In a context of increasing interest in the production of wine-based beverages with lower ethanol content, the present work explored the role of ethanol in the sensory properties of model wines (MW). Four sets of MWs (red and white) with alcohol contents ranging from 0.5 to 15 % (1st study) and from 12 to 15 % (2nd study), the non-volatile fraction of real wines and fixed aroma compositions were all prepared and characterised by sensory descriptive analysis. The results indicate that sensory effects were stronger in red MWs than in white MWs, and that alcohol levels below 10 % in reds and 7.5 % in whites cause the models to become unbalanced with excessive sourness. In whites, low-alcohol MWs also showed reduced levels of perceived bitterness, and only at high ethanol levels were body and alcoholic aroma more intense. In reds, the low alcohol MWs showed less positive aroma persistence (perceived retronasally) and less body; at 0.5 % ethanol the positive odour intensity (perceived orthonasally) was minimal and at higher ethanol levels, the models became sweeter and more alcoholic. Overall, although samples with similar alcoholic contents maintained some sensory similarity, there were relevant discontinuities caused a slight increase in ethanol (0,5 %) to have a dramatic sensory impact, with some sensory descriptors showing significant maxima or minima at these alcohol levels. In reds, sourness, alcohol and astringency perceptions were maximum at 13.5 % and 15 % and body at 13 % and 15 %; meanwhile, red fruit was minimum at 13 % and 15 %, peaking at 14.5 %. In whites, alcohol perception was also maximum at 13.5 % and 15 %, while sweetness was maximum at 13.5 % and 14.5 %. These results demonstrate that ethanol exerts profound effects on sensory properties, probably due to strong perceptual interactions with odour, taste and tactile properties.

Despite the widespread use of yeast derivatives (YDs) in winemaking, comparative studies on the impact of different inactivation technologies remain limited, especially when applied to non-conventional yeast species. To address this, the present study evaluated the impact of Saccharomycodes ludwigii (SL#64) derivatives, a non-conventional species characterized by a high cell wall polysaccharide content, produced via Thermal Inactivation (TI), High-Pressure Processing (HPP), and Partial Lysis combined with HPP (PL + HPP), on the polysaccharide content, colloidal stability, and sensory profiles of Garnacha Blanca and Tempranillo Blanco wines. A commercial Saccharomyces cerevisiae derivative was used as a reference yeast derivative. Polysaccharide concentration and colloidal stability were monitored at 2 and 15 days post-addition. All YDs significantly increased polysaccharide levels (3–21%), primarily within the first 48 h. HPP-treated SL#64-YDs proved the most effective in enhancing protein stability, reducing heat-induced turbidity by 21% after 15 days. SDS-PAGE analysis suggested that YD-derived polysaccharides acted as protective colloids, partially maintaining pathogenesis-related (PR) proteins in solution. In contrast, no significant improvement in tartaric stability was observed across treatments. Overall sensory evaluation, including quality, balance, aroma intensity, and Flash Profile characterization, revealed that YD treatments more clearly modified the sensory profile of the aromatically neutral Garnacha Blanca wines, whereas the greater aromatic complexity of the Tempranillo Blanco matrix partially masked these effects, although prolonged contact with TI and HPP reduced aroma intensity and perceived quality. These results suggest that HPP-derived yeast derivatives could be especially suitable for short contact applications, representing a promising non-thermal strategy for tailoring functional YDs to specific wine matrices.

Wildfires release volatile phenolic compounds (VPs) that can be absorbed by grapevines, potentially resulting in “smoke taint” in wines. This has emerged as a prominent issue for the global wine industry due to negative impact on wine quality and subsequent financial losses. Since effective vineyard mitigation strategies remain limited, this study evaluated the efficacy of different materials applied to grapes to reduce the absorption of smoke marker compounds under simulated wildfire conditions. Twelve materials were applied to individual Cabernet Sauvignon clusters close to harvest. Treated vines were exposed to intentional smoke using a purpose-built tent. Grapes from treated vines, as well as smoke-exposed and non-exposed controls, were harvested at commercial maturity. The results showed a strong stratification of VPs within the tent and in the grapes. Glycosylation began within hours of smoke exposure, with significant increases in almost all glycosylated compounds within 4 hours compared to non-smoked controls. Some materials reduced VP uptake relative to untreated controls (kaolin, charcoal, and two commercial coating formulations—GM3E and GMB6), whereas others increased the absorption of smoke-derived compounds (Parka and wipe-out). These findings highlight that those protective treatments may have variable and sometimes counterproductive effects on smoke compound uptake.