The application to agriculture of wheat-straw spent mushroom substrate amendments (compost/vermicompost) used to grow Pleurotus ostreatus has been analyzed. The study was conducted in a vineyard where the effect on (1) the physicochemical properties of the soil and the leaf and (2) the analytical characteristics and the aromatic composition of the wine were analyzed. The application of the amendments resulted in an increase in organic matter and macronutrients (NO₃⁻, P₂O₅ and K₂O) in the soil. With regard to the leaves, the NO₃⁻ and K₂O contents of those vines fertilized with vermicompost were higher, and the metallic content was the same regardless of the treatment applied. The analysis of the colorimetric parameters showed that there was a higher content of compounds with red and violet colorations in the case of wine obtained after treatment with vermicompost. In addition, for this type of wine, a higher concentration of volatile compounds was obtained. Thus, after grouping the aroma compounds into aroma series, the greatest differences among vermicompost wines and the rest were obtained in the fruit, floral, herbaceous, and green fruit series. The principal component analysis showed that the vermicompost treatment clearly differentiated the wine from the rest of the wines, in addition to its effects on the aromatic series, the values in the total polyphenol index, and the compounds responsible for brown tones.

Traditionally and alternatively aged wines’ odour activity values (OAVs) are investigated to differentiate and highlight the differences between the selected methods. An analysis of the volatile aroma compounds of wines derived from ageing in barrels, oak chips, and staves was performed using stir bar sorptive extraction chromatography–mass spectroscopy (SBSE-GC-MS). The results showed that alcohols, esters, and oak compounds were the main contributors to aroma, and their OAVs were higher in the stave samples after 3 months than in the samples from the other two systems of ageing. Furthermore, wines aged with staves have stronger fruity, spiced, and woody aromas, while samples aged in barrels present more chemistry-driven, floral, caramelly, and creamy aromas. The staves—medium plus toast (SMPT at 3 months > 225) and chips—medium plus toast (CMPT at 3 months > 170) showed the highest levels of aromatic series, suggesting that alternative systems provided more powerful aromas than traditional systems, such as barrels—medium plus toast (BMPT at 3 months > 150). A principal component analysis (PCA), orthogonal partial least squares (OPLS) analysis, and cluster analysis allowed for a clear differentiation to be made between red wines according to ageing systems and ageing times. The odour activity values fingerprint in winemaking is a feasible approach to characterise and distinguish wines. Moreover, OAVs provide important information on the effects of production methods on wine quality and aroma profile.

One of the most notable effects of climate change, especially in warm regions, is the decrease in acidity (i.e., increase in pH) of wines and a reduction in their aromatic profile. To address this issue, must from a white grape variety with low acidity were inoculated with two non-Saccharomyces yeasts (Lachancea thermotolerans and Torulaspora delbrueckii) to enhance the acidity of the resulting wines. Basic oenological variables and major volatile compounds and polyols of the wines were analyzed, and the results were compared with those obtained through a Saccharomyces cerevisiae strain. Through multiple regression analysis, we found relations between the production of lactic acid to compounds involved in yeast metabolism and redox balance, including glycerol, acetic acid, isobutanol, isoamyl alcohols, and 2-phenylethanol. By means of principal component analysis, we obtained three components that explain more than 89% of the observed variability. The first component differentiates wines produced by L. thermotolerans; the second differentiates wines obtained by S. cerevisiae from those obtained by T. delbrueckii; and the third component is related to the temperature of fermentation. Organoleptic wines produced with S. cerevisiae were the best valuated, but taste was a highlight of the wines produced with L. thermotolerans due to possessing the best acidity.

