The Optimisation of Cooking Parameters for Spirt Whiskey Production from Native Irish Wheat: A Response Surface Method Approach

Barley and maize have dominated the Irish whiskey sector, but in recent years, alternative grains have started to gain traction. Ireland has a high average wheat yield, producing grain that is high in starch but low in protein, offering the potential for use in distillation. To successfully utilise Irish-grown wheat in distillation, cultivars that are suitable to the Irish climate and give high yields of alcohol need to be identified. This necessitates the development of a rapid screening test for grain alcohol yield. This study examined the optimal temperature, time period, α-amylase dose rate, and calcium concentration to be used in the cooking of wheat grain to maximise alcohol yields. It was determined that lower cooking temperatures are more successful in achieving higher alcohol yields, and it was confirmed that temperature is a key variable in the cooking process. By optimising all parameters, alcohol yields of 458 LA/tonne were obtained, demonstrating that the optimum parameters can be successfully used for both hard and soft endoderm wheat produced in Ireland as well as for different varieties. This indicates potential for producing higher alcohol yields using Irish-grown wheat in Irish distilleries.