## 2 Results and Discussion
### Orthonasal Aroma Attributes  
A principal component analysis (PCA) was conducted on the descriptive analysis data and calculated using Dimension 1 (eigenvalue: 6.27; variability: 0.627) and Dimension 2 (eigenvalue: 2.78; variability: 0.278) (Figure 1A,B). The resulting PCA explained 90.6% of the variation within the dataset. Dimension 1 separated wines by cap management regime while Dimension 2 separated the wines by fermentation temperature whereby Cold/Hot and Hot wines were distinguished from Cold wines. Additionally, the No PD wines appeared to be more correlated with most of the sensory loadings compared to the PD wines (Figure 1A,B). The stronger correlation between most of the sensory characteristics and No PD wines may be in part due to the sensitivity of Grenache wines to oxidation [7]. The latter has been attributed to the high concentration of hydroxycinnamic acids (270-460 mg/L caftaric acid) in Grenache wines compared to other varieties (50-60 mg/L caftaric acid) as these compounds assist in the oxidation process of wine [1; 43]. Therefore, it seems plausible that excessive cap management may lead to lower aroma retention in Grenache wines due to oxidation. Indeed, a previous study examined the effect of oxygen exposure on the sensory profile of bottled Sangiovese, which is another red variety that is highly susceptible to oxidation [44]. Results indicated that after 10 months of oxygen exposure, wines had significantly higher balsamic aromas (indicative of oxidation) over other aromatic attributes. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Treatment** & \begin{tabular}{c} **Anthocyanins (mg/L** \\ **Malvidim-3-Glucoside**) \\ \end{tabular} & **SPP** & **LPP** & **TPP** & \
\begin{tabular}{c} **Total Tannins** \\ **(mg/L CE)** \\ \end{tabular} &
\begin{tabular}{c} **Total Phenolics** \\ **(mg/L CE)** \\ \end{tabular} \\ \hline Cold PD & 187 \(\pm\) 9.23 b \({}^{1}\) & 0.480 \(\pm\) 0.03 c & 0.026 \(\pm\) 0.02 bc & 0.505 \(\pm\) 0.05 c & 26.4 \(\pm\) 3.70 b & 487 \(\pm\) 36.4 b \\ Cold No PD & 178 \(\pm\) 4.96 s & 0.432 \(\pm\) 0.01 c & 0.004 \(\pm\) 0.01 c & 0.436 \(\pm\) 0.01 c & 22.8 \(\pm\) 4.11 b & 509 \(\pm\) 17.1 b \\ Cold/Hot PD & 280 \(\pm\) 4.61 a & 0.656 \(\pm\) 0.02 b & 0.070 \(\pm\) 0.02 bc & 0.277 \(\pm\) 0.01 b & 94.8 \(\pm\) 7.55 a & 800 \(\pm\) 19.4 a \\ Cold/Hot No PD & 309 \(\pm\) 8.27 a & 0.680 \(\pm\) 0.01 b & 0.022 \(\pm\) 0.02 bc & 0.702 \(\pm\) 0.03 b & 87.7 \(\pm\) 14.7 a & 862 \(\pm\) 44.4 a \\ Hot PD & 220 \(\pm\) 5.39 b & 0.718 \(\pm\) 0.02 b & 0.209 \(\pm\) 0.01 a & 0.927 \(\pm\) 0.02 a & 96.8 \(\pm\) 13.0 a & 735 \(\pm\) 19.6 a \\ Hot No PD & 299 \(\pm\) 41.2 a & 0.793 \(\pm\) 0.04 a & 0.085 \(\pm\) 0.04 b & 0.878 \(\pm\) 0.07 a & 81.0 \(\pm\) 18.8 a & 893 \(\pm\) 112.4 a \\ \(p\)-value \({}^{2}\) & **0.001** & **\textless0.001** & **0.001** & **\textless0.001** & **0.001** & **0.000** \\ \hline \hline \end{tabular}  
* Different letters within columns indicate a significant difference for [PERSON]’s least significant differences test (\(p\) < 0.05). \({}^{2}\) Significant \(p\)-values are shown in bold fonts. SPP: Small polymeric pigments; LPP: Large polymeric pigments; TPP: total polymeric pigments; CE: catechchin equivalents.  
\end{table} 
Table 2: One-way analysis of variance (ANOVA) of the phenolic composition of Grenache wines. Values represent the mean of three replicates followed by the standard error of the mean (\(n\) = 3). Interestingly, according to the one-way ANOVA, the reduction aroma (\(p\) = \(<\)0.0001) was the only statistically significant attribute (Table 1). For reduction (\(p\) = \(<\)0.0001), both the Cold and Hot wines showed statistically significant variation between cap management regimes (Table 1). Cold No PD wines were significantly higher in reduction aroma than Cold PD wines; the same trend was observed between the Hot No PD wines and Hot PD wines. In the two-way ANOVA, the No PD wines regardless of fermentation temperature were significantly higher in reduction aromas (Supplemental Table S1).