In this research, the differences between two terroirs belonging to the Protected Designation of Origin (PDO) Montilla–Moriles (Spain) were analyzed. Both areas share soil and climate characteristics, grape varieties, viticultural practices, and winemaking processes. Therefore, the objective of this study was to establish differences between both areas based on the microbiome of the must, the oenological parameters, and the majority and minority volatile compounds of the wines, thus determining the identity traits that make the wines from both areas so different. The results obtained are quite revealing, since at the microbiome level qualitative differences were established between the various areas. In the quality area, the predominant species is Torulaspora delbrueckii while in the production area it is Hanseniaspora opuntiae. Regarding the volatilome, it was observed that the aromatic profile of the wines from the production area has more citrus-fruity aromas and the quality area has honey-floral aromas, thus producing unique wines from each of the areas.

This study evaluated the oenological potential of two non-Saccharomyces yeast strains, Hanseniaspora opuntiae TR-5 and Zygosaccharomyces bailii L-25, isolated from extreme winemaking environments in southern Spain. Out of 156 yeast isolates screened from high-sugar musts and flor yeast biofilms, strains were selected based on their β-glucosidase activity, killer phenotype, and ethanol production, traits associated with aroma release and microbial competition. Fermentation trials on sugar-rich synthetic medium showed that both H. opuntiae and Z. bailii achieved ethanol yields of 10% v/v and residual sugars at 4 g/L. Co-culture and sequential inoculation, with H. opuntiae introduced first and Z. bailii added on day four, resulted in complete alcoholic fermentation and a reduction in undesirable acetoin levels compared to single-strain fermentations. These findings highlight the practical potential of using selected non-Saccharomyces strains in sequential fermentations to improve aroma complexity, fermentation reliability, and sensory quality in wines, even in the absence of Saccharomyces cerevisiae. The application of these strains offers a novel approach for precision oenology and varietal expression in challenging musts.

Spanish “Fino”-style white wines are traditionally aged by a dynamic process under a flor veil of Saccharomyces cerevisiae, requiring ≥15% (v/v) ethanol, which is typically achieved through fortification. Market demand for lower-alcohol wines and the need to reduce production costs have encouraged the development of alternative approaches. Here, static biological aging was evaluated as a method for producing Fino-type wines with reduced ethanol content. Base wines with ~14% and ~15% (v/v) ethanol were aged for nine months, during which chemical, microbiological, and sensory parameters were analyzed, along with flor veil activity. Lower-ethanol wines showed greater flor activity, with approximately 20 more yeast isolates in the wines with 14% (v/v) ethanol. Higher acetaldehyde levels were detected in these wines, reaching about 377 mg L⁻¹ compared to 230 mg L⁻¹ in the control wines (≥15% v/v ethanol). Significant changes were observed in pH (3.13–3.47 vs. 3.04–3.46), volatile acidity (0.20–0.26 g L⁻¹ vs. 0.31–0.66 g L⁻¹), and several volatile compounds, resulting in chemical and sensory profiles consistent with traditional biologically aged wine. Static biological aging can yield lower-alcohol Fino-style white wines with sensory and chemical attributes comparable to the traditional fortified versions, providing a cost-effective alternative that aligns with evolving consumer preferences.

This study investigates nitrogen metabolism during the middle of the second fermentation in stopped bottles of sparkling wine, focusing on two flor Saccharomyces cerevisiae yeast strains (G1 and N62) isolated from the velum of biologically aged wine. Nitrogen compounds, including amino acids, biogenic amines, and ammonium chloride, were quantified, revealing strain-specific differences in nitrogen utilization and production. Proteomic analysis identified 1053 proteins, with 127 showing significant differences between strains. Strain G1 demonstrated enhanced cell wall remodeling and prioritized nitrogen conservation via arginine and lysine biosynthesis, while strain N62 exhibited increased translational activity and alternative carbon utilization pathways. Notably, strain N62 produced higher concentrations of biogenic amines (putrescine and tyramine), likely due to its greater decarboxylation capacity. Principal Component Analysis (PCA) highlighted clear differentiation in the nitrogen compound profiles across the base wine and wines inoculated with the two strains. The proteome of strain N62 showed increased mitochondrial activity and TCA cycle involvement, facilitating faster fermentation (27 days vs. 52 days for G1), growth (46 × 10⁶ cells/mL vs. 21 × 10⁶ cells/mL for G1) and cell viability (4 × 10⁶ cells/mL vs. 0.7 × 10⁶ cells/mL for G1). These findings suggest that yeast strain selection significantly influences nitrogen metabolism and potentially aroma profiles and and fermentation dynamics in sparkling wine production. Understanding these metabolic adaptations provides valuable insights for optimizing yeast performance to enhance wine quality and preserve regional characteristics.

