International audienceThe low alcohol content in alcohol-free beers (AFB), i.e. below 0.05% v/v ethanol in EU countries, is not the only difference when compared to Lager beers. The pleasant fruity flavour of these beers is one of the most appreciated features, whereas AFBs brewed by cold contact fermentation (CCF) process exhibit a flavour reminiscent of wort and high amount of non-fermented sugars. These differences could alter the release properties of an AFB compared to alcoholic beers, thus affecting their perception threshold. In a previous part of this study, 24 odour regions were identified in SAFE and HS-SPME extracts. Thus, the aim of this study was to determine orthonasal and retronasal detection thresholds of these compounds in a model AFB-CCF and obtain their odour activity values (OAV) in a reference AFB-CCF. The model AFB-CCF was composed of a mixture of mono-, di-, and trisaccharides in carbonated water. Six concentrations of each compound in ascending order were sniffed and tasted by 12 or 24 panellists. The thresholds were calculated by either the standard BET method or logistic regression, and an algorithm for the removal of false positives was also utilised. The results showed significant differences between detection thresholds calculated by using the different methods, thresholds from BET method being always higher than those from logistic regression. The removal of false positives increased the threshold values as well as improved the goodness of fit of the data to the logistic function. Thresholds calculated by logistic regression with the false positives removed were used for the calculation of OAVs. Once the 24 aroma compounds were quantified by a range of analytical techniques, the OAVs showed that the most odour active compound was methional (concentration=85 μg/L, orthonasal detection threshold=0.47 μg/L, OAV=181), followed by 3-methylbutanal (38 μg/L, 0.61 μg/L, 62), phenylacetaldehyde (160 μg/L, 5.4 μg/L, 30), acetaldehyde (1,200 μg/L, 46 μg/L, 26), 2-phenylethanol (20,700 μg/L, 1,880 μg/L, 11), methylpropanal (24 μg/L, 4.3 μg/L, 5.6), and Z-4-heptenal (0.063 μg/L, 0.016 μg/L, 3.9). For the first time, the contribution of flavour compounds to the overall aroma of AFB-CCF has been decoded. The outcomes from this study may be of great relevance for the brewing industry for the reduction of the wortiness of AFBs