The impact of ethanol on the sensory perception and aroma release of alcohol-free beers

Abstract

Health-conscious consumers are increasingly turning to Alcohol-Free Beers (AFBs), leading to a rise in popularity of this category of beer in recent years. However, brewers still face significant challenges in producing AFBs that provide a sensory experience comparable to regular alcoholic beers. The absence of ethanol in AFBs leads to a diminished sensory experience. This study aims to understand the role of ethanol in beer through sensorial and analytical approaches. Commercial alcohol-free lager beers were spiked with ethanol to achieve different alcohol levels (0 %, 0.5 %, 2.5 %, 5 % ABV). The samples were assessed by two sensory panels using NappingTM, and headspace aroma compounds were analysed by Selected Ion Flow Tube Mass Spectrometry (SIFT-MS). Additionally, instrumental viscosity was measured using a rheometer. Results showed that at a 5 % ethanol level, there was a considerable increase in alcoholic, warming, full-bodied, and lingering sensations. In contrast, no-alcohol (0 % ABV) and low-alcohol (0.5 % & 2.5 % ABV) beers were perceived as more watery or light, with the differences driven by beer flavour. The addition of ethanol enhanced the release of aroma compounds (specifically aldehydes and esters) into the headspace and increased viscosity (as determined by instrumental measurement). These findings are relevant for scientists and brewers and contribute to knowledge for the development of AFBs, with acceptable aroma, taste, mouthfeel and an improved sensory experience for consumers.