## 1 Introduction  
Global warming is causing significant changes in climatic conditions, such as rising average temperatures during the grape ripening period, changes in precipitation patterns,and more frequent extreme weather events (e.g., heatwaves, hailstorms, and frosts). These changes cause a lag in the phenology of the vine, leading to a higher accumulation of sugars, a decrease in acidity, and a delay in the accumulation of compounds responsible for the color and odor of grape berries. As a result, wines may have higher ethanol content and reduced acidity, which can contribute to potential microbiological issues or color instability, affecting the composition and quality of grape musets and wines. To mitigate these effects, several tools have been developed, such as the use of non-_Saccharomyces_ yeasts, sequential inoculation, immobilized yeast systems or selected yeast strains in active dry yeast (ADY) format, and nutrient preparations [1; 2; 3; 4]. The introduction of new strains with improved characteristics (e.g., fast fermentation kinetics, high SO2 tolerance, glutathione production, or aromatic profile enhancement) represents an incremental improvement that contributes to an overall enhancement in wine production. These strains have been selected for their ability to withstand the effects of climate change on grape composition, as well as their ability to produce wines with complex sensory profiles [5]. These sensory properties are mainly the result of yeast metabolism during must fermentation, where sugars and nitrogen are essential for the production of ethanol, carbon dioxide, glycerol, and volatile compounds, which are responsible for most of the wine aromas. The use of ADYs, selected for their stress tolerance or aroma production, is currently a source of innovation in wineries, aiming to avoid or prevent stuck fermentations or to create new wines with different sensory characteristics [5], adapted to market trends. Yeast-available nitrogen (YAN) in grape must primarily consists of naturally occurring ammonium ions and amino acids, both of which are essential for yeast metabolism [6]. To prevent slow or stuck fermentations, it is often necessary to supplement the must with authorized nitrogen sources. Furthermore, both the source and the concentration of YAN have a direct effect on the diversity and concentration of volatile organic compounds (VOCs), via the keto-acid pool and the Ehrlich pathway. This pathway plays a key role in the formation of aroma compounds in wine by converting amino acids to higher alcohols and their corresponding esters or aldehydes. During fermentation, yeast metabolizes amino acids through transamination and decarboxylation to produce fused alcohols such as isoamyl alcohol, isobutanol, and phenylethanol. In addition, these alcohols can react with acids to form esters, which impart fruity and floral aromas to the wine [6; 7]. Finally, the balance of compounds derived from the Ehrlich pathway has an important influence on the complexity and sensory profile of the wine. These innovations aim to solve some longstanding winemaking problems, such as improving the reproducibility and speed of fermentation by achieving higher ethanol yields and faster completion, while producing wines with personalized flavors according to consumer demand. Inorganic sources of nitrogen, such as diammonium phosphate (DAP), are widely used by winemakers as an additive to achieve adequate levels of YAN, but several authors mention [6; 8; 9] that their use can lead to the formation of acetic acid, which gives the wine an unpleasant vinegaroma and sour taste. Alternatively, the effect of adding amino acids to the must has been studied on a laboratory scale, resulting in a decrease in this acid and an improvement of other volatile compounds such as keto acids, their corresponding aldehydes, and higher alcohols and their esters [10; 11; 12; 13; 14; 15; 16; 17]; however, the use of pure amino acids in winemaking processes is not included in the European Union's list of authorized additives.