By Dr. Aude Watrelot –
Frontenac grapes are a crossing made from Landot Noir 4511, and Vitis riparia UMN 89. This French-American hybrid, also called MN 1047, was created in 1978 by University of Minnesota breeders and introduced in 1996. Frontenac grape includes Frontenac “noir”, gris and blanc. In this newsletter article, Frontenac “noir” commonly called Frontenac is presented. The grapes are dark skinned and are particularly known for their resistance to the cold. Vitis riparia grapes can survive winter temperatures as low as -33 °F. Frontenac grapes were originally grown in Minnesota but have had some success as far North as the border in Quebec and is currently found in 33 states in the USA.
The yield of Frontenac grapes seems to be higher using the Scott Henry training system compared to the High Cordon and the Vertical Shoot Positioning (Wimmer et al., 2018). Grapevines can be grown in sandy, clay, acidic, dry, or normal soil conditions, and produce medium sized conical clusters that rarely succumb to rot. The cluster weight vary between 130 and 155 g as reported by Wimmer et al., 2018. Berries are small to medium in size, blue and black in color. The harvest period is often late September or early October in Minnesota.
In a study from the same authors, the harvest parameters of Frontenac were between 21.2 and 23.8 °Brix, with a titratable acidity (TA) between 11.9 and 13 g/L tartaric acid equivalent and a pH between 3.35 and 3.46 in 2016 and 2015, respectively.
In another study from the same group (Riesterer-Lopez et al., 2019), the glucose to fructose ratio of Frontenac grapes at harvest was 1.10 and 1.12 in 2015 and 2016, respectively. The tartaric acid to malic acid ratio was between 0.38 and 0.51 in 2016.
Frontenac grapes are usually high in acidity, low in tannins (less than 0.3 mg/berry in seeds and much lower in skins as reported by Rice et al., 2017) and with a concentration of free anthocyanins varying between 272 mg/L and 6,000 mg/L (Scharfetter et al., 2019 and Burtch and Mansfield 2016). Delphinin-3,5-diglucoside accounted for more than 65 % of the monomeric anthocyanins present in Frontenac grapes responsible for the blue-dark skin color (Burtch and Mansfield 2016).
Frontenac grapes have an aroma profile dominated by hexanal, acetic acid, beta-damascenone (Pedneault et al., 2013) and with floral, banana, fruity and strawberry flavors (Rice et al., 2019).
For in-depth information:
Burtch, C., & Mansfield, A. K. (2016). Comparing Red Wine Color in V. vinifera and Hybrid Cultivars. 6.
Pedneault, K., Dorais, M., & Angers, P. (2013). Flavor of Cold-Hardy Grapes: Impact of Berry Maturity and Environmental Conditions. Journal of Agricultural and Food Chemistry, 61(44), 10418–10438. https://doi.org/10.1021/jf402473u
Rice, S., Koziel, J. A., Dharmadhikari, M., & Fennell, A. (2017). Evaluation of Tannins and Anthocyanins in Marquette, Frontenac, and St. Croix Cold-Hardy Grape Cultivars. Fermentation-Basel, 3(3), 47. https://doi.org/10.3390/fermentation3030047
Rice, S., Tursumbayeva, M., Clark, M., Greenlee, D., Dharmadhikari, M., Fennell, A., & Koziel, J. A. (2019). Effects of Harvest Time on the Aroma of White Wines Made from Cold-Hardy Brianna and Frontenac Gris Grapes Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry-Olfactometry. Foods, 8(1), 29. https://doi.org/10.3390/foods8010029
Riesterer-Loper, J., Workmaster, B. A., & Atucha, A. (2019). Impact of Fruit Zone Sunlight Exposure on Ripening Profiles of Cold Climate Interspecific Hybrid Winegrapes. American Journal of Enology and Viticulture, 70(3), 286–296. https://doi.org/10.5344/ajev.2019.18080
Scharfetter, J., Workmaster, B. A., & Atucha, A. (2019). Preveraison Leaf Removal Changes Fruit Zone Microclimate and Phenolics in Cold Climate Interspecific Hybrid Grapes Grown under Cool Climate Conditions. American Journal of Enology and Viticulture, 70(3), 297–307. https://doi.org/10.5344/ajev.2019.18052
Wimmer, M., Workmaster, B. A., & Atucha, A. (2018). Training Systems for Cold Climate Interspecific Hybrid Grape Cultivars in Northern Climate Regions. Horttechnology, 28(2), 202–211. https://doi.org/10.21273/HORTTECH03946-17