Grenache wines from the Central Coast of California were subjected to different alcoholic fermentation temperature regimes (Cold, Cold/Hot, Hot) and cap management protocols, namely, punch down (PD), or no punch down (No PD), to determine the effect of these practices on the color, aroma, and the retronasal and mouthfeel sensory characteristics of the resulting wines. Descriptive analysis (n = 8, line scale rating 0–15) results indicated that the combination of a hot fermentation temperature and no punch downs led to a significantly higher intensity in perceived color saturation (7.89) and purple hue (8.62). A two-way analysis of variance (ANOVA) showed that cap management was significantly more impactful on the perception of orthonasal aromas than fermentation temperature. The reduction aroma was significantly higher in No PD wines (5.02) compared to PD wines (3.50), while rose and hot aromas had significantly higher intensity perception for PD wines (5.18, 6.80) than for No PD wines (6.80, 6.14). Conversely, analysis of selected volatile compounds indicated that fermentation temperature was more impactful than cap management regime. Cold/Hot wines had higher concentrations of important esters such as ethyl hexanoate (650 µg/L) and isoamyl acetate (992 µg/L). Cold wines had a higher concentration of β-damascenone (0.719 µg/L). TCATA evaluation (n = 8) indicated that Cold/Hot PD wines had a significantly higher citation proportion of fruit flavor (1.0) and velvet astringency perception (0.80) without significant reduction flavors. Finally, the present study represents a contribution with the main volatile compounds (e.g., β-damascenone and esters in the Cold and Cold/Hot fermented wines, respectively; hexanol in PD wines, which may be potentially responsible for a hot mouthfeel), and sensory characteristics (red fruit, tropical fruit, white pepper, and rose) of Grenache wines grown in the Mediterranean climate of the Central Coast of California.

The present study examined the effect of different cap management techniques, maceration length, and ethanol levels through chaptalization on the chemical and sensory composition of Syrah wines from the Edna Valley AVA in California. Punch down wines had significantly higher anthocyanins, tannins, and total polymeric pigments compared to all other treatments. In terms of volatile chemistry, the submerged cap wines tended to have a higher concentration of esters and terpenes compared to the other treatments. Additionally, ethanol levels were more impactful on the chemical composition of the wines. As expected, chaptalized wines had significantly higher ethanol and glucose + fructose levels but also tended to have higher concentrations of esters and terpenes. Sensory evaluation was done through a modification of the Pivot© Profile method using an expert panel of winemakers (n = 15). The results suggested that cap management and the maceration length were more impactful on the sensory profile than the ethanol level whereby each cap management and maceration length treatment had a distinctive profile. As such, the punch down, chaptalized wines showed higher purple hue and color saturation attributes, blueberry orthonasal aromas as well as jammy and black fruit retronasal aromas. Submerged cap wines were associated with significantly meatier orthonasal aromas and reductive retronasal aromas. Extended maceration wines were characterized by more jammy orthonasal aromas and dried fruit retronasal aromas. However, within the extended maceration wines, the effect of chaptalization was apparent whereby the chaptalized wines showed more acetaldehyde aromas while the non-chaptalized wines were characterized by more herbal aromas.

Pinot noir is rapidly becoming a winemaking staple in the Central Coast of California. Therefore, it is important to understand how factors such as fermentation temperature and cap management affect the chemical and sensory impact of such wines. Herein, Pinot noir wines were made with three contrasting alcoholic fermentation temperature regimes (Cold, Cold/Hot, Hot) and combined factorially with two cap management regimes (with or without punch downs). The impact of these factors on colour, aroma, and the temporal retronasal aroma and mouthfeel profile was assessed by a trained sensory panel (n = 13) using descriptive analysis (DA) and time-intensity (TI), respectively. Combining a hot fermentation temperature and no punch downs led to wines with higher colour saturation and purple hue. In contrast, wines fermented at cold fermentation temperatures with no punch downs showed reduction aromas. In terms of individual main effects, wines fermented at cold temperatures had more orthonasal aroma, while wines fermented at hot temperatures had higher astringency. To understand the relationship between selected volatile aromas and perceived sensory results, a partial least square regression (PLSR) was conducted. PLSR indicated that cold fermentation temperature wines with punch downs were associated with esters, including ethyl hexanoate and ethyl heptanoate, as well as β-damascenone, which aligned with sensory results. The effect of salivary flow rate on the temporal sensory profile post-expectoration was also analysed. Low salivary flow rate panellists perceived both astringency and length significantly later and more intensely than high salivary flow rate panellists. However, the time of maximum intensity was perceived significantly later for high salivary flow rate panellists. Overall, fermentation temperature had a more significant impact on the sensory and volatile composition of Pinot noir wines than the cap management regime. However, cap management still appeared to affect sensory and volatile chemistry results through significant interactions. Therefore, the relationship between fermentation temperature and cap management was not straightforward from avolatile chemistry or sensory perspective. The importance of accounting for salivary flow rate in panellists when using time-based sensory analysis was also highlighted.