## 2 Results and Discussion  
### Perceived Color  
Two color properties (saturation and purple hue) were assessed to understand the effects of fermentation temperature (Cold, Cold/Hot, and Hot) and of two cap management styles (PD and No PD) in Grenache wines. Results for color and aroma attributes are shown in Table 1. Both color attributes, saturation (\(p\) = \(<\)0.0001) and purple hue (\(p\) = \(<\)0.0001), were statistically significant. Hot No PD wines had significantly higher color intensity compared to all other wines, including the Hot PD wines. Cold No PD wines were significantly lower in saturation compared to all other wines. According to a two-way ANOVA, fermentation temperature was statistically significant for saturation (\(p\) = \(<\)0.0001) with Hot wines significantly higher than all other fermentation temperatures (Supplemental Table S1). The factor of cap management on its own was not significant but there was a significant interaction between the two factors for saturation (\(p\) = <0.0001). To date, there have not been many studies that have examined the sensory impact of fermentation temperature on perceived color saturation. Results of past studies have shown that an increase in fermentation temperature led to increased color properties from a chemical perspective [24]. For example, a study conducted on Pinot nor which was fermented at 20 \({}^{\circ}\)C, 30 \({}^{\circ}\)C, and using a high intensity/short time heat treatment (90 \({}^{\circ}\)C to 95 \({}^{\circ}\)C) found that concentration of polymeric pigments had a strong, inverse correlation to the lightness (L*) parameter in CIE Lab measurements, meaning the wines were darker in saturation [42]. Another study examined the impact of flash release (heating fermenting musts 95 \({}^{\circ}\)C or more) on the resulting phenolic composition of Grenache, Mourvedre, and Carignan wines over two vintages [43]. The application of flash release led to higher levels of anthocyanins during fermentation. However, after alcoholic fermentation, flash-release wines saw a decrease in anthocyanins and an increase in tannin to anthocyanin ratio. It is important to note that this study was limited in that it examined anthocyanin, tannins, and total polyphenol index, but the relationship between heat during fermentation and polymeric pigment formation was not examined. Findings from the previous literature align with the chemical results of the present study. Herein, Hot wines regardless of cap management procedure had significantly higher total polymeric pigments (\(p\) = <0.0001) compared to the other fermentation temperatures (Table 2). For anthocyanins (\(p\) = 0.001), both Cold wines and the Hot PD wines were significantly lower compared to Hot No PD wines and both Cold/Hot wines which suggested a potential influence of cap management. Both total anthocyanins (\(p\) = 0.001) and total polymeric pigments (\(p\) = <0.0001), were statistically significant for the factor fermentation temperature, but not for the factor cap management (Supplemental Table S2). Additionally, total polymeric pigment concentration showed a positive correlation to perceived color saturation whereby Hot wines had significantly higher saturation. However, there was a significant interaction between cap management and fermentation temperature for both parameters, therefore it was likely cap management had some influence on color extraction. A potential explanation for the interaction between fermentation temperature and cap management could be a mixing effect proper of alcoholic fermentation, whereby carbon dioxide naturally mixes the bottom of the fermenting cap and promotes phenolics extraction [31]. This explanation was suggested by a previous experiment that examined the impact of pump-over volume and frequency in Cabernet Sauvignon [31]. Purple hue intensity also increased with fermentation temperature. Significant differences were apparent for purple hue (\(p\) = <0.0001) between fermentation temperature regimes but not cap management (Table 1).