sensory analysis of spirit was conducted using a trained panel.<br>Significant differences were observed between fermentation profiles. These were then correlated with changes to analytic and sensory profiles. Through changing various parameters of fermentation, novel flavour attributes may be explored, giving new characteristics to the new-spirit and resulting mature product. This work demonstrates the ability to fermentations, and the potential to use this tool to aid process control in a distillery, ensuring consistent new-make spirit.