Mashing Isothermally at High Temperature Compared to Infusion Mashing for the Production of Full-Bodied, Alcohol-Reduced Beer

Abstract

The objective of this study was to investigate the influence of the mashing temperatures on alcohol content and taste of bottom-fermented Pilsner style beers and to ascertain whether these beers exhibit comparable sensorial properties. For this purpose, three beers brewed with three different mashing procedures were compared. The worts produced were sampled during mashing and after boiling, and subsequently analysed for their original gravity, fermentable sugars, and free amino nitrogen. The beers were analysed for their alcohol content, aroma compounds, apparent degree of fermentation, pH value, foam, and bitterness units as well as being evaluated sensorially according to DLG (= “Deutsche Landwirtschafts-Gesellschaft - German Agricultural Society”) grading in the categories: odour, purity of taste, body, carbonation, quality of bitterness. Overall it was shown, that the isothermal mashing procedure yielded less fermentable but more unfermentable sugars than the two more traditional mashing procedures, leading to a comparable original wort of 11.6°P in the final beer and lower alcohol content of 2.8% v/v in comparison to the more traditional mashing procedures (“high-short” and “simplified high-short” mashing procedure) with original worts of 12.1°P and alcohol contents of 4.5% v/v and 5.0% v/v, respectively. The DLG-rating showed that the beers derived from the different mashing procedures were all classified similarly with scores above 4.5 on average (out of 5.0) in all categories with no significant differences.