Currently, there is little scientific data to support the importance of selecting non-Saccharomyces yeasts from different wineries in the Protected Designation of Origin (PDO) in Andalusia, southern Spain, and how this group of yeasts can affect the sensory properties of wine. Therefore, this research aimed to study some specific microbiological properties and the metabolites they could produce in order to evaluate the oenological potential of two non-Saccharomyces yeast strains isolated from a region of Andalusia (Córdoba, Spain), Hanseniaspora uvarum TJ-27 and Lachancea thermotolerans T-9, isolated from musts with high sugar content. Of 80 yeast isolates selected, these two strains were chosen for their notable β-glucosidase activity (observed in up to 40% of isolates), cellulase activity (present in 24%), and killer phenotype (found in 40%). In this study, strains that displayed characteristics associated with aroma release were selected. Fermentation assays using a high-sugar synthetic medium revealed that neither H. uvarum TJ-27 nor L. thermotolerans T-9 was able to complete alcoholic fermentation independently, achieving ethanol yields of only 5–6% v/v, indicating the need for subsequent fermentation by Saccharomyces cerevisiae. The originality of this study provides insight into the metabolites contributed by these strains to the wines produced. The best results were obtained when both strains were inoculated together. Furthermore, volatilome analysis showed elevated levels of key compounds such as isoamyl alcohols and 2,3-butanediol. These findings highlight the practical potential of using selected non-Saccharomyces strains from Andalusia to improve fermentation results and wine quality. The novelty of this study lies mainly in confirmation within region-specific isolates.

The global sparkling wine market continues to grow steadily, reaching approximately 24 million hectoliters in 2023, with an annual increase of around 4% despite a general decline in overall alcoholic beverage consumption. This growth highlights the importance of employing diverse yeast strains to improve product variety and quality. Flor yeasts are specialized strains of Saccharomyces cerevisiae that develop a biofilm on the surface of certain wines during biological ageing. They possess unique physiological properties, including high ethanol tolerance and the capacity to adhere, which supports wine clarification. They also have the ability to contribute unique volatile compounds and aroma profiles, making them promising candidates for sparkling wine production. This study evaluated two flor yeast strains (G1 and N62), which were isolated from the Pérez Barquero winery during the second fermentation process using the traditional method. Sparkling wines were produced by inoculating base wine (BW) with each strain, and the wines were monitored at 3 bar CO₂ pressure and after 9 months of ageing on lees. Comprehensive metabolomic analysis was performed using GC-MS for volatile compounds and HPLC for nitrogen compounds, with statistical analysis including PCA, ANOVA, Fisher’s LSD, and correction FDR tests. Strain N62 demonstrated faster fermentation kinetics and higher cellular concentration, reaching 3 bar pressure in 27 days compared to 52 days for strain G1. Both strains achieved similar final pressures, 5.1–5.4 bars. Metabolomic profiling revealed significant differences in the profiles of volatile and nitrogen compounds between the two strains. G1 produced higher concentrations of 3-methyl-1-butanol, 2-methyl-1-butanol, and acetaldehyde, while N62 generated elevated levels of glycerol, ethyl esters, and amino acids, including glutamic acid, aspartic acid, and alanine. These findings demonstrate that both flor yeast strains successfully complete sparkling wine fermentation while producing distinct metabolic signatures that could contribute to unique sensory characteristics. This supports their potential as alternatives to conventional sparkling wine yeasts for enhanced product diversification.