Six wild-type non-Saccharomyces strains, belonging to the species Zygosaccharomyces bailii, Priceomyces carsonii, Trigonopsis californica, and Pichia manshurica, were evaluated for white wine production using Assyrtiko grapes from Santorini in Greece. Fermentation kinetics, in terms of glucose and fructose consumption and sensory analysis, was first employed to test the enological potential of the yeast strains. Based on their performance, two strains of Z. bailii (Zb-A19Y5 and Zb-K29Y2) and one strain of T. californica (Tc-A9Y1) selected for further analysis. The selected strains were tested in larger fermentation volumes for sugar consumption, while the produced wines were assessed for classical enological parameters, volatile compounds (GC/MS), and sensory analysis. Tc-A9Y1 could lead to dry wine (1 g/L of residual sugars) with 1.6 vol (12%) less alcohol than the other experimental wines. The wines that were fermented with the strain Zb-K29Y2 exhibited very high concentrations of isoamyl alcohol (604.33 ± 76.8 mg/L), but at the same time, they were characterized by low fruity notes. None of the produced wines presented any off-flavor aromas. Exploiting non-Saccharomyces strains with great fermentation capacity, which are able to produce high-quality wines and adapted to global warming conditions, is a new challenge for the wine industry.

Rootstocks play a crucial role in viticulture because of both their agronomic benefits and impact on grape and wine chemical composition. Their influence on vigor, yield, and phenolic maturity has been widely studied, but only recently have studies begun to examine their effects on wine aroma compounds and sensory profiles. This review compiles findings of studies investigating 33 rootstocks for their influence on wine aroma composition and 29 rootstocks for sensory evaluation across 10 red and four white grape varieties. The most studied rootstocks include 1103 Paulsen, 110 Richter, Sélection Oppenheim 4 and 101-14 Millardet et de Grasset. Shiraz, Merlot, and Cabernet-Sauvignon are the most frequently assessed varieties. Despite growing works in this research area, results are highly variable due to differences in experimental design, winemaking protocols, and sensory methodologies. Only five studies have simultaneously analyzed both wine aroma compounds and sensory attributes. While some consistent trends emerge for certain aroma compounds, such as β-damascenone or linalool, most findings remain context-dependent. This review emphasizes a lack of standardization, including that of winemaking conditions, and highlights the critical need for multi-site, multi-year studies to better understand rootstock effects on wine aroma and sensory quality.

As an alternative to traditional red wine production during an economic crisis, we investigated the sensory perception and appreciation (liking) of young consumers for organic red grape juice from the Plantet cultivar (Seibel 5455) with or without the addition of sugar or organic acid. This was evaluated through four studies involving panels of young adults with an average age of 22 years. The goal was to determine how adding tartaric acid or hexoses (glucose and fructose) affected hedonic scores as well as gustatory and aromatic attributes. Surprisingly, adding acid to a must that experts deemed overly sweet (with 255 g/L of endogenous sugar in the control) did not improve liking scores. Similarly, the addition of hexoses did not enhance liking. Instead, natural grape juice, without any added sugar or acid, was the most preferred product among the young adult panelists. This preference was shared by a panel of enology students, who can be considered future key decision makers in the wine and juice industries, in the last study. As expected, the addition of hexoses led to a perception of ‘jam’ and ‘sweet’ attributes, while the addition of tartaric acid resulted in a more ‘acidic’ profile. Interestingly, the fruit attributes most associated with hexose addition were ‘apricot’ and ’strawberry’, whereas tartaric acid addition was most strongly associated with ‘raspberry’.