This study evaluates the impact of two non-Saccharomyces yeasts, Lachancea thermotolerans and Metschnikowia pulcherrima, on the oenological and sensory characteristics of Pedro Ximénez (PX) white wines produced in warm regions of southern Spain. PX wines are particularly affected by climate change, often exhibiting low acidity and limited aromatic complexity. Fermentations were performed using pure and sequential cultures of these yeasts and compared to a control inoculated with Saccharomyces cerevisiae. Wines fermented with L. thermotolerans showed increased titratable acidity (up to 6.83 g/L), reduced pH (down to 3.02), and higher lactic acid concentrations, contributing to improved freshness and microbial stability. The use of M. pulcherrima led to a significant rise in ester production, enhancing fruity and floral aromatic notes. Sequential fermentation using both yeasts produced wines with the highest overall aromatic complexity and superior performance in sensory evaluations. These findings support the use of L. thermotolerans and M. pulcherrima as a promising biotechnological strategy to improve white wine quality under climate change conditions.

The most notable effects of climate change on wine production are higher alcohol levels, lower acidity and changes to the regions suitable for growing grapes. One solution to acidity problems is the use of Lachancea thermotolerans, a yeast that produces lactic acid during fermentation, albeit at the cost of reduced aromatic complexity. A novel approach to addressing this problem is to use L. thermotolerans to produce wines with a very high acidity, regardless of other parameters, for subsequent blending with a control wine with a naturally low acidity. This achieves a balanced acidity while retaining the organoleptic characteristics of the control wine. This is a novel idea, as L. thermotolerans is not usually used in the final wine. However, the objective from the beginning is to create a blend that combines the best characteristics of the control wine with the improved acidity provided by L. thermotolerans. Base wines were produced by inoculating Saccharomyces cerevisiae 20, 40, or 60 h after inoculating L. thermotolerans. Base wines generally show an increase in lactic acid content and a decrease in certain key aromatic compounds, such as isoamyl acetate, 2-phenylethyl acetate, ethyl hexanoate, and ethyl octanoate. Concentrations of other compounds such as acetaldehyde and higher alcohols also increase. The base wines were then blended with a low-acidity control wine. The resulting blends exhibited higher acidity than the control wine, as well as better aromatic profiles, particularly regarding fruity and green fruit aromatic compounds, compared to base wines. Ten volatile compounds have been correlated with lactic acid production by L. thermotolerans, namely ethyl hexanoate; ethyl butanoate; 2-methylbutanol; ethyl heptanoate; isoamyl acetate; acetaldehyde; isobutanol; 2-phenylethanol; dodecanol; and acetoin. The first five are negatively correlated and the rest are positively correlated. Lastly, sensory analysis revealed that the blends achieved the best balance between acidity and aroma, making them the most popular with tasters.

This study evaluates the agronomic potential of two types of vermicompost—one produced solely from wine industry residues (WIR) and one incorporating sewage sludge (WIR + SS)—under rainfed and deficit irrigation conditions in Mediterranean vineyards. The vermicompost was obtained through a two-phase process involving initial thermophilic pre-composting, followed by vermicomposting using Eisenia fetida for 90 days. The conditions were optimized to ensure aerobic decomposition and maintain proper moisture levels (70–85%) and temperature control. This resulted in end products that met the legal standards required for agricultural use. However, population dynamics revealed significantly higher worm reproduction and biomass in the WIR treatment, suggesting superior substrate quality. When applied to grapevines, WIR vermicompost increased soil organic matter, nitrogen availability, and overall fertility. Under rainfed conditions, it improved vegetative growth, yield, and must quality, with increases in yeast assimilable nitrogen (YAN), sugar content, and amino acid levels comparable to those achieved using chemical fertilizers, as opposed to the no-fertilizer trial. Foliar analyses at veraison revealed stronger nutrient uptake, particularly of nitrogen and potassium, which was correlated with improved oenological parameters compared to the no-fertilizer trial. In contrast, WIR + SS compost was less favorable due to lower worm activity and elevated trace elements, despite remaining within legal limits. These results support the use of vermicompost derived solely from wine residues as a sustainable alternative to chemical fertilizers, in line with the goals of the circular economy in viticulture.