# Influence of Region on Sensory and Chemical Profiles of Pennsylvania Gruner Veltliner Wines
## 3 Results and Discussion  
### Descriptive Analysis  
In the first year (wines made in 2018), the trained panel found the wines to differ significantly in both appearance attributes, three aroma attributes (earthy, sulfur, and thiol), two taste and mouthfeel attributes (sour taste, warm/hot mouthfeel), and two flavor attributes (thiol and ethanol). There was a significant fermentation replicate effect for haziness and sulfur aroma. The significant haziness effect was attributed to excess sulfur additions to SE1 wine replicates, based on false low readings from aeration oxidation, and so this attribute was not included in the PCA. Among the significantly different attributes, only yellow color and haziness were different by region in Year 1 (Table S2). Wines from the NW region were rated significantly higher in yellow color than the other three regions (5.52 vs. 2.51 (SE), 2.87 (NC), and 4.20 (NE) on a 10-point scale; Table S2). Additionally, wines from the NE region were significantly higher in yellow color than those from the SE and NC regions (4.20 vs. 2.51 (SE) and 2.87 (NC)). Grape maturity at harvest may have affected the resulting wine color, with more mature grapes producing wines that were more yellow in color. Previous work on white wines found grapes harvested at an earlier date to be lighter in color and less intense, as indicated by higher \(L^{\star}\) and lower C* and \(b^{\star}\) values (Nw2 and NE1 were the last sites to be harvested and had two of the highest TSS levels (19.6 and 16.4 \({}^{\circ}\)Brix, respectively) (Table S3), indicating these sites provided more mature grapes for virification compared to sites harvested earlier at lower TSS levels. Weather effects may have also contributed to the regional color differences. Elevated temperatures could contribute to greater accumulation of phenolic compounds that influence wine color. Increased daytime temperatures in the vineyard can increase berry color ratings in white _viinfen_ varieties, which could affect final wine color ([PERSON], 2018). However, we tend to exclude that differences in GDD across sites explained regional trends in wine color alone in this study because cumulative GDD (GDD_T) was lowest for the NE and NW regions compared to the other wine regions (Table S1). Furthermore, GDD during fruit ripening (GDD_V), which tend to be more important for phenolic compounds accumulation, did not differ markedly across sites, except for NC1. It is possible that differences in temperature may have not been large enough to result in significant color differences in finished wines. In addition, fruit sunlight exposure may have also played a role in terms of final wine color. All 7 significant wine sensory attributes were used in the PCA, with the exception of haziness which was a result from excess SO2 addition to SE1 wines. The PCA (Figure 2A) captured 74.86% of the total variance in the first two dimensions, and consistent regional trends among the wines were observed. The NC sample, located in the bottom left quadrant of the biplot, separated from all other wine samples. While the two NW wines are significantly different from each other, as indicated by the 95% CE not overlapping, the wines were both positively loaded on PC 1. All 5 SE wines, except for SE5, were positively loaded on PC 2, and three of the 5 samples (SE1, 2, and 3) were located on the negative PC 1 axis. SE5 and NE1 showed sensory profiles that were not significantly different as indicated by their overlapping confidence ellipses, while wines NE1 and NW2 were also not significantly different. Yellow color was a clear driver of separation between wines from the different regions along the first dimension, PC 1 (Figure 2A). Wines that were rated highest in yellow color (NW1 and NW2) were positively loaded along the first dimension, while wines from the  
Figure 2: Principal component analysis (PCA) biplot for the significant wine sensory attributes of Year 1 (made in 2018) (**A**) and Year 2 (made in 2019) (**B**) Grüner V. wines.