## 2 Materials and Methods  
### Samples, Standards, and Matrix Blank  
Marquette and Frontenac grapes from the 2014 growing season were harvested at 22\({}^{\circ}\) and 24\({}^{\circ}\) Brix at South Dakota State University (Brookings, South Dakota--44.3114\({}^{\circ}\) N, 93.7984\({}^{\circ}\) W). The vineyard was part of an NE1020 evaluation trial and was a randomized complete block design. There were four replicates for each cultivar (1 replicate per block with six vines in each replicate). Vines were grown as high cordon in standard NE1020 viticulture protocol. Three clusters were taken from each vine weekly to monitor Brix and for other sample aliquots. All berries were removed from clusters and aliquots were taken from the pool of berries for each replicate. Marquette at 22\({}^{\circ}\) Brix was harvested on 9 September 2013 and 24\({}^{\circ}\) Brix on 21 September 2013. Frontenac at 22\({}^{\circ}\) Brix was harvested on 13 September 2013 and 24\({}^{\circ}\) Brix on 21 September 2013.  
A single batch of red wine was made from each harvest time point using the same winemaking protocol. Briefly, 5 gallon fermenters were used for each fermentation, 3 vines from each replicate (12 vines total). Single fermentations were used as the fruit is from the NE1020 coordinated evaluation trial, not a commercial grower.  
Wines were produced according to a standard lab protocol at Tucker's Walk Vineyard and Farm Winery (Garretson, SD, USA). Red grapes were mechanically crushed/destemmed, treated with SO\({}_{2}\) to 25 ppm, and the must inoculated with Pasteur Red (Red star) yeast for fermentation on the skins at 70 \({}^{\circ}\)F (21.1 \({}^{\circ}\)C). After 5 days, must was dejuiced and fermentation continued in glass carboys at 70 \({}^{\circ}\)F (21.1 \({}^{\circ}\)C) until dry. Malo indicate culture was added during the last third of the alcoholic fermentation, as determined by sugar content.  
Figure 1: Pedigree of Frontenac and Marquette cultivars. Parentage of Marquette includes Pinot Noir, Cabernet Sauvignon, Merlot, Cabernet Franc, and Sauvignon Blanc. Marquette and Frontenac share common parentage (about 70%). This figure is adapted from pedigree maps from Chateau Stripmine [31; 32].  
This wine was shipped to Iowa State University (Ames, IA, USA) for chemical and sensory analysis. Wine samples were aliquoted into 40 mL, pre-cleaned, glass amber vials with a PTFE lined screw cap. These vials were purged with helium to prevent oxidation of the wine samples and stored in a refrigerator before analysis.  
A 5 mg/mL potassium bitartrate in 12.5% ethanol, pH 3.3 model wine was prepared by dissolving 5 g of potassium bitartrate (Fischer Scientific, Waltham, MA, USA) in 120 mL absolute ethanol (Fischer Scientific, Waltham, MA, USA) and q.s. to 1000 mL with deionized water in a 1000 mL volumetric flask. The solution was stirred for 10 min at room temperature, then filtered to remove any solids. The pH was adjusted with a 3.3 N hydrogen chloride. This model wine was used for all successive dilutions of wine samples and verified with the analytical method to be a suitable aroma and matrix blank.  
For analysis of the undiluted sample, 4 mL of wine was pipetted into a cleaned 10 mL glass amber vial with metal screw top lid fitted with a PTFE-lined septum. The 10 mL vial also contained 2 g of sodium chloride, CAS 7440-23-5 (Sigma-Aldrich, St. Louis, MO, USA). 3-nonanone (99%), CAS 925-78-0 (Sigma-Aldrich, St. Louis, MO, USA), was used as an internal standard (IS) for semi-quantification of aroma compounds. The final concentration of IS in wine (0.205 mg/L) was achieved by adding 10 \(\upmu\)L of an 81.9 mg/L IS in ethanol (\(w/v\)) to each 4 mL of wine. Triplicate samples were analyzed.