The Impacts of a beta-glucanase Step Pre-Cooking on Alcohol Yields during Irish Rye Whiskey Production

Recent industry roadmaps such as Crops 2030 and the Irish Whiskey Association's Sustainability Roadmap 2022 emphasize the importance of increasing the use of Irish-grown grain in brewing and distilling. With the growth of the Irish distilling sector, there is a corresponding demand for raw materials and locally sourced grains. In Ireland, approximately 500 hectares of rye are harvested annually, with rye containing a similar range of starch as wheat. However, because rye contains more hemicelluloses and pentosans than other cereals, and because water-soluble pentosans tend to form viscous solutions in concentrated flour-water slurries, it is not widely utilised as a fermentation substrate. The purpose of this study is to examine pre-treatment with beta-glucanase to enhance the alcohol output from rye flour. The research determined a baseline alcohol production of 187.1 LA/ tonne dwb without the addition of beta-glucanase. Using four predictor variables, response surface techniques were used to investigate the influence of beta-glucanase on alcohol yield. A Box-Bekhan design was used to investigate time, temperature, calcium ions, and beta-glucanase. When beta-glucanase was administered at a dose rate of 3 U/g with the addition of 200 mg/L calcium ions and run at 50 degrees C for 30 min, the response surface approach yielded the highest alcohol output of 406 LA/tonne dwb. While, this yield is consistent with previous authors' findings; it is lower than average yields for malted barley, wheat, and maize.

Automated summary

Recent industry roadmaps highlight the need to increase the use of Irish-grown grains in brewing and distilling. However, rye, despite its similar starch content to wheat, is not widely utilized as a fermentation substrate due to its higher level of hemicelluloses and pentosans. This study explores the use of beta-glucanase treatment to enhance alcohol output from rye flour, finding that a combination of beta-glucanase, calcium ions, time, and temperature resulted in the highest alcohol yield of 406 LA/tonne dwb. While this yield is consistent with previous findings, it is lower than average yields for other grains like barley, wheat, and maize.