Flavour instability and aroma profiles of non-alcoholic beers across production principles and beer styles

Abstract

Flavour instability is a major quality challenge in non-alcoholic beers (<0.5 vol.% alcohol), as their reduced Ethanol content alters aroma retention, antioxidative capacity, and ageing pathways compared with conventional beer. Consequently, non-alcoholic beers are often more susceptible to flavour deterioration during storage.
In this study, the aroma composition, sensory profile, and ageing behaviour of 45 commercial non-alcoholic beers from 30 breweries were investigated. Samples were grouped into physically dealcoholised, stopped fermentation, alternative yeast, and hybrid beers. Aroma compounds and ageing-relevant aldehydes were analysed in fresh and forced-aged samples, complemented by trained-panel sensory evaluation. In addition, ageing potential was assessed through alkaline-induced release of aldehydes from bound states.
Distinct differences between production principles were observed. Biologically produced non-alcoholic beers, particularly stopped-fermentation beers, exhibited higher wort-like character, elevated concentrations of Strecker aldehydes, and larger pools of releasable aldehydes. In contrast, physically dealcoholised beers generally showed lower initial aldehyde concentrations but often experienced the strongest increases in ageing-related compounds during forced ageing. Across all production principles, Strecker aldehydes and Furfural increased markedly during ageing and were identified as major contributors to flavour deterioration. The alkaline release approach revealed a substantial aldehyde-related ageing potential exceeding the Aldehyde increases observed during forced ageing, indicating the presence of both bound aldehydes and matrix-dependent formation pathways. Hybrid beers displayed the most favourable ageing behaviour, combining comparatively low aldehyde concentrations with the smallest sensory deterioration after ageing.
Overall, flavour instability was influenced more strongly by production principle than by beer style, demonstrating that technology selection is a key determinant of long-term sensory quality in non-alcoholic beers. These findings highlight the importance of production-specific strategies to improve flavour instability and shelf life.