## 2 Materials and Methods
### Grapes and Winemaking  
The experiment was conducted in 2018 with a red grapevine cultivar, Teran (_Vitis vinifera_ L). Grape ripeness was assessed using standard chemical analyses, revealing average harvest metrics of 21.6\({}^{\circ}\) Brix, 8.3 g/L total acidity (expressed as tartaric acid), and a pH of 3.20. Grapes were manually harvested on 3 October 2018, from an experimental vineyard at the Institute of Agriculture and Tourism in Porex, Istria, Croatia. Upon harvesting, the grapes were promptly destemmed and crushed, then evenly transferred to 110-L stainless steel vats located in the experimental \"Minivinification\" wine cellar of the Institute. To initiate winemaking, the crushed grapes received treatments of potassium metabasulfite (5 g/hL, AEB SPA Brescia, Italy) and Aromax (5 g/hL, AEB SPA). Additionally, the petolytic enzyme Endozym Rouge (4 g/hL, AEB SPA), a mixture of several enzymes including pectinylase, pectinsterase, polygalacturonase, and cellulase, was added to all treatments. While this enzyme may have some influence on the aroma profile, its consistent application across all treatments means its effect was uniform and thus not a focus of this study. The grape musts were inoculated with selected dry yeast _Saccharomyces cerevisiae_ Fermol Mediterraneane (30 g/hL, AEB SPA) rehydrated with Fermol Plus Starter (10 g/hL, AEB SPA Brescia, Italy). Fermol Plus H2\({}_{\text{S}}\) Free (10 g/hL, AEB SPA) was supplemented on the second and fifth days of fermentation. Four distinct vinication protocols were implemented: a control treatment with 7 days of maceration--TM7 (Y), prolonged 10-day maceration--TM10 (Y), extended 21-day post-fermentation maceration--TM21 (Y), and a 48-h pre-fermentation maceration heating at 45 \({}^{\circ}\)C followed by 8 days of maceration--TPHT (Y). The \"Y\" denotes young wines. In the control (TM7-Y), prolonged maceration (TM10-Y), and extended maceration (TM21-Y) treatments, maceration lasted for 7 days, 10 days, and 21 days, respectively. Yeast (_Saccharomyces cerevisiae_ Fermol Mediterraneane) was added on the first day in all three treatments, so fermentation and maceration began simultaneously. In all of the treatments, fermentation lasted for 7 days. There was no pre-fermentation maceration (cold soaking); instead, fermentation started immediately with maceration. In the TM21-Y treatment, the 21-day maceration process included both fermentation and post-fermentation maceration, with the lees remaining in the tanks until racking, which was performed at the end of maceration. In the TPHT-Y treatment, the pomace was heated to 45 \({}^{\circ}\)C for 48 h as part of a pre-fermentation maceration process. After this heating period, the pomace was cooled to 24 \({}^{\circ}\)C, and yeast (_Saccharomyces cerevisiae_ Fermol Mediterraneane) was added. Following yeast addition, fermentation, which lasted for 7 days as in the other treatments, occurred simultaneously with maceration for an additional 8 days, bringing the total maceration duration to 10 days. Each treatment was replicated three times, with fermentations maintained at 24 \({}^{\circ}\)C and the cap punched down three times daily during maceration. After complete maceration, the wines underwent pressing using a closed-type pneumatic press (Letina Inox d.o.o., Cakovec, Croatia) set at pressures of 3 \(\times\) 0.3 bars and 1 \(\times\) 0.5 bars. Once alcoholic fermentation reached completion (reducing sugars <2 g/L), the wines were stored under cellar conditions (12-15 \({}^{\circ}\)C) for 3 months. Subsequently, they were racked and sampled into 0.75-L bottles for analysis. Throughout the process, levels of free and bound SO2 were closely monitored and adjusted as necessary. Following the second rack, the young wines from each treatment were aged for six months in 100-L oak barrels (LT-light toasted) (Bacvarija Golub, Jastrebarsko, Croatia) to evaluate the maturation differences between young and aged Teran wines produced via different vniification techniques.